Toxoplasma gondii primary infection in renal transplant recipients. Two case reports and literature review

Toxoplasmosis after solid organ transplantation is a complication associated with high morbidity and mortality. Universal prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is effective to prevent post-transplant toxoplasmosis. We report two cases of renal transplant recipients with negative antibodies against Toxoplasma gondii pretransplant who developed toxoplasmosis after TMP-SMX discontinuation. We have also performed a review of published cases of primary toxoplasmosis after renal transplantation. Of 20 cases reviewed, 11 were male and the mean age was 37.8 years (SD = 13.8). Donor serology for T. gondii was determined in 15 donors, two of them (13%) with negative immunoglobulin (Ig)G and four (27%) with positive IgG and IgM antibodies. Fever was present in 85% of primary toxoplasmosis and hematologic abnormalities were observed in 69% of the cases. Ten patients died (50%). All patients with fatal outcomes had clinical evidence of toxoplasmosis during the early post-transplant period (first 90 days), while no patient with late toxoplasmosis died (P = 0.003). Primary toxoplasmosis is associated with high mortality rates and TMP-SMX prophylaxis can delay the onset of symptoms resulting in an improvement of prognosis.