Modulation of T and B cell subpopulations during high dose intravenous immunoglobulin therapy

Abstract

The absolute number of T and B lymphocytes in 15 patients before, during and after high dose intravenous infusions of immunoglobulin (IgG) solution was determined. 12 patients (10 chronic, 2 acute) had idiopathic thrombocytopenic purpura (ITP), one had auto immune haemolytic anaemia (AIHA), one had Evans Syndrome and another had acquired haemophilia with antibodies to Factor VIII. In 14 of the patients, a reduction in total lymphocyte count was observed during the infusion period; this correlated with a reduction in B cell numbers. The total number of T lymphocytes was constant but a reduction in the helper/inducer (T4) subset and an increase in the suppressor/cytotoxic (T8) subset occurred. A corresponding reduction in purified protein derivative (PPD) and pokeweed mitogen (PWM) transformation indices was detected. These findings occurred in 13 of the patients in association with a positive clinical response and we speculate that, in many patients receiving intravenous IgG, an alteration in the immune response occurs, and that, in conjunction with other mechanisms, this probably affects the patient's clinical state.