Lupus anticoagulant and protein S deficiency in otherwise healthy childrenwith acute varicella infection

Acquired protein S deficiency and lupus anticoagulant have been described i n children with varicella who had pul-pura fulminans. disseminated intravas cular coagulation or thrombosis. The sim of this study was to investigate t he natural anticoagulants, hypercoagulability markers, other parameters of coagulation and fibrinolytic systems, and the presence of the lupus anticoa gulant in otherwise healthy children with acute varicella infection. Blood samples were obtained from 17 children with varicella without thrombosis du ring acute varicella infection and 1 mo after onset. Coagulation tests incl uded determinations of the prothrombin time, the activated partial thrombop lastin time. the thrombin time, the thrombin antithrombin complex, the prot hrombin fragment F 1 + 2, the tissue plasminogen activator, the plasminogen activator inhibitor-1, protein C activity and free protein S antigen. Anti phospholipid antibodies were determined in enzyme-linked immunosorbent assa ys. The mean free protein S concentration in the acute phase (0.63 +/- 0.16 U/ml) was significantly lower than that of the concentration determined 1 mo later (0.82 +/- 0.17 U/ml). The children with acquired free protein S de ficiency also had a lupus anticoagulant. Elevated concentrations of the pro thrombin fragment F 1 + 2, the thrombin antithrombin complex, D-Dimer, tiss ue plasminogen activator and plasminogen activator inhibitor-1 were detecte d in most of the children. Conclusion: There is a significantly increased prevalence of lupus anticoag ulant, a significantly reduced plasma concentration of free protein S and e levations in coagulation and fibrinolytic parameters in otherwise healthy c hildren with acute varicella infection.