The specific antibody production in patients with rheumatoid arthritis in response to three antigen-heep cell stroma, Brucellin and Limulus polyphemus hemocyanin-was examined. Several antigens were used in expectation that an abnormality in antibody production might be selective and not uniform for all , antigens. Patients with rheumatoid arthritis were deficient in their IgM response to sheep cell stroma and Brucellin, especially the latter. This deficiency was limited to the primary response and to secondary responses characterized by only slight increases in antibody levels. More intensive stimulation resulted in equal production of IgM antibody in both groups. Antigenic competition may explain the deficiency in IgM antibody production. Levels of rheumatoid factor increased after repeated stimulation paralleling, in general, the specific antibody responses.The presence of rheumatoid factor (RF), an IgM antibody reacting with autologous and heterologous IgG (1,2) , and the frequent increase in the concentrations of immunoglobulins in patients with rheuFrom the Mayo Clinic and Mayo Foundation, Rochester, Minn and

No abstract

Four patients with macroglobulinemia demonstrated an impaired ability to produce IgM antibody when stimulated with a relatively weak antigen, sheep cell stroma, but not with a more potent antigen, Brucellin. The explanation of this defect is unknown. It may be in part the cause of the greater-than-normal infection rate seen in patients with macroglobulinemia.

No abstract