[Analysis of serum immunoglobulins and complement factors in children with chronic ITP and after reversible postinfectious thrombocytopenia (author's transl)].

Levels of immunoglobulins G, A and M and complement factor C3 and C4 were determined by single radial immunodiffusion techniques in a group of 26 children with a history of postinfectious thrombocytopenic purpura and in another group of 6 children with chronic ITP. The statistical evaluation of the data of patients with chronic ITP did not show any significant deviation from normal. In patients with previously acute, reversible ITP, levels of IgG and IgM were elevated. Whether this elevation was significant or not depended upon the statistical analysis applied. C3 levels tended to be above the average normal mean, C4 levels, in contrast, to be below. The importance of increased IgG and IgM concentrations in patients with the history of postinfectious ITP is discussed. The raised IgG and IgM levels are interpreted as an expression of a certain type of hyperimmune state rather than as an impairment of immunoregulatory mechanisms.