CCR5-Δ32 Deletion Research Articles

P.R72P, PIN3 Ins16bp Polymorphisms of TP53 and CCR5Δ32 in North Indian Breast Cancer Patients

The present study aimed to find the prognostic implications of two polymorphisms in TP53 (p.R72P, PIN3 Ins16bp) and one in CCR5 (CCR5/32) in sporadic breast cancer patients. DNA samples of 80 breast cancer patients and 80 age and gender matched unrelated healthy control individuals from Punjab, North West India were analyzed. For p.R72P, the genotype frequency was 13.8% (RR), 58.8% (RP), 27.5% (PP) in patients and 33.9% (RR), 40.0% (RP), 26.5% (PP) in controls. For PIN3 Ins16bp, the genotype frequencies were 53.75% (A1A1), 37.5% (A1A2), 8.75% (A2A2) in patients and 66.3% (A1A1), 31.3% (A1A2), 2.5% (A2A2) in controls. Only 4 (5%) breast cancer patients were heterozygous for CCR5Δ32 deletion. Common RR-A1A1-WT/WT genotype was lower while RP-A1A2-WT/WT genotype was higher in patients as compared to controls. RP-A1A1-WT/WT genotype was significantly higher in patients as compared to control individuals (p = 0.008). Though a clear association of any particular genotype with sporadic breast cancer or stage was not apparent, the results of present study were suggestive that sporadic breast cancer patients with RR-A1A1-WT/WT genotype might have a better response to chemotherapy, thus improving their chances of survival.

HIV-1 Infection and CCR5 Δ 32 Homozygosis

HIV susceptibility shows a substantial degree of individual heterogeneity, much of which can be conferred by host genetic variation. Several polymorphisms in the CCR5 gene that influence HIV transmission and/or disease progression have highlighted the importance of this co-receptor in vivo. One of them, the CCR5Δ32 deletion, was the first host genetic factor with a demonstrated effect on HIV-1 disease and has been unequivocally associated with strong resistance against HIV-1 infection. Here, we review the CCR5Δ32 homozygous HIV-1 patients cases reported. The discovery of CCR5Δ32 was of key importance to demonstrate that host genetic factors could influence the course of HIV infection, providing insights into the mechanisms of control and a relevant proof of principle for the development of new therapeutic strategies.

Risk of All-Cause Mortality in HIV Infected Patients Is Associated with Clinical, Immunologic Predictors and the CCR5 Δ32 Deletion

ObjectiveInvestigation of the interplay between the CCR5 Δ32/wt genotype and demographic, epidemiological, clinical and immunological factors associated with mortality in the cART era.DesignLongitudinal data from 507 HIV-infected patients following the Δ32 allele detection were analyzed.MethodsCumulative 15 years mortality was calculated using Kaplan-Meyer methodology. Hazard ratios were estimated using univariate Cox models. Basing on Akakie information criteria and statistical significance multivariate Cox model was constructed and effect plots presenting adjusted hazard ratio time-dependency were drawn. Analysis of the association of all-cause mortality and CCR5 Δ32/wt genotype prior to the antiretroviral treatment (cART) initiation (n = 507) and on the therapy (n = 422) was also performed.ResultsA mortality rate of 2.66 (CI 2.57–3.19) per 100 person-years was observed. Univariate analysis factors modifying the risk of death included the CCR5 genotype, gender, history of cART, AIDS diagnosis and also CD4 lymphocyte nadir, zenith, the latest CD4 count and stable levels >500 cells/µl. For multivariate analysis the following predictors were selected: CCR5 genotype (HR for wt/wt 2.53, CI 1.16–5.53, p = 0.02), gender (HR for males 1.91, 95%CI 1.1–3.36, p = 0.023), introduction of combined antiretroviral treatment (HR 4.85, CI 3.0–7.89, if untreated or treated <1 month, p<0.0001) CD4 count of 500 cells/µl for six months or more (HR 4.16, CI 1.95–8.88 if not achieved, p = 0.028), the latest CD4 count (HR 5.44, CI 3.39–8.74 for <100 cells/µl, p<0.0001) and history of AIDS (HR 1.69, CI 1.03–2.79, p = 0.039). Among untreated individuals the Δ32/wt genotype was associated with notably better survival (p = 0.026), while among cART treated individuals the Δ32 mutation did not correlate significantly with higher survival rates (p = 0.23).ConclusionsThe Δ32 CCR5 allele is associated with a reduction of the risk of all-cause mortality in HIV (+) patients alongside clinical and immunologic predictors such as AIDS, history of cART, lymphocyte CD4 cell count and gender.

CCR5 Chemokine Receptor Polymorphism in Patients With HIV-1 From Western India

To the Editors: AIDS is a set of symptoms and infections resulting from the damage to the human immune system caused by HIV. The rate of disease progression depends on viral characteristics and host factors. Entry of HIV-1 into target cells requires both CD4 and chemokine receptors. A 32-nucleotide deletion (Δ32) within the β-chemokine CCR5 gene has been described in HIV-1 subjects who remain uninfected. We investigated the frequency of Δ32 deletion in CCR5 among HIV-1-infected patients and normal uninfected healthy individuals belonging to the same ethnic background. A total of 251 samples comprised 161 patients with HIV-1 and 90 normal healthy individuals from the same ethnic group. Genomic DNA from patients and control subjects was extracted and amplified for CCR5 gene segment using polymerase chain reaction. Amplified products were analyzed on 12% acrylamide gel, which yielded an 189-bp fragment for the wild-type allele and 157-bp fragment for the deleted (mutant) allele. Our results revealed patients with HIV-1 were homozygotous for ccr5Δ32 deletion (6.21%) and heterozygous for ccr5Δ32 deletion (0.67%) compared with 6.66% and 0%, respectively, in control subjects (Table 1). Genetic susceptibility to HIV infection has proven to be influenced by chemokine receptor gene polymorphisms culturing on chomosome 3p21. The chemokine receptors CCR2V64I, CCR5-Delta 32, CCR5 m303, CXCR4,(-2459)A CCR5, G190A CCR2,744A, CX3CR1, C838T, and SDF1-3A have been implicated in HIV. Homozygocity for the CCR5 (delta32/delta32) gene is associated with strong resistance against HIV infection. Hetrozygocity for CCR5 (delta32/wt) is associated with protection of HIV disease progression. Global survey for this genotype has revealed that 13% of whites have this mutant allele, whereas in Africans, Eurasians, and Indians, the allele ranges from 5% to 10%.1 The CCR5 delta is a heterozygous deletion in Slovakian patients with HIV-1 (15.4%)2 and heterozygous deletion in white patients with HIV ( 17.5%) and in Polish patients with HIV-1 (16.1%).1 The CCR5 delta32 homozygous deletion is reported in a single German seroconverter,3 not identified in North Indians,4 but identified (6.21%) in our present investigation from Western Indians. Studies revealed that a second mutation in CCR5 that is a single base pair mutation, m303, introduces a stop codon that prevents cell surface expression of a functional CCR5 receptor. A recent study reported the CCR5Delta32 (2.8%) and CCR5m303 (0%) allele polymorphisms among Bahraini population.5 Considering the ethnicity of the Indian subcontinent, CCR5 gene studies in patients with HIV-1 from other parts of India will give us more information. Our study shows that the CCR5 allele frequency varies in different ethnic groups and 7.84% of the patients with HIV-1 have not been protected although they have the presence of the homo- or heterozygous ccr532bp deletion.TABLE 1: CCR5 Polymorphism in Patients With HIV-1 and Control SubjectsAruna Shankarkumar, PhD Umapathy Shankarkumar, PhD Kanjaksha Ghosh, MD National Institute of Immunohaematology, KEM Hospital, Parel, Mumbai, India

CCR5Δ32 variant and cardiovascular disease in patients with rheumatoid arthritis: a cohort study

IntroductionThe aim of our study was to analyze the influence of the CCR5Δ32 polymorphism in the risk of cardiovascular (CV) events and subclinical atherosclerosis among patients with rheumatoid arthritis (RA).MethodsA total of 645 patients fulfilling the American Rheumatism Association 1987 revised classification criteria for RA were studied. Patients were genotyped for the CCR5 rs333 polymorphism using predesigned TaqMan assays. Also, HLA DRB1 genotyping was performed using molecular-based methods. Carotid intima-media thickness, flow-mediated endothelium-dependent dilatation (FMD) and endothelium-independent vasodilatation, which were used as surrogate markers of subclinical atherosclerosis, were measured in a subgroup of patients with no clinical CV disease.ResultsA lower frequency of carriers of the CCR5Δ32 allele among patients with CV events (3.4% versus 11.3%, P = 0.025, odds ratio 0.28, 95% confidence interval (95% CI) 0.06 to 0.89) was observed. However, after adjusting for gender, age at time of RA diagnosis, and the presence of shared epitope, rheumatoid factor and classic CV risk factors in the Cox regression analysis, this reduction of CV events in CCR5Δ32 allele carriers was slightly outside the range of significance (P = 0.097; hazard ratio 0.37 (95% CI 0.12 to 1.19)). Carriers of the CCR5Δ32 deletion also showed higher FMD values than the remaining patients (CCR5/CCR5Δ32 patients: 7.03% ± 6.61% versus CCR5/CCR5 patients: 5.51% ± 4.66%). This difference was statistically significant when analysis of covariance was performed (P = 0.024).ConclusionsOur results show a potential influence of the CCR5Δ32 deletion on the risk of CV disease among patients with RA. This may be due to a protective effect of this allelic variant against the development of vascular endothelial dysfunction.

Using the distribution of the CCR5-Δ32 allele in third-generation Maltese citizens to disprove the Black Death hypothesis

Malta was under Norman rule for over 400 years and has had three major documented plague outbreaks (and a number of minor ones) since the 14th century with death tolls of 5-15% of the population at the time. This makes the Maltese population ideal for testing the hypothesis that the Black Death (particularly that of 1346-52) was responsible for a genetic shift that spread the CCR5-Δ32 allele. By enrolling 300 blood donors to determine the percentage of the Maltese population resistant to HIV-1 (which uses the CCR5-receptor to infect cells), it was established that the CCR5-Δ32 allele frequency is almost zero in third-generation Maltese citizens and sequencing showed that the deletion observed in the region of interest is the 32-base deletion expected. Thus, despite the extensive Norman occupation and the repeated plague cullings, the CCR5-Δ32 allele frequency is extremely low. This provides a basis for the discussion of conflicting hypotheses regarding the possible origin, function and spread of the CCR5-Δ32 deletion.

Genetic Association of the CCR5 Region With Lipid Levels in At-Risk Cardiovascular Patients

There is mounting evidence to suggest that chemokine receptor 5 (CCR5) plays an important role in the development and progression of atherosclerosis. A naturally occurring variant of the CCR5 gene CCR532, exists at allele frequencies of typically 10% in European populations and results in a nonfunctional CCR5 receptor. The CCR5Delta32 deletion and 26 other variants within the chemokine receptor 2-CCR5-chemokine receptor-like protein 2 (CCRL2) gene cluster spanning 59 kilobases of chromosome 3 were genotyped in 5748 subjects from the Treating to New Targets atorvastatin trial to determine whether genetic associations could be identified with circulating lipid values and cardiovascular disease. Our results demonstrate an association between the CCR5Delta32 deletion and increased plasma high-density lipoprotein cholesterol and decreased plasma triglycerides, both of which are beneficial from a cardiovascular perspective. Three single-nucleotide polymorphisms (rs1154428, rs6808835, and rs6791599) in CCRL2 in linkage disequilibrium (r(2)> or =0.65) with CCR5Delta32 and located up to 45 kilobases distal to it were associated with high-density lipoprotein cholesterol. The high-density lipoprotein cholesterol and triglycerides findings were replicated in an additional set of >6000 individuals from the Incremental Decrease in Endpoints through Aggressive Lipid Lowering atorvastatin trial. Our study provides evidence that a locus within the region of the genome encompassing the CCR5-CCRL2 region is associated with lipid levels and suggests that chemokine activity influences lipid levels in populations with preexisting cardiovascular disease. CLINICAL TRIAL REGISTRATION- clinicaltrials.gov. Identifier: TNT, NCT00327691; IDEAL, NCT00159835.

Chemokine polymorphisms and lymphoma: a pooled analysis

Polymorphisms in chemokine genes have been associated with human immunodeficiency virus (HIV)-related non-Hodgkin lymphoma (NHL) but are understudied in non-HIV-related NHL. Associations of NHL and NHL subtypes with polymorphisms and haplotypes in CCR5, CCR2, CCL5, CXCL12, and CX3CR1 were explored in a pooled analysis of three case–control studies (San Francisco Bay Area, California; United Kingdom; total: cases N = 1610, controls N = 1992). Adjusted unconditional logistic regression was used to estimate relative risks among HIV-negative non-Hispanic Caucasians. The CCR5 Δ32 deletion reduced the risk of NHL (odds ratio = 0.56, 95% confidence interval = 0.38–0.83) in men but not women with similar effects observed for diffuse large-cell and follicular lymphoma (FL). NHL risk also was reduced in men with the CCR2/CCR5 haplotype characterized by the CCR5 Δ32 deletion. The CCL5 -403A allele conferred reduced risks of FL and chronic lymphocytic leukemia/small lymphocytic lymphoma. Results should be interpreted conservatively. Continued investigation is warranted to confirm these findings.

CCR5Δ32 genotype is associated with outcome in type 2 diabetes mellitus

Aims To test whether the genetic variant CCR5Δ32 in the CC-chemokine receptor 5, which is known to lead to CCR5 deficiency, is associated with mortality in type 2 diabetes patients. Methods We examined the effect of presence or absence of the CCR5Δ32 on overall and cardiovascular mortality risk in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort, a type 2 diabetes patient cohort. Results We studied 756 patients with a mean duration of follow-up of 5.4 (± 1.4) years. 194 patients died during follow up of which 83 were cardiovascular deaths. 144 subjects (19%) carried the CCR5Δ32 deletion. CCR5Δ32 carriers had an adjusted hazard ratio of 0.62 (95%CI: 0.40–0.96; p = 0.03) for all-cause mortality and 0.63 (95%CI: 0.33–1.19; p = 0.16) for cardiovascular mortality. Conclusions The presence of CCR5Δ32 is associated with better survival in type 2 diabetes patients. These data suggest that it is worthwhile to explore the protective potential of pharmacological blockade of CCR5 in type 2 diabetic patients.

Synergism between the CCR5Δ32 deletion and APOEε4 polymorphisms in vascular and mixed dementia of the very old

Synergism between the CCR5Δ32 deletion and APOEε4 polymorphisms in vascular and mixed dementia of the very old

CCR5 Proinflammatory Allele in Prostate Cancer Risk

Prostate cancer (PCa) is the most common malignant neoplasm in older men in Western countries. The number of affected older men is increasing. Therefore, strategies for prevention of prostate cancer are crucial. To this purpose it is essential to know the mechanisms involved in development and progression of this malignancy. Recently, an increasing body of genetic and epidemiological studies proposed new hypotheses for prostate carcinogenesis. It has been suggested that genetic factors as well as exposure to environmental factors such as infectious agents, dietary carcinogens, and hormonal imbalances participate in PCa development. Besides, chronic inflammation plays a key role in PCa. Taking into consideration this complex scenario, in the present study we evaluated whether CCR5Delta32 deletion of CCR5 gene might be associated with PCa susceptibility. For the control group we used centenarians, since they represent a disease-free human model. These preliminary results suggest that the CCR5Delta32 anti-inflammatory variant might be a resistance factor for the development of PCa.

Differential CCR5Δ32 allelic frequencies in juvenile idiopathic arthritis subtypes: evidence for different regulatory roles of CCR5 in rheumatological diseases

Background: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease of childhood and is characterized by persistent arthritis for at least 6 weeks. Its aetiopathogenesis is unknown but there is strong evidence that there is a substantial genetic component. Chemokine receptors genes are among the candidate genes for association with arthritis and other inflammatory diseases. The CC chemokine receptor 5 (CCR5)Δ32 polymorphism has been associated with rheumatoid arthritis (RA), conferring a protective effect.Objective: To determine whether the CCR5Δ32 polymorphism is associated with JIA and RA in Brazilian patients.Methods: We investigated 203 RA patients, 101 JIA patients, and 104 healthy individuals by amplification of the CCR5Δ32 deletion. We compared the allelic frequencies among these groups, as well as among different JIA subtypes.Results: The frequency of the Δ32 allele was higher in JIA patients (9.4%) as compared to control subjects (3.8%) and RA patients (3.2%). Grouping the patients according to JIA subtypes, we observed a higher CCR5Δ32 allelic frequency in the subtypes with a greater inflammatory component: 4.1% in oligoarticular (n = 49), 11.2% in polyarticular (n = 40) [9.5% in rheumatoid factor negative (RF−) and 33.3% in RF positive (+)], and 25% in systemic JIA (n = 12).Conclusions: This study suggests that in JIA, unlike in RA, CCR5Δ32 does not have a protective effect, but instead it could be a factor associated with more inflammatory forms of the disease. These observations give rise to new questions about the mechanism and the cellular types involved in JIA as well as about the aetiology of JIA.

Identification of the CCR5-Δ32 HIV resistance allele and new mutations of the CCR5 gene in different Tunisian populations

Polymorphisms in some chemokine receptor genes are associated with susceptibility to and progression of human immunodeficiency virus-1 (HIV-1) infection. Most mutations detected in the CC-chemokine receptor 5 (CCR5) gene are specific to different populations. In this study, we focused on polymorphisms of the CCR5 coding region in three healthy populations from Tunisia, corresponding to a cosmopolitan population from Tunis, and two isolated Berber populations. In addition to the CCR5-Delta32 deletion, eleven single nucleotide polymorphisms were detected. Some of these point mutations were associated with the same genotype and even the same haplotype. The (L55Q-C101X), I124, V131F, T143N, A159V, I237, T239A and G301R alleles have not been described previously, whereas the CCR5-Delta32, L55Q, A335V and Y339F variants have already been reported in the literature. The distribution and frequency of these variants were different among the three groups studied, a result in agreement with the mosaic genetic structure of the Tunisian population. To determine whether these alleles affect HIV-1 transmission, we compared allele frequencies between healthy and HIV-1 infected individuals from Tunis. The frequency of the CCR5-Delta32 variant was significantly different between the two groups, leading us to conclude that this mutation might confer protection against HIV infection in Tunisian populations.

Copy number variation of the CCL3L1 gene in chronic HCV infection: Influence on susceptibility and fibro-inflammatory response

Introduction: Recently copy number variation (CNV) of DNA sequences has been identified throughout the human genome (Redon et al. Nature 2006). Furthermore, CNV of the CCL3L1 gene has been associated with susceptibility to HIV infection (Gonzales et al. Science 2006). CCL3L1 is a potent HIV-suppressive chemokine and ligand for the HIV coreceptor CCR5. The frequency of the HIV-protective CCR5-Δ32 deletion has been reported to be increased in hepatitis C virus (HCV) infected patients. Hence, we hypothesized that variation in the gene dose of CCL3L1 may contribute to differences in the inflammatory response to HCV. Thus, our aims were (1) to compare CNV of the CCL3L1 gene between patients with HCV infection, HCV/HIV and controls and (2) to test for association with grades of inflammation and stages of fibrosis in HCV patients.

CCR5 and RANTES/CCL5 Gene Polymorphisms Affect the Risk of EBV Reactivations after Allogeneic HSCT.

Epstein-Barr virus (EBV) reactivation is a serious complication affecting the recipients of allogeneic hematopoietic stem cell transplants (HSCT). Chemokines and their receptors play a major role in the inflammatory and immune responses that mediate allograft outcome. CC-chemokine receptor-5 (CCR5) is known to be involved in perpetuation of HIV infection (as a co-receptor for HIV entry) and the clinical course of this infection is favored by the presence of the 32-nucleotide deletion within the CCR5 gene (CCR5Δ32 polymorphism). The CCR5 deletion mutation (CCR5Δ32) results in a non-functional chemokine receptor. In the present study the CCR5Δ32 polymorphism and two single nucleotide substitutions (−28 C/G; −403 G/A) within, one of the CCR5 ligands, the CCL5/RANTES gene were analyzed in 75 HSCT recipients, 75 donors and related with EBV load. The control group constituted 99 healthy individuals. DNA was extracted from peripheral blood taken into EDTA using silica membranes. Viral load were assessed 2-3 moths after transplantation in blood cells employing a real-time PCR technique. The detection threshold for viral reactivation equaled 10 EBV-DNA copies/105 peripheral blood cells. EBV reactivation was detected in 26 patients. The CCR5Δ32 and RANTES (−28 C/G; −403 G/A) polymorphisms were analyzed by PCR and PCR-RFLP technique, respectively. Distributions of CCR5 and RANTES −28 genotypes were similar in patients, donors and healthy individuals. RANTES −403 AA homozygosity was more frequent in donors than controls (0.61 vs 0.47, p=0.036). The higher number of EBV copies was detected in patients lacking CCR5Δ32 deletion (0.92 vs 0.71, p=0.031). No significant correlation between EBV reactivation and RANTES −28 C/G polymorphism. However, patients transplanted with donors homozygous for RANTES −403 AA (genotype associated with an increased expression of the RANTES gene) more frequently presented with EBV reactivation (0.85 vs 0.49, p=0.002). In conclusion, the presence of the CCR5 deletion-mutation in the recipient and RANTES-403 G in the donor of HSC appeared to lower the susceptibility for EBV reactivation.

Genetic risk factor characterizes abdominal aortic aneurysm from arterial occlusive disease in human beings: CCR5 Δ32 deletion

Inflammation is involved in the pathogenesis of atherosclerosis and abdominal aortic aneurysm (AAA), and chemokines are mediators of the inflammatory process. The homozygous Delta 32 deletion mutation of the gene of the chemokine receptor CCR5 is a cause of its lack in inflammatory cells. The purpose of this study was to investigate the relationship between CCR5 Delta 32 deletion mutation and AAA, peripheral arterial occlusive disease (PAOD), and carotid stenosis. The CCR5 Delta 32 polymorphism was genotyped in 380 subjects: 70 patients operated on to treat AAA (21 ruptured AAAs, 49 elective repair), 76 patients with PAOD, 62 patients with carotid stenosis, and 172 age-matched and sex-matched healthy control subjects. Risk factors for AAA were considered. Each patient was assessed according to a diagnostic procedure tailored to symptoms at presentation. In patients with AAA the Delta allelic variation was significantly different compared with control subjects (P = .002; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.41-5.15). The increased presence of this allele differentiates AAA from both PAOD (P = .017; OR, 2.77; 95% CI, 1.17-6.52) and carotid stenosis (P = .01; OR, 3.47; 95% CI, 1.31-9.11). The presence in the genotype of patients with AAA of at least 1 Delta 32 allele is more frequent in ruptured AAAs than in electively repaired AAAs (genotype: OR, 4.04; 95% CI, 1.34-12.1; P = .011; allelic frequency: OR, 2.75; 95% CI, 1.07-7.07; P = .035). Among the patients, multiple regression analysis showed that the Delta 32 allele is an independent risk factor for AAA vs PAOD (OR, 3.13; 95% CI, 1.33-7.33; P = .012) and for ruptured AAAs vs electively repaired AAAs (OR, 3.52; 95% CI, 1.01-11.80; P = .045). CCR5 Delta 32 deletion mutation is significantly more frequent in patients with AAA than in control subjects and in both patients with PAOD and carotid stenosis, and could be a factor that differentiates AAA from PAOD, and ruptured AAAs from AAAs that can be electively repaired. The major threat of abdominal aortic aneurysm (AAA) is rupture, accounting for extremely high mortality. This occurrence has been correlated to aneurysm size, but it is a common observation that small AAAs can rupture and large AAAs can remain stable for many years. This study was carried out in an attempt to search for genetic markers of aneurysm rupture. Some single nucleotide polymorphisms are implicated in acceleration of transcription for enzymes involved in the inflammatory process and in extracellular matrix remodeling. An association between single nucleotide polymorphisms and aneurysm rupture could enable better selection for surgical indications in patients with small AAs and in patients at poor risk with large AAAs.

CCR2-64I polymorphism and CCR5Δ32 deletion in patients with Alzheimer's disease

Monocyte chemoattractant protein-1 (MCP-1) and RANTES, as well as their related receptors, have been shown to be involved in Alzheimer's disease (AD) pathogenesis. Genes for their related receptors, CCR2 and CCR5, respectively, are characterized by the presence of two polymorphisms: a conservative change of a valine with an isoleucine at codon 64 of CCR2 ( CCR2-64I) and a 32-bp deletion in the coding region of CCR5 ( CCR5Δ 32), which leads to the expression of a nonfunctional receptor. The distribution of the CCR2-64I and CCR5Δ 32 polymorphisms was determined in 290 AD patients and in 222 controls. A decreased frequency and an absence of homozygous for the polymorphism CCR2-64I were found, thus suggesting a protective effect of the mutated allele on the occurrence of AD. However, these findings must be cautiously interpreted as the overall significance was found without adjustment for multiple comparisons and is coming from the complete absence of the genotype 64I/64I in AD patients. Conversely, no different distribution of the CCR5Δ 32 deletion in the two populations was shown. Stratifying by the presence of ApoE ɛ4 allele, gender or age at onset, no differences in either allele frequencies were observed.

Rapid determination of the Delta32 deletion in the human CC-chemokine receptor 5 (CCR5) gene without DNA extraction by lightcycler real-time polymerase chain reaction.

CCR5 is a major coreceptor for cellular entry of macrophage-tropic isolates of the human immunodeficiency virus (HIV). A 32-base pair deletion of the CCR5 gene (CCR5Delta32) protects against HIV infection because the frame shift leads to a truncated protein not expressed on the cell surface. CCR5Delta32 also delays progression in heterozygous HIV-infected patients and improves responses to antiretroviral therapy. Available methods for CCR5 genotyping, however, are cost expensive and/or time consuming. To improve CCR5 genotyping we studied four primer sets flanking the CCR5Delta32 deletion site using real-time polymerase chain reaction (PCR) on a LightCycler device. Primers amplified fragments of different length depending on the presence or absence of the Delta32 mutation. Next, melting curves of the amplified fragments were analyzed using SYBR green, a conventional double-strand DNA dye. To circumvent initial DNA extraction, we also studied serially diluted "interphase" leukocytes as PCR templates after centrifugation of EDTA blood. Finally, the validity of the new method was checked by analyzing 100 blood samples with known CCR5 genotypes. Amplicons of 82 bp:50 bp and 97 bp:65 bp fragment ratios could easily be discriminated due to the differences in their melting temperatures (3 degrees C and 2 degrees C, respectively). Furthermore, CCR5 genotyping was possible without initial DNA extraction and yielded optimal results at 1:400 to 1:600 dilution of the "interphase" leukocytes. Results of the new LightCycler PCR protocol were identical to conventional CCR5 genotyping but required considerably less time and expenditures. We have established a new real-time PCR protocol, which enables fast, cost-saving, and reliable CCR5 genotyping.

Is the CCR5-59029-G/G genotype a protective factor for cardiomyopathy in Chagas disease?

Investigated were two CCR5 gene polymorphisms, the CCR5Δ32 deletion and the pCCR5 59029 A→G promoter point mutation, in 107 ethnically mixed Venezuelan patients serologically positive for Trypanosoma cruzi (34 asymptomatic, 38 arrhythmic, 35 cardiomyopathic). No difference in the distribution of CCR5Δ32 among asymptomatic and symptomatic patients was found. We have observed an increase of the 59029-G phenotype among asymptomatic compared with symptomatic chagasic patients (68% vs. 58%), in agreement with previously reported data (57% vs. 31%). This frequency difference, although not statistically significant, is more marked when the 59029-G allele is present in homozygous form. However, a similar distribution of the G/G genotype is present among asymptomatic patients and patients with heart failure. Because it has been reported that the 59029G/G genotype associates with lower CCR5 expression, 37% of our T. cruzi–infected patients with heart failure are genetically predisposed to express low levels of CCR5 on the surface of CD8 + T cells, contrary to what would be expected if an inflammatory response is required for severe cardiac damage. If confirmed, the possible protection that might be conferred by the G/G genotype may be due to the existence of other genes in linkage disequilibria.

Association of CCR5 Δ32 deletion with early death in multiple sclerosis

Purpose: The interaction between chemokines and their receptors is extremely important in controlling T cell migration into sites of CNS inflammation. Because trafficking of inflammatory T cells into the central nervous system (CNS) is a key player in the pathogenesis of multiple sclerosis (MS), we investigated the possible association of CCR5 Δ32 deletion in this disorder.Methods: DNA isolated from postmortem brain tissue samples of 132 patients with MS and from blood tissue samples of 163 gender and ethnicity-matched healthy controls was used to screen for the CCR5 Δ32 deletion allele.Results: An increased frequency of 32-bp deletion allele was found to be associated with early death (P = 0.00005) and with a progressive reduction in the years of survival (onset to death). The death hazard ratio of CCR5 with deletion versus no deletion was 2.12, suggesting that MS patients with the 32-bp deletion have twice the mortality rate of patients with the normal genotype. This effect was more significant in females (hazard ratio 3.58).Conclusion: A strong association of the CCR5 Δ32 deletion with early death could serve as a prognostic marker for MS.