Granulocyte function in malignant monoclonal gammopathy.

Granulocyte function was studied in 22 patients with untreated myelomatosis or macroglobulinaemia. Granulocyte adhesiveness (GA) and migration in capillary tubes (Tm) were, except for light chain disease, significantly decreased in patients of all gammopathy classes especially IgG myelomatosis. A plasma factor inhibited GA. The impairment of Tm was due to an inhibiting factor as well as lack of a stimulating plasma factor. Migration of granulocytes to skin chambers was decreased in patients with IgG myelomatosis. Chemiluminescence production during phagocytosis of opsonized zymosan was decreased. Compared to control sera, the opsonic activity of patient sera was strongly decreased. The impaired granulocyte functions in patients with malignant monoclonal gammopathy may contribute to the enhanced susceptibility to infections in these patients.