Transient lupus anticoagulant associated with hypoprothrombinemia and factor XII deficiency following adenovirus infection.

A potent lupus anticoagulant (LA) was detected in four children, 1 week after the clinical onset of an adenovirus infection. The adenovirus infection was documented by direct virus detection in the stool of one patient and serologically in the others. None of the children had elevated titers of IgM- and only one of IgG-anticardiolipin antibodies (ACA). All patients had a marked reduction of prothrombin activity as well as antigen. Prothrombin-antibody complexes were demonstrated in the patients' plasma or mixtures of patient and normal plasma. Factor XII activity was moderately reduced in three of the patients. All coagulation abnormalities returned to normal within 4-12 weeks. Localized bleeding was observed in two cases, but there was no generalized bleeding tendency or evidence of thrombosis.