An interesting finding in the epidemiology of human immunodeficiency virus (HIV) infection is that certain mutations in genes coding for chemokine receptors and their ligands may confer resistance to HIV-1 infection and/or AIDS progression. The mutations most frequently studied are the CCR5-delta32, CCR2-64I and SDF1-3'A. We examined the frequency of the above polymorphisms within the Cretan population, evaluating their contribution to a protective genetic background against HIV infection and progression. Two hundred blood samples were recruited at random among prospective blood donors from Crete. Genotyping was initially performed by polymerase chain reaction (PCR) analysis. CCR2 and SDF-1 PCR-amplified genomic regions were further subjected to restriction fragment length polymorphism (RFLP) analysis for genotype determination. The CCR5-delta32 allele frequency among our study group was 3.25%, although no respective homozygous samples were detected. The screening for the CCR2-64I polymorphism yielded 39 heterozygous (19.5%) and 4 homozygous (2%) subjects, revealing a CCR2-64I allele frequency of 11.75%. Among our 200 PCR-RFLP analysed samples, 73 (36.5%) were found heterozygous and 23 (11.5%) homozygous for the SDF1-3'A mutant variant. The allele frequency of the above polymorphism reached 29.75%. The frequency of the CCR5-delta32 allele among our study population seems to be remarkably lower compared to previously reported frequencies in other Caucasian groups. However, the SDF1-3'A allele frequency shows significantly higher distribution profiles within our study group compared to those observed in other Caucasian-European populations. The indicated difference could be attributed to the increased homogeneity of our population, which is well balanced and dispersed over a small geographical area. Since this polymorphism is related with delayed progression from HIV infection to AIDS, it could be used for prognostic genotyping in HIV infected Cretan individuals.
"Geographic distribution of CCR5 Delta-32 allele varies favoring that each region or population has a different genetic resistance profile to HIV-1 infection and epidemiology variation of HIV-1/AIDS . It has been difficult to establish if CCR5 Delta-32 allele confers resistance to infection at population level. "
[Show abstract][Hide abstract] ABSTRACT: C-C chemokine receptor type 5 (CCR5) is known for its role as a co-receptor for HIV-1 infection. Some individuals possess a 32 bp deletion, known as Delta-32 allele which has been reported to confer resistance to HIV-1 infection. In order to estimate the distribution of Delta-32 allele of CCR5 gene, 1034 mestizo individuals from the Northwest of Mexico, including 385 HIV-1-infected individuals, 472 healthy controls and 177 uninfected female sex workers; were examined by allele-specific PCR. There was no statistically significant difference in the frequency of Delta-32 allele between HIV-1 positive and healthy individuals (OR= 1.1, p= 0.6). However, we found a significantly reduced prevalence of CCR5 Delta-32 heterozygous genotype in female patients (OR= 0.084, 95% CI= 0.011 - 0.630, p= 0.002), as well as in allele frequency, compared to male patients. Furthermore, we observed an inverse relationship between allele frequency and the risk of HIV-1 transmission and AIDS progression among female healthy controls, sex workers and HIV-1 infected groups. Our findings support previous data showing Delta-32 as a genetic protective factor against HIV-1 infection in Mexican women, as well as in women from other populations.
Current HIV research 03/2014; 11(6). DOI:10.2174/1570162X11666140101120225 · 1.76 Impact Factor
"South Indians (1-3%), and ethnic population of Kashmir (3-4%). A similar study conducted from the Island of Crete, Greece showed allele frequency of 3.25%, with a 95% confidence interval (CI) for conformity with Hardy-Weinberg equilibrium of 0.74-5.7%. The CCR5-∆32 polymorphism is found all across Europe at different allele frequencies, with a North to South decreasing gradient and lower distribution in the regions of Southeast Mediterranean. "
[Show abstract][Hide abstract] ABSTRACT: Genetic relationships among the ethnic groups are not uniform across the geographical region. Considering this assumption, we analyzed the frequency of the CC-chemokine receptor-5 (CCR5)-∆32 allele of the CCR5 chemokine receptor, which is considered a Caucasian marker, in Bhil tribal and Brahmin caste sample sets from the population.
108 blood samples were collected from 6 tribe's populations and a caste population from the district of Vidarbha region.
The presence of low frequencies of CCR5-Δ32 in an individual of Bhil tribe (0.034, χ(2) value 0.017) in the present study implies that these communities may have a better resistance toward human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) than the other studied tribe sample, as non-show such mutation.
The marginal presence of the allele seen in the studied tribal population could be due to gene flow from the people of European descent. However, lack of the homozygous CCR5-Δ32 mutation and the low prevalence of heterozygous CCR5-Δ32 mutations suggest that the Indians are highly susceptible to HIV/AIDS, and this correlates with the highest number of HIV/AIDS infected individuals in India.
Indian Journal of Human Genetics 03/2013; 19(1):65-70. DOI:10.4103/0971-6866.112894
"PTPRC MAF 0.15 in Crete vs. 0.12, AFF3 0.53 vs. 0.50, CD226 0.44 vs. 0.48, STAT4 0.24 vs. 0.25 [7,9,10]. These findings emphasize on the lack of any substantial genetic differences between Cretan and other European populations although various previous reports reported some distinct population-specific differences [26–28]. The two RA susceptibility loci analyzed, TRAF1/C5 and STAT4, may also need further investigation. "
[Show abstract][Hide abstract] ABSTRACT: Treatment strategies blocking tumor necrosis factor (anti-TNF) have proven very successful in patients with rheumatoid arthritis (RA), showing beneficial effects in approximately 50-60% of the patients. However, a significant subset of patients does not respond to anti-TNF agents, for reasons that are still unknown. The aim of this study was to validate five single nucleotide polymorphisms (SNPs) of PTPRC, CD226, AFF3, MyD88 and CHUK gene loci that have previously been reported to predict anti-TNF outcome. In addition, two markers of RA susceptibility, namely TRAF1/C5 and STAT4 were assessed, in a cohort of anti-TNF-treated RA patients, from the homogeneous Greek island of Crete, Greece. The RA patient cohort consisted of 183 patients treated with either of 3 anti-TNF biologic agents (infliximab, adalimumab and etanercept) from the Clinic of Rheumatology of the University Hospital of Crete. The SNPs were genotyped by TaqMan assays or following the Restriction Fragments Length Polymorphisms (RFLPs) approach. Disease activity score in 28 joints (DAS28) at baseline and after 6 months were available for all patients and analysis of good versus poor response at 6 months was performed for each SNP. None of the 7 genetic markers correlated with treatment response. We conclude that the gene polymorphisms under investigation are not strongly predictive of anti-TNF response in RA patients from Greece.
PLoS ONE 02/2013; 8(9):e74375. DOI:10.1371/journal.pone.0074375 · 3.23 Impact Factor
Greicy Kelly Gouveia Dias Bittencourt, Maria Adelaide Silva Paredes Moreira, Lindiane Constâncio da Silva Meira, Maria Miriam Lima da Nóbrega, Jordana Almeida Nogueira, Antonia Oliveira Silva
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