A 49-yr-old woman with severe hemolytic anemia had marked depression of serum IgG and IgA along with monoclonal serum IgM detectable in both high and low molecular-weight forms. Antiglobulin tests by instrumented and manual techniques showed only IgM coating of the erythrocytes and an eluate contained low-molecular-weight IgM. The IgM fraction of the patient's serum contained anti-I agglutinins active at 37°C. Lymphocyte response to Concanavalin A was diminished, whereas response to phytohemagglutinin and pokeweed mitogen was normal. Blood monocyte Fc receptor activity was increased in comparison to controls. The finding of a low-molecular-weight IgM possibly related to hemolysis in addition to 19S IgM anti-I activity with high thermal optimum in a patient with hypogammaglobulinemia represents an unusual form of immune hemolytic anemia.
ASJC Scopus subject areas
- Immunology and Allergy
- Pathology and Forensic Medicine