Hypoprothrombinemia in childhood systemic lupus erythematosus.

Three children with systemic lupus erythematosus who developed hemorrhagic tendencies as a consequence of a clotting factor II (prothrombin) deficiency are described. All three responded rapidly to treatment with corticosteroids. A literature review added 25 case reports, with the following findings. First, factor II deficiency occurs in the presence of the lupus anticoagulant, although the interrelationship between the two is not understood. Second, the deficiency is presumed to be secondary to rapid clearing of the antigen/antibody factor II complex in the liver. Finally, most cases respond to corticosteroid therapy with or without the coadministration of vitamin K or fresh frozen plasma. In corticosteroid-dependent patients, the addition of antimetabolites such as azathioprine has enabled reduction in steroid doses.