[Spontaneous lymphocyte transformation in chronic renal insufficiency (author's transl)]

3H-thymidine uptake of lymphocytes cultured from patients with regular dialysis treatment was determined at the time of maximal transformation, which was ascertained in previous investigations to be 5 days after the beginning of incubation. Spontaneous DNS synthesis was found to be significantly depressed: 1137 plus or minus 1122 c.p.m./culture; controls: 9783 plus or minus 7499 c.p.m./culture, whereas LDH activity in the supernatant culture medium measured as a parameter of continuous cell destruction showed no alteration. After stimulation with 400 mug PHA DNS synthesis in 7 patients was also decreased, but elevated in 5 patients with previous infections. After incubation with added serum from 11 chronic uremic patients, spontaneous lymphocyte transformation in cultures sampled from 2 healthy subjects was also found to be depressed with positive correlation to the hemoglobin and hematocrit levels in the corresponding blood. The significantly increased LDH activity values in the medium as the consequence of impaired cll viability showed also positive correlation with 3-H-thymidine uptake levels; therefore depressed DNS synthesis cannot be due alone to accelerated cell destruction. In analogy to the erythrocytes, two stimultaneous effects of uremic toxins in serum are assumed to be exerted on the lymphocytes: metabolic inhibition of DNS synthesis and impaired cell viability.