Patterned relationships between IgM and blast cells in peripheral blood in a child with acute leukemia

1. Serum IgM determinations and blast cell counts were performed at regular frequent intervals in a case of acute lymphoblastic leukemia in a child. 2. An inverse relationship tended to exist between the concentration of IgM in serum and blast cells in blood during the course of relapses and remissions. 3. High dosage immunosuppressive chemotherapy caused a marked reduction in serum IgM. 4. A relationship appears to exist between IgM and blast cells which may support the concept that impaired ability to produce antibody to leukemia antigens may be an intrinsic component of this disease.