Assessment of Galectin-3 Polymorphism in Subjects with Chronic Chagas Disease / Avaliação do Polimorfismo da Galectina-3 em Indivíduos com Doença de Chagas Crônica

AbstractBackground:Galectin-3, a β-galactoside binding lectin, has been described as a mediator of cardiac fibrosis in experimental studies and as a risk factor associated with cardiovascular events in subjects with heart failure. Previous studies have evaluated the genetic susceptibility to Chagas disease in humans, including the polymorphisms of cytokine genes, demonstrating correlations between the genetic polymorphism and cardiomyopathy development in the chronic phase. However, the relationship between the galectin-3 single nucleotide polymorphism (SNP) and phenotypic variations in Chagas disease has not been evaluated.Objective:The present study aimed to determine whether genetic polymorphisms of galectin-3 may predispose to the development of cardiac forms of Chagas disease.Methods:Fifty-five subjects with Chagas disease were enrolled in this observational study. Real-time polymerase chain reaction (PCR) was used for genotyping the variants rs4644 and rs4652 of the galectin-3 gene.Results:For the SNP rs4644, the relative risk for the cardiac form was not associated with the genotypes AA (OR = 0.79, p = 0.759), AC (OR = 4.38, p = 0.058), or CC (OR = 0.39, p = 0.127). Similarly, for the SNP rs4652, no association was found between the genotypes AA (OR = 0.64, p = 0.571), AC (OR = 2.85, p = 0.105), or CC (OR = 0.49, p = 0.227) and the cardiac form of the disease.Conclusion:Our results showed no association between the different genotypes for both SNPs of the galectin-3 gene and the cardiac form of Chagas disease. (Arq Bras Cardiol. 2015; [online].ahead print, PP.0-0).

ResumoFundamento:A galectina-3, uma lectina de ligação à β-galactosidase, foi descrita como um mediador de fibrose cardíaca em estudos experimentais e um fator de risco associado com eventos cardiovasculares em indivíduos com insuficiência cardíaca. Estudos prévios avaliaram a susceptibilidade genética para doença de Chagas em humanos, incluindo polimorfismos dos genes de citocinas, demonstrando correlações entre o polimorfismo genético e o desenvolvimento de cardiomiopatia na fase crônica. No entanto, a relação entre polimorfismos de nucleotídeo único (single nucleotide polymorphism, SNP) e variações fenotípicas na doença de Chagas ainda não foi avaliada.Objetivo:O presente estudo teve como objetivo determinar se os polimorfismos genéticos da galectina-3 podem predispor ao desenvolvimento de formas cardíacas da doença de Chagas.Métodos:Cinquenta e cinco indivíduos com doença de Chagas foram incluídos neste estudo observacional. A genotipagem das variantes rs4644 e rs4652 do gene da galectina-3 foi realizada por PCR (reação em cadeia de polimerase).Resultados:Para o SNP rs4644, não houve associação entre o risco relativo para a forma cardíaca e os genótipos AA (OR = 0,79, p = 0,759), AC (OR = 4,38, p = 0,058), ou CC (OR = 0,39, p = 0,127). Similarmente, para o SNP rs4652, não foi encontrada associação entre os genótipos AA (OR = 0,64, p = 0,571), AC (OR = 2,85, p = 0,105), ou CC (OR = 0,49, p = 0,227) e a forma cardíaca da doença.Conclusão:Nossos resultados não mostraram associação entre os diferentes genótipos para ambos SNPs do gene da galectina-3 e a forma cardíaca da doença de Chagas. (Arq Bras Cardiol. 2015; [online].ahead print, PP.0-0).

High degree of concordance between flow cytometry and geno2pheno methods for HIV-1 tropism determination in proviral DNA

Use of CCR5 antagonists requires previous viral tropism determination. The available methods have high cost, are time-consuming, or require highly trained personnel, and sophisticated equipment. We compared a flow cytometry-based tropism assay with geno2pheno method to determine HIV-1 tropism in AIDS patients, in Bahia, Brazil. We tested peripheral blood mononuclear cells of 102 AIDS patients under antiretroviral therapy by using a cytometry-based tropism assay and geno2pheno assay. Cellular membrane receptors were identified by using CXCR4, CCR5 and CD4 monoclonal antibodies, while detection of cytoplasmic mRNAs for gag and pol HIV regions was achieved by using a labeled probe. Genotypic identification of X4 and R5 tropic viruses was attempted by geno2pheno algorithm. There was a high degree of concordance between cytometry-based tropism assay and geno2pheno algorithm in determination of HIV-1 tropism. Cytometry-based tropism assay demonstrated higher sensitivity and specificity in comparison to geno2pheno, which was used as a gold-standard. One sample could not be amplified by geno2pheno method, but was classified as duotropic by cytometry-based tropism assay. We did not find any association between CD4+ count or plasma HIV-1 RNA viral load and tropism results. The overall performances of cytometry-based tropism assay and geno2pheno assay were almost identical in determination of HIV-1 tropism.

Myxovirus resistance, osteopontin and suppressor of cytokine signaling 3 polymorphisms predict hepatitis C virus therapy response in an admixed patient population: comparison with IL28B

OBJECTIVES: Suppressor of cytokine signaling 3, myxovirus resistance protein and osteopontin gene polymorphisms may influence the therapeutic response in patients with chronic hepatitis C, and an association with IL28 might increase the power to predict sustained virologic response. Our aims were to evaluate the association between myxovirus resistance protein, osteopontin and suppressor of cytokine signaling 3 gene polymorphisms in combination with IL28B and to assess the therapy response in hepatitis C patients treated with pegylated-interferon plus ribavirin. METHOD: Myxovirus resistance protein, osteopontin, suppressor of cytokine signaling 3 and IL28B polymorphisms were analyzed by PCR-restriction fragment length polymorphism, direct sequencing and real-time PCR. Ancestry was determined using genetic markers. RESULTS: We analyzed 181 individuals, including 52 who were sustained virologic responders. The protective genotype frequencies among the sustained virologic response group were as follows: the G/G suppressor of cytokine signaling 3 (rs4969170) (62.2%); T/T osteopontin (rs2853744) (60%); T/T osteopontin (rs11730582) (64.3%); and the G/T myxovirus resistance protein (rs2071430) genotype (54%). The patients who had ≥3 of the protective genotypes from the myxovirus resistance protein, the suppressor of cytokine signaling 3 and osteopontin had a greater than 90% probability of achieving a sustained response (p<0.0001). The C/C IL28B genotype was present in 58.8% of the subjects in this group. The sustained virological response rates increased to 85.7% and 91.7% by analyzing C/C IL28B with the T/T osteopontin genotype at rs11730582 and the G/G suppressor of cytokine signaling 3 genotype, respectively. Genetic ancestry analysis revealed an admixed population. CONCLUSION: Hepatitis C genotype 1 patients who were responders to interferon-based therapy had a high frequency of multiple protective polymorphisms in the myxovirus ...

Establishing th reference range for t lymphocyes subpopulations in adults andd children from Brazil / Estabelecimento de valores de referencias para subpopulacoes de linfocitos T em adultos e criancas no Brasil

SUMMARY In Brazil, the existing reference values for T-lymphocytes subsets are based on data originated in other countries. There is no local information on normal variation for these parameters in Brazilian adults and children. We evaluated the normal variation found in blood donors from five large Brazilian cities, in different regions, and in children living in Salvador, and Rio de Janeiro. All samples were processed by flow cytometry. The results were analyzed according to region, gender, and lifestyle of blood donors. A total of 641 adults (63% males), and 280 children (58% males) were involved in the study. The absolute CD3+, and CD4+ cells count were significantly higher for females (adults and children). Higher CD4+ cell count in adults was associated with smoking, while higher CD8+ count was found among female children. Higher counts, for all T-cells subsets, were detected in blood donors from southeast / south regions while those living in the northern region had the lowest values. Individuals from midwestern and northeastern regions had an intermediate count for all these cells subsets. However, these differences did not reach statistical significance. In Brazil, gender and smoking, were the main determinants of differences in T-lymphocytes reference values. .

RESUMO Os valores de referências de linfócitos T existentes no Brasil são baseados em dados originados de outros países. Não existem dados locais da variação normal para estes parâmetros em adultos e crianças brasileiras. Avaliamos a variação normal encontrada em doadores de sangue de cinco grandes cidades brasileiras em diferentes regiões e em crianças residentes em Salvador e Rio de Janeiro. Todas as amostras foram processadas por citometria de fluxo. Os resultados foram analisados de acordo com região, gênero e estilo de vida dos doadores. Um total de 641 adultos (63% homens) e 280 crianças (58% meninos) participaram do estudo. Valores absolutos de CD3+ e CD4+ foram significantemente maiores no gênero feminino (adultos e crianças). Maiores valores de CD4+ em adultos foram associados com tabagismo, enquanto que maiores valores de CD8+ foram encontrados entre crianças do sexo feminino. Adultos das regiões sul e sudeste apresentaram maiores valores absolutos para todas as células T enquanto que adultos da região norte, apresentaram menores valores. Indivíduos residentes no nordeste e centro-oeste obtiveram contagens intermediárias para todas as populações de células T. Entretanto, estas diferenças entre as regiões, não demonstraram diferença estatística. No Brasil, gênero e tabagismo foram os principais determinantes para diferenças em valores de referências de linfócitos T. .

Evaluating total lymphocyte counts as a substitute for CD4 counts in the follow up of AIDS patients

This study evaluated total lymphocyte count (TLC) as a substitute marker for CD4+ cell counts to identify patients who need prophylaxis against opportunistic infection (CD4 < 200 cells/mm³) and patients with CD4 < 350 cells/mm³ (Brazilian threshold value of CD4 count to define AIDS). We evaluated TLC and CD4+ cells count of 1,174 HIV-infected patients, in Salvador, Brazil, from May 2003 to September 2004. CD4+ cell counts were performed by flow cytometry, and TLC was measured with an automated hematological counter. The mean CD4 count was 430 cells/mm³ (range: 4 to 2,531 cells/mm³). Mean TLC was 1,900 cells/mm³ (range: 300 to 6,200 cells/mm³). Using a threshold value of 1,000 cells/mm³ for TLC, the positive predictive value (PPV) was 77 percent for CD4 < 200 cells/mm³, but the sensitivity was only 29 percent, while the negative predictive value (NPV) was 88 percent, with 98 percent specificity. Similar findings were observed for CD4 count < 350. Using the same threshold value of 1,000 cells/mm³ for TLC, sensitivity was 14 percent, and specificity 99 percent (PPV= 94 percent; NPV=62 percent). In 70/1,510 (5 percent) of the samples the sum of CD4 and CD8 cell counts was greater than the TLC and in 27 percent (419/1,510) this sum was below 65 percent of the TLC. TLC has a high specificity to identify patients for prophylaxis, but a quite low sensitivity. It is not useful as an alternative to CD4+ T-cell counts as a marker in HIV-infected patients.