NIH CLINICAL CENTER GRAND ROUNDS
Episode 2010-07
Time: 1:02:10
Recorded February 24, 2010

Phenotypes as Clues to Deciphering the Pathogenesis and Treatment of Myositis
Lisa G. Rider, MD,
Deputy Chief, Environmental Autoimmunity Group,
Office of Clinical Research, NIEHS

Frederick W. Miller, MD, PhD
Chief, Environmental Autoimmunity Group,
Office of Clinical Research, NIEHS

ANNOUNCER: Discussing Outstanding Science of the Past, Present and Future - this is NIH Clinical Center Grand Rounds.

(Music establishes, goes under VO)

ANNOUNCER: Greetings and welcome to NIH Clinical Center Grand Rounds, recorded February 24, 2010. Today we have two speakers from the National Institute of Environmental Health Sciences who will take on the topic "Phenotypes as Clues to Deciphering the Pathogenesis and Treatment of Myositis" Our speakers are Dr. Lisa Rider, deputy chief of the Environmental Autoimmunity Group in the Office of Clinical Research at the NIEHS. She will be joined by Dr. Frederick Miller, chief of the Environmental Autoimmunity Group in the Office of Clinical Research at the NIEHS.

We take you to the Lipsett Ampitheater at the NIH Clinical Center in Bethesda, Maryland for today's presentation.

RIDER: Thank you very much. My disclosures I have no financial interests or commercial interest, but I will discuss some therapies for myositis that are not approved by the food and drug administration as there are currently no approved treatments for myositis. I appreciate the opportunity to update you on certain aspects with the result of patients seen here at the NIH Clinical Center. Today I will focus in particular on the clinical and autoantibody phenotypes and their role in the assessment and therapy of adult and juvenile myositis.

And these are my learning objectives for this talk.

The idiopathic and inflammatory myopathies are a group of syndromes with a hallmark of chronic muscle weakness and inflammation of unknown cause. These are rare disorders with an estimated annual incidence in adults of 5 to 10 cases per million and 2 to 5 fold less in children. The estimated prevalence is 50 to 100 cases per million such that there are less than 30,000 patients affected in this country.

To dermatomyositis, the form with characteristic skin rashes, and polyomyositis, the form without characteristics skin rashes, and inclusion of body myotsitis a progressive form affecting older individuals and the most common clinical phenotype.the pathogenesis likely involves chronic immune activation, and genetically susceptible individuals following exposure to specific environmental triggers. This will be the topic of Dr. Miller's presentation. Therapy consists of immunosuppresants to decrease tissue inflammation and the rehabilitation to strengthen the damaged muscle.

We continue to diagnose these conditions by criteria developed more than 30 years ago by [inaudible] Peters. These are based on laboratory features and first require exclusion of other forms and myopathy including drug and toxin induced myopathies, infectious myopathies, distrophies, mitochondrial and metabolic myopathies. So we would require the presence of 3 out of 5 criteria at minimum to stay that the patient probably has myositis and 4 out of 5 to say that they definitely have might myositis. And these include the presence of symmetric proximal muscle weakness that is often chronic and progressive.

The elevation of serum levels and muscle enzymes notably only 2/3rds of children elevate the ck level so it's important to check other muscle enzymes including the elderly, LDH and transaminases.

On EMG, there are characteristic myopathic changes indicating muscle increase irritability and on muscle biopsy there's a characteristic pathology of degeneration of myofibers, regeneration of myofibers, a chronic inflammation and perifascicular atrophy. In dermatomyositis, one of the required changes is the presence of 1 of 2 characteristic skin rashes including the presence of the heliotrope rash, a purplish or reddish discoloration over the eyelid associated with periorbital edema and papules which are raised red plaques over the extensive surfaces of the joints with the pathology of the dermatitis.

Recently an international myositis collabrative group that we led clarified that the muscle biopsy should be required with patients with polymyositis without a skin rash and the findings have been clarified, and that international group continues to work on these criteria.

Now we understand these not only affect the skin and muscles, they're also systemic autoimmune diseases and often affecting other organ systems including the joints, intestinal tract, and heart and lungs. It's our colleagues in the NCI dermatology branch that help us in recognizing the full spectrum of skin findings that we see in association with the dermatomyositis and the other inflammatory myopathies. So there are not only the characteristics in changes of these papules and heliotrope rash, but many of the patients have photosensitive skin rashes including the malar rash and other photosensitive skin rashes.

There are also rashes that are characterized by the vasculopathy resulting from the immune attack on the muscle capillaries and skin capillaries. This includes capillary changes of dilation,tortuosity and drop out of the periungual capillaries.

Jane Atkinson from the dental institute has recognized that these changes also occur on the gingival capillaries and in more severe changes there can be a resulting ischemia resulting in skin ulceration with a serious diagnosis. Up to 25% of children and we understand a good number of adults also develop dystrophic calcification which occurs in the skin, subcutaneous tissue and muscle misfunction of disabling.

Now we have found it useful in the hundreds of patients we've seen here at the clinical center to identify phenotypes of these disorders that are based on commonalities and epidemiology, clinical features, responses to treatment and outcomes.

So first we focus on the clinical phenotypes for these diseases and we find a number of them to be present. We find that these same phenotypes are present in both children and adults with myositis but in different frequencies. So in children, dermatomyositis is the most prevalent form seen in 80% of patients whereas it's the most common form in adults as well but it's seen in only 37% of patients. Polymyositis, the form without skin rashes is relatively uncommon in children, but much more frequent in adults seen in more than a quarter of the patients. Myositis associated with other connective tissue diseases, such as systemic sclerosis, lupus or rehumatoid arthritis is seen in 10% of children and 17% of adults.

We have several forms of myositis that are seen much more frequently in adult patients. This is includes cancer associated myositisin which a malignancy may be diagnosed within 2 years of the myositis and often paraneoplastic, and inclusion body myositis which is primarily an older individuals and is slowly progressive resulting in muscle atrophy. There are a number of other rarer forms of disease, that are defined by specific pathologic changes or the involvement of certain muscle groups and I guess won't talk further about these today. Now these clinical phenotypes differ also in the epidemiologic features. Polymositis, dermatomyositis, and juvenile dermatomyositis are racially similar to the general population, while inclusion body myositis seen more frequently in caucasian individuals.

Polymyositis, and dermatomyositis peak in prevalence with a broad peak with the median age of about 7 and half years and in the middle of life in the age spectrum of 30 to 50 years.

Inclusion body myositis in contrast, peaks after age 50.

And in you have juvenile dermatomyositis, polymyositis, and adult dermatomyositis and females are preferentially affected in a ratio of 3 to 1.for however, inclusion bodied myositis this ratio is inversed there with male predominance.

Several epidemiologic studies including one from Homestead County Minnesota and another from Allegheny county Pennsylvania suggest that dermatomyositis, polymyositis, and inclusive body myositis are increasing in prevalence suggesting here that there are strong environmental factors. These clinical phenotypes differ in their clinical presentation as well as in their prognosis. Polymyositis, the form without the characteristic skin rashes has a moderate to severe muscle weakness which tends to involve proximal and distal muscles.

More than up to half the patients have interstitial lung disease and most commonly this is nonspecific interstitial pneumonia.

The heart muscle is also frequently affected in almost half of the adult patients resulting in congestive heart failure, ventricular dysfunction, and arrythmias and survival rate at 5 years of 75 to 94% but may be 20 to 30% lower in patients with the heart or lung involvement. Dermatomyositis and juvenile dermatomyositis in contrast have mild to moderate muscle weakness, affecting the axial and proximal muscles.

Up to 25% of the children and here at the clinical center up to 15% of our adult patients have calcinosis with dystrophic calcification. About 10% of our patients have the finding of skin or GI tract alterations and only in children rarely in adult patients do we find that they have lipodystrophy generalized or partial.

The survival rate in adult patients with dermatomyositis is comparable to polymyositis ranging from 75 to 90% for survival, but juvenile dermatomyositis has much better survival at 99% of 5 years. The next form cancer associated myocysitis, really has the predeliction for dermatomyositis with the 2 to 4 fold elevated risk. And polymyositis less so thought perhaps at the 1.5 elevated risk. This form is more commonly in men of older age and presents with extremely severe muscle weakness and expensive skin rashes. The patients tend to have higher sedimentation rates and lower ck levels and the cancer that's most often diagnosed in a 2 year period seem to be adenocarcinoma and most frequently these include the lung, stomach, large intestine, pancreas and ovary as well as lymphomas. Survival is poor related to the underlying cancer in the 60% of 5 years.

And then inclusion body myositis affects men more than women.

It is a slowly progressive insidious disease affecting both proximal and distal muscles with the particular predeliction for the finger flexors and the quadriceps. There is early atrophy and assimetry of the disease.the esophageal muscles are also involved with frequent dysphasia and survival is quite good at 100% at 5 years however, patients have a large degree of functional disability and are often in wheelchairs at 5 years or 10 years.

These phenotypes also differ in their pathology in that the tack and polymyositis and inclusion body myositisis is the infiltration of positive cd8 t cells attacking the myofibers resulting in the release of cytotoxic granules and cell mediated lysis, and inclusion body myositis also has associated inclusions of the vaccules in the tissue.in dermatomyositis there is infiltration of cd4, positive t cells and dendritic cells and some activation of b cells with infiltration primarily periovascularly and this results in antibodies and activation of comlement which is then deposited on the capillaries resulting in drop out.

Now we've been able to study further the effects of these pathology changes through noninvasive images technique, with regard to magnetic resonance and this has been particularly helpful. On t 1 images, axial images we see the degree of muscle loss and fatty infiltratio in the muscle. On images we see brightness in the muscle by muscle edema or inflammation.

And in dermatomyositis the muscle adema tends to be wide spread, but there's also frequent involvement of the subcutaneous tissue and skin. And from our studies we find that these patients have less muscle damage.

Polymyositis patients in contrast have more patchy muscle edema often involving the anterior muscle groups but frequently have a prominence of the myofacial with these myofacial rings.

And polymyositis patients tend to have more damage from our studies although this patient was earlier in the disease course, and only has patchy muscle fibrosis. Inclusion body myositis tends to include the quadriceps muscles early with early atrophy and the remaining muscle groups tend to be active with edema.

Now another way to classify these patients is based on the presence of certain autoantibodies and these also similarly define certain phenotypes of disease. Myositis specific antibodies are those seen specifically in patients with myositis include the trna synth tase, signal recognition particule, and MI 2. Myositis associated autoantibodies have a growing list and the first of these P155 MJ and CADM 140 have been only recently recognized so we call them myositis associated until we can understand better whether they are specific for myositis. The others, URMP, RO, PMSCL, and KU may also be seen in patients with other automimune diseases.

So we find that the same autoantibody phenotypes are seen both in children and adults with myositi sexcept that the children less frequently have the autoannotated antibody whereas this is one of the most common autoantibody in subgroups of adult patients. And now with the recognition of P15 and MJ, we have a declining number of children without autorecognized antibodies.

These myositis specific autoantibodies target translational and transcriptional factors that are ubiquitous to all cells but are upregulated in regenerating myoblasts and overexpress in the muscle tissue of myositis patients. In polymyositis the translational factors tend to be targeted and aminoacyl trna synthtases target the enzyme that is there for a cognate aminoacyl with trna which is the first step in protein translation, the antisignal recognition particle antibody targets the signal recognition particle which docks the nacent polypeptide to the endoplasmic reticulum allowing it to enter the endoplasmic reticulum for further processesing.

Dermatomyositis autoantibodies in contrast tend to target transcriptional factors. MI 2 is part of a complex that includes a histodacetylase and regulate transcription.

Transcriptional intermedeiary factor 1 gamma or P155, target transcriptional protein that is phosphorylating now 2 and 3, and then being induced by DGF beta and then XP 2 is also a nuclear transcription factor. These autoantibody subgroups also have distinct clinical phenotypes and prognoses. The aminoacyl trna synthetases the most common of which is Joe 1 has moderate to severe muscle weakness. There's a frequent presence of interstitial lung disease as well as small joint arthritis, fevers, raynaud's and mechanics hand or scaling on the extensor surfaces of the fingers. These patients have a 75% 5 year survival. The contrast signal antirecognition particles is present in patients only with polymyositis. They have acute and severe muscle weakness involving proximal and distal muscle groups, extremely high ck levels and extreme functional disability. The adult patients also frequently have cardiac muscle involvement with frequent myocarditis and arrythmia and the 25% prognosis is this 5 year survival is 25%.

And my 2 autoantibodies have classic dermatomyositis with mild weakness. They tend to have V sign rashes and other rashes and overgrowth of the cuticular onto the nail bed and their survical rate is quite good. The newer identified autoantibody, p155, is done exclusively in patients with dermatomyositis.

25% of those with adult and juvenile dermatomyositis, similar percentage of overlap myositis who all have dermatomyositis and then in as many as 85% of patients with cancer associated myocyteis. These patients have moderate to severe muscle weakness, a high frequency of skin, very wide spread skin rashes, generalized edema and our patients that are generalized with the dystrophy more than 90% of them have this autoantibody.

And antiMJ, now has been identified in patients both with adult and juvenile dermatomyositis. This antibody is associated with the higher frequency of calcinosis and joint contractures and less truncalrashes. And finally CADM 140 to date has been reported only in Japanese individuals. These patients do not have muscle weakness but only the characteristic skin rashes of dermatomyositis. However, 90% of them have rapidly progressive interstitial lung disease and arthritis and these patients have a very high mortality.

The prognosis of these illness is also determined by the phenotype and may be based on demographic features, with older patients, either older adults or adult as opposed to children, not doing as well as younger patients. Patients with more delayed diagnosis and treatment also don't do as well.

Patients based on science symptoms complexes also differ in the phenotypes. Those with more severe muscle weakness, dysphasia or other manifestations we've spoken about also do not do as well with as those with a delay in the capillary regeneration. And then based on the clinical or serologic group that we've discussed, prognosis is different.

In terms of the treatment of myositis is, our results are based not from controlled trials but from case series and anecdotal reports. Corticosteroids remain the mainstay of therapy but should be supplemented in cases with poor prognosis.

Limited data, suggests that methetrexate, IVIG, cyclosporine and others have similar response rates in refractory patients.

There are newer immunosuppresants that are providing increased treatment options. Currently while prednisone is the mainstay, we are finding other agents are used as part of first line therapy including pulse mehtylprednisolone and high dose methotrexate. In adults these are used with patients with poor prognostic factors whereas in children these are now being used as part of first line therapy with patients with moderate to severe illness.

A second line therapy includes intravenous gammaglobulin based on randomized control trials, including azathiprine and cyclosporin. And then combinations of these agents may be used and based on the study conducted here by doctors fox and miller, they will be particularly effective for treatment refractory patients. Several new drugs and biologic therapies are emirntling as promising for patient who are refractory.

Based on case series in adult polymyositis this shows improvement in strength enzymes and rashes for patients with refractory disease.

An open label study of tacro alignments and adult polymyositis, suggest in children, improvement in strength and remarkable improvement in interstitial lung disease. The story with anti-TNF antibody therapy is more mixed. Reports in children suggest remarkable improvement whereas those in adults appear to be mixed. And a recently completed randomized control trial, conducted here by doctors Orelly and Plotz again suggest mixed results.

Alemtozumab is promising new treatment based on the study conducted by Dr. Delockus and myocyte is patients.

In his study remarkably some patients improved in the strength and daily function while others slowed the rate of their decline. This was an open labeled study and the improvement paralleled the depletion of t cells in the periphery as well as muscle. Another promising biologic therapy is retuxamab, or anti CD monoclonal antibody therapy. Initial open label studies and adult myositis and polymyositis suggested remarkable response rate in treatment refractory patients. This was followed by several reports of less impressive response, including one report from Stanford which found no improvement in the skin disease.

Children with juvenile dermatomyositis have had a remarkable improvement with 3 out of 4 patients entering remission and several of the patients on antisynthetase or SMP autoantibodies seem to have responded to this therapy and open label reports.

The improvement seems to be observed as early as 4 to 8 weeks following B cell elimination and might last quite a long time, 12 months or 18 months when B cells return. There are only a small number of adverse events with this treatment to date, which are primarily infusion related although there are some rare adverse event reports including worsening of underlying cardiac disease, the development of progressive multifocal leukoencepholopathy and intestinal proliferation.

We are awaiting the results of a randomized control trial funded by NIAMS, which is the largest trial conducted to date for patients with myositis and involves 200 patients. The trial is particularly interesting for its randumize placebo design in which patients are randomized to receive retuxamab at either week 8 or 9 and looking for the difference in time to respond.

The clinical phenotypes, then, seem to differ in their response to treatment. Dermatomyositis then seems to require lower doses prednison, fewer toxic agents and patients respond well, enjoying a good amount of time or therapy. Patients with polymyositis require higher doses of prednisone and as many as 40% of these patients will flair when prednison and others are tapered and they don't return to the same functional level with each of these players; patients with inclusion body myositis as we have discussed, those with particularly active disease will either slow the rate of their progression or even show a definite response to treatment. Similarly the autoantibody subgroups have differences in the response to treatment.

Patients with MI2 require the lowest doses of prednisone and are able to enjoy a good amount of time off therapy without flare-up. Patients with autosynthetase antibodies require prednisne and these patients often flare when therapy is tapered and patients with signal recognition autoantibodies require the highest dose of therapy and often require other agents and are not able to enjoy any time off therapy and still have active disease.

In juvenile patients we have a lesser understanding of the disease phenotypes that are responsive to therapy with these.

We understand there are different disease course phenotypes, monocyclic patients responding to therapy within the 2 year period and then seemingly entering remission. This is associated with more mild disease and a shorter delay to diagnosis. Polycyclic patients have a relancing remitting for it in patients with a chronic continuous course of illness, and don't seem to enter remission. These patients tend to have more severe illness features including calcinosis and ulcerations and these are associated with TNF alpha and AALLEVS which is associated with the production of more TNF alpha.

So in summary then, the myositis syndromes are a clinically, pathologically and serologically heterogeneous group of systemic autoimmune diseases. The treatment consists of immunosuppresent medication with adjunctive physical therapy and promising biologic agents are in trial. The careful phenotyping of patients is critical in describing or predicting clinical manifestations, responses to treatment, disease courses and prognosis.

I'd like to particularly thank and acknowledge Fred Miller who has been my colleague and mentor for 16 years for all of his wisdom, Paul Plotz who introduced my to myositis and introduced me to Fred Miller and our collaborator with the autoantibodies, the staff and students of the environmental autoimmunity group and the number of NIH clinical center collaborator who have helped us in carefully phenotyping these patients.

Thank you very much.

MILLER: well I appreciate the opportunity to talk about some of our work today and to follow up on Lisa's very nice summary of myositis and the role of phenotypes in understanding responses of therapy, prognosis and clinical presentations. What I'd like to do today is to step back to the beginning of the process of pathogenesis of these diseases and think about the genetic and environmental aspect of these diseases. I'll start by introducing the potential roles these environmental and genetic influences may have on systemic autoimmune diseases, and move on to talk about their roles in myositis phenotypes and illustrate compact genic mechimisms are actually different in different myositis phenotypes. I have no financial conflicts of interest that I'm aware of this talk.

Why do we think the environment is important for development of autoimmune diseases? There are a number of complementary lines of evidence supporting this and there are strong temporal associations with some exposures and disease onset, disease improvement after removing particular agents and disease recurrence sometimes in the same patient after to reexposing that agent to that patient. The concept of rechallenge.

There has been a 50% disease concordance resistant in the studies that have been done in autoimmune disease. There's seasonality in birth dates in season onset, changes in disease prevalence over time but most data for most autoimmune diseases suggest other dramatic increases over the last several decades. Biologic plausibility from in vitro and animal model studies. And epidemiologic associations of course between particular agents and diseases.

Of course genetics also play a major roll here. We have increased prevalence of disease in certain families and ethnic groups and there are gradients of disease concordance in pedigrees such that if have you a monozygotic twin who as an autoimmune disease, you have a much greater chance of developing that disease, compared to if you had a diozygottic twin or more distantly related individually relative.

And finally there are a number of associations with a lot of different genes, many of which are actually shared among many different autoimmune diseases. And this slide shows the major risk factors for the development of a number of different autoimmune diseases. These are immune response genes. These are important in deciding the types and the levels of immune responses to different environmental agents and for the most part, these are HLA or human leukocyte antigen alleles as shown by the DR numbers here in this slide. The overall concept is that some genes are risk factors for distinct autoimmune diseases but more frequently you see genes that are actually common risk factors for a number of different autoimmune diseases.

And the evolving hypothesis is that environmental agents in the outside ring here need to interact with various genes and genomes on the inside ring to lead to particular disorders.

You like to think of these disorders in nice boxes defined by certain criteria, but the reality is that the borders are not that clean between different diseases of this slide suggests.

The other concept is that disease as we understand them are composed of many distinct phenotypes represented by these individual circles here. And it's a development of the phenotypes themselves after exposures with the genetic risk factors it's probably one of the most important aspects to incorporate into this hypothesis. This slide also introduces the concept of protective genotypes, genes that prevent the development of disease after particular permissive exposures and other genotypes would lead to disease. And there are very few examples unfortunately that support this working hypothesis right now but here's a slide showing the better established ones. Certain diseases that have been associated with particular exposures and then with certain genetic risk factors that are known to modulate that risk. These are all immune response genes and we've had the opportunity recently to add to this rather short list by evaluating a syndrome that was characterized by very high acenofill levels and incapacitating allergens that developed in epidemic proportions after ingestion of certain batches of the dietary supplement l triptophan. We found there were risks increasing it dramatically whereas there were other genes that were protective with the development of this syndrome after l tryptophan exposure.

Well, how do these concepts apply to the myositis syndromes. This slide is an attempt to describe the working hypothesis that's been trying many of our investigations over the last several years. And as Dr. Rider suggested, the myositis syndromes that are encompassed in this large box are actually composed of many distinct phenotypes and then there are ultimate indivisible forms, I would call these elemental disearedders and elemental disorder in this construct would be a unique collection of clinical signs, symptoms and laboratory abnormalities that develop after a distinct pathologic process that occurred as a result of the interaction of the necessary and sufficient genetic environmental risk factors.

We hypothesize that these different phenotypes each have different pathologic processes and different kinetic and environmental risk factors and in some cases multiple genes are required and perhaps multiple environmental exposures.

What are the environmental exposures that might be relevant to the development of these diseases? There are actually very few epidemiological investigations in this area. The slide lists all of the publishes ones to date and some of these such as investigation as dr. Riders lab, looking at parvovirus, and juvenile myositis found fewer patients that had this virus than the healthy batch control individuals that they were compared to. This was also the case for upper respiratory infections in adult dm and pm patients which were found to be lower in frequency or onset compared to the unaffected sibling they were compared to. Other studies however have shown that the group based streptoccuss in children, physical exertion in adults and collagen implants particularly in dermatomyositis were risk factors for the development of the disease. There's been a study that found no association with vaccines and myositis.

But beyond these careful epidemiological investigations, there are a number of case reports, case series, laboratory investigations and animal model studies that suggest that there may be other environmental exposures that are important in the development of myositis and particularly in certain phenotypes.

These include a number of infectious agents, notably upper respiratory infections in children, a number of different viruses, particularly echo viruses and juvenile disease, and occasional patients with adult pm and dm associated with retrovirus infections and several parasites in these patients as well. Other environmental exposures include emotional stress, cigarette smoking and the development of antisynthetase syndrome and those other autobodies, and the variety of medications associated with one or more phenotype. Particularly penicillin, a variety of interferons, some statins and growth hormone in children. UV radiation is also thought to be important in development of dermatomyositis phenotypes and we'll describe it later.

One way of looking at environmental exposures is to assess if there's a seasonal pattern in the onset of these diseases or if there's a seasonal pattern in birth dates and seasonality has been reported in the onset of many infections but also some autoimmune diseases. Seasonal patterns in birth dates have also been described in a number of autoimmune diseases, suggesting that perinatal exposure may have effects that are long lasting and may be have long latencys to the development of the disease.

We don't know the reasons for these seasonal associations but it's interesting to note that seasonal hormones, innate and adaptive immune function and susceptibility to infections are known to vary by season, so I think a careful study of seasonal associations with these disease may be a first step to beginning to understand the possible environmental triggers when you don't have much else to go on in evaluating environmental risk factors.

So in order to assess this we look at about 500 patients, most of them seen here at NIH, to assess the season of onset in myositis. And if we look at all patients with myositis we see no seasonal association, it was only when we identify these penhontypes that these patterns emerge. Patients with antiautosynthetase antibodies for example, they have a spring onset, and strongest associations here were seen in men with polymyositis. Whereas patients who did not have these myositis autoantibodies tended to have an onset to keep in the summer with the strongest associations in women with dermatomyositis. Of course we don't know what these seasonal exposures may be that account for these patterns but we're planning to follow this up in a study of new onset myositis patients that we hope to begin soon.

We will also be looking at birth date distributions in myositis and again if we look at all the patients, we did not find any evidence of association in all patients but again only when we begin dividing these patient intos particular phenotypes, ethnic, or autoantibody phenotypes in particular, a few HLA phenotypes as well did we see seasonal distributions in birth dates. Here's an example of Hispanic children for example, who have a seasonal distribution in birthdays that differs from that seen and matched with Hispanic healthy controls. Here's another example of the children who have the anti p155 antibodies that Dr. Rider mentioned where there's a different pattern in birth date distributions in these patients compared to those who do not have these autoantibodies. These data again suggest there may be environmental exposures perhaps seasonal that occur in sensitive times of development that might have long lasting effects and might result in disease in decades later.

Another way of evaluating disease is to evaluate the ethnogeography of diseases, and i know that different diseases seem to present differently and have different frequencies around the world. We don't know why that is, but of course, the natural global variations may play a role here, so that a careful evaluation of these differences may give clues to understanding the pathogenesis and the environmental risk factors for these diseases. I've been impressed in my roaming around the world in how different myositis is in different regions of the world and to assess this formally I initiated the first international evaluation and first global evaluation myocyte is and number of referral centers around four continents to assess how patients may present differently.

The first assessment was to simply ask, what is the frequency of the different forms of these diseases at these locations.

And this is an example of looking at proportion of dermatomyositis patients, compared to polymyositis patients at these different referral centers in which we found dramatic differences. In Guatemala for example 90% of these patients had dermatomyositis whereas in Glasgow this was only about 25% of these patients. Well we asked if referral biases could have accounted for this. This didn't seem to be the case.

We asked if different genetics in these populations could account for this, although we saw different genetic associations with different ethnic groups this is also did not seem to account for this pattern.

So we moved on to look at environmental associations with these patterns and in the collabrative study with the national oceanic and atmospheric administration and using a combination of satellite and ground base data, looking at a wide variety of geoclimactic variables, we found it was global ultraviolet radiation levels at each of these locations, that actually was the best predictor of the proportion of dermatomyositis of these patients that these referral centers. This is a rather strong association in these thousands of parents here and in fact the strongest clinical association of ultraviolet radiation reported yet to date. But of course ultraviolet radiation has been an interesting exposure for sometime. And if I had known that ultraviolet radiation in individuals had induced disease flares in lupus and myositis, you know that ultraviolet radiation induces skin inflammation excessive exposure levels and this inflammation is actually greater in female, compared to male mice based on a variety of different measures. Suggesting there are gender differences here and of course, these autoimune diseases tend to be predominantly female.

We've also found recently in collaboration with Trevor Archer that ultraviolet radiation increases the expression of the MI2 antigen in a variety of different cell lines, and in a dose dependent and time dependent fashion.

This is the target of a major immune response in dermatomyositis patients. So we hypothesize that ambien ultraviolet intensity at the location of disease onset could predict the relative prevalence of dermatomyositis and autoantibodies to MI2 and these effects may vary with gender. And looking at around 450 patients across the united states, we found in fact that this was the case. That the amount of ultra violet radiation in these regions as measured by the UV index did correlate and predict the proportion of patients with dermatomyositis and those with the antiMI2 antibodies, so that did so only in women and not in men.

So we try and find the follow up study by assessing the effects of ultraviolet radiation, estrogen in various combinations on the expression of different myositis antigens to see if that might be part of the explanation here. And we're also determining if ultraviolet radiation may be a risk factor for the development of systemic autoimmune diseases. This includes rheumatoid arthritis, lupus and myositis by looking at sibling pairs that are discordant for these diseases. We are actively recruiting for this study and I will say that we would be happy to talk to you about any referrals, for this investigation right now.

Well, moving on to genetic risk factors we think these come in 2 different forms. They come in forms that are common to many different autoimmune diseases and common to many different phenotypes and that there are also forms that are probably unique to particular phenotypes. And one of the reasons we're thinking about common genes here is the finding that autoimmune diseases are increased about 8 fold and relatives and first degree relatives of myositis patients compared to matched healthy control individuals. In the study which was done here at the clinical center, found that these diseases tended to match the frequency of the general distribution of diseases in the population, very common diseases, we've seen commonly in other words, we found these increased over time. These were dependent on age, we found the female predominance as expected and we found if you understand by modeling these that these were most consistent with a nonmendelian polygeneric inheritance factor, suggesting that genes from other autoimmune diseases are shared. But of course myositis patients have their own unique genetic risk factors as well and some of our earlier studies we found that in the case of autoimmune disease, there was a myositis shared epitome and higher region 1 motif which happens in the antigen binding region indicate by these red amino acids here and in the middle of a number of different DR 31113 and 14 molecules that allows for the alteration potentially and the binding of particular antigens that will be presented to the immune size.

As we extended our studies up to a thousand patients we found a more complex pattern of genes, associations with particular phenotypes.we found that a number of genes that are linked together in the mac region known as the HLAA .1 ancestral haplotype are risk factors for multiple clinical and certain autobody phenotypes. But they found even stronger associations, when we found genes that were risk factors for individual phenotypes. Some of these were class 1 genes.

Some of these are class 2 genes, and some of these result in what may be called a rather complex phenotype interaction here and we also found protective genes, genes that were found in much higher frequency and healthy control population, compared to the myositis patients that we're looking at and again we found these primarily associated with particular phenotypes.

These are DR beta 1. Alpha 1. Gq beta 1. Genes as well as DQ alpha motif here as well. So again a rather complex genotype phenotype interaction for protective gene as well as risk pathogenes.

Another interesting phenomenon is that many of these clinical and autoantibody phenotypes are mutually exclusive and are stable for decades. Patients do not move from one to another of these and we don't know the reason for that of course, but one interesting find progresses our genetic study system that alleles concur in the risk, one phenotype, are actually protective for another phenotype. We found a number of examples of this, but here for example, is HLER7 which is a relatively strong risk factor for the antibodies relatively strong in the development for the protection for the development of antisynth tase antibodies and again patients do not have any of them both of these antibodies, patients do not move from the proteaks of these to another. This may be a clue to 1 of the reasons that's produced why these are mutually exclusive and stable phenotypes.

Of course, there are a number of nonHLA genes that are also at risk for protective factors for the myositis phenotypes that we and others have identified and this is a list of those predominant ones, and these again are all immune response genes, and in general they tend to be polymorphisms in terms of risk factors that tend to upregulate or proinflammatory, increasing TNF levels or Il1 levels or immunoglobulin levels for all 3 T cell signals in a proinflammatory way, but of course the basal targeted gene analysis are now in the past, when we have a whole genome association methods that allow us to look at hundreds of thousands of snips at a time. And if we take advantage of some of these new technology, I inform the myositis genetics consortium which is a group of over 2 dozen centers in North America and Europe, which are collaborating with peter gregerson to evaluate genes as risk factors and protective factors for myocyte is phenotypes.

And these are first preliminary analysis and 1100 patients and these data suggest that many new genes and pathways are important. And these also appear to vary in different phenotypes. It's the pathways to the responses RNA and DNA processing and cell signals and we're in process of confirming these and if confirmed, I think we hope these can lead to identifying novel mechanisms and perhaps novel treatments for these diseases.

Well, pathologic processes by definition of course are not known in idiopathic diseases. But, putting together the data that's in the literature, we developed a scheme that we think is at least consistent with these data and I'll go over that briefly with you. Environmental risk factors interact with genetic risk factors to induce inflammatory changes and the expression of proinflammatory cytokines, to autoantibody production which we've shown occurs months after the development of disease.

We have different pathologic processes going on in different phenotypes with polymyositis patients as you've heard from Dr. Rider being involved in cytotoxic T cell activation, perforin meadiated myotoxicity, whereas in dermatomyositis, there's evidence of more compilation, there's complex effects on endothelial cells and influxion of dendritic cells and CD4 cells.

We'll later see cleavage of autoantigens as a possible way that they're targeted and in some cases a chemokines are the result of different fragmentation of some of these autoantigens, we see endoplasm reticulum response and these together lead to increased NF Kappa B expression, tissue damages, attempts to reregenerate that tissue and repair it.and but most importantly these positive feedback loops, that amplify and perpetuate this information.

I don't have time to go over in detail, the specific other pathologic differences in many of the phenotypes I've talked about here so I'll spend a little time talking about the evidence of the roll of type 1 interferon, specifically in dermato myositis phenotypes. It's been known that dermatomyositis can develop after interferon therapy for sometime, but only recently have increased type 1 interferon signatures been described in the blood, muscle and skin from adults and juvenile myositis patients, related to dendritic cells that are present in these tissues. Ultraviolet radiation may be involved based on parallel sides in lupus and some other autobody groups may also have this process going on, because increased type 1 interferon secretion can occur in normal blood mononuclear cells after incubation of the serum containing antisynthetase and anti-IL-1 antibodies. This may occur as a result of IR of different genetic and environmental risk factors.

I think the message is that careful clinical phenotypes of complex disorder system actually critical for optimizing the yields from environmental genetic pathogenic prognostic and therapeutic studies and I think more of this needs to be done for us to really make progress in many of the diseases today.

I'd like to thank those that have participated in developing the data that I presented today. In particular those in my group here, doctors Rider or Hamlin, and others. Others we've collaborated with at NIEHS in North Carolina, including my colleagues listed here. We have the colleagues from the arthritis institute who have been constant companions on your journey to understand these diseases over the last several decades. And a number of clinical centers and I'll focus on Karen Adams and others, and from the fine stein institute and last but not least our patients and their families and the funding agencies without whom this work would not have been completed.

I thank you for your attention and I'll stop at this time.

If we have time for some questions we will take time for the questions.

QUESTION: Thank you very much, did you notice that vitamin D might be affected as a factor for the ultraviolet radiation could induce more vitamin D and that could affect the cytokine expression through action?

MILLER: Yes, the roll of vitamin d in the development or lack thereof for other autoimmune diseases hypothesized for a while strictly in the context of multiple clearoseis and other diseases where you see an inverse association with ultraviolet radiation, I think those studies are yet to be confirmed and I think it's still a preliminary concept and a preliminary association we've not done studies of myositis to ask that question.

QUESTION: Are there any controlled studies of androgens as affecting myositis? Testosterones?

MILLER: We haven't looked at the levels of hormones in these antigens or to see if therapies may be helpful. Antigen surrogate has been tried in inclusion body myositis with rather limited success but we've not looked in other forms.

QUESTION: You highlighted the roll of ultraviolet radiation and mentioned it is photosensitivity features of some of these phenotypes. My question is, experimentally, can this be potentiated by drugs that are known to be associated with photosensitivity, as a side effect?

MILLER: Yes, the question of whether the drugs some of which we use to treat these diseases may actually induce photosensitivity is a very good one and in fact, there are hundreds of drugs as you know that are photosensitized.

We have not explored that carefully although we're collecting that data in our studies to try to answer that question and see if they may be playing a factor in this process.

[APPLAUSE]

ANNOUNCER: You've been listening to NIH Clinical Center Grand Rounds recorded February 24, 2010. Today we heard two speakers from the National Institute of Environmental Health Sciences taking on the topic "Phenotypes as Clues to Deciphering the Pathogenesis and Treatment of Myositis" Our speakers were Dr. Lisa Rider, deputy chief of the Environmental Autoimmunity Group in the Office of Clinical Research at the NIEHS. She was joined by Dr. Frederick Miller, chief of the Environmental Autoimmunity Group in the Office of Clinical Research at the NIEHS. You can see a closed-captioned videocast of this lecture by logging onto http://videocast.nih.gov -- click the "Past Events" link -- or by clicking the "View Videocast" link on the podcast homepage at www.cc.nih.gov/podcast. The NIH CLINICAL CENTER GRAND ROUNDS podcast is a presentation of the NIH Clinical Center, Office of Communications, Patient Recruitment and Public Liaison. For more information about clinical research going on every day at the NIH Clinical Center, log on to http://clinicalcenter.nih.gov. From America's Clinical Research Hospital, this has been NIH CLINICAL CENTER GRAND ROUNDS. In Bethesda, Maryland, I'm Bill Schmalfeldt at the National Institutes of Health, an agency of the United States Department of Health and Human Services.