Clinical-Epidemiological Characteristics and IFITM-3 (rs12252) Variant Involvement in HIV-1 Mother-to-Children Transmission Susceptibility in a Brazilian Population.

Mother-to-children transmission (MTCT) is the main infection route for HIV-1 in children, and may occur during pregnancy, delivery, and/or postpartum. It is a multifactorial phenomenon, where genetic variants play an important role. This study aims at analyzing the influence of clinical epidemiological characteristics and a variant (rs12252) in interferon-induced transmembrane protein 3 (IFITM-3), a gene encoding an important viral restriction factor, on the susceptibility to HIV-1 mother-to-children transmission (MTCT). A case-control study was performed on 209 HIV-1-infected mothers and their exposed infected (87) and uninfected (122) children from Pernambuco, Brazil. Clinical-epidemiological characteristics are significantly associated with MTCT susceptibility. Transmitter mothers have a significantly lower age at delivery, late diagnosis, deficiency in ART use (pregnancy and delivery), and detectable viral load in the third trimester of pregnancy compared with non-transmitter mothers. Infected children show late diagnosis, vaginal delivery frequency, and tend to breastfeed, differing significantly from uninfected children. The IFITM-3 rs12252-C allele and TC/CC genotypes (dominant model) are significantly more frequent among infected than uninfected children, but the statistical significance does not remain when adjusted for clinical factors. No significant differences are observed between transmitter and non-transmitter mothers in relation to the IFITM-3 variant.

Brief Report: Polymorphisms in TNF-α/TNFR1 Pathway Genes Are Associated With CD4+ T-Cell Recovery in HIV-1-Infected Individuals on Antiretroviral Therapy.

BACKGROUND: Antiretroviral therapy (ART) is an important hallmark of HIV-1 treatment, enabling viral load suppression to undetectable levels and CD4+ T-cell recovery. However, some individuals do not recover the CD4+ T-cell count to normal levels, despite viral suppression. We hypothesize that variation in genes involved in extrinsic apoptosis pathways may influence interindividual immune recovery during ART. METHODS: We assessed clinical-epidemiological variables and the allelic/genotypic distribution of functional single nucleotide polymorphisms in genes involved in extrinsic apoptosis pathways (TNFRSF1A: rs1800692 and rs767455; TNFAIP3: rs2270926; NFKBIA: rs8904; and TNF-α: rs1800629) and their relationship with immune recovery in ART-treated (1 year) HIV-1-infected individuals. We enrolled 155 HIV-1-infected individuals, with 102 individuals showing immunological success and 53 with immunological failure. RESULTS: Through univariate analysis, we observed that the male sex (60.4%, P = 0.002) showed a higher median of age at treatment onset (34.8 years, P = 0.034) and higher time until virological suppression (6 months, P = 0.035), both risk factors for immune failure. Survival analysis revealed that individuals who started ART treatment with CD4+ T-cell count <200 cells/mm3 took a longer time to immunological recovery (median time = 27 months, P = 0.029). ART containing zidovudine also was associated with immune recovery in univariate e multivariate analysis. Variants in TNFRSF1A (rs767455: T and TT; rs1800692-rs767455: T-T combination) and NFKBIA (rs8904: A) genes were associated with immune failure, whereas NFKBIA (rs8904: GA) and TNF-α (rs1800629: GA) were with CD4+ T-cell recovery. CONCLUSIONS: Clinical-epidemiological variants in genes involved in extrinsic apoptosis pathways might influence the CD4+ T-cell immune recovery.

Association of SNPs in HLA-C and ZNRD1 Genes With HIV-1 Mother-to-Child Transmission in Zambia Population.

BACKGROUND: Human leukocyte antigen C (HLA-C) and Zinc ribbon domain containing 1 (ZNRD1) are considered HIV-1 restriction factors and are expressed in the placenta. Variations in HLA-C and ZNRD1 genes are known to influence HIV-1 infection, including viral replication and progression to AIDS. Little is known about the role of variants in these genes in HIV-1 mother-to-child transmission. METHODS: We evaluated the distribution of HLA-C (rs10484554, rs9264942) and ZNRD1 (rs8321, rs3869068) variants in a Zambian population composed of 333 children born to HIV-1+ mothers (248 HIV-1 noninfected/85 HIV-1 infected) and 97 HIV-1+ mothers. RESULTS: Genotypic distribution of HLA-C and ZNRD1 were in Hardy-Weinberg equilibrium, except for HLA-C rs10484554 in both groups. In mothers, no significant differences were observed in their allele and genotypic distributions for both genes. The T and TT variants (rs10484554-HLA-C) were significantly more frequent among HIV-1+ children, specifically those who acquired the infection in utero (IU) and intrapartum (IP). For ZNRD1, the T allele (rs3869068) was more frequent in HIV-1- children, showing significant differences in relation to those infected via IP and postpartum (PP). The CT and TT genotypes were significantly more frequent in HIV-1- children. CONCLUSIONS: Variations in HLA-C (T and TT-rs10484554) and ZNRD1 (T and CT/TT-rs3869068) can increase and decrease the susceptibility to HIV-1 infection via mother-to-child transmission, respectively. Further studies are encouraged focusing on a greater number of variants and sample size, with functional validation and in other populations.

Evaluation of DEFB1 polymorphisms in individuals with chronic periodontitis and diabetes mellitus type 2 in a population of northeastern Brazil.

AIMS: The role of genetic variations in genes related to innate response, as ß-defensin-1 (DEFB1), in the context of chronic periodontitis (CP) and diabetes mellitus type 2 (DM2), is still not clear. The present study evaluates the distribution of DEFB1 single nucleotide polymorphisms (SNPs) 5'-untranslated (5'UTR) region and its relation with the CP in DM2 individuals in northeastern Brazilians. METHODS: Two hundred and eighty individuals participated in the study, being 116 DM2+CP, 95 CP, and 69 healthy individuals. Three known DEFB1 functional SNPs [-52 G > A (rs1799946), -44 C > G (rs1800972), -20 G > A (rs11362)] were genotyped with allele-specific assays. RESULTS: Association was found for the DEFB1 -20 G > A SNP. The G allele, the GA and GG genotypes were significantly (P < 0.05) more frequent in the DM2+CP (59.5%, 50%, and 34.5%, respectively) and CP (61%, 44.2%, and 38.9%, respectively) than in healthy individuals (26.8%, 36.2%, and 8.7%, respectively). The GCG and ACG combinations (-52, -44, -20) were significantly more frequent among DM2+CP and CP than in the healthy individuals. CONCLUSION: The results indicate that genetic variations of DEFB1 gene (SNP-20: G allele and GA and GG genotypes) and the DEFB1 5'UTR haplotypes (GCG and ACG) may be associated with a susceptibility to CP in DM2 individuals as well as CP individuals without DM2.

HLA-C Single Nucleotide Polymorphism Associated with Increased Viral Load Level in HIV-1 Infected Individuals from Northeast Brazil.

BACKGROUND: Genetic variations in Human leukocyte antigen C (HLA-C), Zinc ribbon domain containing 1 (ZNRD1) and its antisense RNA (ZNRD1-AS1) genes are known to influence the HIV-1 replication and disease progression. OBJECTIVE AND METHOD: We evaluated the distribution of HLA-C (rs10484554, rs9264942) and ZNRD1 (rs8321) and ZNRD1-AS1 (rs3869068), single nucleotide polymorphisms (SNPs) in 266 HIV-1-infected and 223 unexposed-uninfected individuals from Northeast Brazil and their relation to HIV-1 infection, CD4 T cells count and viral load pre-treatment. RESULTS: HLA-C SNPs were in Linkage Disequilibrium (D'=0.84), constituting four possible haplotypes. Our results showed that HLA-C, ZNRD1 and ZNRD1-AS1 SNPs as well as HLA-C haplotypes frequencies were not significantly different between HIV-1-infected and unexposed-uninfected individuals. In addition, we analyzed HLA-C and ZNRD-1 and ZNRD1-AS1 SNPs considering CD4+ T cell counts and viral load before the antiretroviral treatment. Individuals carrying HLA-C rs9264942 TT genotype showed a significant increased level of HIV-1 viral load pre-treatment, in comparison with individuals carrying the CC genotype (p-value = 0.0092). Finally, we stratified our findings according to CCR5Δ32 allele presence along with the studied SNPs: no statistically significant influence over viral load pre-treatment has been found. CONCLUSION: The association between HLA-C rs9264942 SNP and viral load prior treatment in an admixed population from North East Brazil was in agreement with findings from previous studies obtained on different ethnic groups; however more studies should be conducted in order to clarify how HLA-C impair the HIV-1 replication.

TRIM5 gene polymorphisms in HIV-1-infected patients and healthy controls from Northeastern Brazil.

Humans show heterogeneity in vulnerability to HIV-1 infection, partially under control of genes involved in host immunity and virus replication. TRIM5α protein has restriction activity against replication of many retroviruses. Human TRIM5 gene single nucleotide polymorphisms have been reported as involved in susceptibility to HIV-1 infection. We recruited 213 HIV-1-positive patients and 234 healthy uninfected controls from Northeast Brazil; two non-synonymous variants at exon 2, rs3740996 (H43Y) and rs10838525 (R136Q), and one regulatory polymorphism (rs16934386) at 5'UTR region of TRIM5 were analyzed. The R136Q variation presented significant differences between HIV-1-positive patients and healthy controls. The 136Q allele and the 136QQ genotype were more frequent in healthy controls (32.7 and 10.2 %, respectively) than in HIV-1-positive patients (136Q allele: 24.4 %; OR 0.66; CI 95 % 0.49-0.90; p value = 0.008/136QQ genotype: 4.2 %; OR 0.33; CI 95 % 0.13-0.79, p = 0.008) also after adjusting for age and sex. We also stratified our findings according to the presence of CCR5Δ32 variation, but the results remained the same. We observed that rs10838525 (R136Q) and rs3740996 (H43Y) were in linkage disequilibrium (D' = 0.71), forming four possible haplotypes. The H43-136Q haplotype was significantly more frequent in healthy controls (28.2 %) than in HIV-positive patients (21.4 %; OR 0.69; CI 95 % 0.50-0.96; p = 0.022). An increased frequency of allele (136Q) and genotype (136QQ) of the non-synonymous rs10838525 (R136Q) variant and the haplotype (43H-136Q) was observed among healthy controls individuals. Being aware of the limitation of this study (unavailability of exposed but uninfected individuals), we hypothesize a potential role for TRIM5 variations in the protection against HIV-1 infection.

DEFB1 gene polymorphisms and tuberculosis in a Northeastern Brazilian population.

ß-Defensin-1, an antimicrobial peptide encoded by the DEFB1 gene, is known to play an important role in lung mucosal immunity. In our association study we analyzed three DEFB1 functional polymorphisms -52G>A (rs1799946), -44C>G (rs1800972) and -20G>A (rs11362) in 92 tuberculosis patients and 286 healthy controls, both from Northeast Brazil: no association was found between the studied DEFB1 polymorphisms and the disease. However we cannot exclude that this lack of association could be due to the low number of subjects analyzed, as suggested by the low statistical power achieved for the three analyzed SNPs (values between 0.16 and 0.50).

Chemokines SNPs in HIV-1+ Patients and Healthy Controls from Northeast Brazil: Association with Protection against HIV-1 Infection.

BACKGROUND: HIV-1 virus is known to infect the host mainly through CD4+ T-lymphocyte cells, by interactions among the viral envelope proteins, CD4 receptor and HIV-1 coreceptors, such as chemokines receptors. Variations in the genes encoding HIV-1 coreceptors and their natural ligands have been shown to modify HIV-1 infection susceptibility and disease progression. METHODS AND RESULTS: We analysed the distribution of SNPs in chemokines (CCL3, CCL4, CCL5, CXCL12) and chemokine receptor (CXCR6) genes, in 268 HIV-1 infected patients (HIV-1+) and 221 healthy controls from Northeast Brazil, and their possible connection with susceptibility to HIV-1 infection. The genotyping were performed through allele specific fluorogenic probes using real time PCR. We observed that the T alleles and AT genotype of rs1719153 CCL4 SNP were more frequent in healthy controls (19.8% and 35.0%, respectively) than in HIV-1+ patients (T allele: 14.1%; OR=0.67; 95%CI=0.47-0.95; p-value=0.020; and AT genotype: 24.4%; OR=0.61; 95%CI=0.40- 0.93; p-value=0.021) after correcting for age and sex. The rs1719134 (CCL3) and rs1719153 (CCL4) SNPs presented linkage disequilibrium (D'=0.83). The AT haplotype frequency was increased in healthy controls (17.3%) in relation to HIV-1+ patients (11.0%; OR=0.62; 95%CI=0.42-0.93; p-value=0.020). CONCLUSION: Since our results revealed an increased frequency of alleles and genotypes of CCL3/CCL4 SNPs and haplotype (CCL3-CCL4) among healthy controls, we suggest that these variations might have a potential protective role against HIV-1 infection.