CHAGAS-DISEASE REACTIVATION AFTER HEART-TRANSPLANTATION - EFFICACY OFALLOPURINOL TREATMENT

Background: Chagas' disease is a parasitic infection that provokes a s evere form of dilated cardiomyopathy. In the initial experience with h eart transplantation with Chagas' disease, a high rate of acute reacti vation has been reported. Although benzinidazole and nifurtimox are ef fective in the treatment of reactivation or of the acute phase of the disease they ate associated with important adverse effects. Allopurino l has substantial activity against Trypanosoma cruzi in vitro, in the experimental laboratory and in chronic human Chagas' disease; however, there is no information regarding its action in Chagas' reactivation after heart transplantation. Methods and Results: We describe two pati ents with Chagas' disease who underwent heart transplantation. The fir st one had asthenia, anorexia, and several painful subcutaneous nodule s in the legs after transplantation; biopsy showed an inflammatory inf iltrate with intracytoplasmatic nests of Trypanosoma cruzi, confirmed by immunohistochemical stains with monoclonal antibodies specific to p arasitic antigens. Allopurinol (600 mg/day) produced complete regressi on of the symptoms and the nodules with a negative control biopsy with in 2 weeks. Treatment was maintained for 2 months. Mild leukopenia dev eloped which improved after azathioprine reduction, and no further sid e-effects were noted. The second patient had sudden heart failure 6 mo nths after transplantation; endomyocardial biopsy showed myocardial fi bers infested with Trypanosoma, and a concomitantly performed right he art catheterization showed a low cardiac index and high filling pressu res. The patient received allopurinol at a daily dose of 900 mg and co nventional treatment for heart failure. Echocardiogram showed improved wall motion and decreased left ventricular dimensions, and control bi opsy showed no inflammatory activity; cardiac index and filling pressu res normalized. Treatment was maintained for 2 months without side eff ects. The two patients have not had recurrences and were in New York H eart Association functional class I 12 and 3 months, respectively, aft er discontinuation of allopurinol. Conclusions: Allopurinol seems to b e safe and effective in treating Chagas' disease reactivation after he art transplantation. A larger number of case studies seems to be neces sary to properly evaluate its role in the treatment of Chagas' disease reactivation.