[The antisynthetase syndrome: a subgroup of inflammatory myopathies not to be unrecognized]

Joint and muscle inflammatory disease: A scoping review of the published evidence

OBJECTIVES

Polyarthritis is commonly reported in idiopathic inflammatory myositis patients, but few studies have focused on the overlap of myositis with rheumatoid arthritis which is a difficult diagnosis in the absence of well-defined diagnostic criteria. The primary objective of this scoping review was to map the field of research to explore the potential diagnoses in patients presenting with both myositis and polyarthritis.

METHODS

Two electronic databases (MEDLINE/PubMed® and Web of Science®) were systematically searched using the terms (myositis OR 'inflammatory idiopathic myopathies') AND (polyarthritis OR 'rheumatoid arthritis') without any publication date limit.

RESULTS

Among individual records, 280 reports met inclusion criteria after full-text review. There was heterogeneity in the definition of overlap myositis as well as the characteristics of rheumatoid arthritis. In many studies, key data were lacking; rheumatoid factor status was reported in 56.8% (n=151), anti-citrullinated proteins antibodies status in 18.8% (n=50), and presence or absence of bone erosions in 45.1% (n=120) of the studies. Thirteen different diagnoses were found to associate myositis with polyarthritis: antisynthetase syndrome (29.6%, n=83), overlap myositis with rheumatoid arthritis (16.1%, n=45), drug-induced myositis (20.0%, n=56), rheumatoid myositis (7.5%, n=21), inclusion body myositis (1.8%, n=5), overlap with connective tissue disease (20.0%, n=56), and others (5.0%, n=14).

CONCLUSION

The spectrum of joint and muscle inflammatory diseases encompasses many diagnoses including primitive and secondary myositis associated with RA or arthritis mimicking RA. This review highlights the need for a consensual definition of OM with RA to better individualise this entity from the numerous differential diagnoses.

Unusual presentation of antisynthetase syndrome: a case series and review of the literature

BACKGROUND

Antisynthetase syndrome is an inflammatory myopathy that is characterized by the presence of anti-aminoacyl-tRNA synthetase antibodies. Only 30% of those who suffer from the disease can be identified. We present three Hispanic cases of antisynthetase syndrome with unusual clinical pictures were extended myositis panel results enable disease diagnosis and treatment.

CASE PRESENTATION

A 57-year-old Hispanic/Latino female with an erythematous scaly plaque, unresolved fever and non-immune haemolytic anaemia in whom inpatient work-up for fever of unknown origin was positive for anti-PL12 positive myositis extended panel. A 72-year-old Hispanic/Latino male with amyopathic weakness syndrome and mechanic hands in whom impatient work-up was relevant for proximal muscle uptake and anti-PM75 and AntiPL-12 myositis extended panel. And a 67-year-old Hispanic/Latino male with progressive interstitial lung disease and unresolved fever ended in myositis extended panel positive for antiPL-7. After systemic immunosuppressor treatment, patients had favourable clinical and paraclinical responses during outpatient follow-up.

CONCLUSIONS

The high variability of the antisynthetase syndrome in these cases demonstrates the importance of identification through an expanded panel and highlights the probability that this is a variable disease and that we need to include emerging molecular tests to promote the timely treatment of patients.

A multidisciplinary approach to the diagnosis of antisynthetase syndrome

Antisynthetase syndrome is a subtype of idiopathic inflammatory myopathy, strongly associated with the presence of interstitial lung disease. Diagnosis is made by identifying myositis-specific antibodies directed against aminoacyl tRNA synthetase, and relevant clinical and radiologic features. Given the multisystem nature of the disease, diagnosis requires the careful synthesis of subtle clinical and radiological features with the interpretation of specialized autoimmune serological testing. This is provided in a multidisciplinary environment with input from rheumatologists, respiratory physicians, and radiologists. Differentiation from other idiopathic interstitial lung diseases is key; treatment and prognosis differ between patients with antisynthetase syndrome and idiopathic interstitial lung disease. In this review article, we look at the role of the multidisciplinary team and its individual members in the initial diagnosis of the antisynthetase syndrome, including the role of physicians, radiologists, and the wider team.

[Antisynthetase syndrome: a report of four cases and literature review]

The antisynthetase syndrome (ASS) includes inflammatory myopathy (polymyositis or dermatomyositis), interstitial lung disease (ILD), arthritis, Raynaud's phenomenon, and mechanic's hands, associated with antibodies against aminoacyl-tRNA-synthetases, the most well-recognized being the anti-Jo1 antibody (anti-histidyl-tRNAsynthetase). We report four cases of antisynthetase syndrome and review the clinical characteristics and prognosis factors dominated by ILD. We report the cases of four women with a mean age of 42 years (28-62 years). The interstitial lung disease was found in four cases and was objectified by CT-scan in all cases. The pulmonary symptoms were consisted of dyspnea (one case) and respiratory distress (one case). The anti-Jo1 antibodies were present in the four patients. The myopathy was concomitant with pulmonary involvement (two cases), preceded it in 6 months (one case) and in the course of evolution and after 1 month (one case). All patients received corticosteroid treatment. The immunosuppressive treatment was necessary for two patients because of the severity of the pulmonary involvement. The outcome was favorable in two patients, partially favorable in a patient who presented pulmonary fibrosis. However, one patient died after developing brain abscesses.

Antisynthetases syndrome associated with right heart failure

Cardiac involvement is a complication of end stage polymyositis with left heart insufficiency reported to be the most frequent manifestation. We here describe an unusual clinical presentation of antisynthetases syndrome, beginning with right-sided cardiomyopathy associated with right heart failure. A 26 year-old Caucasian male experienced a 6-month clinical course of polyarthritis, fever, sweats, and myalgia. Laboratory studies showed elevated C reactive protein, elevated sedimentation rate, and myolysis associated with anti SSA and anti JO1 antibodies. Electromyography showed a myopathic pattern. Muscle biopsy confirmed the diagnosis of polymyositis. Chest X ray, chest scan, and cardiac echography were normal. One week after hospital admission, the patient developed acute right heart insufficiency, and magnetic resonance imaging showed a right ventricular myocarditis with myocardial inflammatory thickening. Treatment with corticosteroids rapidly improved both symptoms and biological abnormalities.

[Acute respiratory distress syndrome as the presenting manifestation of an antisynthetase syndrome]

The antisynthetase syndrome is a subgroup of idiopathic inflammatory muscle diseases. Its characteristics are interstitial lung disease, myositis, polyarthritis, mechanic's hand like cutaneous involvement, and the presence of antisynthetase antibodies (anti-Jo1). The lung disease is the presenting feature in 50% of cases. We report a patient with an antisynthetase syndrome, revealed by an acute respiratory distress syndrome. This patient was already followed-up for a scleroderma and presented a probable overlap syndrome. The disease course was favourable with anti-CD20 therapy.

[Dense cytoplasmic fluorescence on Hep-2 cells: do not overlook anti-PL]

OBJECTIVE

Any dense cytoplasmic fluorescence on Hep-2000 cells seen in the immunology laboratory of the Clermont-Ferrand teaching hospital was closely studied to determine the presence or not of anti-PL antibodies.

PATIENTS AND METHODS

From January 2006 to January 2007, twelve patients presented a dense cytoplasmic fluorescence on Hep-2000 cells. So we activated a Hep-2 cells'slide, a triple substrate's slide and a dot in order to exclude antiribosomes and anti-JO1 antibodies. After having excluded these antibodies, we sent the sera to the immunology laboratory of the South Lyon hospital to confirm the dense cytoplasmic fluorescence and to detect anti-PL antibodies.

RESULTS

Four patients presented anti-PL7 and three anti-PL12. For four other patients, the dense cytoplasmic fluorescence was only due to anti-SSA antibodies. Last for one patient, no antibody was found despite an evocative clinic of myositis.

CONCLUSION

The systematically extensive exploration during the discovery of a dense cytoplasmic fluorescence proved very efficient, permitting to diagnose five new cases of antisynthetases syndrome including three not evoked by the clinician and to confirm two cases clinically known. This study permitted us to better recognize anti-PL from others dense cytoplasmic fluorescences and not to mix them up with particular anti-SSA.

Polymyosites induites ou associées aux traitements hypolipémiants ?

PURPOSE

Rhabdomyolysis and myositis are rare, dose-related complications of statins and fenofibrates. The outcome is favorable as a rule with rapid regression after stopping the responsible drug. Recently, various auto-immune disease with evidence of hypersensitivity to HMG-CoA reductase inhibitors or fibrates drugs have been reported. Less than ten cases of dermatomyositis and polymyositis due to cholesterol-lowering drugs (CLD) have been previously reported. Five more cases polymyositis associated with CLD are reported.

METHODS

Symptoms were compatible with diagnosis of polymyositis according to Bohan and Peter and with previous reported criteria for drug-induced myopathy in all cases. None of these patients had previous other connective tissue disorders.

RESULTS

Five patients (median age 68 [54-78], female N =4) with CLD treatment (statin N =4, fenofibrates N =1) have developed iatrogenic polymyositis. All of them presented both proximal muscular weakness and increased muscle enzyme levels. One patient had iatrogenic antisynthetase syndrome characterized by mechanic's hand, Raynaud's phenomenon and anti JO1 antibodies. One other had sclerodermic hand oedema. Antinuclear antibodies were positive in 4 cases and muscle biopsy revealed polymyositis infiltrate in 4 cases. CLD treatment was discontinued with partial clinical improvement in 3 cases. Clinical remission was obtained with corticosteroid (N =5) in association with immunosuppresive agents in 3 cases.

CONCLUSION

Muscular symptoms in patient with CLD treatment could be the first symptom of a polymyositis revealed or increased by this treatment and must encourage physician with antinuclear antibodies screening especially in case of proximal muscular weakness and increased muscle enzyme levels.