Systematic survey of monoclonal gammapathies in the sera from blood donors.

Routine screening of monoclonal gammapathies (M.G.) was performed on the serum of 13,914 blood donors by cellulose acetate electrophoresis. Twenty-six cases of M.G. were detected corresponding to a frequency of 0.19 per cent. The incidence of the M.G. progresses with increasing age comparatively to the age distribution of the blood donors under investigation. Most of the M.G. detected can be classified as "asymptomatic" M.G. (23 of the 26) and heavy chain classes are only IgG or IgM with a large predominance of IgG class (about 90%). It is suggested that donors in whom M.G. have been detected should not be eligible for blood donation. A yearly clinical, hematologic and immunoglobulin checkup is recommended for these patients in order to detect a possible malignant transformation.