[Lymphocyte response to mitogens in serum-free and serum-containing medium in patients with rheumatoid arthritis (author's transl)].

Mitogenic transformation of lymphocytes from patients with rheumatoid arthritis (RA) has revealed divergent results in different laboratories. Since the sera used for medium supplementation in these previous studies might have influenced the results, we investigated lymphocyte transformation in serum-free medium in 28 RA-patients and 25 controls. It was shown that a majority of patients with RA responded weakly to PHA. Comparing some of these serum-free cultures with cultures that were set in parallel in 10% ABserum, no difference between patients and controls was observed after transformation in supplemented medium. It is concluded that lymphocyte reactivity to PHA (however not to ConA and PWM) is diminished in patients with RA and that this defect--at least partially--is reversible by addition of serum. The use of parallel cultures in serum-free and serum-containing medium is recommended for evaluation of the lymphocyte mitogenic response.