Résumé
The in vitro immunomodulating effects of theophylline on E-rosette formation, phytohemagglutinin (PHA) response, and Ig surface receptors of B lymphocytes were studied on fresh as well as on preincubated lymphocytes from patients with B cell chronic lymphocytic leukemia (CLL). In 11 out of 14 CLL patients, 24 hours preincubation at 37 degrees C significantly enhanced E-rosette formation. Subsequent treatment of preincubated cells with appropriate concentrations of theophylline further enhanced E-rosette formation in 11 cases. On fresh lymphocytes the enhancing effect of theophylline on E-rosette formation was not significant. The same was true for PHA stimulation; in 5 out of 7 cases the mitogen enhanced the stimulating effect of preincubation and had no significant effect on fresh lymphocytes from CLL patients. Preincubation significantly reduced the percentage of surface immunoglobulin positive B cells from CLL patients in all cases studied, and theophylline treatment had an additional effect on this phenomenon. No such effect of theophylline on fresh B cells from CLL patients could be observed. Preincubation had no significant effect on control lymphocytes. The effect of theophylline on control lymphocytes as compared to lymphocytes from CLL patients was completely different for T as well as for B lymphocytes. E-rosette formation from control lymphocytes (fresh and preincubated) was significantly inhibited in the presence of theophylline. No significantly enhanced responsiveness to PHA could be observed after treatment of fresh or preincubated lymphocytes with theophylline. Preincubation and theophylline treatment had no significant effect on the percentage of Ig positive B cells from control lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)