Serological and Molecular Investigation of the Presence and Association of Toxoplasma gondii in Bipolar Affective Disorder and Schizophrenic Patients

Introduction: Toxoplasma gondii is an intracellular parasite that affects about one third of the population in developed countries. It is known that in the brain and muscle tissues of infected people, this parasite maintains its stagnant phase lifelong. T. gondii relation, in terms of neurotropism is shown up to 60% in anxiety, depression, even schizophrenic psychoses. Schizophrenia and bipolar affective disorder (BAD) are neuropsychiatric disorders seen worldwide and their etiologies are not fully understood. Recently, it is suggested that although it is clinically indefinite, it may be a neurotropic agent, such as the trophozoites of the parasite, that have a special affinity to the glia cells of the brain. Materials and Methods: This study consisted of 87 bipolar affective disorder and 63 schizophrenia patients who applied to Eskisehir Osmangazi University Medical Faculty Psychiatry Clinic in a one-year period, and 50 healthy volunteers that had no psychiatric disorders or antipsychotic and antidepressant drug usage history. Blood samples were evaluated for T. gondii presence by real time polymerase chain reaction (PCR) and ELISA. In addition, the relationship between parasitic-mental disorder and social variables was assessed by questionnaires consisting of 29 questions in the patient group and 21 questions in the control group, which included social variables and T. gondii transmission routes and contacts. Results: All serum samples of 150 patients and 50 controls were tested by ELISA and PCR methods, and those identified with T. gondii presence by any of the tests were evaluated as positive. Seropositivity of T. gondii was detected in 61 (30.5%) of 200 serum samples. In 53 (26.5%) of the samples, only anti-toxo IgG antibodies were detected by ELISA and in 8 (4%), positivity was defined by PCR. Anti Toxo IgM antibodies were negative in both groups. PCR positivity was determined only in the patient group. T. gondii presence was defined in 29 (33.3%) of the BAD patients, 18 (28.5%) of the schizophrenic patients and 14 (28%) of the controls. There was no significant difference between patient and control groups. In the evaluation of the study data, Pearson chi-square and Fisher exact chi-square were used and p< 0.05 value was accepted as statistically significant. Conclusion: In this study, though it was not statistically significant, there was a higher frequency of Toxoplasma particularly in the patients with BAD and schizophrenia patients than in the healthy persons. Large cohort studies are required to determine the relationship between this parasite and the neuropsychiatric disorders