Immunoregulatory T cells in human toxoplasmosis

ABSTRACT

The quantitative alterations in T lymphocyte subsets as well as B lymphocytes in peripheral blood were studied in 22 patients with Toxoplasma infection using the monoclonal antibodies technique. No changes were found to be associated with infection with the parasite per se [latent infection]. Patients with lymphadenopathy showed marked and significant changes in T cells. Those during the acute phase showed an elevation of suppressor cells and a drop in helper cells leading to a reversed helper suppressor [H/S] ratio, while non acute cases showed only a reduction in helper cells. The results indicate that the expansion of suppressor cells may probably have a role in determining the severity of infection and may be correlated to the time course of the disease. A depletion in B lymphocytes was occasionally encountered indicating that a high titre of specific antibodies is not always associated with acute toxoplasmosis