ABSTRACT
Toxoplasma gondii infects humans through the gastrointestinal tract (GIT), which elicits humoral immune response with specific antibodies. The expression of the ABO blood group glycoconjugates also occurs in this same system and may influence the human susceptibility of infection by T. gondii. The aim of the present study was to investigate the association between ABO blood group phenotypes and the presence of anti-T. gondii antibodies. Data - including age, results of serology tests for T. gondii infection and ABO blood group phenotypes - were assembled from the medical records of 1,006 pregnant women attended in the Base Hospital of the Medical School of São José do Rio Preto, Brazil, between 2001 and 2004. The chi-square test was used to compare the results with the level of significance set at 5 percent. Of the studied cases, 64.1 percent (645/1006) and 35.9 percent (391/1006) presented respectively positive and negative serology tests for anti-T. gondii antibodies. The mean age of those who tested positive was higher than those with negative serology tests (p = 0.0004). The frequencies of ABO blood group phenotypes were similar in those with and without anti-T. gondii antibodies (p = 0.35). In conclusion, the ABO blood group system is not associated with the presence or absence of anti-T. gondii antibodies.