Pulmonary Capillaritis and Diffuse Alveolar Hemorrhage in a Patient With Moderately Positive Anti-PL-12 Antibodies

Abstract

INTRODUCTION: We present a case of pulmonary capillaritis and diffuse alveolar hemorrhage (DAH) in association with anti-PL-12 antisynthetase antibodies. CASE PRESENTATION: A previously healthy 32 years old woman was admitted to an outside hospital with worsening shortness of breath. Her physical examination was significant for oxygen desaturation with exertion and bilateral, basilar crackles. Her skin, joints, and physical examination was unremarkable. Chest imaging was performed (figure 1). Her erythrocyte sedimentation rate was 54 mm/h. Anti-nuclear antibody, anti-smith, anti-ribonucleoprotein, anti-SSA Ro, anti-SSB La, anti-cardiolipin, beta-2- glycoprotein, and scleroderma antibodies were all negative. The anti-neutrophil cytoplasmic antibody against myeloperoxidase (p-ANCA) and proteinase 3 (c-ANCA) were negative. Complement, creatine kinase, and aldolase were normal. A myositis antibody panel was moderately positive for PL-12 antibodies (Mayo Medical Laboratories, Rochester MN). She underwent VATS right upper and lower lobe wedge biopsies (figure 2). She was started on prednisone. Her activities remained limited by dyspnea on exertion. She was discharged home on oxygen and prednisone and seen in our clinic four months after the initial presentation for a second opinion. She was initiated on rituximab infusion therapy 375 mg/m2 once weekly for four weeks in combination with intravenous methylprednisolone for three days and subsequent steroid taper. Nine months after her initial presentation her symptoms have improved and she remains on maintenance therapy with mycophenolate. DISCUSSION: Pulmonary capillaritis with DAH is extremely rare in patients with antisynthetase syndrome (AS), but has been described with other autoimmune disorders. Two cases of polymyositis and capillaritis with DAH have been previously described (1). One of the patients had AS with anti-Jo-1 antibodies detected. The initial therapy of choice for AS is corticosteroids. Other immunosuppressant therapies have been successfully used, but there have been no comparison studies. Pulmonary capillaritis with DAH is also treated with steroids and immunosuppresants. In a recent study, rituximab was non-inferior to cyclophosphamide for inducing remission in ANCA associated vasculitis (2). One group successfully used rituximab to treat a case of life threatening AS. CONCLUSIONS: Moderately positive anti-PL-12 antibodies should be considered in the differential in patients who present with idiopathic DAH and pulmonary capillaritis.