Detection of IgM and IgG anti-Toxoplasma antibodies in renal transplant recipients using ELFA, ELISA and ISAGA methods: comparison of pre- and post-transplantation status.

In the transplant recipient patients receive immunosuppressive therapy, the possibility of reactivation of the old infection or acquisition of infection from a donor's tissue increases. In this study, IgM and IgG anti-Toxoplasma immunoglobulins seroconversion in renal transplant recipients (RTRs) have been evaluated before and after transplantation. This is a prospective cohort study on a total of 102 RTRs. Two serum samples were obtained from each patient. The first was taken before administration of any immunosuppressive drugs such as corticosteroids and the second was taken 3 months after transplantation. The IgM and IgG anti-Toxoplasma antibodies were assayed by enzyme-linked flourescence assay (ELFA) and enzyme-linked immunosorbent assay (ELISA) techniques. IgM/immunosorbent agglutination assay (ISAGA) method has also been used. All RTRs were tested for toxoplasmosis before and after transplantation. ELFA identified 65 (63·7%) pre-transplantation samples as IgG+ and did not detect any positive IgM samples. However, IgM was detected in three (2·9%) post-transplantation samples by this method. Forty-nine (48%) pre-transplantation samples were reported IgG+ by ELISA and no IgM positive sample was identified by this method. ELISA has detected two (1·9%) IgM-positive reactions in post-transplantation samples. By IgM/ISAGA method, we have detected no IgM positive reactions in pre-transplantation samples, whereas 3 months later (second sampling) IgM antibody was detected in 3 (2·9%) cases. Secondary toxoplasmosis infection was observed in 30 cases per 1000 RTRs, which indicates that screening for toxoplasmosis infection should be performed in developed countries for these patients. On the other hand, as the risk of re-active toxoplasmosis infection exists in developing nations, they should consider the necessary preventive measures to control this condition.