The Prevalence of Early Toxoplasmosis after Bone Marrow Transplantation Using PCR: A Study in Iranian Patients

Background: In immuno-compromised organ transplant recipients, toxoplasmosis can be caused by either an infected graft or a latent infection, during which transformation from a chronic state to an active infection (reactivation) is observed. PCR is an accurate and sensitive molecular method widely used in medical sciences, especially in diagnostic procedures. Objective: The aim of this study was to determine the prevalence of early toxoplasmosis infection in bone marrow transplant patients by PCR. Methods: The blood samples of 50 patients with hematological disorders who had received bone marrow transplants were collected using a standard phlebotomy technique. To evaluate antitoxoplasma antibodies, we utilized the enzyme-linked immunosorbent assay (ELISA) method using a specific commercial kit (Akon) based on the manufacturer’s instructions. Genomic DNA extracted from toxoplasma tachyzoite was used as the template for PCR. Results: 22 (44%) patients were women, and 28 (56%) were men. There were no significant differences in the distribution of genders and age groups in patients with various cancers. Antitoxoplasma IgG was positive in 39 patients, while none of them were IgM positive. According to PCR results, 5 patients were positive for toxoplasmosis. All of the PCR-positive cases (2 with AML, 2 with HL, and 1 with AA) had successful engraftment at 40 days post-transplantation. Conclusion: Because of the higher efficacy of PCR in the diagnosis of toxoplasmosis, using this method along with other routine diagnostic modalities in this condition is recommended. PCR-based techniques can also be utilized to periodically determine parasite load in blood after transplantation.