[Hypogammaglobulinemia G and A with hypergammaglobulinemia M. Apropos of 12 cases].

Hyper IgM with low IgG and IgA is a rare humoral immunodeficiency. We presently report 12 new observations which have been clinically and immunologically studied. On one occasion the syndrome was found to be associated with congenital rubella. Since 10/12 children were male, X-linked inheritance is suggested which has been confirmed in 2 cases. In most cases (9/12), the first infections occurred within the first year of life. The syndrome is causing upper and lower respiratory tract infections due to bacteria, as well as gut infections. Lymphoid organ hyperplasia has been noted in 11/12 patients. Polyclonal hyper IgM serum contrasts with low or absent IgG, IgA and IgE. In some instances, some IgM antibody response was detected. A dysfunction of cellular immunity was not detected. Autoimmunity was detected in 3 patients. Finally, transient neutropenia occurred in 50% of the patients. Intravenous immunoglobulin G substitution treatment resulted in a significant reduction in the occurrence of infections as well as in normalization of growth rate. Immunoglobulin infusion also frequently induced correction of hyper IgM and neutropenia.