Changes in lymphocytic cluster distribution during extracorporeal immunoadsorption.

The success of apheresis treatment is often measured as a decrease in the detected antibodies and an improvement in different disease-related scores. Sometimes, however, the seriousness of the disease does not correlate with the antibody level. During a period of 8 years, 15 patients (3 myasthenia gravis, 1 multiple sclerosis, 2 systemic lupus erythematosus, 3 alloimmunized kidney transplant, 6 rheumatoid arthritis) were treated by protein A immunoadsorption. Lymphocyte subpopulations (activated T cells, cytolytic T cells, B cells, natural killer cells) and inflammatory proteins (ferritin, C-reactive protein, alpha1-antitrypsin, alpha2-macroglobulin) were analyzed. After observing clinical outcomes, the patients could be divided into 2 groups, respectively: Group 1, responding patients with remission of disease; and Group 2, delayed-responding patients, who required chronic treatment. Group 1 patients characteristically showed a greater increase in activated T and cytolytic T cells which correlated with a greater decrease of B cells. It might be possible that protein A immunoadsorption induced immunomodulation. Further immunological investigation is required to verify these findings.