CCR2-64I and CXCL12 3′A alleles confer a favorable prognosis to AIDS patients undergoing HAART therapy

CCR5∆32 and SDF1 3'A: Gene Variants, Expression and Influence on Biological Markers for the Clinical Progression to AIDS among HIV-1 Virus Controllers in a Mixed Population of the Amazon Region of Brazil

CCR5Δ32 and SDF1-3'A polymorphisms were investigated in a cohort of viremia controllers, without the use of therapy, along with their influence on CD4+ T lymphocytes (TLs), CD8+ TLs, and plasma viral load (VL). The samples were analyzed from 32 HIV-1-infected individuals classified as viremia controllers 1 and 2 and viremia non-controllers, from both sexes, mostly heterosexuals, paired with 300 individuals from a control group. CCR5∆32 polymorphism was identified by PCR amplification of a fragment of 189 bp for the wild-type allele and 157 bp for the allele with the ∆32 deletion. SDF1-3'A polymorphism was identified by PCR, followed by enzymatic digestion (restriction fragment length polymorphism) with the Msp I enzyme. The relative quantification of gene expression was performed by real-time PCR. The distribution of allele and genotype frequencies did not show significant differences between the groups. The gene expression of CCR5 and SDF1 was not different between the profiles of AIDS progression. There was no significant correlation between the progression markers (CD4+ TL/CD8+ TL and VL) and the CCR5∆32 polymorphism carrier status. The 3'A allele variant was associated with a marked loss of CD4+ TLs and a higher plasma VL. Neither CCR5∆32 nor SDF1-3'A was associated with viremia control or the controlling phenotype.

Factors Influencing Immune Restoration in People Living with HIV/AIDS

Introduction: Immune restoration is a key clinical aspect that is pursued in the care of human immunodeficiency virus (HIV)-infected patients. Despite effective antiretroviral treatment and undetectable viremia, immune recovery is often incomplete. Materials and methods: Data from 311 Caucasian patients were collected. SNP in CCR2(rs1799864), CX3CR1(rs3732378), HLAC-35(rs9264942), and CCR5(promoter, rs1799988); a 32bp deletion(Δ32) in CCR5; and HLA-B*5701 genotypes were correlated with clinical data and selected endpoints. Kaplan−Meier and Cox proportional hazards models were used to analyze the effects of genetic factors over time. Results: For HLA-B*5701, the effect on the CD4+/CD8+ >0.8 cell ratio was lost within 48 months (HR = 2.04, 95% CI: 1.04−4.03), and the effect on the CD4+ cell count >500 cells/µL was lost within 12 months (HR = 2.12, CI: 1.11−4.04). The effect of CCR2 GG on the CD4+/CD8+ >0.8 cell ratio was lost within 36 months (HR = 1.7, CI: 1.05−2.75). For CCR5 wt/Δ32, the effect on the CD4+/CD8+ >1.0 cell ratio was lost within 24 months (HR = 2.0, CI: 1.08−3.69), and the effect on the CD4+ >800 cells/µL cell count was lost within 18 months (HR = 1.98, CI: 1.14−4.73). Conclusions: Selected genetic polymorphisms, namely CCR2 GG and CCR5 Δ32, and the presence of the HLA-B*5701 allele positively influenced immune restoration in cART-treated patients with HIV/AIDS.

Clinical parameters, selected HLA and chemokine gene variants associated with late presentation into care of people living with HIV/AIDS

INTRODUCTION

Late presentation into care remains a significant problem in the diagnosis of HIV infection, and may negatively impact the Joint United Nations Program HIV/AIDS elimination targets. Host genetics affects the tempo of HIV disease progression and therefore may influence clinical status at care entry.

MATERIALS AND METHODS

Longitudinal data were collected for 863 Caucasian patients followed up at Pomeranian Medical University, Szczecin, Poland. Single nucleotide polymorphisms in CCR2 (rs1799864), CX3CR1 (rs3732378), HLAC-35 (rs9264942), CCR5 promoter (rs1799988) as well as 32 base pair CCR5 mutation and HLA-B*5701 genotypes were correlated with the clinical and immunologic patient status at care entry. Late presentation was defined as baseline CD4 lymphocyte count <350 cells/μL or history of AIDS-defining illness, while advanced HIV disease as baseline CD4 lymphocyte count <200 cells/μL or AIDS.

RESULTS

Of the analyzed gene variants, the CCR2 (rs1799864) GG genotype was more frequent among patients presenting for care with a CD4 lymphocyte count <200/μL (82.6% for GG homozygotes vs. 74.5% for allele A carriers, p = 0.01). The presence of the heterozygous wt/Δ32 genotype at the CCR5 gene was associated with a higher frequency of asymptomatic infection (18.9% for wt/Δ32 heterozygotes vs. 12% for wt/wt homozygotes, p = 0.03). As expected, this association was also observed among late presenters compared to patients presenting for care earlier (13.7% vs. 19,7%, respectively, p = 0.04). Finally, HLA-B*5701 was less common among late presenters (5%) compared to patients who entered care early (9.6%, p = 0.01) or patients with advanced HIV disease (8.9% vs. 5.2%, p = 0.02).

CONCLUSIONS

Late presentation was associated with the GG homozygous genotype at the CCR2 rs1799864 SNP, while both the HLA-B*5701 variant and the CCR5 wt/Δ32 were associated with more favorable clinical profile at care entry.

Genetic variation in CCR2 and CXCL12 genes impacts on CD4 restoration in patients initiating cART with advanced immunesupression

OBJECTIVE

We investigated the association of genetic polymorphisms in chemokine and chemokine receptor genes with poor immunological recovery in HIV patients starting combined antiretroviral therapy (cART) with low CD4 T-cell counts.

METHODS

A case-control study was conducted in 412 HIV-infected patients starting cART with CD4 T-cell count <200 cells/μL and successful viral control for two years. CD4 count increase below 200 cells/μL after two years on cART was used to define INR (immunological non-responder) patients. Polymorphisms in CXCL12, CCL5 and CCR2 genes were genotyped using sequenom's MassARRAY platform.

RESULTS

Thirty two percent (134/412) of patients were classified as INR. After adjusting by age, route of HIV infection, length of infection before cART and viral hepatitis coinfection, CCR2 rs1799864-AG genotype was significantly associated with INR status (OR [95% CI]: 1.80 [1.04-3.11]; p = 0.04), and CXCL12 rs1801157-TT genotype showed a trend (OR [95% CI]: 2.47 [0.96-6.35]; p = 0.06).

CONCLUSIONS

CCR2 rs1799864-AG or CXCL12 rs1801157-TT genotypes influence on the probability of poor CD4 recovery in the population of HIV patients starting cART with low CD4 counts. Genotyping of these polymorphisms could be used to estimate the risk of poor CD4 restoration, mainly in patients who are diagnosed late in the course of infection.

IRS1- rs10498210 G/A and CCR5-59029 A/G polymorphisms in patients with type 2 diabetes in Kurdistan

Background

The insulin receptor substrate 1 (IRS1) is a critical factor in the signaling pathway for insulin, and mutations in this gene have been reported, which contribute to the ability to develop type 2 diabetes. The polymorphisms in the promoter region of C‐C motif chemokine receptor5 (CCR5) are also being studied as candidates for susceptibility to develop type 2 diabetes. The aim of the current study was to determine the relationship between IRS1 and CCR5 polymorphisms with type 2 diabetes in the Kurdistan population.

Methods

Genomic DNA was isolated from the blood by salt extraction method and the polymorphisms were examined using Restriction Fragment Length Polymorphism (RFLP) method.

Results

The results of current study indicated that the frequency of AA genotype in type 2 diabetic patients in both CCR5 (OR = 2.9, p = 0.04) and IRS1 (OR = 3.3, p = 0.036) were significantly more than controls.

Conclusion

According to the results of this study, the presence of AA genotype in both CCR5 and IRS1 is associated with type 2 diabetes. There was no significant association between AG or GG genotypes with type 2 diabetes.

Genetic variants linked to T2DM risk in Kurdish populations

Background: The polymorphisms of the C-C chemokine receptor type 5 (CCR5) and the insulin receptor substrate 1 (IRS1) have been studied as candidates for the susceptibility to develop type 2 diabetes mellitus (T2DM). CCR5 is a chemokine receptor, and the polymorphisms in the promoter region of this receptor are being studied as candidates for the susceptibility to develop T2DM. Also, IRS1 is a critical factor in the signaling pathway for insulin, and mutations in this gene have been reported, which contribute to the ability to develop T2DM. The aim of the current study was to determine the relationship between CCR5 (59029A/G) and IRS1 (rs10498210) polymorphisms with T2DM in Sanandajian patients. Methods: Genomic DNA was isolated from 200 healthy individuals and 220 Kurdish T2DM patients by salt extraction method and the polymorphisms were examined by restriction fragment length polymorphism (RFLP) method and then the results were analyzed using Chi-square test. Results: The frequency of AA genotype in 220 Kurdish patients for both genes CCR5 (OR=1.9, P=0.02) and IRS1 (OR [95% CI]=2.62, P=0.02) were significantly more than controls. There was no significant association between AG or GG genotypes in with T2DM. Conclusion: The presence of AA homozygote alleles in both loci of IRS1 (rs10498210) and CCR5 (59029A/G) genes increased the risk of T2DM.

CCR2, CCR5, and CXCL12 variation and HIV/AIDS in Papua New Guinea

Polymorphisms in chemokine receptors, serving as HIV co-receptors, and their ligands are among the well-known host genetic factors associated with susceptibility to HIV infection and/or disease progression. Papua New Guinea (PNG) has one of the highest adult HIV prevalences in the Asia-Pacific region. However, information regarding the distribution of polymorphisms in chemokine receptor (CCR5, CCR2) and chemokine (CXCL12) genes in PNG is very limited. In this study, we genotyped a total of nine CCR2-CCR5 polymorphisms, including CCR2 190G >A, CCR5 -2459G >A and Δ32, and CXCL12 801G >A in PNG (n=258), North America (n=184), and five countries in West Africa (n=178). Using this data, we determined previously characterized CCR5 haplotypes. In addition, based on the previously reported associations of CCR2 190, CCR5 -2459, CCR5 open reading frame, and CXCL12 801 genotypes with HIV acquisition and/or disease progression, we calculated composite full risk scores, considering both protective as well as susceptibility effects of the CXCL12 801 AA genotype. We observed a very high frequency of the CCR5 -2459A allele (0.98) in the PNG population, which together with the absence of Δ32 resulted in a very high frequency of the HHE haplotype (0.92). These frequencies were significantly higher than in any other population (all P-values<0.001). Regardless of whether we considered the CXCL12 801 AA genotype protective or susceptible, the risk scores were significantly higher in the PNG population compared with any other population (all P-values<0.001). The results of this study provide new insights regarding CCR5 variation in the PNG population, and suggest that the collective variation in CCR2, CCR5, and CXCL12 may increase the risk of HIV/AIDS in a large majority of Papua New Guineans.

Evaluation of the pharmacogenetics of immune recovery in treated HIV-infected patients

INTRODUCTION

Combination antiretroviral therapy has markedly improved the survival rate and quality of life in patients infected with HIV due to the powerful suppressor effect that current antiretroviral drugs have on the viral load. Consequently, the immune system undergoes a substantial qualitative and quantitative improvement; and this leads to an increase in the absolute CD4(+) T-lymphocyte count and the restoration of lost T-cell responses against certain opportunistic pathogens. Unfortunately, not all patients who successfully suppress plasma viremia experience sufficient CD4(+) T-cell gain and these patients, in turn, are associated with worse outcomes. Pharmacogenetic studies have been used to investigate how a patient's genetic predisposition may affect their response to antiretroviral drugs.

AREAS COVERED

This article reviews the investigations that have been published on the association between host genetic determinants of CD4(+) T-cell gain in treated HIV-infected patients. Studies were identified through a PubMed database search. Longitudinal studies into pharmacogenetic association were specifically selected.

EXPERT OPINION

While the possibility of genetic predisposition to HIV therapeutics has potential, most studies provide inconsistent data. Inconsistency is often due to partial genetic evaluation, different categorization of poor immune recovery or due to small numbers of patients evaluated. Currently, studies still belong to the research laboratory stage and more studies are required to improve our understanding.

The effect of combined polymorphisms in chemokines and chemokine receptors on the clinical course of HIV-1 infection in a Brazilian population

Polymorphisms in genes that encode chemokines or their receptors can modulate susceptibility to human immunodeficiency virus (HIV) infection and disease progression. The objective of this study was to assess the frequency of polymorphisms CCR5-Δ32, CCR2-64I, CCR5-59029A and SDF1-3'A and their role in the course of HIV infection in a Southern Brazilian population. Clinical data were obtained from 249 patients for an average period of 6.4 years and genotypes were determined by standard polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. Survival analyses were conducted for three outcomes: CD4+ T-cell counts below 200 cells/µL, acquired immune deficiency syndrome (AIDS) or death. The frequency of the polymorphisms CCR5-Δ32, CCR2-64I, CCR5-59029A and SDF1-3'A were 0.024, 0.113, 0.487 and 0.207, respectively. CCR5-Δ32 was associated with a reduction in the risk for CD4+ T-cell depletion and with an increased risk for death after AIDS diagnosis. CCR2-64I was associated with a reduction in the risk for developing AIDS. SDF1-3'A was also associated with decreased risk for AIDS, but its effect was only evident when CCR2-64I was present as well. These results highlight the possibility of using these markers as indicators for the prognosis of disease progression and provide evidence for the importance of analysing the effects of gene polymorphisms in a combined fashion.

Chemokine (C-C motif) receptor 5 -2459 genotype in patients receiving highly active antiretroviral therapy: race-specific influence on virologic success

BACKGROUND

In patients receiving highly active antiretroviral therapy (HAART), antiretroviral drug-metabolizing enzyme and transporter gene polymorphisms, as well as chemokine receptor gene polymorphisms, may influence response to treatment.

METHODS

In a North American, treated, adherent human immunodeficiency virus (HIV)-positive cohort (self-identified whites, n = 175; blacks, n = 218), we investigated whether CYP2B6 (516G>T, 983T>C), UGT2B7 (IVS1+985A>G, 802C>T), MDR1 3435C>T, chemokine (C-C motif) receptor 2 (CCR2) 190G>A, and CCR5 (-2459G>A, Δ32) polymorphisms influenced the time to achieve virologic success (TVLS).

RESULTS

No difference in TVLS was observed between races. In Kaplan-Meier analyses, only 516G>T (log-rank P = .045 for comparison of GG, GT, and TT and P = .02 GG + GT vs TT) and -2459G>A (log-rank P = .04 for GG, GA, and AA and P = .02 for GG + GA vs AA) genotypes were significantly associated with TVLS in black patients but not in white patients. However, in the Cox proportional hazards model that included age, sex, baseline CD4(+) T cell count, and baseline viral load, no significant association was observed between 516G>T and TVLS, whereas the association between -2459G>A and TVLS remained significant even after including CCR2 190G>A as well as all the drug-metabolizing enzyme and transporter genotypes.

CONCLUSIONS

These findings suggest that CCR5 -2459G>A genotype had a strong, race-specific influence on TVLS in this cohort. Understanding the possible mechanisms underlying this influence requires further studies.

Host genetic influences on highly active antiretroviral therapy efficacy and AIDS-free survival

We studied the influence of AIDS restriction genes (ARGs) CCR5-Delta32, CCR2-64I, SDF1-3'A, IL10-5'A, CX3CR1-V249I, CX3CR1-T280M, and MDR1-C3435T and haplotypes of the CCR5 P1 promoter and RANTES variants -403A, In1.1C, 3'222C, and -28G among HIV-1 infected patients on highly active antiretroviral therapy (HAART) in the Multicenter AIDS Cohort Study (MACS) and the Multicenter Hemophilia Cohort Study (MHCS). Our results indicate that several ARGs also influence therapy efficacy (ie, the success in viral suppression) and subsequent progression to AIDS while on HAART. CCR5-Delta32 decreased time to viral suppression (<200 HIV RNA copies/mL, relative hazard [RH]=1.40; P=0.008) and was protective against AIDS (RH=0.11; P=or<0.0001), whereas the CCR5 P1 haplotype was associated with delayed viral suppression (RNA<50 copies/mL, odds ratio [OR]=0.65; P=0.03) and accelerated time to AIDS (RH=2.68; P=0.02). SDF1-3'A reduced viral suppression (OR=0.61; P=0.02) and accelerated AIDS (RH=3.18; P=0.009). Accelerated AIDS progression was also observed with the RANTES haplotype carrying RANTES-IN1.1C and RANTES-3'222C (P=0.005 to 0.007). In contrast, the RANTES haplotype H1, which lacks suspected deleterious single-nucleotide polymorphisms, was protective against AIDS. CX3CR1-V249I seemed to accelerate viral suppression (RNA<50 copies/mL, OR=1.27; P=0.01). ARG influence after HAART suggests residual HIV-1 replication, and spread continues even in patients successfully suppressing detectable viral RNA.

Polymorphisms of Cx(3)CR1 and CXCR6 receptors in relation to HAART therapy of HIV type 1 patients

The chemokine polymorphisms CXCR6-3E/K, In1.1T/C, H7 haplotype, CX(3)CR1-V249I, and CX(3)CR1-T280M have been shown to affect the course of HIV infection. We studied their influence on immunologic and virologic response to HAART in a group of 143 HIV-1 patients. We performed Kaplan-Meier analysis using the following end-point criteria: (1) time from HAART initiation to undetectable viral load (VL < 50 copies/ml), (2) maximum duration of viral suppression, (3) time from HAART administration until CD4 elevation above 200 cells/microl for patients with baseline CD4 below 200 cells/microl and above 500 cells/microl for patients with baseline CD4 between 200 and 500 cells/microl, respectively, and (4) time from HAART initiation until CD4 reduction below baseline values. Our results revealed an improved immunologic response to HAART in patients with the CX(3)CR1-249I or CX(3)CR1-280M allele. On the contrary, patients with initial VL suppression due to HAART showed a faster virologic failure in the presence of the CXCR6-3K allele. The In1.1T/C polymorphism and H7 haplotype did not reveal any specific effect on HAART response.

Concurrent CMV and EBV DNAemia is significantly correlated with a delay in the response to HAART in treatment-naive HIV type 1-positive patients

The purpose of this study was to assess the qualitative single and multiple herpes virus DNAemia in the peripheral blood leukocytes (PBLs) of HIV-1-positive patients and its impact on the response to highly active antiretroviral therapy (HAART) and immune reconstitution. All (163) HIV-1-positive patients attending "Syngros AIDS Referral Center" from November 2000 to February 2001 were recruited. CMV, HSV-1, HSV-2, EBV, and HHV-8 DNA were detected in PBLs by polymerase chain reaction (PCR). Patients' follow-up comprised regular measurements of CD4(+) T cell count and HIV-1 viral load (VL) for an average period of 21 months. Immune reconstitution was defined as an increase in the CD4 T cell count by above 200 cells/micro l, while response to HAART was defined as a decrease in HIV-1 VL to undetectable levels. Single and multiple herpetic DNAemia in PBLs was found to be significantly higher in HIV-1-positive patients compared to healthy controls (p < 0.02) for all the viruses detected apart from HSV-2, which was not detected in the PBLs of either population. Concurrent CMV and EBV DNAemia significantly correlates with a delay in the response to HAART (p = 0.033) in treatment-naive patients. Untreated patients with a CD4(+) T cell count <200 cells/micro l, and with either CMV or EBV DNAemia, presented a delayed increase in the CD4 count after initiation of HAART (p = 0.035 and p = 0.037 respectively), while multiple herpetic DNAemia in the above patients was borderline associated with immune reconstitution (p = 0.068). Conclusively, CMV and EBV DNAemia may be poor prognostic factors for the response to HAART in treatment-naive HIV-1 patients.

CCR5 expression and duration of high risk sexual activity among HIV-seronegative men who have sex with men

OBJECTIVES

To test the hypothesis that in comparison with those with shorter risk duration, individuals with longer HIV risk duration would have reduced susceptibility to HIV-1 infection as measured by CCR5 expression, and to evaluate whether variation in CCR5 expression could be explained by known genetic polymorphisms.

DESIGN AND METHODS

A cross-sectional study of HIV-1 exposed but uninfected men who have sex with men. The risk duration was estimated from self-reported years since first receptive anal intercourse. CCR5 expression on peripheral blood CD4+ monocytes and T cells was determined by flow cytometry. The CCR5-Delta32 mutation and polymorphisms in the CCR5 promoter and CCR2 as well as the copy number of CCL3L1 were analyzed by polymerase chain reaction. Plasma levels of MIP-1alpha (CCL3), MIP-1beta (CCL4) and RANTES (CCL5) were also measured. As risk duration varied with age, analyses were restricted to 67 individuals aged 30-49 years.

RESULTS

Multiple linear regression analyses, adjusted for age and race, showed a significant negative association between HIV risk duration and CCR5 expression on monocytes (P = 0.01), and in a separate model, a similar negative association with CCR5 expression on T cells (P = 0.03). Low CCR5 expression was attributable mainly to CCR5-Delta32 heterozygosity and the CCR5-59029G allele.

CONCLUSIONS

We confirmed a role for reduced CCR5 expression in HIV-1 resistance. CCR5-Delta32 heterozygosity and the CCR5-59029G allele were significant predictors of low CCR5 expression. Individuals with high CCR5 expression who resisted infection despite long HIV risk duration form an interesting group within which to search for additional mechanisms of resistance to HIV infection.

Distribution of HIV/AIDS protective SDF1, CCR5 and CCR2 gene variants within Cretan population

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.