Risk factor for death in hematopoietic stem cell transplantation: are biomarkers useful to foresee the prognosis in this population of patients?

BACKGROUND: The morbidity and mortality in hematopoietic stem cell transplantation (HSCT) occur due to infectious complications and constitute the major clinical problems in HSCT recipients. The role of the use of biomarkers in post-HSCT patients is still controversial. OBJECTIVES: To assess the serum values of biomarkers interleukin 6 (IL-6), procalcitonin (PCT) and C-reactive protein (CRP) and risk factors for post-HSCT death. PATIENTS AND METHODS: Prospective study conducted in patients submitted to HSCT at a university hospital. Biomarkers (IL-6, PCT and CRP) were assessed on the day afebrile neutropenia was detected, in the febrile event, 24 and 72 h after fever onset and 48 h or 5 days if fever persisted. Patients were compared as to the death outcome within 30 days from the HSCT. Variables with p < 0.15 were included in the multivariate analysis model (MVA) that were performed for all patients included in the study and separated for autologous and allogeneic HSCT patients. RESULTS: 296 patients with ages ranging between 15 and 70 years, neutropenic, submitted to HSCT, being 216 (73%) autologous and 80 (20%) allogeneic were assessed. One hundred and ninety (64.2%) patients presented fever after the transplantation and infection microbiologically controlled in 78 (26.4%). Twenty-three cases (7.8%) evolved to death. The risk factors associated with death in the bivariate analysis were age, allogeneic transplantation, unrelated transplantation, GVHD, bloodstream infection by Gram-negative, IL-6 >140 pg/mL and CRP ≥ 120 mg/L and the protective ones were lymphoma and hospital outpatient support. The independent variables in the MVA associated with death were allogeneic and unrelated transplantation, blood stream infection (BSI) by Gram-negative, LDH ≥ 390 UI/L, urea ≥ 25 mg/dL and CRP ≥ 120 mg/L for HSCT transplanted patients and BSI due to Gram-negative and CRP ≥ 120 mg/L for allogeneic HSCT, however, CRP ≥ 120 mg/L did not remain in the model when urea ≥ 25 mg/L was included. No independent risk factor was found for autologous patients. CONCLUSIONS: Out of the biomarkers assessed, only CRP ≥ 120 mg/L was independently associated with death. Other risk factors found were: type of transplantation (allogeneic and unrelated), bloodstream infection by Gram-negative, LDH ≥ 390 UI/L and urea ≥ 25 mg/dL. For allogeneic patients only CRP ≥ 120 mg/L and BSI due to Gram-negative were risk factors for death; however, CRP did not remain in the model when urea ≥ 25 mg/L was included.

Seroconversion of 2009 pandemic influenza A (H1N1) vaccination in kidney transplant patients and the influence of different risk factors.

BACKGROUND: Influenza may present a high morbidity and mortality in solid organ transplanted patients (SOTP). Annual influenza virus vaccine is recommended for SOTP. However, low levels of seroconversion in SOTP have been reported. The aim of this study was to evaluate the immunogenicity of 2009 pandemic influenza A (H1N1) - A(H1N1)pdm09--vaccine in kidney transplant patients and to analyze which features might affect seroconversion. METHODS: This study was conducted from March to August 2010 at the Renal Transplantation Unit of University of São Paulo, Brazil. A total of 85 renal transplant patients attending the outpatient unit received one 15-µg intramuscular dose of A(H1N1) pdm09 influenza vaccine (reassortant vaccine virus A/California/7/2009 [NYMC X-179A]). Blood samples were collected immediately before and 21 days after the vaccine was given. Antibody response was measured by the standard hemagglutination-inhibition (HI) assay. The primary immunogenicity endpoint for this study was seroconversion in previously seronegative patients (HI titers <1:40), and the secondary endpoint was the identification of features that could affect seroconversion in this population. RESULTS: Five (5.9%) patients presented HI titers prevaccination ≥ 1:40 and were excluded from further analysis. Seroconversion in previously negative patients occurred in 27 (34%) of 80 patients. Prevaccination HI titers geometrical mean was 5.8 and postvaccination 19.6 (ratio 3.4). Significant seroconversion rate factors were female gender, non-Caucasian ethnicity, and post-transplant time before vaccination. No impact was seen on seroconversion for age, donor type, tacrolimus and cyclosporine blood levels, renal function, or blood lymphocyte counts. Mycophenolate (MPA) showed a lower rate of seroconversion when compared with azathioprine. Tacrolimus and cyclosporine had similar seroconversion rates. Sirolimus use was associated with the highest rate of seroconversion, although these patient numbers were low. Immunosuppresssion containing MPA was considerably less effective in seroconversion than drug combinations with no MPA. Patients receiving sirolimus had more chance of seroconversion. HI titers geometric means pre/post vaccine were as follows: MPA (n = 56): 5.8/12.8; tacrolimus (n = 50): 5.9/16.2; cyclosporine (n = 18): 5.4/24.2; azathioprine (n = 19): 6.2/51.6; and sirolimus (n = 6): 8/80. By univariate analysis, being female and non-White were variables associated with 3.3 times more chance of seroconversion than being male and White. In the multivariate analysis, the variables remaining in the model showed similar hazard ratios. CONCLUSIONS: In this study, the monovalent A(H1N1)pdm09 influenza vaccine demonstrated low rates of seroconversion, particularly in patients on MPA, but with potentially higher response rates in patients on sirolimus.

An outbreak of respiratory syncytial virus infection in hematopoietic stem cell transplantation outpatients: good outcome without specific antiviral treatment.

BACKGROUND: Respiratory syncytial virus (RSV) is a common cause of seasonal respiratory viral infection in hematopoietic stem cell transplantations (HSCT) patients. The efficacy of treatment, however, remains controversial. We describe an outbreak of 31 cases of RSV that occurred in an HSCT outpatient care unit in the fall season from March through May 2010, with a good outcome without any specific antiviral treatment. METHODS: During these 3 months, 222 nasal wash samples were tested and, of these, 31 outpatients were positive for RSV. In 2009, 99 samples had been tested and only 10 outpatients were positive for RSV in the same period. RESULTS: Seven (22.5%) patients had severe neutropenia (<500 cells/µL); severe lymphopenia (<200 cells/µL) was present in 13 (41.9%) patients, and 14 (45%) had received intravenous broad-spectrum antibiotics. Hospitalization was necessary only for 8 patients (25.8%); 20 had lower respiratory tract infection (64.5%). Only 1 patient died as a result of proven invasive aspergillosis. CONCLUSION: This report suggests that HSCT outpatients with no risk factors may not always require specific treatment for RSV.

Chronic paracoccidioidomycosis of the intestine as single organ involvement points to an alternative pathogenesis of the mycosis.

Current knowledge on the natural history of paracoccidioidomycosis states that the chronic form of the disease results from reactivation of quiescent foci established years or decades before during the primary lung infection. Once reactivated, the fungi can disseminate to virtually any organ or system. We present herein two chronic paracoccidioidomycosis patients with a single organ involvement that points to an alternative pathogenesis of the mycosis. These patients suggest that the chronic form may also arise from reactivation of foci not confined to the lungs, due to the early dissemination of yeast cells during the primary infection.

Malakoplakia after renal transplantation in the current era of immunosuppressive therapy: case report and literature review.

Malakoplakia is a rare chronic granulomatous disease of unknown cause. It is thought to be caused by an acquired bactericidal defect of macrophages. Malakoplakia is associated with chronic infections and immunosuppression. Although it occurs mainly in the urinary tract, it has already been reported in almost every organ system. The isolation of bacteria, especially Escherichia coli, is common in malakoplakia patients. Here, we present a case of primary cutaneous malakoplakia in a kidney transplant recipient who had been taking prednisone, tacrolimus, and mycophenolate. Culture of a lesion grew Burkholderia cepacia complex. Treatment with high doses of trimethoprim-sulfamethoxazole was successful. We also present a systematic review of the literature, identifying 4 previously reported cases of malakoplakia after renal transplantation under similar immunosuppressive therapy, most occurring in the urinary tract or perineum and following benign courses to cure. Data in the literature suggest that malakoplakia has become even rarer since changes were made in the immunosuppressive therapy employed after kidney transplantation.

Characterization of monocyte-derived dendritic cells from patients with active and treated paracoccidioidomycosis.

Cellular immune responses are a significant defence mechanism in human paracoccidioidomycosis (PCM), an endemic mycosis in Latin America; however, little is known about the role of dendritic cells (DCs) in human PCM. We investigated monocyte-derived DCs from patients with treated (TP) and active PCM (AP) compared with healthy non-PCM donors (CO). DCs from the TP group showed higher expression of HLA-DR, CD86 and DC-SIGN compared with CO, whereas AP showed similar expression to CO. Production of IL-10 was downregulated by TNF-α in all groups and lower levels were observed in untreated DCs from AP compared with CO. Conversely, IL-12p40 was significantly upregulated in the DCs of the TP group. TNF-α-activated DCs from the CO group produced significantly lower levels of IL-12p40 when differentiated from magnetic-sorted monocytes (MACS) compared with adhered monocyte-derived DCs. This comparison in the TP group revealed similar levels of IL-12p40, suggesting a T cell-independent increase in the production of IL-12p40. Higher expression of surface molecules with increased IL-12p40 may indicate a better activation of DCs after the treatment of PCM. Our findings suggest that DCs may be crucial in the protective response to Paracoccidioides brasiliensis and that in vitro-generated DCs might be useful in enhancing antifungal immunity, especially during active PCM.

Endemic and opportunistic infections in Brazilian solid organ transplant recipients.

OBJECTIVE: To evaluate the frequency and clinical features of endemic and other opportunistic infections in liver or kidney transplant recipients in four transplant centres in different geographical areas of Brazil. METHODS: Retrospective analysis of medical and laboratory records of four transplant centres on endemic and other opportunistic infections in liver or kidney transplant recipients. Analyses were performed with spss statistical software. RESULTS: From 2001 to 2006, 1046 kidney and 708 liver transplants were registered in all centres. The average age was 42 years. Among 82 (4.7%) cases with infections, the most frequent was tuberculosis (2.0%), followed by systemic protozoal infections (0.7%), toxoplasmosis (0.4%) and visceral leishmaniasis (0.3%). Systemic fungal infections occurred in 0.6%, of which 0.4% were cryptococcosis and 0.2% were histoplasmosis. Dengue was the only systemic viral infection and was registered in two cases (0.1%), of which one was classified as the classic form and the other as dengue haemorrhagic fever. Nocardiosis was described in one case (0.05%). The infectious agents most frequently associated with diarrhoea were Blastocystis sp., Schistosoma mansoni and Strongyloides stercoralis. CONCLUSIONS: Opportunistic Infections in transplant patients have a wide spectrum and may vary from asymptomatic to severe infections with high mortality. A better understanding of the epidemiology of endemic pathogens and clinical manifestations can contribute to the establishment of an early diagnosis as well as correct treatment aimed at decreasing morbidity and mortality.

Polymorphisms on IFNG, IL12B and IL12RB1 genes and paracoccidioidomycosis in the Brazilian population.

Paracoccidioidomycosis (PCM) is a systemic chronic mycosis, endemic in Latin America, especially Brazil, and is the eighth leading cause of death among chronic and recurrent infectious diseases. PCM infection is characterized by the presence of Th1 immune response; the acute form, by a mixed Th2/Th9, while the chronic form is characterized by Th17/Th22 profiles. The occurrence and severity of human PCM may also be associated with genetic factors such as single nucleotide polymorphisms (SNP) on cytokines encoding genes. We investigated the association between these polymorphisms and the different clinical forms of PCM. We included 156 patients with PCM (40 with the acute form, 99 with the chronic multifocal and 17 with the chronic unifocal form) and assayed their DNA samples for IFNG +874 T/A SNP by PCR-ARMS (Amplification Refractory Mutational System), IL12B +1188 A/C SNP on 3' UTR and IL12RB1 641 A/G SNP on exon 7 by PCR-RFLP (Restriction Fragment Length Polymorphism). We found similar genotypic and allelic frequencies of the investigated SNPs among the clinical forms of PCM. Considering male patients, the IL12RB1 641 AA genotype was more frequent in the chronic multifocal form while heterozygosis was in the chronic unifocal form of PCM (p=0.048). Although our data suggest that the AA genotype (IL12RB1) may be associated with the more disseminated chronic disease, more patients of the chronic unifocal PCM group need to be analyzed as well as the secretion patterns of IFN-γ combined with the IL-12Rß1 expression for a better comprehension of this association.

Antibody response to the 43 kDa glycoprotein of Paracoccidioides brasiliensis as a marker for the evaluation of patients under treatment.

Sera of patients with paracoccidioidomycosis contained IgG-, IgA-, and IgM-specific antibodies to a 43 kDa antigen contained in the filtrate of a culture of Paracoccidioides brasiliensis. IgG- and IgA-specific antibodies were present in all observed patients. The IgM response was more frequent in acute cases, and the mean titers of IgG- and IgM-specific antibodies were higher in the acute forms. By the fourth month of chemotherapy, there was a decay of IgG, IgA, and IgM antibody titers to this antigen in acute cases, correlating with clinical improvement. The detection of IgG and IgA antibodies and the sequential determination of antibodies to the 43 kDa glycoprotein may be useful tools for serodiagnosis and evaluation of therapeutic efficacy.

Antigen-specific immunosuppression in paracoccidioidomycosis.

To characterize the immune dysfunction associated with paracoccidioidomycosis, we studied the in vitro lymphocyte reactivity to phytohemagglutinin (PHA), pokeweed mitogen (PWM), a Candida albicans antigen (CMA), and a Paracoccidioides brasiliensis antigen (PbAg) in 32 patients with the acute and the chronic form of the disease before or during the initial phase of treatment and after clinical cure. We also studied, as controls, 30 healthy individuals, 15 of them immune to P. brasiliensis. Results showed a strong hyporesponsiveness to the PbAg while responses to mitogens and CMA were comparable with those of controls. Patients with the acute form of the disease (usually more severe) had more marked PbAg hyporesponsiveness than those with the chronic form. After patients' clinical cure, PbAg proliferative responses were similar to controls and greater than those seen before pretreatment. Changes in other parameters were also seen in the treated patients; skin test anergy to paracoccidioidin, high levels of anti-P. brasiliensis antibodies, leukocytosis, and eosinophilia. These changes were usually more intense in patients with the acute form of the disease. The post-treatment CD4+, CD8+, and total lymphocyte counts were similar to those of controls. Correlation between these parameters and the lymphoproliferative responses to the various stimuli was only found with PbAg: PbAg responses correlated inversely with eosinophil and anti P. brasiliensis antibody levels. Overall, our results demonstrate an antigen-specific-cellular immunity defect, which is reversible with treatment and possibly related to a T helper cell-2 pattern of immune response during active disease.

Reactivation of Chagas' disease in a human immunodeficiency virus-infected patient leading to severe heart disease with a late positive direct microscopic examination of the blood.

We report a human immunodeficiency virus (HIV)-infected man with chronic Chagas' disease who developed a congestive heart failure that could not be clinically controlled. Endomyocardial biopsy revealed severe myocarditis and the xenodiagnosis result was positive, but Trypanosoma cruzi by direct microscopic examination of the blood was found only four months after the symptoms had started. Treatment with benznidazole was effective in reducing parasitemia, stabilizing the clinical status, and controlling tissue damage related to the parasite. Although the finding of T. cruzi trypomastigotes by direct microscopic examination of the blood has been considered the mark of Chagas' reactivation in immunocompromised patients with chronic disease, in this case it was a late finding.

Paracoccidioidomycosis: an epidemiologic survey in a pediatric population from the Brazilian Amazon using skin tests.

Since Paracoccidioides brasiliensis and Histoplasma capsulatum are known to be present in similar environments, there have been many epidemiologic investigations regarding the prevalences of these two organisms. However, cross-reactivity can occur in paracoccidioidin and histoplasmin skin tests, and this usually results in the overestimation of the prevalence of P. brasiliensis. The prevalence of infection with P. brasiliensis was evaluated in a cross-sectional study of 298 asymptomatic school children in the Brazilian Amazon region (Mato Grosso State). In this investigation, the reactivity of children to two different P. brasiliensis antigen preparations, paracoccidioidin and a purified 43-kD glycoprotein (gp43), was compared with or without the co-administration of histoplasmin. In the group of individuals receiving paracoccidioidin who had a positive histoplasmin skin test result, the prevalence of exposure to P. brasiliensis was 44% (16 of 36). This reactivity to P. brasiliensis was significantly higher than that observed in other groups, which ranged from 4% to 6% (P < 5 x 10(-4) for each). Overall prevalence was 4.6% (95% confidence interval = 2.5-7.7%). These data suggest that gp43 provides a better estimate of exposure to P. brasiliensis when the co-administration of histoplasmin is desired.

Clinical analysis and parasite genetic diversity in human immunodeficiency virus/Chagas' disease coinfections in Brazil.

To evaluate the possible role of parasitemia on Chagas' disease reactivation in Chagas' disease/human immunodeficiency virus (HIV) coinfection cases and the impact of HIV coinfection on Trypanosoma cruzi genetic diversity, 71 patients with Chagas' disease (34 HIV+ and 37 HIV-) were surveyed. Moreover, 92 T. cruzi stocks from 47 chronic chagasic patients (29 HIV+ and 18 HIV-) were isolated and analyzed by multilocus enzyme electrophoresis and a random amplified polymorphic DNA procedure. High parasitemia appeared to play a major role in cases of Chagas' disease reactivation. In HIV+ patients, the genetic diversity and population structure (clonality) of T. cruzi was similar to that previously observed in HIV- patients, which indicates that immunodepression does not modify drastically genotype repartition of the parasite. There was no apparent association between given T. cruzi genotypes and specific clinical forms of Chagas' disease/HIV associations.

Use of the polymerase chain reaction for detecting Trypanosoma cruzi in triatomine vectors.

Determination of the rate of Trypanosoma cruzi infection in its triatomine vectors is an element in control programmes directed at reducing transmission of the organism to humans. Traditionally, T. cruzi has been detected in these insects by microscopical examination of intestinal contents or excreta. The sensitivity of this laborious process has not been defined because of the lack of a bench-mark method against which microscopical examination could be compared. The purpose of this study was to compare the sensitivity of a polymerase chain reaction (PCR) assay with that of microscopical examination for detecting T. cruzi in Triatoma infestans nymphs that had fed on patients with chronic Chagas disease. To this end, we analysed 54 pairs of samples, each containing 2 groups of 10 insects, obtained by feedings on 19 patients with chronic T. cruzi infection, 17 of whom were fed upon 3 times. One group of insects in each pair was analysed by PCR and the other by microscopical examination of excreta. Overall, the PCR assay gave positive results in 32 of 54 groups of insects examined (59%), whereas only 7 of 54 groups (13%) were positive by microscopical examination (P = 0.038). These results demonstrate that the PCR assay is significantly more sensitive for the detection of T. cruzi in triatomine vectors than is microscopical examination, and suggest that the PCR assay could be a useful tool in epizootiological studies.

Magnetic resonance imaging in intracranial paracoccidioidomycosis.

Paracoccidioidomycosis is a systemic mycosis, endemic in South and Central America, that affects the central nervous system (CNS) in almost 10% of patients. Neurological involvement includes two different clinical forms: meningeal and granulomatous, also known as the pseudotumor form. Five patients with biopsy-proved systemic paracoccidioidomycosis and neurological complaints were studied by magnetic resonance imaging. CNS involvement was detected in all patients in the form of multiple round or lobulated lesions, predominantly hypointense on T2-weighted images and ring or nodular enhancement on post-gadolinium T1-weighted images. The lesions were distributed diffusely, with a slight predominance in the supratentorial compartment, although infratentorial lesions were also observed, mainly in the cerebellum. Hypointense lesions on T2-weighted images persisted in all 3 patients reexamined after treatment, whereas enhancing lesions on post-gadolinium T1-weighted images turned isointense in 2 patients. Magnetic resonance imaging is a sensitive method in documenting CNS paracoccidioidomycosis, most frequently as supratentorial and infratentorial multiple, round or lobulated hypointense lesions on T2-weighted images.

Lung tissue mechanics in the early stages of induced paracoccidioidomycosis in rats.

Pulmonary dysfunction represents the most important cause of death in patients with paracoccidioidomycosis (PBM). In order to investigate the functional changes of the lungs in the early stages of PBM, a model of benign disease was developed by intratracheal challenge of 12-week old isogenic Wistar rats with 1 x 10(6) yeast forms of Paracoccidioides brasiliensis. Animals were studied 30 and 60 days after infection, when fully developed granulomas were demonstrable in the lungs. Measurements of airway resistance, lung elastance and tissue hysteresis were made during sinusoidal deformations (100 breaths/min, tidal volume = 2 ml) with direct measurement of alveolar pressure using the alveolar capsule technique. Infection caused a significant increase in hysteresis (infected: 1.69, N = 13; control: 1.13, N = 12, P = 0.024, ANOVA), with no alterations in airway resistance or lung elastance. Histopathological analysis revealed the presence of fully developed granulomas located in the axial compartment of the lung interstitial space. These results suggest that alterations of tissue mechanics represent an early event in experimental PBM.

[Fluorescent method (fluorescein diacetate and ethidium bromide) to study the viability of Cryptococcus neoformans in liquor]. / Método fluorescente (diacetato de fluoresceína e brometo de etídio) para o estudo da viabilidade de Cryptococcus neoformans em líquor.

The utilization of the fluorescent method (fluorescein diacetate DF and ethidium bromide BE), to verify the viability of fungal cells, was studied in 40 samples of liquor, from patients with neurocryptococcosis. For removing leukocytes and red blood cells, which produce interfering fluorescence, good results were obtained with 0.3% saponin solution. After processing of liquor, 0.1 ml aliquots of resulting suspension were mixed to equal volumes of fresh DF-BE solution. The best incubation period for staining was 30 minutes, resulting in good differentiation between viable (green fluorescence) and non viable (red fluorescence) cells.

[Evaluation of counterimmunoelectrophoresis with antigens of icterohaemorrhagiae and patoc serovars in the serodiagnosis of human leptospirosis]. / Avaliação da contraimunoeletroforese com antígenos dos sorovars icterohaemorrhagiae E patoc no diagnóstico sorológico da leptospirose humana.

Counterimmunoelectrophoresis (CIE) was applied on paired sera from 135 patients with leptospirosis and on 69 sera from a control group. The sera from patients were subdivided in 4 groups according to the results obtained by the Microscopic Agglutination Test (MAT). The first samples sera from 58 patients were non reagent by MAT. Six monthly samples of sera were taken from 7 patients to follow-up and to determine the level of agglutinin and precipitin antibodies present using MAT and CIE. Serovars icterohaemorrhagiae and patoc were used as antigens. Three types of antigens were compared, 1) Triton-X-100 extracted; 2) heat extracted and 3) a pool of them. The CIE using icterohaemorrhagiae derived antigens types agreed with MAT in 92.64, 92.64 and 94.11% of the leptospirosis sera. The patoc antigens types reacted with the control group in 7.24, 86.95 and 84.05% of the samples, and consequently were eliminated from the present study. The icterohaemorrhagiae CIE reaction become positive earlier than MAT negative sera, and reverted to negative earlier in the follow-up samples from the patients. The CIE was sensitive and specific, gave rapid results and was easy to perform.

[Bone marrow involvement and eosinophilia in paracoccidioidomycosis]. / Comprometimento da medula óssea e eosinofilia na paracoccidioidomicose.

The authors described three acute paracoccidioidomycosis patients with bone marrow involvement. P. brasiliensis yeast forms were observed in bone marrow smears of all them, and in one case, culture also revealed fungus growth. The mononuclear phagocytic system involvement, the blood eosinophilia and the negative skin hypersensibility responses were emphasized in all of them, as well as the severity of the disease in one case, with disseminated bone lesions and 20.260 eosinophils/mm3 in peripheral blood. The authors discuss the possible role of eosinophil in the host-parasite interaction in paracoccidioidomycosis, suggesting that TH 2 subpopulation activation and increased IL 5 and GM-CSF secretions may be responsible by eosinophilia in the most severe case.

[Acute Chagas' disease: transmission routes, clinical aspects and response to specific therapy in diagnosed cases in an urban center]. / Doença de Chagas aguda: vias de transmissão, aspectos clínicos e resposta à terapêutica específica em casos diagnosticados em um centro urbano.

The authors report clinical features and therapeutic response of 24 outpatients with acute Chagas' disease, and 3 in the initial chronic phase, referred to the Clinic for Infectious and Parasitic Diseases of the FMUSP "Clínicas" Hospital between 1974 and 1987. The following transmission routes were involved: triatominae in 7 cases, blood transfusion in 9, kidney transplantation and/or blood transfusion in 4, accidental in 1, oral route in 3, probably breast feeding in 1, congenital or breast feeding in 1, and congenital or blood transfusion in 1. Six patients infected by triatominac acquired the disease between 1974 and 1980 and one in 1987. The blood transfusion infected patients acquired the disease in Greater São Paulo, seven of whom after 1983. The acute phase Chagas' disease was oligosymptomatic in 4 patients: three of such patients being immunocompromised by drugs or other diseases. Another two adult immunocompromised patients developed myocarditis and congestive heart failure. Clinical features were severe in 5 from 6 children under two years, irrespective of the transmission route. Evaluation of the acute phase patients treated with benznidazol (4-10 mg/kg/day) showed: therapeutic failure in 4/16 (25.0%); possible cure in 9/16 (53.2%) and inconclusive results in 3/16 (18.8%). The antibody and complement-mediated lysis reaction was in keeping with the xenodiagnosis in 18/22 cases, having shown negative results after treatment earlier than classical serological reactions. One aplastic anaemia patient receiving corticosteroid presented lymphoproliferative disease 6 years after being treated with benznidazol for acute Chagas' disease.