Humoral and cellular immune responses as diagnostic tools in human toxoplasmosis

ABSTRACT

The study was conducted to assess the humoral and cellular immune responses in patients suspected to have Toxoplasma infection, and to evaluate their use as diagnostic tools. Seventy six persons were enrolled in the study, 56 of them are patients with toxoplasmosis. In addition to 20 apparently healthy persons were served as control. They were divided into 4 main groups according to their signs and symptoms, Group I, 17 patients with ocular signs and symptoms suggestive of toxoplasmosis Group II, 23 patients complaining of complicated obstetric problems, Group III, 9 infants and children with signs and symptoms of congenital toxoplasmosis, and Group IV, 7 patients with manifestations suggesting toxoplasmic lymphadenopathy. RH Toxoplasma strain was used. Experimental animals 400 mice were used, 10 each time, for maintainance of Toxoplasma strain, by regular serial passage and for preparation of antigen. Enzyme linked immunosorbent assay [ELISA] for detection of anti Toxoplasma IgG and IgM antibodies. Lymphocyte transformation test were done for detection of specific lymphocyte proliferation [blastogenic response]. Out of total 56 patients, 49 patients [87.5%] gave positive results to Toxopasma antigen in one or more of the specific techniques applied. Seven patients gave negative results were recommended for periodic follow up before exclusion of toxoplasmosis. High rates of seropositivity detected among suspected patients suggest the reliability of ELISA in diagnosis of toxoplasmosis. Specific lymphoblastognic response would confirm the results and reveal dormant infection in some suspected subjects. However, rising titre/ seroconversion is a prerequisite for therapy