In vitro secretion of immunoglobulin in early syphilis evaluated with the plaque forming cell assay.

We have studied the secretion of immunoglobulin in vitro from blood lymphocytes in twenty-one patients with primary or secondary syphilis before and after treatment of their disease. Polyclonal activation of B lymphocytes with pokeweed mitogen is dependent upon T lymphocytes. Using the inversed haemolytic plaque cell assay we found a normal secretion in vitro of immunoglobulin in both primary and secondary syphilis. Our results indicate that patients with syphilis retain a normal immune regulation of B lymphocyte immunoglobulin secretion in vitro.