Antisynthetase syndrome presenting as interstitial lung disease: a case report

Abstract

Background Antisynthetase syndrome is a relatively uncommon entity, and can be easily missed if not specifically looked for in adults whose initial presentation is with interstitial lung disease. Its presentation with interstitial lung disease alters its prognosis. Case presentation This case report describes a 27-year-old Pakistani, Asian man, a medical student, with no previous comorbidities or significant family history who presented with a 3 months’ history of low grade fever and lower respiratory tract infections, associated with exertional dyspnea, arthralgias, and gradual weight loss. During these 3 months, he had received multiple orally administered antibiotics for suspected community-acquired pneumonia. When he presented to us, he was pale and febrile. A chest examination was significant for bi-basal end-inspiratory crackles. Preliminary investigations revealed raised erythrocyte sedimentation rate. High resolution computed tomography of his chest showed fine ground-glass attenuation in posterior basal segments of both lower lobes suggestive of interstitial lung disease. He was started on dexamethasone, to which he responded and showed improvement. However, during the course of events, he developed progressive proximal muscle weakness. Further investigations revealed raised creatinine phosphokinase and lactate dehydrogenase. A thorough autoimmune profile was carried out which showed positive anti-Jo-1 antibodies in high titers. A muscle biopsy was consistent with inflammatory myopathy. Clinical, radiological, serological, and histopathological markers aided in making the definitive diagnosis of antisynthetase syndrome. Antisynthetase syndrome is a variant of polymyositis but with visceral involvement, that is, interstitial lung disease and positive anti-Jo-1 antibodies. Our patient responded very well to glucocorticoids and azathioprine. Conclusion Antisynthetase syndrome is a rare clinical entity which apart from clinical presentation requires specific serological investigations for diagnosis. Concomitant association of interstitial lung disease gives it a guarded prognosis.

Anti-synthetase syndrome: a rare and challenging diagnosis for bilateral ground-glass opacities—a case report with literature review

“…Patients usually present with dyspnea on exertion accompanied by dry cough [ 6 ]. Instrumentally, ILD is defined by PFTs (pulmonary function tests) which show restrictive picture, indicated by total lung capacity (TLC) < 80% predicted, diffusion capacity of lung for carbon monoxide (DLCO) < 70% of predicted value, and/or forced vital capacity (FVC) < 80% predicted, and/ or specific findings on HRCT scans of the lungs [ 2 , 5 ]. The usual type of ILD seen on HRCT is nonspecific interstitial pneumonia (NSIP) which characterized by ground-glass opacities.…”

“…The usual type of ILD seen on HRCT is nonspecific interstitial pneumonia (NSIP) which characterized by ground-glass opacities. Other types include COP (cryptogenic organizing pneumonia) characterized by consolidation and linear opacities, and usual interstitial pneumonia (UIP) characterized by honeycomb pattern and traction bronchiectasis [ 5 , 11 ]. Bronchoscopy and lung biopsy are not indicated routinely for diagnosis of ASS; however, it could be considered to rule out other causes or exclude infection [ 2 ].…”

“…ASS is considered by some authors as a separate disease entity within the idiopathic inflammatory myopathy (IIM) besides dermatomyositis (DM) and polymyositis (PM) [ 2 ]. ASS occurs mainly in adults with average age 50 years and more commonly in Caucasian females than males [ 5 , 6 ].…”

Antisynthetase Syndrome in Senegalese Patients: Report of Three Cases

“…The strongest predictor of ILD in patients with ASS is the presence of anti-Jo-1 antibodies. Nearly 70% of patients with ASS with ILD have detectable an-Open Journal of Internal Medicine ti-Jo-1 antibodies [3].…”

“…Anti-Jo1 antibody is the first to have been described and is the most commonly found [5]. ASAs constitute one of the key laboratory features of ASS, which is defined as an association of inflammatory myopathy, diffuse interstitial lung disease, joint involvement, fever and cutaneous signs such as mechanic's hands and Raynaud's syndrome [3] [5] [6].…”