Predicting acute vs chronic childhood idiopathic thrombocytopenic purpura.

We studied 12 children with idiopathic thrombocytopenic purpura (ITP) to determine if selected immune measurements could prospectively distinguish chronic ITP from acute ITP. Immunologic assessment included immunoglobulin levels, T- and B-cell enumeration, in vitro lymphocyte stimulation by phytohemagglutinin, and a screen for autoantibodies. The most consistent difference observed was that unstimulated lymphocytes in chronic ITP had an increased basal rate of thymidine incorporation. The same assays were performed on eight other children in whom the diagnosis of chronic ITP already had been established. A similar abnormality was found in this group. Study of lymphocyte proliferation in patients with ITP appears useful in predicting the course of the disease.