Cytokine responses to Toxoplasma Gondii in immune-competent and immune-compromised individuals at Korle-Bu Teaching Hospital, Ghana.

Thumbnail Image
JULY 2016
Journal Title
Journal ISSN
Volume Title
Toxoplasmosis, a disease known to impart a significant burden to public health, is caused by the parasite Toxoplasma gondii. An understanding of the relationship between the cellular immune response and pathology of the disease is needed to control this disease. The study thus sought to characterize the cellular immune responses to T. gondii in immune-competent and immune-compromised persons in Ghana. Venous blood was collected from 54 blood donors (HIV sero-negative) and 38 HIV seropositive (ART naïve) participants and transported to the Noguchi Memorial Institute for Medical Research. Laboratory analysis was performed for the presence or absence and further genotyping of T. gondii using PCR. ELISA was done to obtain levels of cytokines in supernatants of stimulated PBMCs. Socio-demographic data and information on risk factors were obtained from the participants through questionnaires and hospital folders. The results did not show any statistically significant associations between Toxoplasma gondii positivity and exposure to any known risk factors such as cat ownership (p<0.05). The overall prevalence of T. gondii DNA was 26.3% and 14.8% in the HIV seropositive and blood donor participants; respectively. Levels of cytokines IL-10, TNF-α, IFN-γ, TGF-β were found to be significantly higher (p <0.05) in HIV seropositive participants than blood donor participants, however, differences in the cytokine levels of T. gondii positive, HIV-seropositive individuals compared against T. gondii positive, blood donor individuals, showed no statistical significance indicating that other pathogens may play contributing roles to the cytokine levels in the HIV seropositive participants. TGF-β levels for T. gondii positive persons differed significantly (p<0.05) suggesting that TGF-β may influence the immune status of T. gondii-infected persons. The patterns of the cytokine profiles in T. gondii-positive and P. falciparum-positive individuals were found to be comparable indicating a similar mechanism of action of these parasites.
A thesis submitted to the Department of Clinical Microbiology, Kwame Nkrumah University of Science and Technology in partial fulfilment of the requirements for the degree of master of Philosophy School of Medical Science,