A 54-year-old butcher was referred because of a suspected right renal hemorrhagic infarction. Computed tomography showed thrombosis of the common iliac veins, inferior vena cava, and right renal vein. Intravenous heparin, followed by oral warfarin, resulted in the recanalization of the inferior vena cava, common iliac veins, and deep venous circle of the limbs.

In the past 20 years, he had had many episodes of leg thrombophlebitis. He had no familial history of coagulation disorders or other hereditary diseases. Antithrombin III, protein S, protein C, and plasminogen levels were normal. No clinical or humoral signs of cancer were evident.

He was thrombocytopenic (platelet count, 500 to 700 x 10⁹/L) as he had been for the past decade, with circulating and adherent IgG antiplatelet antibodies. The C4 complement fraction was reduced (6 to 10 mg/dL; normal, 15 to 45 mg/dL); the antinuclear antibody titer was 320, anti-Ro/SS-A antibodies were present, and a direct Coombs test was positive. There were no antinative DNA autoantibodies, cryoagglutinins, or circulating immunocomplexes. Lupus anticoagulant activity was detected. The IgG and IgM anticardiolipins were 21.3 GPL units with a cut-off of 15 and 25.6 MPL units with a cut-off of 13, respectively, but IgA anticardiolipins were absent. The VDRL was negative. Serum protein electrophoresis showed a broad and high (32% to 47%) gammaglobulin band, present for 10 years. High IgG polyclonal levels (2600 to 3300 mg/dL; normal, 800 to 1800 mg/dL) and low IgA concentrations (7.6 to 15 mg/dL; normal, 60 to 400 mg/dL) were noted; his IgM was normal. Exposure to drugs known to result in IgA deficiency was ruled out.

This patient did not fulfill the diagnostic criteria for systemic lupus erythematosus or other defined autoimmune syndromes. Although several autoimmune diseases are associated with IgA deficiency [1] and although anticardiolipin is the most frequent antibody in this immunodeficiency [2], the antiphospholipid syndrome has never been described. This is the first report of an association between the two conditions.

A proposed association between severe thromboembolic disease and IgA antiphospholipids has been suggested [3]. However, Asherson and colleagues [4] observed that IgA antiphospholipids were not associated with thrombosis in the Sjogren syndrome. The condition of our patient is consistent with this observation (that is, non-IgA antiphospholipids associated with severe thrombosis) and supports the idea that IgA antiphospholipids have a low thrombogenicity [4].