Rare genetic variants of NLRP12 in Admixed Latino-American Children with SARS-CoV-2-related Multisystem Inflammatory Syndrome.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare, potentially fatal complication of SARS-CoV-2 infection. Genetic defects in inflammation-related pathways have been linked to MIS-C, but additional research is needed, especially in diverse ethnic groups. The present study aimed to identify genetic variants underlying MIS-C in Brazilian patients. Whole-exome sequencing was performed, focusing on genes involved in the host immune response to SARS-CoV-2. Functional assays assessed the impact of selected variants on NF-κB signaling. Nine rare, potentially deleterious variants were found in eight of 21 patients, located in IL17RC, IFNA10, or NLRP12 genes. Unlike the wild-type NLRP12 protein, which inhibits NF-κB activation in HEK 293T cells, the mutant NLRP12 proteins have significantly reduced inhibitory properties. In conclusion, our results indicate that rare autosomal variants in immune-related genes may underlie MIS-C, highlighting the potential role of NLRP12 in its predisposition. These findings provide new insights for the appropriate management of MIS-C.

Methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF) polymorphisms in Brazilian patients with Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

OBJECTIVE: The folate pathway is involved in hepatic carcinogenesis and angiogenesis. Polymorphisms in genes related to such processes, including methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF)] may play an important role in the development of hepatocellular carcinoma (HCC). The objective of this study was to evaluate MTHFR and VEGF polymorphisms in Brazilian patients with hepatitis C virus (HCV)-related HCC. METHODS: A total of 119 patients diagnosed with confirmed HCC and HCV were included in the study. SNP genotyping assays were performed using real-time PCR. VEGFA (rs2010963, rs3025039, and rs833061) and MTHFRC677T (rs1801133, rs1801131) polymorphisms were evaluated. RESULTS: The C alleles of MTHFR (rs1801131) and VEGF (rs2010963) were associated with protection against the development of multinodular HCC, while the T allele of MTHFR (rs1801133) was associated with a higher risk of multinodular presentation [p=0.04 OR 1.835 CI (1.022-3.297)]. Multivariate analysis revealed that the GG/GC genotypes of VEGF rs2010963 were independently associated with multinodular tumors at diagnosis (p=0.013; OR 4.78 CI (1.38-16.67)]. CONCLUSION: Our results suggest that these polymorphisms may increase the risk of rapid tumor progression in patients with HCV infection. This subgroup of patients with HCC and who present polymorphism is more likely to be diagnosed with multinodular disease and not be amenable to receiving curative treatments. These data must be validated in larger cohorts, and the screening intervals can be customized based on genetic history.

Methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF) polymorphisms in Brazilian patients with Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC)

OBJECTIVE: The folate pathway is involved in hepatic carcinogenesis and angiogenesis. Polymorphisms in genes related to such processes, including methylene tetrahydrofolate reductase (MTHFR) and vascular endothelial growth factor (VEGF)] may play an important role in the development of hepatocellular carcinoma (HCC). The objective of this study was to evaluate MTHFR and VEGF polymorphisms in Brazilian patients with hepatitis C virus (HCV)-related HCC. METHODS: A total of 119 patients diagnosed with confirmed HCC and HCV were included in the study. SNP genotyping assays were performed using real-time PCR. VEGFA (rs2010963, rs3025039, and rs833061) and MTHFRC677T (rs1801133, rs1801131) polymorphisms were evaluated. RESULTS: The C alleles of MTHFR (rs1801131) and VEGF (rs2010963) were associated with protection against the development of multinodular HCC, while the T allele of MTHFR (rs1801133) was associated with a higher risk of multinodular presentation [p=0.04 OR 1.835 CI (1.022-3.297)]. Multivariate analysis revealed that the GG/GC genotypes of VEGF rs2010963 were independently associated with multinodular tumors at diagnosis (p=0.013; OR 4.78 CI (1.38-16.67)]. CONCLUSION: Our results suggest that these polymorphisms may increase the risk of rapid tumor progression in patients with HCV infection. This subgroup of patients with HCC and who present polymorphism is more likely to be diagnosed with multinodular disease and not be amenable to receiving curative treatments. These data must be validated in larger cohorts, and the screening intervals can be customized based on genetic history.

Molecular profile of mannan-binding lectin in hepatitis C patients with MBL gene polymorphisms by a modified mannan-coated nitrocellulose assay.

The aim of this study was to develop an assay to analyze the serum profile of Mannose-binding lectin (MBL) through a simple and "in-house" method (called "dot-N-man"). Furthermore, the study attempted to associate molecular masses of MBL to the profile of MBL gene polymorphisms in patients with hepatitis C. Heterogeneity in molecular masses of MBL is due to the impairment of oligomers formation, which is linked to genetic polymorphisms in the MBL gene. Individuals with AA genotype (wild-type) produce high-molecular-mass proteins, whereas AO and OO individuals produce intermediate and low-molecular-mass proteins, respectively. Sera of thirty patients carrying the hepatitis C virus (HCV) were investigated using MBL binding assay with mannan-coated nitrocellulose (dot-N-man). Purified MBL was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Dot-N-Man assay yielded MBL with molecular masses ranging between 55 and 320 kDa, comparable to low and high molecular mass forms of MBL. Nonreducing SDS-PAGE showed high molecular mass bands in all AA individuals while bands of 270 and 205 kDa were observed in sera for a number of patients with AO and OO genotypes, respectively. Immunoblotting confirmed the MBL samples obtained from the dot-N-man. These results provide new insights to understand the MBL molecular forms profile in patients infected with HCV- which could be useful in future investigations on the influence of the MBL structure/genotype on both the progression of infection and the response to hepatitis C therapy.

IL17A Polymorphism Is Not Associated with Human T-Lymphotropic Virus 1-Associated Myelopathy/Tropical Spastic Paraparesis.

The human T-lymphotropic virus 1 (HTLV-1) is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The present study investigated the association between the rs2275913 polymorphism in the IL17A gene and the development of HAM/TSP. Peripheral blood samples were collected from 116 patients (29 symptomatic patients with HAM/TSP and 87 asymptomatic) with a positive diagnosis of HTLV-1. The single nucleotide polymorphism genotyping was carried out by real time PCR using TaqMan probes. In addition, serum levels of IL-2, IFN-γ, TNF-α, IL-4, IL-6, IL-10, and IL-17 were measured in 64 infected individuals from the study (47 asymptomatic and 17 HAM/TSP), using cytometric bead array technique. No significant differences were found in genotypic and allelic frequencies between the groups. Analysis of cytokine levels showed highest concentrations of IFN-γ and TNF-α in HAM/TSP patients. The results of the present study, therefore, suggest a lack of association between the rs2275913 polymorphism in the IL17A gene and the presence of HAM/TSP.

Association of Catalase and Glutathione Peroxidase 1 Polymorphisms with Chronic Hepatitis C Outcome.

The hepatic damage caused by hepatitis C virus (HCV) infection is associated with the host immune response and viral regulatory factors. Catalase (CAT) and glutathione peroxidase 1 (GPX1) are antioxidant enzymes located in the peroxisomes and mitochondria, respectively, and are responsible for the control of intracellular hydrogen peroxide levels. Polymorphisms in CAT (C-262T) and GPX1 (Pro198Leu) are correlated with serum levels and enzyme activity. This study aimed to investigate the association of genetic polymorphisms of CAT C-262T (rs1001179) and GPX1 Pro198Leu (rs1050450) with different stages of liver fibrosis and development of hepatocellular carcinoma (HCC). This study included 445 patients with chronic hepatitis C, of whom 139 patients had mild fibrosis (F0-F1), 200 had moderate/severe fibrosis (F2-F4), and 106 had HCC. Genotyping of SNPs was performed by real-time PCR using TaqMan probes. The Pro/Pro genotype of GPX1 was significantly associated with fibrosis severity, HCC, Child Pugh score, and BCLC staging. Additionally, patients carrying both CT+TT genotypes in the CAT gene and the Pro/Pro genotype in the GPX1 gene had higher risk for developing moderate/severe fibrosis or HCC (p = 0.009, OR 2.40 and p = 0.002, OR 3.56, respectively). CAT and GPX1 polymorphisms may be implicated in the severity of liver fibrosis and HCC caused by HCV.

High frequency of variant alleles of the mannose-binding lectin 2 (MBL2) gene are associated with patients infected by hepatitis B virus.

Patients with hepatitis B virus (HBV) infection may develop severe chronic liver disease. Carriers of HBV have an increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Worldwide an estimated 350 million people are infected with HBV, and 15-40% will develop serious sequelae in their lifetime. In our study we investigated the association of single nucleotide polymorphisms (SNPs) in the first exon and promoter region of the mannose-binding lectin gene 2 (MBL2) situated on chromosome 10, with susceptibility to HBV infection. One-hundred and two patients infected with HBV were included in this study, and 232 uninfected individuals were used as healthy controls. Genotyping of the first exon (alleles A/O) was performed using a melting temperature assay. Genotyping of the promoter region (-550 H/L; -221 Y/X) was performed using the Taqman PCR technique. In the HBV-infected group we found a significantly increased frequency of haplotypes associated with low serum MBL. Our findings may indicate that MBL has a protective role against HBV infection in the studied population.