One year in review 2015: idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM) are a group of rare acquired muscle diseases that mainly affect skeletal muscles. Recently, novel insights into the pathogenesis, diagnosis and treatment of these complex diseases have been provided. Herewith we provided an overview of the most significant literature contributions published over the year.

[Acquired inflammatory myopathies: interest of specific autoantibodies for their classification]

The former classification of myositis based on the clinical phenotype and muscle histology is now changing. We started from the concept of "dermatopolymyositis" to the recognition of inclusion body myositis and more recently of immune mediated necrotizing myopathies. Furthermore, during the last 10 years, the routine access to myositis associated or specific auto-antibodies permitted to fine tune homogenous subgroups of myositis patients with common phenotype, immunopathology and prognosis. Using this approach, the polymyositis group has completely disappeared, the former patients now being reclassified as having and inclusion body myositis or an overlap syndrome such as the anti-synthetase syndrome. The different subgroups of myositis associated with their specific auto-antibodies are described here.

Clinical, neuropathological and radiological evidence for a rare complication of rituximab therapy

We report a rare case of myofasciitis and meningitis with deafness caused by systemic enterovirus infection in the setting of hypogammaglobulinaemia induced by rituximab. Whilst effective and generally safe, anti- CD 20 antibody therapy is increasingly recognised to result in unusual infectious complications to be considered in a treated patient presenting with neurological symptoms. These cases may pose diagnostic difficulties and can have atypical presentations. We present this rare complication of rituximab therapy, with histopathological confirmation of myofasciitis. In the older literature, enterovirus associated myofasciitis may have erroneously been termed dermatomyositis and we review the literature to demonstrate this important nosological point.

[The anti-synthetases syndrome: diagnostic and treatments]

The anti-synthetases syndrome is a rare disease with a specific constellation of clinical symptoms present in a subset of patients with inflammatory myopathy. Besides constitutional symptoms and myositis, it is associated with mechanic's hands, Raynaud phenomenon, and non-erosive arthritis. This syndrome is characterized by the presence of one of eight auto-antibodies to aminoacyl-transfer ribonucleic acid synthetase enzymes in the serum. Interstitial lung disease is more frequent in this subpopulation of inflammatory myopathy and worsens the patient's prognosis.

Myositis registries and biorepositories: powerful tools to advance clinical, epidemiologic and pathogenic research

PURPOSE OF REVIEW

Clinical registries and biorepositories have proven extremely useful in many studies of diseases, especially rare diseases. Given their rarity and diversity, the idiopathic inflammatory myopathies, or myositis syndromes, have benefited from individual researchers' collections of cohorts of patients. Major efforts are being made to establish large registries and biorepositories that will allow many additional studies to be performed that were not possible before. Here, we describe the registries developed by investigators and patient support groups that are currently available for collaborative research purposes.

RECENT FINDINGS

We have identified 46 myositis research registries, including many with biorepositories, which have been developed for a wide variety of purposes and have resulted in great advances in understanding the range of phenotypes, clinical presentations, risk factors, pathogenic mechanisms, outcome assessment, therapeutic responses, and prognoses. These are now available for collaborative use to undertake additional studies. Two myositis patient registries have been developed for research, and myositis patient support groups maintain demographic registries with large numbers of patients available to be contacted for potential research participation.

SUMMARY

Investigator-initiated myositis research registries and biorepositories have proven extremely useful in understanding many aspects of these rare and diverse autoimmune diseases. These registries and biorepositories, in addition to those developed by myositis patient support groups, deserve continued support to maintain the momentum in this field as they offer major opportunities to improve understanding of the pathogenesis and treatment of these diseases in cost-effective ways.

[A case of myasthenia gravis with invasive thymoma associated with diffuse panbronchiolitis, alopecia, dysgeusia, cholangitis and myositis]

A 43-year-old man was admitted to our hospital because of diplopia, ptosis, and dysphagia that had begun three years previously. He was diagnosed with myasthenia gravis (MG) and invasive thymoma and treated with corticosteroid, thymectomy, and radiation therapy. Ten years after the thymectomy, computed tomography (CT) showed metastasis of the thymoma in the left lower lobe of the lung. Two years after this recurrence, when the patient was 55, respiratory symptoms such as wheezing, persistent cough, and dyspnea appeared. Chronic sinusitis, diffuse centrilobular opacities on CT, and positivity for HLA-B54 led to a diagnosis of diffuse panbronchiolitis (DPB). Despite treatment with clarithromycin, the respiratory symptoms worsened. The patient developed alopecia and body hair loss at the age of 56 followed by dysgeusia, cholangitis, and myositis with positivity for anti-Kv1.4 antibodies. Although treatment with an increased dose of corticosteroid improved hair loss, dysgeusia, cholangitis, and myositis, he died of progression of DPB and serious respiratory infection at the age of 58. In this case, various autoimmune disorders occurred together with MG as complications of thymoma. Although alopecia, dysgeusia, and myositis are already known as complications of MG associated with thymoma, cholangitis is not well-recognized since there have been few reports suggesting a causal relationship between cholangitis and thymoma. Furthermore, DPB caused by immunodeficiency and respiratory tract hypersensitivity associated with thymoma and HLA-B54, respectively, is the distinctive feature of our case. Neurologists should be aware that various organs can be damaged directly and indirectly by abnormal T cells from thymoma in patients with MG.

[Idiopathic inflammatory myopathies: main clinical and immunological variants, difficulties of differential diagnostics and therapy]

Idiopathic inflammatory myopathies are rare autoimmune diseases with inflammatory lesions in skeletal muscles. They include polymyositis, dermatomyositis, juvenile myositis and inclusion body myositis. These are clinically and immunologically heterogeneous conditions differently responding to therapy. The authors consider the main manifestations of polymyositis/dermatomyositis and principal differences between them. Therapy is based on the prescription of glucocorticoids in combination with immunesuppressors. Better understanding immunological, genetic, and molecular mechanisms opens up new prospects for the management of idiopathic inflammatory myopathies.

[Use of anti-B-cell therapy in case of antisynthetase syndrome as the severest subtype of polymyositis/dermatomyositis]

Antisynthetase syndrome encompassing a symptom complex with severe interstitial lung disease is the severest subtype of polymyositis and dermatomyositis. The characteristic feature of antisynthetase syndrome is the insufficient efficiency of traditional therapy with glucocorticosteroids and cytostatics, which determines the prognosis of the disease and the need for new therapeutic approaches to treating these patients.

Update in juvenile myositis

PURPOSE OF REVIEW

This update on childhood idiopathic inflammatory myopathies (IIMs) reviews recent progress in the field of translational science and clinical research over the past 12-18 months.

RECENT FINDINGS

Several new studies, including results from the international genome-wide association study, point to abnormalities of the adaptive immune system in childhood IIMs. Circulating T-follicular helper cells promote plasma cell differentiation and have been found in high levels in juvenile dermatomyositis (JDM), which may account the frequency of autoantibodies seen in this disease. One of the latest to be identified in JDM targets the protein NXP-2 and is associated with an increased risk of calcinosis in young patients. The first randomized controlled clinical trial in refractory adult and childhood IIMs was reported this year. B-cell depletion with the anti-CD20 antibody, rituximab, failed to achieve its primary end point, but patients with JDM did show good improvement in disease activity. A new international definition of disease remission in JDM has been agreed, which will aid disease assessment in future therapeutic trials.

SUMMARY

The challenges of studying a rare disease such as JDM have been overcome by several collaborative studies and have led to significant progress in understanding the cause, treatment and prognosis of childhood IIMs.

[Comprehensive understanding and study on idiopathic inflammatory myopathies to improve its diagnosis and treatment]

Idiopathic inflammatory myopathies(IIM) are a group of autoimmune diseases characterized by muscle inflammation and progressive weakness. Diagnosis of IIM relies on the combination of clinical manifestation, blood biochemical indicators, myositis specific antibodies, electromyogram and pathology of muscle. Classification criteria of IIM keeps developing, and different criteria has different value on clinical application. IIM may involve important organs such as skin, joint, cardiac muscle and lung, except for skeletal muscle. Internal organs involvement should be evaluated and predicted, which could help to improve the prognosis of IIM. It is necessary to evaluate the disease activity objectively and accurately, which now could be accomplished with uniform and standardized clinical assessment system established by international organizations as the International Myositis Assessment and Clinical Studies Group. The immune pathological progress of IIM has already been well-known but the pathogenesis mechanism needs further study. Comprehensive evaluation of disease activity and organ damage need be emphasized before the beginning of treatments. Treatment strategies should be individualized, and the side effects of therapeutic drugs should be monitored. Multidisciplinary collaboration contributes to the improvement of diagnosis and therapy for IIM.

[Benign acute myositis in a 17-year-old boy]

We describe the case of a 17-year-old teenager who consulted in an emergency unit for acute lateral chest pain with tumefaction. The boy was healthy and had no medical problems or allergies. Upon awakening, he felt faintness and a left lateral chest pain. Movement of the left shoulder was difficult. In the emergency department, the clinical examination showed a painful left axillary mass, normal respiratory and heart function, and normal clinical parameters. Biological assessment revealed substantial cytolysis with major elevation of creatine phosphokinase (CPK) (41 times the normal value) and moderately elevated liver enzymes (2.5 times the normal value), with no inflammatory syndrome, hematology signs, or kidney failure. Axillary ultrasound found a low echogenic and well-limited mass, 6.2cm long, compatible with lipoma. MRI showed a T2-weighted hypersignal of the left serratus anterior muscle, with intramuscular infiltrate compatible with inflammatory disease of this muscle. Clinical symptoms ended in a few days with no after-effects and CPK gradually decreased. This study reports a case of benign acute myositis of the serratus anterior muscle in a healthy 17-year-old teenager. Although no infectious etiology was found, it seems that this semiological entity is a form of benign acute myositis (BAM), a benign muscular inflammation, arising from viral infection and occurring in school-age children, more frequently in males, between 6 and 12 years of age. On average, the symptoms begin 7 days after infection, more often the flu (Influenza virus B or A, parainfluenza virus). It is important to note that this pathology is acute and benign and there is no need for any invasive investigations. The family should be reassured because BAM is a self-limited disease and in the great majority of cases has no after-effects.

[Myositis-specific autoantibodies]

Idiopathic inflammatory myopathies are a group of acquired skeletal muscle diseases that include polymyositis, dermatomyositis, and inclusion body myositis. Studies have shown many myositis-specific autoantibodies (MSAs) that are useful for the diagnoses as well as classification of idiopathic inflammatory myopathies, because they have been shown to correlate with distinct clinical phenotypes. Anti-Jo-1, anti-PL-7, anti-PL-12, anti-EJ, anti-KS, anti-OJ, anti-Ha, and anti-Zo antibodies target aminoacyl tRNA synthetases, and represent anti-synthetase syndrome. Anti-synthetase syndrome is characterized by myositis, interstitial lung disease, arthritis, fever, Raynaud's phenomenon, and mechanic's hands. Anti-Mi-2, anti-MDA5 (anti-CADM140), anti-TIF1 (anti-155/140, anti-p155), anti-NXP-2 (anti-MJ), and anti-SAE antibodies are specific for dermatomyositis. In particular, anti-MDA5 antibodies are clinically associated with amyopathic dermatomyositis developing into rapidly progressive interstitial lung disease, whereas anti-TIF1 and anti-NXP-2 antibodies are closely correlated with cancer-associated dermatomyositis in adults. In addition, anti-TIF1 and anti-NXP-2 antibodies are predominant MSAs found in juvenile dermatomyositis, and the latter was correlated with a high incidence of calcinosis. Furthermore, anti-SRP and anti-3-hydroxy-3-methylglutaryl-coenzyme A (anti-HMG-CoA) antibodies have been found in patients with necrotizing myopathy. Moreover, a recent study suggested the presence of autoantibodies to a 43-kDa muscle protein in patients with inclusion body myositis. Although the pathogenic role of MSAs remains unknown, recent studies have shown that myositis autoantigens are expressed at high levels in regenerating muscle fibers, which may initiate or amplify autoimmune responses in idiopathic inflammatory myopathies.

Inflammatory myopathies--a review of newly diagnosed patients (2004-2008) in the Counties Manukau region

AIMS

To estimate incidence, review clinical characteristics and management of newly diagnosed patients with idiopathic inflammatory myositis in Counties Manukau and to compare the findings with other reported series in New Zealand and overseas.

METHODS

A case note study of computer generated data of patients having a diagnosis of inflammatory myopathy from January 2004 to December 2008 were included in this retrospective review.

RESULTS

Twelve patients were newly diagnosed in the 5-year period. Polymyositis (PM) was diagnosed in 58%, dermatomyositis (DM) in 33% and inclusion body myositis (IBM) in 8%. Amyopathic dermatomyositis (ADM) and malignancy associated dermatomyositis were diagnosed in one patient each. There was slight preponderance of men in dermatomyositis and women in polymyositis. Muscle biopsy was performed in 75% and electromyography was reported in 58%. High-dose prednisone was administered to 83%, and 50 % required other immunosuppressives, such as methotrexate (33%) and azathioprine (16%). Overall therapeutic response was good (75%) with 2 deaths (17%), one each in dermatomyositis and polymyositis. Regular follow-up was maintained in 92 %. Nasopharyngeal carcinoma was diagnosed in a patient with polymositis during follow up.

CONCLUSIONS

Idiopathic inflammatory myositis is a challenging group of heterogenous disorders. This study highlights the need to review current criteria to include subcategories, such as amyopathic dermatomyositis, and the importance of long term surveillance to detect occult malignancy.

[Antisynthetase syndrome - a case report]

Twenty-eight year-old woman with predominant signs of polymyositis, pulmonary interstitium involvement and with positive anti-Jo1 antibodies was suspected for antisynthetase syndrome. Over the next three months sores and ulcerations have appeared at the fingertips. In the later course of the disease clinical picture of mixed connective tissue disease associated with interstitial lung disease, with a dominant picture of systemic sclerosis have emerged. She was treated with glucocorticoides and immunosuppressive therapy. Patient condition was mostly stable, without significant progression of lung lesions. Early diagnosis and treatment antisynthetase syndrome significantly contributes to more favorable course and outcome of disease. A prerequisite for that are well-defined diagnostic criteria and an appropriate choice of treatment.

Idiopathic inflammatory myopathies: current trends in pathogenesis, clinical features, and up-to-date treatment recommendations

Recently, there have been important advances in the understanding of the pathophysiologic features, assessment, and management of patients with a newly diagnosed idiopathic inflammatory myopathy (IIM). Myositis-specific autoantibodies have been identified to define patient subgroups and offer prognostic implications. Similarly, proinflammatory cytokines, such as interleukin 6 and type 1 interferon-dependent genes, may serve as potential biomarkers of disease activity in adult and juvenile patients with dermatomyositis (DM). Moreover, magnetic resonance imaging has become an important modality for the assessment of muscle inflammation in adult IIM and juvenile DM. Immune-mediated necrotizing myopathies also are being recognized as a subset of IIM triggered by medications such as statins. However, confusion exists regarding effective management strategies for patients with IIM because of the lack of large-scale, randomized, controlled studies. This review focuses primarily on our current management and treatment algorithms for IIM including the care of pediatric patients with juvenile DM. For this review, we conducted a search of PubMed and MEDLINE for articles published from January 1, 1970, to December 1, 2011, using the following search terms: idiopathic inflammatory myopathies, dermatomyositis, polymyositis, juvenile dermatomyositis, sporadic inclusion body myositis, inclusion body myositis, inflammatory myositis, myositis, myopathies, pathogenesis, therapy, and treatment. Studies published in English were selected for inclusion in our review as well as additional articles identified from bibliographies.

[Occupational myofibrosis - main aspects of clinics, diagnosis and treatment]

Occupational chronic myofibrosis is a disease resulting from physical overstrain and functional overload of upper extremities and shoulder girdle and beeing the most prevalent occupational diseases related to the so-called "working hand". Myofibrosis occur among persons employed actually in all industries, building and agriculture and may develop as an isolated disease or combined with other occupational diseases of musculoskeletal and peripheral nervous systems. Today problems of diagnostics, especially at the early stage of the disease, and the development of knew methods of treatment are still topical.

Anti-PL-7 (anti-threonyl-tRNA synthetase) antisynthetase syndrome: clinical manifestations in a series of patients from a European multicenter study (EUMYONET) and review of the literature

Autoantibodies against several aminoacyl-transfer-RNA synthetases have been described in patients with myositis; anti-threonyl-tRNA synthetase (anti-PL-7) is one of the rarest. We describe the clinical and laboratory characteristics of a cohort of European anti-PL-7 patients, and compare them with previously reported cases. This multicenter study of patients positive for anti-PL-7, identified between 1984 and 2011, derives from the EUMYONET cohort. Clinical and serologic data were obtained by retrospective laboratory and medical record review, and statistical analyses were performed with chi-squared and Fisher exact tests. Eighteen patients, 15 women, were anti-PL-7 antibody positive. Median follow-up was 5.25 years (interquartile range, 2.8-10.7 yr), and 4 patients died. All patients had myositis (12 polymyositis, 5 dermatomyositis, and 1 amyopathic dermatomyositis), 10 (55.6%) had interstitial lung disease, and 9 (50%) had pericardial effusion. Occupational exposure to organic/inorganic particles was more frequent in patients with interstitial lung disease than in the remaining patients (5 of 10 vs. 1 of 7; p = 0.152), although the difference was not significant. Concurrent autoantibodies against Ro60 and Ro52 were seen in 8 of 14 (57%) patients studied. In the literature review the most common manifestations of anti-PL-7 antisynthetase syndrome were interstitial lung disease (77%), myositis (75%), and arthritis (56%). As in other subsets of the antisynthetase syndrome, myositis and interstitial lung disease are common features of the anti-PL-7 antisynthetase syndrome. In addition, we can add pericarditis as a possible manifestation related to anti-PL-7 antibodies.

Long-term outcome of an unusual haemophilic pseudotumour

Haemophilia, a lifelong congenital bleeding disease, is a highly demanding disorder, due to the costs of its replacement therapy. In the absence of this pivotal treatment, life expectancy and quality of life are deleteriously affected. As illustration, we present a 14 years long follow-up of a patient with severe haemophilia A, treated sporadically with fresh plasma, cryoprecipitate and factor concentrates, who developed a giant iliopsoas pseudotumor. Since he was an infant, under on demand therapy with fresh frozen plasma, cryoprecipitate and low doses of factor concentrates he presented many spontaneous bleedings, developing multiple disabling arthropathies. At the age of 14 years, an iliopsoas hematoma occurred, which relapsed several times, developing an iliopsoas pseudotumour. After 5 years, sepsis with Klebsiella was diagnosed. A CT scan revealed fistula between the pseudotumor and the gut. Under antibiotics, the evolution of sepsis improved, but over a period of 10 months 5 episodes of haematemesis and melena, followed by one episode of macroscopic haematuria occurred; two months later he developed an inguino-crural mass, which fistulized through the abdominal wall. A mixt german-romanian team solved the clinical concern. After 108 hospitalization days and consumption of 104840 IU factor VIII he left the clinic in good condition. One year later, the temporary colostomy with anus praeter was closed. The follow-up reveals now, after almost 10 years with favourable outcome, that the patient is well, active within his family and profession.