[Triclonal gammopathy and malignant immunoproliferative syndrome]. / Gammapathie triclonale et syndrome immunoprolifératif malin.

Three distinct monoclonal gammopathies were identified in the serum of a 79 year-old man. In 1972 he presented with Waldenström's macroglobulinemia IgM Kappa. Twenty years later multiple myeloma was diagnoses. Serum protein electrophoresis performed at this time showed three monoclonal bands. Immunofixation identified these bands as monoclonal IgM kappa, IgG kappa and IgA kappa. Twenty-six cases of triclonal gammopathies were previously reported. Sixteen cases were associated with malignant immuno-proliferative diseases (non-hodgkin lymphoma, Waldenström's macroglobulinemia, multiple myeloma); five cases with non-hematologic diseases; three cases were of undetermined significance. The origin of three distinct monoclonal proteins may derive from three unrelated clones or alternatively from a single clone in which an isotype switch has occurred.