[Effect of lobenzarit disodium (CCA) on B cell differentiation to antibody secreting cells].

We investigated the effect of the immunomodulator CCA on B cells, using the system of Staphylococcus aureus Cowan 1-stimulated B cells developing into antibody secreting cells in the presence of T cell factors. Results were expressed as the number of plaque-forming cells (PFC), as measured by reverse hemolytic plaque assay. Serially diluted CCA was added to the culture system to evaluate its effect (500-0.005 micrograms/ml). Different results were obtained by adding CCA at a high dose or a low dose. High-dose CCA showed an inhibitory effect on PFC (p less than 0.01). On the other hand, low-dose CCA showed an inhibitory effect on high PFC responses of B cells and a stimulatory effect on low responses. Our data suggest that CCA has a direct effect on B cells and that low-dose CCA has immunomodulatory action on normal variations in immune responses.