Antiphospholipid Syndrome Complicated by Unilateral Pleural Effusion
A 75-year-old Japanese man was admitted to our hospital for spreading erythema on his trunk and extremities, as well as dyspnea. One year prior to admission, he visited us with a 1-year history of erythema and purpura on his legs, accompanied by intermittent fever. Results of laboratory examinations for antiphospholipid antibodies, lupus anticoagulant (using the phospholipid neutralization test), and anticardiolipin antibody had been positive 12 weeks apart. In addition, he showed positive antinuclear antibody (1:80, homogeneous pattern), but was negative for anti-dsDNA antibody, anti-Sm antibody, anti-RNP antibody, anti-SS-A antibody, anti-SS-B antibody, antitopoisomerase I antibody, and anticentromere antibody. MPO-ANCA, PR3-ANCA, and cryoglobulin were negative. Given the diagnosis of APS, we initiated combination therapy with aspirin (100 mg daily) and warfarin (target international normalized ratio, 2.0–3.0), but the skin lesions continued to gradually worsen. Violaceous erythema, purpura, and pigmentation were widely noted on his trunk and extremities (fig. ); they were associated with low platelets (93,000/μl) and elevated partial thromboplastin time (48.4 s). A biopsy specimen revealed marked thrombosis in the dermal and subcutaneous small vessels (fig. ). There were interface changes of the dermo-epidermal junction and mild inflammatory infiltrates in the perivascular area of the dermis, but mucin deposition and thickening of the basal layer of the epidermis were not apparent. In addition, a chest X-ray and computed tomography demonstrated a large pleural effusion in the left lung (fig. ), without evidence of large vessel thrombus. Electrocardiogram and echocardiogram were normal. Despite serial thoracenteses, effusion recurred. Thoracoscopy and parietal pleura biopsy showed only marked lymphocytic infiltration without evidence of malignancy. An analysis of the pleural fluid also indicated a benign exudative effusion. Bacterial and fungal cultures, as well as cytology analyses for malignant cells, were all negative. After excluding infectious diseases, malignancies, pulmonary thrombosis, and heart failure, we added oral prednisolone (30 mg daily) to his prior anticoagulant regimen. The skin lesions and the pleural effusion improved rapidly, eventually disappearing without complication (fig. ). On follow-up clinical examinations, no symptoms related to SLE or other collagen diseases were noted.