Chagas disease in bone marrow transplantation: an approach to preemptive therapy.

The efficacy of preemptive therapy was evaluated in bone marrow transplantation (BMT) recipients associated with Chagas disease (CD). The criterion to include patients in the protocol was the serological reactivity for CD in recipients and/or donors before transplant. After BMT, the monitoring was performed using the direct Strout method (SM), which detects clinical levels of Trypanosome cruzi parasitemia, and CD conventional serological tests. Monitoring took place during 60 days in ABMT and throughout the immunosuppressive period in allogeneic BMT. Reactivation of CD was diagnosed by detecting T. cruzi parasites in blood or tissues. In primary T. cruzi infection, an additional diagnostic criterion was the serological conversion. A total of 25 CD-BMT patients were included. Two ABMT and four allogeneic BMT recipients showed CD recurrences diagnosed by SM. One patient also showed skin lesions with T. cruzi amastigotes. Benznidazole treatment (Roche Lab), an antiparasitic drug, was prescribed at a dose of 5 mg/kg/day during 4-8 weeks with recovery of patients. Primary T. cruzi infection was not observed. This report proves the relevance of monitoring CD in BMT patients and demonstrates that preemptive therapy was able to abrogate the development of clinical and systemic disease.

Mycoses in the transplanted patient.

The incidence of invasive fungal infection (IFI) has increased considerably over the past 20 years, and transplant recipients are at especially high risk for fungal infections owing to their overall immunosuppressed condition. Organ transplantation procedures were incorporated as a therapeutic option for many patients who lacked the normal functions of organs such as the heart, liver, kidney, lung, pancreas and small bowel. The prevalence of IFI in solid organ transplant (SOTR) patients ranges from 5 to 50% in kidney and liver transplants, respectively. In bone marrow transplant (BMT) patients, IFI are major causes of morbidity and mortality due to the protracted neutropenic period and graft-versus-host disease. Candida spp. and Aspergillus spp. account for >80% of fungal episodes in both SOTR and BMT. The development of new immunosuppressive agents, new prophylaxis strategies (as pre-emptive therapy) and the improvement in surgical techniques led to increase survival of transplant recipients. In this session, a clear and concise update of the recent advances in the laboratory diagnosis of candidiasis and aspergillosis in this kind of patients was presented. However, we still need to establish more rapid, sensitive and specific methods for IFI diagnosis. Representatives of the 'Subcomision de Infecciones en el Paciente Neutropenico y Transplantado (SIPNYT)' de la Sociedad Argentina de Infectologia (SADI), presented the results of an unusual multicenter study both retrospective and descriptive studies of IFI in SOTR and BMT patients in Argentina. In addition, a study of IFI in 1,861 SOTR patients from four centers and the analysis of IFI in 2,066 BMT patients from all 12 BMT centers from Argentina was presented. From these studies it can be concluded that 'all transplant recipients are not the same' and that they should be stratified according to their different risk degrees in order to determine the best prophylaxis and treatment strategies.

Recipients and donors of bone marrow transplants suffering from Chagas' disease: management and preemptive therapy of parasitemia.

We report the clinical course of five adult patients with chronic Chagas' disease (Cd) who underwent BMT. Two patients with non-Hodgkin's lymphoma and one with ALL received an ABMT. Allogeneic BMT was performed in two patients with AML and CML respectively. One donor had chronic Cd. Samples of peripheral blood for parasite investigation by the Strout method, blood culture, and immunological studies by indirect immunofluorescent assay, ELISA and indirect hemagglutination tests were performed weekly from the start of chemotherapy until day +60 for ABMT and during the period of immunosuppression for allogeneic BMT. No prophylaxis was given to any of these patients. In only one ABMT patient were trypomastigotes detected early by blood culture without symptoms of reactivation. Benznidazole as preemptive treatment was administered at 5-8 mg/kg/daily for 30 days. Parasitemia was rapidly cleared and at the end of therapy xenodiagnosis was negative. The other Cd patients showed no evidence of relapse of parasitemia or signs and symptoms of reactivation. In brief, evidence of Cd should be sought in all BMT patients coming from endemic areas because parasitemia and reactivation are potential complications during the period of neutropenia and immunosuppression. The strategy used for early detection and treatment of parasitemia and reactivation was safe and effective.