Agammaglobulinaemia associated with the occurrence of a monoclonal immunoglobulin.

A patient is described with a monoclonal immunoglobulin of the IgG class in the serum and no detectable IgM and IgA. Extensive immunological investigations showed the absence of B-lymphocytes in bone marrow and peripheral blood. Moreover, plasma cells were not present in the bone marrow. The monoclonal IgG was synthesized in the gastrointestinal tract. The cellular immune-status of the patient was synthesized in the gastrointestinal tract. The cellular immune-status of the patient was normal. Clinically the patient suffered from gastrointestinal and severe respiratory tract infections. It was concluded that the findings are consistent with the diagnosis congenital agammaglobulinaemia with concurrence of monoclonal IgG. It was postulated that the cell clone in the gastrointestinal tract resulted from an escape of a pre-B cell clone from the recongized arrest of pre-B cells in congenital agammaglobulinaemia.