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.

[Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]. / Trasplante hematopoyético alogénico con células progenitoras extraidas de la sangre periférica.

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkin's disease, major thalasemia and Hunter's syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15%. Acute graft versus host disease (GVHD) was observed in 43.4% of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4% by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.

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.

Trasplante hematopoyético alogénico con células progenitoras extraidas de la sangre periférica. / [Allogeneic hematopoietic transplantation with stem cells extracted from peripheral blood]

Fifty three patients (pts) received an allogeneic hematopoietic transplant using peripheral blood progenitor cells (PBPC). Diagnosis were acute myeloid leukemia (AML) in 16 pts, acute lymphoblastic leukemia (ALL) in 15, chronic myeloid leukemia (CML) in first chronic phase in 12, aplastic anemia in 4, myelodysplasia in 3 and Hodgkins disease, major thalasemia and Hunters syndrome in one each. Mean age was 20 years-old (2-55), 28 males and 25 females. Conditioning regimens were total body irradiation with 1200 cGy and cyclophosphamide 120 mg/kg in 38 pts, busulfan 16 mg/kg and cyclophosphamide 120 mg/kg in 10 pts, total lymphoid irradiation and cyclophosphamide in 3, 2 pts received other chemotherapy based conditionings. PBPC were infused unmanipulated through a central catheter. Graft versus host disease (GVHD) prophylaxis was cyclosporin and short course methotrexate. Donors were 6/6 HLA compatible siblings in 52 cases and 5/6 match in one case. PBPC mobilization was done with G-CSF at a dose of 10 micrograms/kg/day subcutaneously for four days, pheresis started on day 5. Bone marrow harvest was also done in the first thirty cases. Mean cellularities for CD34, CD3, CD4, CD8, CD56, CD19 (cel x 10(6)/kg) were 4.12; 4.59; 2.57; 1.9; 0.55 and 0.68, respectively. Mean recovery of neutrophils > 500/microL was obtained on day +11 and platelets > 20,000/microL on day +13. Patients were hospitalized for a mean period of 26 days (range 18-39) and days with parenteral antibiotics were 12.2 (5-45). Two pts had venoocclusive disease of the liver. Transplant related mortality was 15

. Acute graft versus host disease (GVHD) was observed in 43.4

of pts, only 5 pts had acute GVHD III or IV. Mean time for aGVHD diagnosis was +23 (8-76). Forty three pts were evaluable for chronic GVHD with a mean follow-up of 18 months (4-39). Chronic GVHD was observed in 26.4

by day +240, only 2 pts developed severe cGVHD. The present experience demonstrates an acceptable incidence for cGVHD; however, taking into account recent reports showing an increase of this complication, it seems reasonable not to perform this procedure for non-malignant diseases in which graft versus malignancy effect is not to be expected.

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.

Frecuencia y grado de "tolerancia" a penicilina en streptococcus pyogenes / Frequency and degree of \"tolerance\" to penicillin in streptococcus pyogenes

Se emplearon distintas técnicas con el objetivo de determinar la frecuencia y grado de "tolerancia" en 65 cepas de Streptococcus pyogenes aislados sucesivamente de materiales clínicos. Utilizando el método de "curva de muerte" se detectó un 7,7 ciento por ciento de cepas "tolerantes" mientras que sólo se encontró un 6,2 ciento por ciento de cepas con la relación CBM/CIM > 32. Al evaluarse el grado de población sobreviviente se encontró que en un 35,4 por ciento del total de las cepas fue > 0,1 por ciento. En las cepas que se definieron como "tolerantes" por los métodos utilizados fue siempre > 0,2 por ciento, por lo que se consideró a este valor como un punto de corte apropiado para diferenciar cepas "tolerantes" de no "tolerantes". Utilizando el método de "curva de muerte" se detectó "tolerancia" en una cepa más que con el método CBM/CIM. Como la diferencia no es estadísticamente significativa no podemos afirmar que un método sea más sensible que el otro

Frecuencia y grado de "tolerancia" a penicilina en streptococcus pyogenes / Frequency and degree of "tolerance" to penicillin in streptococcus pyogenes

Se emplearon distintas técnicas con el objetivo de determinar la frecuencia y grado de "tolerancia" en 65 cepas de Streptococcus pyogenes aislados sucesivamente de materiales clínicos. Utilizando el método de "curva de muerte" se detectó un 7,7 ciento por ciento de cepas "tolerantes" mientras que sólo se encontró un 6,2 ciento por ciento de cepas con la relación CBM/CIM > 32. Al evaluarse el grado de población sobreviviente se encontró que en un 35,4 por ciento del total de las cepas fue > 0,1 por ciento. En las cepas que se definieron como "tolerantes" por los métodos utilizados fue siempre > 0,2 por ciento, por lo que se consideró a este valor como un punto de corte apropiado para diferenciar cepas "tolerantes" de no "tolerantes". Utilizando el método de "curva de muerte" se detectó "tolerancia" en una cepa más que con el método CBM/CIM. Como la diferencia no es estadísticamente significativa no podemos afirmar que un método sea más sensible que el otro (AU)