Low molecular weight serum immunoglobulin M in experimental trypanosomiasis

ANTIGENIC stimulation in different species of lower vertebrates elicits formation of high and low molecular weight antibodies, both belonging to the μ-heavy chain class. In mammals, the occurrence of low molecular weight (LMW) IgM immunoglobulins has been described mainly in man2 affected by various immunological deficiencies, myelomas, collagen diseases3-7 and, in recent years, in trypanosomiasis caused by Trypanosoma gambiense species8. © 1970 Nature Publishing Group.