OUTCOME OF TOXOPLASMA-GONDII MISMATCHES IN HEART-TRANSPLANT RECIPIENTS OVER A PERIOD OF 8 YEARS

Donor-related infection due to Toxoplasma gondii is a well-recorded co mplication of cardiac transplantation. In order to assess the efficacy of co-trimoxazole in small doses as prophylaxis for primary Toxoplasm a gondii infection in seronegative heart and heart-lung transplant rec ipients receiving organs from seropositive donors, we reviewed the ser ostatus and clinical outcome of all such mismatched transplants perfor med at our unit over a period of 8 years. Of 310 transplants performed between May 1985 and May 1993, donor and recipient serum samples were available for 257 heart and 33 heart-lung transplants. Of these, 13 ( 4.5 %) were toxoplasma mismatches. Post-transplant review serum sample s were available for 3 months or longer for nine of the 13 mismatches. The first three patients received co-trimoxazole 480 mg bd orally for 3 months (regimen A) while the remainder received only the standard p rophylaxis designed for Pneumocystis carinii i.e., 960 mg bd orally th ree times per week for 3 months (regimen B). Seroconversion was demons trated in only one patient (regimen A). Furthermore, none of the misma tched patients developed serious infection compatible with primary tox oplasmosis. We therefore conclude that in centres with a low prevalenc e of toxoplasma seropositivity, testing of donor and recipient serum f or Toxoplasma gondii antibody should be performed only when clinically indicated and, in addition, standard prophylaxis for Pneumocystis car inii may be adequate for preventing primary toxoplasmosis.