Benznidazole: Hero or villain of cellular immune response in chronic Chagas disease patients?

Although the treatment of chronic Chagas disease (CCD) patients with Benznidazole (Bz) is still controversial, its use may prevent or delay the progression of the disease to the most severe forms. One of the main factors that can influence the effectiveness of the treatment is the possible cooperation between drug effect and the host immune response. Herein, we evaluated the immune response of peripheral blood mononuclear cells (PBMCs) infected with Trypanosoma cruzi and submitted to Bz treatment. Blood samples of CCD patients (n = 7) and non-infected individuals (n = 6) were drawn to obtain PBMCs. After cell culture, the supernatants were harvested and stored, and the cell analyzed by flow cytometer. The results showed that Bz positively regulated the molecular process of cell activation (CD80) and antigen presentation (HLA-DR), increased phagocytosis receptor and macrophage activation (CD64), and did not induce an exacerbated immune response. In conclusion, these results highlight the relevance of using Bz that, despite not being a true hero, it is also not a villain, as it presents a wide range of pharmacological/immunological response interactions, important for the immune balance in the clinical progression of CCD.

Acute Chagas disease in Brazil from 2001 to 2018: A nationwide spatiotemporal analysis.

BACKGROUND: In Brazil, acute Chagas disease (ACD) surveillance involves mandatory notification, which allows for population-based epidemiological studies. We conducted a nationwide population-based ecological analysis of the spatiotemporal patterns of ACD notifications in Brazil using secondary surveillance data obtained from the Notifiable Diseases Information System (SINAN) maintained by Brazilian Ministry of Health. METHODOLOGY/PRINCIPAL FINDINGS: In this nationwide population-based ecological all cases of ACD reported in Brazil between 2001 and 2018 were included. Epidemiological characteristics and time trends were analyzed through joinpoint regression models and spatial distribution using microregions as the unit of analysis. A total of 5,184 cases of ACD were recorded during the period under study. The annual incidence rate in Brazil was 0.16 per 100,000 inhabitants/year. Three statistically significant changes in time trends were identified: a rapid increase prior to 2005 (Period 1), a stable drop from 2005 to 2009 (Period 2), followed by another increasing trend after 2009 (Period 3). Higher frequencies were noted in males and females in the North (all three periods) and in females in Northeast (Periods 1 and 2) macroregions, as well as in individuals aged between 20-64 years in the Northeast, and children, adolescents and the elderly in the North macroregion. Vectorial transmission was the main route reported during Period 1, while oral transmission was found to increase significantly in the North during the other periods. Spatiotemporal distribution was heterogeneous in Brazil over time. Despite regional differences, over time cases of ACD decreased significantly nationwide. An increasing trend was noted in the North (especially after 2007), and significant decreases occurred after 2008 among all microregions other than those in the North, especially those in the Northeast and Central-West macroregions. CONCLUSIONS/SIGNIFICANCE: In light of the newly identified epidemiological profile of CD transmission in Brazil, we emphasize the need for strategically integrated entomological and health surveillance actions.

Performance of recombinant chimeric proteins in the serological diagnosis of Trypanosoma cruzi infection in dogs.

BACKGROUND: Dogs are considered sentinels in areas of Trypanosoma cruzi transmission risk to humans. ELISA is generally the method of choice for diagnosing T. cruzi exposure in dogs, but its performance substantially depends on the antigenic matrix employed. In previous studies, our group has developed four chimeric antigens (IBMP-8.1, 8.2, 8.3, and 8.4) and evaluated their potential for diagnosing T. cruzi exposure in humans. For human sera, these chimeric antigens presented superior diagnostic performances as compared to commercial tests available in Brazil, Spain, and Argentina. Therefore, in this study we have evaluated the potential of these antigenic proteins for detection of anti-T. cruzi IgG antibodies in dog sera. METHODOLOGY/PRINCIPAL FINDINGS: The IBMP-ELISA assays were optimized by checkerboard titration. Subsequently, the diagnostic potential was validated through analysis of ROC curves and the performance of the tests was determined using double entry tables. Cross-reactivity was also evaluated for babesiosis, ehrlichiosis, dirofilariosis, anaplasmosis, and visceral leishmaniasis. Best performance was shown by IBMP-8.3 and IBMP-8.4, although all four antigens demonstrated a high diagnostic performance with 46 positive and 149 negative samples tested. IBMP-8.3 demonstrated 100% sensitivity, followed by IBMP-8.4 (96.7-100%), IBMP-8.2 (73.3-87.5%), and IBMP-8.1 (50-100%). The highest specificities were achieved with IBMP-8.2 (100%) and IBMP-8.4 (100%), followed by IBMP-8.3 (96.7-97.5%) and IBMP 8.1 (89.1-100%). CONCLUSIONS/SIGNIFICANCE: The use of chimeric antigenic matrices in immunoassays for anti-T. cruzi IgG antibody detection in sera of infected dogs was shown to be a promising tool for veterinary diagnosis and epidemiological studies. The chimeric antigens used in this work allowed also to overcome the common hurdles related to serodiagnosis of T. cruzi infection, especially regarding variation of efficiency parameters according to different strains and cross-reactivity with other infectious diseases.

Binding capacity of mannose-binding lectin (MBL) is associated with the severity of chronic Chagas cardiomyopathy.

Chagas disease (CD) is a global problem. Currently, it affects approximately 15 million individuals in Latin America. It is well know that the human immune response is related to different clinical manifestations. Mannose binding lectin (MBL) plays an important role in innate immunity, and it mediates the phagocytosis and complement-mediated destruction of pathogens. The binding capacity is enhanced by the oligomerization of MBL. In this study, we evaluated the serum concentration and the binding capacity of MBL in patients with chronic chagasic cardiomyopathy. A total of 77 patients with chronic CD were included with indeterminate (n = 19), mild cardiac (n = 29) and severe cardiac (n = 29) forms. The serum concentration and the binding capacity were measured using enzyme-linked immunosorbent assays (ELISA). There was no significant difference in the serum MBL levels between the groups of patients. However, we found a relationship between the binding capacity and the groups studied. Our results suggest that binding capacity of MBL could be an indicator of clinical manifestation in Chronic Chagas cardiomyopathy. Furthermore, combined with the Mannose Binding Index results in a useful clinical tool for management of Chronic Chagas Patients.

Genetic susceptibility to chronic Chagas disease: an overview of single nucleotide polymorphisms of cytokine genes.

Chagas disease is a parasitic infection that is a significant public health problem in Latin America. The mechanisms responsible for susceptibility to the infection and the mechanisms involved in the development of cardiac and digestive forms of chronic Chagas disease remain poorly understood. However, there is growing evidence that differences in susceptibility in endemic areas may be attributable to host genetic factors. The aim of this overview was to analyze the genetic susceptibility to human Chagas disease, particularly that of single nucleotide polymorphisms of cytokine genes. A review of the literature was conducted on the following databases: PubMed/MEDLINE and Scopus. The search strategy included using the following terms: "Cytokines", "Single Nucleotide Polymorphisms" and "Chagas Disease". After screening 25 citations from the databases, 19 studies were selected for the overview. A critical analysis of the data presented in the articles suggests that genetic susceptibility to Chagas disease and chronic Chagas cardiomyopathy is highly influenced by the complexity of the immune response of the host. Follow-up studies based on other populations where Chagas disease is endemic (with distinct ethnic and genetic backgrounds) need to be conducted. These should use a large sample population so as to establish what cytokine genes are involved in susceptibility to and/or progression of the disease.

Characterization of novel Leishmania infantum recombinant proteins encoded by genes from five families with distinct capacities for serodiagnosis of canine and human visceral leishmaniasis.

To expand the available panel of recombinant proteins that can be useful for identifying Leishmania-infected dogs and for diagnosing human visceral leishmaniasis (VL), we selected recombinant antigens from L. infantum, cDNA, and genomic libraries by using pools of serum samples from infected dogs and humans. The selected DNA fragments encoded homologs of a cytoplasmic heat-shock protein 70, a kinesin, a polyubiquitin, and two novel hypothetical proteins. Histidine-tagged recombinant proteins were produced after subcloning these DNA fragments and evaluated by using an enzyme-linked immunosorbent assays with panels of canine and human serum samples. The enzyme-linked immunosorbent assays with different recombinant proteins had different sensitivities (67.4-93.0% and 36.4-97.2%) and specificities (76.1-100% and 90.4-97.3%) when tested with serum samples from Leishmania-infected dogs and human patients with VL. Overall, no single recombinant antigen was sufficient to serodiagnosis all canine or human VL cases.

Immunoglobulin M antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi in chronic chagasic patients.

Previous works of our research group have demonstrated aspects of the humoral immune response of chronic Chagas disease using the cytoplasmatic repetitive antigen (CRA) and the flagellar repetitive antigen (FRA) of Trypanosoma cruzi. The aim of this work was to analyze the presence of specific immunoglobulin M (IgM) antibodies in chronic chagasic patients using these recombinant antigens of T. cruzi. The positivity of IgM in chronic chagasic patients against CRA and FRA antigens was determined by indirect enzyme-linked immunosorbent assay. We reported no statistical significant differences between the levels of IgM for both recombinant antigens and the different chronic clinical forms of Chagas disease. However, a small proportion of chronic chagasic patients analyzed in this study was positive for this antibody isotype. The findings of this study indicate that the IgM antibodies cannot be used to elucidate the differences in the profile of humoral immune response among chronic chagasic patients with different clinical forms using the CRA and FRA recombinant antigens of T. cruzi.

Increased levels of IgA antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi differentiate digestive forms of Chagas disease.

In the chronic phase of Chagas disease, individuals infected by Trypanosoma cruzi may be asymptomatic or may present cardiac and/or digestive complications. Our aim here was to analyze the relationship between the presence of specific immunoglobulin A antibodies and the different chronic clinical forms of Chagas disease using two recombinant antigens of Trypanosoma cruzi, cytoplasmatic repetitive antigen and flagellar repetitive antigen. The association of this immunoglobulin isotype with the digestive and cardio-digestive forms of the disease determined by indirect enzyme-linked immunosorbent assay, strongly suggests that IgA antibodies against these recombinant antigens of T. cruzi can be used as an immunological marker of the digestive alterations caused by Chagas disease. The tests performed in this study show that it is possible to differentiate digestive forms of Chagas disease. The knowledge provided by these results may help physicians to manage early alterations in the digestive tract of patients with the indeterminate or cardiac forms of Chagas disease. Prospective studies, however, with follow-up of the patients that presenting with high levels of immunoglobulin A against cytoplasmatic repetitive antigen and flagellar repetitive antigen recombinant antigens, need to be conducted to confirm this hypothesis.

Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies?

In the acute phase and in the chronic forms of Chagas disease, the etiological diagnosis may be performed by detection of the parasite using direct or indirect parasitological methods and by the presence of antibodies in the serum by way of serological tests. Several techniques are easily available, ranging from the simplest wet smear preparation to immuno-enzymatic assays with recombinant antigens that will meet most diagnostic needs. Other tests under evaluation include a molecular test using polymerase chain reaction, which has shown promising results and may be used as a confirmatory test both in the acute and chronic phases of the disease. Better rapid tests are needed for diagnosis, some of which are already under evaluation. Additionally, there is a need for tools that can identify patients cured shortly after specific treatment. Other needs include a marker for prognosis and early diagnosis of congenital transmission.

Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies?

In the acute phase and in the chronic forms of Chagas disease, the etiological diagnosis may be performed by detection of the parasite using direct or indirect parasitological methods and by the presence of antibodies in the serum by way of serological tests. Several techniques are easily available, ranging from the simplest wet smear preparation to immuno-enzymatic assays with recombinant antigens that will meet most diagnostic needs. Other tests under evaluation include a molecular test using polymerase chain reaction, which has shown promising results and may be used as a confirmatory test both in the acute and chronic phases of the disease. Better rapid tests are needed for diagnosis, some of which are already under evaluation. Additionally, there is a need for tools that can identify patients cured shortly after specific treatment. Other needs include a marker for prognosis and early diagnosis of congenital transmission.

Prevalência de infecção chagásica em doadores de sangue no estado de Pernambuco, Brasil / The prevalence of chagasic infection among blood donors in the State of Pernambuco, Brazil

A doença de Chagas é uma infecção sistêmica de evolução crônica cujo agente etiológico é o parasita Trypanosoma cruzi. O último relato encontrado sobre a soroprevalência da doença em doadores de sangue realizado na capital pernambucana, Recife, data de 1970, onde foi encontrada uma prevalência de 4,4 por cento em doadores de um hospital local. Devido à falta de informações divulgadas sobre a infecção por T. cruzi e sendo Pernambuco uma região endêmica para esta enfermidade, o presente estudo se propôs a analisar o perfil dos doadores de sangue do Hemocentro de Pernambuco (Hemope), que apresentaram reatividade para doença de Chagas, no período de 2002 a 2007. O perfil dos doadores inaptos foi avaliado de acordo com gênero, idade e procedência segundo as mesorregiões de Pernambuco. Foi encontrada uma prevalência de 0,17 por cento para doença de Chagas e 6,89 por cento das bolsas descartadas deveram-se a essa reatividade. Em relação ao gênero dos doadores, foi significativamente maior a contribuição dos homens (p<0,0001). A faixa etária de 18-30 anos apresentou menor quantidade de sorologias reativas (20,21 por cento). Foi verificado também que, na Região Metropolitana do Recife, a quantidade de reações inconclusivas foi estatisticamente maior que a quantidade de sorologias reagentes (p=0,0440). Desta forma, estudos epidemiológicos fornecem dados importantes no sentido de se avaliar diretamente o risco de transmissão de uma doença por transfusão sanguínea e permitem que também em regiões endêmicas se avalie a eficácia das medidas para o controle vetorial.

Chagas disease is a systemic infection with a chronic onset transmitted by Trypanosoma cruzi. The last study conducted in Recife, capital of Pernambuco state, was carried out during 1970. At that time a prevalence of 4.4 percent was found among blood donors of a local hospital. Due to the lack of epidemiology data on T. cruzi infection and as Pernambuco is an endemic region, the present study describes the profile of blood donors who presented reactivity for Chagas disease during the period of 2002 to 2007 in the state's blood bank (Hemope). The profile of unsuitable donors was evaluated according to gender, age and according to the meso-regions of Pernambuco. A prevalence of 0.17 percent was found for Chagas disease, whereas 6.89 percent of the rejected blood bags were due to this reactivity. As far as gender is concerned, the reactivity of men was higher than that of women (p<0.0001). Additionally, the age group between 18-30 years was less infected (20.21 percent). On analyzing the reactivity in each one of the meso-regions of the state, it was found that, in the Metropolitan Region of Recife, the number of inconclusive reaction cases was statistically higher than the number of reactive serology cases (p=0.0440). Thus, epidemiological studies provide important data to indirectly evaluate the risk of blood-borne diseases and allow indirect evaluation of the effectiveness of vectorial control measures in endemic regions.

Evaluation of real time PCR technique to diagnosis of human T-lymphotropic virus type I (HTLV-I) in patients in the Hematologia da Fundação Hemope Hospital, in Northeastern Brazil / Avaliação da técnica de PCR em tempo real para o diagnóstico do virus linfotrópico tipo I de células T humana (HTLV-I) em pacientes do Hospital de Hematologia da Fundação Hemope, no Nordeste do Brasil

As a high degree of homology exists between the proviral genomes of HTLV-I and HTLV-II, there is significant cross-reactivity. Therefore although detection of HTLV antibodies is characteristic of viral infection, it is not sufficient to confirm the presence of the viral type. Molecular tests used to diagnose the HTLV-I/II viruses are based oninvestigations of proviral genomic sequences, and allow for an infection to be diagnosed prior to the appearance of any sign or symptom. The HTLV proviral load in infected individuals can be determined using real-time PCR, a faster method with less risk of contamination than simple or nested PCR. We analyzed 63 samples from the Hemope Hospital, of which 33 were from HTLV seropositive individuals and 30 from blood donors, to determine the type of virus and the proviral load. The sensitivity of qualitative PCR in comparison to ELISA was 87.5% (95% IC: 70.1 - 95.9%) and the specificitywas 100% (IC 95%: 85.9 - 100.0%). The sensitivity and specificity of real-time PCR in comparison to the serological test (ELISA) were 100% (95% IC: 86.7 - 100.0%) and 96.67% (95% IC: 80.9 - 99.8%) respectively. The proviral load in the seropositiveindividuals ranged from 13 to 343820 copies/106 PBMC cells. Our study also observed that individuals with TSP/HAM had a higher proviral load than those who showed no symptoms. The use of real time PCR for routine clinical testing of infected individuals will play a significant role in identifying the virus type and determining the proviral load, thereby providing more appropriate treatment.

Como os genomas provirais do HTLV-I e HTLV-II exibem grande homologia, há uma expressiva sororeatividade cruzada. Assim, a detecção de anticorpos anti-HTLV-I/II embora caracterize infecção viral, não permite estabelecer distinção entre os agentes. Os testes moleculares empregados para o diagnóstico dos vírus HTLV-I/II, baseiam-se na pesquisa de seqüências genômicas provirais permitindo o diagnóstico da infecção antes de aparecer sinal ou sintoma. A carga proviral de HTLV pode ser determinadaatravés da utilização da PCR em tempo real, uma técnica rápida e com menor risco de contaminação que a PCR simples ou nested PCR. Analisamos, 63 amostras do Hospital HEMOPE, das quais 33 foram de indivíduos com sorologia reagente para HTLV e 30 de doadores de sangue, para determinar o tipo de vírus e a carga proviral. A sensibilidade da PCR qualitativa emrelação ao ELISA foi de 87,9% (IC 95%: 70,9-96,0%) e a especificidade foi de 100% (IC 95%: 85,9-100,0%). A sensibilidade e especificidade da PCR em tempo real foram de 100% (IC95%: 86,7-100,0%) e 96,67% (IC 95%: 80,9-99,8%), respectivamente.A carga proviral variou entre 13 cópias/106 células PBMC e 343820 cópias/106 células PBMC. Nosso estudo também observou que os indivíduos com PET/MAH tiveram carga proviral mais elevada que a dos indivíduos assintomáticos. A utilização da PCR em tempo real na rotina clínica dos indivíduos infectados poderá desempenhar um papel relevante na identificação do vírus e na determinação da carga proviral, contribuindo para direcionar um tratamento adequado.

Triagem familiar para o gene HBB*S e detecção de novos casos de traço falciforme em Pernambuco / Family screening for HBB*S gene and detection of new cases of sickle cell trait in Northeastern Brazil

OBJETIVO: Estimar o incremento no número adicional de afetados com base na prevalência de síndromes falciformes em familiares de casos-índice. MÉTODOS: Estudo transversal em familiares de amostra aleatória dos casos-índice identificados por programa de triagem neonatal em Pernambuco, no período de 2001 a 2005. O modelo de triagem familiar ampliado incluiu 463 membros familiares de 21 casos-índice. Os familiares foram categorizados como: núcleo reduzido (NR -pai, mãe e irmãos); de primeiro grau (N1 - avós, tios e primos de primeiro grau); de segundo grau (N2 - filhos dos primos de primeiro grau); ampliado (NA - NR+N1+N2) e ampliado de primeiro grau (NA1 -NR+N1). A confirmação da presença de HBB*S e detecção de hemoglobinas anormais foram realizadas por meio da High Performance Liquid Chromathgraphy. A associação entre a presença de HBB*S e variáveis foi testada pelo cálculo da razão de prevalência e respectivos IC 95 por cento e a diferença entre médias verificadas pelo teste t de Student, ao nível de significância de 5 por cento. RESULTADOS: A anemia falciforme era desconhecida por 81 por cento dos familiares; o gene HBB*S esteve presente em 114 familiares. Observou-se que 53,3 por cento da população estudada estava na faixa considerada reprodutiva e 80 por cento das pessoas portadoras do gene HBB*S já tinham gerado filhos. A freqüência foi maior no núcleo NR (69 por cento), mas também elevada no N1 (22,8 por cento). O NA1 resultou na detecção de 69 portadores adicionais (aumento de 172 por cento). CONCLUSÕES: Os resultados indicam que a triagem familiar para identificação de portadores de síndrome falciforme deve ser estendida para os familiares até o primeiro grau.

OBJECTIVE: To estimate the additional number of affected individuals based on the prevalence of sickle-cell syndromes among relatives of index cases. METHODS: Cross-sectional study of relatives of a random sample of index cases identified through a neonatal screening program in Northeastern Brazil, between 2001 and 2005. The extended family trial model included 463 relatives of 21 index cases. Relatives were classified as nuclear family (NF: father, mother, and siblings); first degree extended family (N1: grandparents, uncles and aunts, and first cousins); second degree extended family (N2: children of first cousins); extended family (NA: NF+N1+N2); and extended nuclear family (NA1: NF+N1). The presence of HBB*S and other abnormal hemoglobins was confirmed by high-performance liquid chromatography. The association between the presence of HBB*S and other variables was calculated using prevalence ratios and their respective 95 percent confidence intervals, and differences between means were calculated using Student's t test with a 5 percent significance level. RESULTS: Of relatives, 81 percent had no knowledge of sickle-cell anemia and HBB*S was present in 114 family members. A total of 53.3 percent of the studied population was considered as of reproductive age, and 80 percent of HBB*S carriers had already had children. Frequency was higher among NF (69 percent), but was also high in N1 (22.8 percent). NA1 screening resulted in the detection of 69 carriers additional (a 172 percent increase). CONCLUSIONS: These results indicate that family screening for the identification of sickle-cell carriers should be extended to first degree relatives.

Cellular immune response from Chagasic patients to CRA or FRA recombinant antigens of Trypanosoma cruzi.

We propose to analyze the relation between the cellular immune response of Chagas' disease patients after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant antigens cytoplasmatic repetitive antigen (CRA) or flagellar repetitive antigen (FRA) of T. cruzi and the chronic clinical forms of disease. Cells were stimulated using phytohemagglutinin, CRA, FRA, or a soluble antigen of Epimastigota (Ag-Epi) for 24 hr, 72 hr, or 6 days. The proliferation of cells was evaluated after 6 days of culture by quantification of incorporated 3H-thymidine. Cytokines were measured in the supernatants obtained after 24 hr (tumor necrosis factor [TNF]-alpha and interleukin [IL]-4), 72 hr (IL-10), and 6 days (interferon [IFN]-gamma) using enzyme-linked immunosorbent assay (ELISA). Cells of the Chagas patients stimulated with the recombinant antigens exhibited higher proliferation responses compared with that of non-Chagas (NC) individuals. However, when proliferation was compared between patients with the cardiac form (CF) or indeterminate form (IF), it was not possible to establish a difference in the response. So far as the cytokines secreted in the culture supernatants after stimulation in vitro with T. cruzi antigens were concerned, the results showed that CRA, as well as Epi-Ag, were able to stimulate the production of TNF-alpha and IFN-gamma in Chagas patients as compared with NC individuals. However, the cytokine levels after stimulation with the T. cruzi antigens were not different between the patients with CF and IF. CRA was capable of inducing a T helper type 1 (Th1) immune response, with elevated production of TNF-alpha and IFN-gamma in Chagas patients that are carriers of CF and IF clinical forms.

[Family screening for HBB*S gene and detection of new cases of sickle cell trait in Northeastern Brazil]. / Triagem familiar para o gene HBB*S e detecção de novos casos de traço falciforme em Pernambuco.

OBJECTIVE: To estimate the additional number of affected individuals based on the prevalence of sickle-cell syndromes among relatives of index cases. METHODS: Cross-sectional study of relatives of a random sample of index cases identified through a neonatal screening program in Northeastern Brazil, between 2001 and 2005. The extended family trial model included 463 relatives of 21 index cases. Relatives were classified as nuclear family (NF: father, mother, and siblings); first degree extended family (N1: grandparents, uncles and aunts, and first cousins); second degree extended family (N2: children of first cousins); extended family (NA: NF+N1+N2); and extended nuclear family (NA1: NF+N1). The presence of HBB*S and other abnormal hemoglobins was confirmed by high-performance liquid chromatography. The association between the presence of HBB*S and other variables was calculated using prevalence ratios and their respective 95% confidence intervals, and differences between means were calculated using Student's t test with a 5% significance level. RESULTS: Of relatives, 81% had no knowledge of sickle-cell anemia and HBB*S was present in 114 family members. A total of 53.3% of the studied population was considered as of reproductive age, and 80% of HBB*S carriers had already had children. Frequency was higher among NF (69%), but was also high in N1 (22.8%). NA1 screening resulted in the detection of 69 carriers additional (a 172% increase). CONCLUSIONS: These results indicate that family screening for the identification of sickle-cell carriers should be extended to first degree relatives.

Importância dos programas de triagem para o gene da hemoglobina S / Importance of screening programs of the hemoglobin S gene

A anemia falciforme caracteriza-se como quadro hemolítico hereditário que evolui cronicamente causando danos físicos e emocionais às pessoas acometidas. Até o presente momento não se dispõe de tratamento curativo, a não ser o transplante de medula óssea, que ainda tem sido realizado de maneira experimental. A triagem neonatal de hemoglobinopatias, principalmente da anemia falciforme, tem sido essencial ao diagnóstico precoce e à instituição de medidas preventivas e promotoras de saúde. No entanto, o Ministério da Saúde do Brasil recomenda o exame dos pais a partir da identificação de heterozigotos, mas não faz alusão quanto à ampliação da triagem para outros familiares. Uma família que possua uma criança afetada com estas síndromes passa a ter um marcador para um grupo genético de risco. Neste caso, a triagem ampliada para os familiares mais próximos (avós, pais, irmãos, tios e primos) poderá identificar muitos portadores ou casais em risco, antes do casamento e procriação, além de servir de base a programas de assessoramento genético e de controle epidemiológico das hemoglobinopatias, uma herança genética bastante freqüente em nossa população.

Sickle cell anemia is a hereditary condition that evolves to a chronic illness, causing physical and emotional disorders to those involved. As yet there is no cure except for bone marrow transplantation which is still in the experimental stage. Neonatal screening for hemoglobin disorders, particularly sickle cell anemia, has been crucial for ensuring early diagnosis and the application of preventive and health-promoting measures. The Brazilian Health Ministry recommends testing parents thereby identifying heterozygotes, but does not propose extending this screening to other family members. A family that has a child affected by one of these syndromes is a marker for an at-risk group. In this case extending screning to close relatives (grandparents, siblings, aunts and uncles, and cousins) may identify individuals affected by the disease or couples at risk before marriage and reproduction and serve as the basis for programs providing genetic evaluation and epidemiological control of hemoglobin diseases that are relatively common in the Brazilian population.

Molecular variations linked to the grouping of beta- and alpha-globin genes in neonatal patients with sickle cell disease in the State of Pernambuco, Brazil.

Various factors have been described as phenotypic modulators of sickle cell disease, such as levels of fetal hemoglobin (Hb F), presence of alpha-thalassemia (thal), and haplotypes of the beta-globin genes. In order to characterize and determine the frequency of the betaS and betaC mutations and the prevalence of -alpha3.7-thal, 74 patients with sickle cell disease detected during neonatal screening in the State of Pernambuco, Brazil, were studied. The haplotypes of the beta gene and -alpha3.7-thal were determined using polymerase chain reaction (PCR), and specific restriction endonucleases were used to establish the polymorphic sites of the haplotypes. The results showed the high frequency of the Central African Republic (CAR) or Bantu haplotype in the State of Pernambuco, Brazil. The low frequency of the Benin haplotype recorded in this study, in comparison with other states in northeast Brazil, suggests the diversity of origins of Afro-Brazilians in this region.

Screening of diseases transmissible by blood in recipients prior to transfusion at a university hospital in the northeast of Brazil / Triagem de doenças transmissíveis por sangue em receptores de um hospital universitário no nordeste do Brasil, antes da transfusão

The Brazilian Ministry of Health has made tests for HIV1 and HIV2, HTLV I and HTLV II, HCV, HBV, T. cruzi, T. pallidum and Plasmodium in endemic areas, mandatory for all blood collection bags used in the country. However, blood-borne infectious diseases are not investigated in blood recipients before transfusion. For this study, a serological evaluation of recipients before transfusion was carried out. Prior to transfusion, serum samples from 159 blood recipients were analyzed using the same tests used in the serological screening of blood donors. The blood recipients were divided into three groups: Group 1 (G1), patients who had never received blood, Group 2 (G2), patients who had received multiple transfusions and Group 3 (G3) one-off recipients. SPSS v.8 was used for statistical analysis. Values of p<0.05 were taken to be significant. The results showed that 62 blood recipients tested positively for one or more blood-borne infectious diseases. In addition, several recipients were unaware of their serological status before the transfusion. The identification of blood-borne infectious diseases in recipients before transfusion could avoid the State being held responsible by recipients who were unaware that they were carriers of such diseases and only found out about their contamination after transfusion.

O Ministério da Saúde brasileiro determina a realização de testes sorológicos para HIV 1 e 2, HTLV I e II, HCV, HBV, T. cruzi, T. pallidum e Plasmodium nas áreas endêmicas, em todas as bolsas de coleta de sangue utilizadas no País. Entretanto, as doenças infecciosas transmissíveis através do sangue não são inves­tigadas nos receptores de sangue (RS) antes da transfusão. Neste estudo, realizamos uma avaliação sorológica dos RS anterior à transfusão. Amostras de soro de 159 RS foram analisadas aplicando-se os mesmos testes utilizados na triagem soro­lógica dos doadores de sangue. Os RS foram divididos em três grupos: Grupo 1 (G1), pacientes que nunca receberam sangue, Grupo 2 (G2), pacientes politransfundidos e Grupo 3 (G3) receptores eventuais. Para a análise estatística utilizou-se o pro­grama SPSS v.8. Valores de p<0,05 foram considerados signi­ficantes. Os resultados mostraram que 62 RS apresentaram positividade para uma ou mais doenças infecciosas trans­missíveis pelo sangue. Além disso, vários RS desconheciam seu estado sorológico anterior à transfusão. A identificação de doenças infecciosas transmissíveis pelo sangue em RS anterior à transfusão poderia evitar a responsabilidade do Estado pelos RS que desconheciam ser portadores de tais doenças e apenas tiveram conhecimento de sua contaminação após a transfusão.

Humoral and cellular immune responses in BALB/c and C57BL/6 mice immunized with cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens, in acute experimental Trypanosoma cruzi infection.

In previous studies, cytoplasmic repetitive antigen (CRA) and flagellar repetitive antigen (FRA) proteins induced specific humoral and cellular immune responses in susceptible and resistant mice in the absence of Trypanosoma cruzi infection with a significant induction of the Interferon-gamma (IFN-gamma) production in those animals. In this follow-up paper, the immunostimulatory and protective effects of these proteins were evaluated by immunizing with CRA or FRA antigens, BALB/c and C57BL/6 mice and challenging with a T. cruzi (Y strain). Both proteins induced humoral response with high levels of IgG isotypes as well as cellular immunity with high levels of IFN-gamma when compared to controls. However, the lymphocyte proliferative response was minimal. The survival rate at 30 days post-infection was significant in CRA (60%) or FRA (50%)--immunized BALB/c mice and CRA (83.3%)--immunized C57BL/6 mice. Taken as a whole these findings indicate that CRA and FRA are immunogenic and potentially important for protective immunity.

Mitogenic activity of Cratylia mollis lectin on human lymphocytes.

The mitogenic effect of Cratylia mollis seed lectin preparations containing two (Cramoll 1,4) or one molecular form (Cramoll 1) showed activity similar to the well known T-cell mitogen, concanavalin A (Con A). The effect on human lymphocytes was analyzed through a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Inhibition of lymphocyte proliferation with methyl-alpha-d-mannoside (both preparations) indicated that the mitogenic effect involved carbohydrate lectin binding sites.