Abstract
Antibodies to phosphorylcholine (PC), as one of the marker of specific antibody, in patients with systemic lupus erythematosus (SLE), multiple myeloma and in cord blood as well as in normals were measured with ELISA. Both IgG and IgM anti-PC antibodies were detectable in the serum from normal individuals. In the serum from SLE which commonly manifests polyclonal hyper-gammaglobulinemia, high concentration of anti-PC antibodies in both classes were observed (28% in IgG class and 16% in IgM, respectively). In the serum from multiple myeloma patients which usually show decreased normal residual immunoglobulines, both classes of anti-PC antibodies were also decreased. In the cord serum which is considered that only the maternal IgG can be transmitted through placenta, not only low concentration of IgM but also low concentration of IgG anti-PC antibodies were observed unexpectedly. At the cellular level, the frequency of B cell precursors specific for PC increased 6-folds after stimulation with pokeweed mitogen (PWM) in normal peripheral blood lymphocytes (PBL). On the other hand, the frequency of PC specific B cell precursor in SLE patients slightly decreased after stimulation with PWM. At the moleculer level of immunoglobulins, anti-PC antibodies from both normals and SLE did not express T15 idiotype which is the most common idiotype of murine anti-PC antibodies.
