Intravenous plasmin-treated gammaglobulin therapy in idiopathic thrombocytopenic purpura. Results in 40 patients.

A study of the effects of high-dose IV plasmin-treated IgG was undertaken in 40 patients (30 children and 10 adults) with idiopathic thrombocytopenic purpura (ITP). After a first course of treatment, a success therapy (platelet counts greater than 100 X 10(9)/l) was observed in 21 patients. The results after additional courses of pH 4 treated IgG in 7 patients tended to indicate that the 2 kinds of concentrates might induce similar platelet responses. No significant side-effects were observed. Platelet associated (PA), IgG, IgM and C3 levels were determined before therapy and on the 7th day after the first infusion (day 8) in 27 patients (36 courses). In spite of great variability, overall results showed a significant decrease in PA IgG (P less than 0.05), PA IgM (P less than 0.01) and PA C3 (P less than 0.001) at day 8. A significant inverse relationship was found between either PA IgG, or PA IgM or PA C3 levels, and platelets counts (respectively, r = -0.57, -0.55, -0.66, P less than 0.001). Our results also showed that pretreatment platelet counts were higher in patients with success therapy (25.8 +/- 16.9 X 10(9)/l) than in others (11.3 +/- 12.1 X 10(9)/l, P less than 0.001). This suggested that pretreatment platelet counts could help predicting the platelet response.