Suppression of T-cell proliferative response in Plasmodium falciparum malaria patients - preliminary results

Abstract

Suppression of T-cell proliferative responses to P. falciparum specific antigen and mitogens is reported. T-cells derived from malaria patients were co-cultured with P. falciparum antigen or mitogens and the T-cell activity determined by radioactive thymidine incorporation assay system. Inhibition of T-cell responses to P. falciparum antigen was found in 13 out of 24 malaria patients from Kenya studied. The suppression ranged from 4%-60%. Results of mitogenic responses of T-cells showed a wide variation. Suppression of concanavalin A (Con A) responses ranged from 48%-64% (4 out of 10 patients), while phytohaemagglutinin (PHA) responses varied from 4%-60% (8 out of 10 patients), and those of purified protein derivative (PPD) antigen from 12%-44% (3 out of 6 patients). Together, these preliminary results show a marked impairment in T-cell responses to parasite antigen and mitogens in P. falciparum infected patients.