CCR5Delta32 Polymorphism Research Articles

Chemokine receptor 5 and primary biliary cirrhosis: a two‐centre genetic association study

Chemokines and their receptors are important mediators of leucocyte trafficking and are suggested to be critical for establishment of inflammatory autoimmune processes. CC chemokine receptor 5 (CCR5) is expressed preferentially by CD4+ T cells. We hypothesised that the CCR5delta(Delta)32 genotype, which impairs surface expression of CCR5 in heterozygotes and is linked to a functional polymorphism of CD45RA expressed on suppressor-inducer-like 'naive' CD4+ T cells, may modulate the inflammatory process in primary biliary cirrhosis (PBC). CCR5Delta32 polymorphism was determined by PCR in 226 Caucasian PBC patients and 197 racially matched controls from two geographical areas, Newcastle, UK and Padua, Italy. (UK: 144 PBC, 105 controls, Italy: 82 PBC, 92 controls). When the two series were analysed separately, there were no significant differences in the genotype distribution comparing patients and controls (UK: wt/wt 72% vs 76%; wt/Delta32 28% vs 22%; Delta32/Delta32 0% vs 2%, P=0.24; Italy: wt/wt 72% vs 82%; wt/Delta32 27% vs 17%; Delta32/Delta32 0% vs 1%, P=0.14). However, when the data for the two series were pooled and reanalysed, we found an increase in the CCR5Delta32 mutation in PBC patients vs controls (28% vs 21%, OR=1.43, P=0.03), but there was no evidence that this Delta32 polymorphism is associated with less severe disease. Although this two-centre genetic association study is large compared with others performed in PBC, taken separately, each geographically based cohort of patients and controls is underpowered to detect a small effect of this functional polymorphism. This emphasises the need for far larger case-control collections to address which polymorphic markers or haplotypes might modify the pathogenesis and clinical course of PBC. We propose that multi-centre collaboration on an international scale in 'orphan' complex liver diseases such as (PBC) is supported by the International Association for the Study of the Liver and promoted via their journal with development of a brief format for web-based publication of studies.

Possible Association Between the Chemokine Receptor Gene CCR5- Delta32 Mutation and Hepatitis C Virus Pathogenesis

Background: CCR5-Delta32, a 32-base pair deletion of the CC chemokine receptor (CCR)5 gene, is associated with slowed human immunodeficiency virus disease progression in heterozygotes and protection against infection in homozygotes between carriers and non-carriers of each genetic variant. The present study investigated the frequency and clinical consequence of the CCR%-Delta32 mutation in Egyptian HCV infected patients. Genomic DNA samples from 150 patients with chronic HCV infection were screened by PCR for the presence of the CCR5-Delta32 polymorphism. One hundred blood donors were used as control population. Results: The frequency of CCR5-Delta32 heterozygosity was 0.67% in chronic hepatitis C virus and 0% in controls. The CCR5-Delta32 allele was not associated with any of the clinical parameters of hepatitis C virus infection. Conclusion: In this study, the frequency of CCR5-Delta32 homozygosity in patients with hepatitis C was similar to controls.

Possible Association Between the Chemokine Receptor Gene CCR5- Delta32 Mutation and Hepatitis C Virus Pathogenesis

CCR5-Delta32, a 32-base pair deletion of the CC chemokine receptor (CCR)5 gene, is associated with slowed human immunodeficiency virus disease progression in heterozygotes and protection against infection in homozygotes between carriers and non-carriers of each genetic variant. The present study investigated the frequency and clinical consequence of the CCR%-Delta32 mutation in Egyptian HCV infected patients. Genomic DNA samples from 150 patients with chronic HCV infection were screened by PCR for the presence of the CCR5-Delta32 polymorphism. One hundred blood donors were used as control population.

CC chemokine receptor 5delta32 polymorphism-a risk factor for ischemic-type biliary lesions following orthotopic liver transplantation.

Ischemic-type biliary lesions are a major complication following orthotopic liver transplantation. They occur in up to 26% of liver transplant recipients. Among other factors, unknown immunologic factors have always been assumed to be partly responsible for these lesions. CC-chemokines and their receptors play a key role in postoperative immunomodulation after liver transplantation. The non-function CC-chemokine receptor 5delta32 polymorphism (CCR5delta32) has been shown to lead to a lower rate of acute rejection after kidney transplantation; in liver transplantation the role of CCR5delta32 is unclear. We investigated the influence of the CCR5delta32 after liver transplantation with special regard to ischemic-type biliary lesions. The CC-chemokine receptor-5 (CCR5) of 146 recipients was analyzed by polymerase chain reaction to detect CCR5delta32 in blood samples of patients after liver transplantation. One hundred twenty patients with wild-type CCR5 and 26 patients with CCR5delta32 (1 homozygote, 25 heterozygote) were identified. Ischemic-type biliary lesions occurred in 14 of 120 patients with wild-type CCR5 and in 8 of 26 patients with CCR5delta32 polymorphism (P = = 0.01). 5 year patient survival with CCR5delta32 and CCR5 was 70% and 85%, respectively (P =.0067). Our results show that the CCR5delta32 is a significant risk factor for the development of ischemic-type biliary lesions after liver transplantation and leads to a reduction in 5-year survival. In conclusion, the CCR5 status should be screened prospectively before liver transplantation.

Effect of CCR5-delta32 heterozygosity on the risk of perinatal HIV-1 infection: a meta-analysis.

Several studies have investigated whether heterozygosity for a 32-basepair deletion in the CC chemokine receptor 5 gene (CCR5-Delta32 ) affects susceptibility to perinatal HIV-1 infection, but results have been inconclusive. We performed a meta-analysis of published data from 11 studies of HIV-1 perinatally exposed children who were genotyped for the CCR5-Delta32 polymorphism. The crude overall HIV-1 infection rates, by simple data pooling, were 20% (one of five) amongCCR5-Delta32 homozygote children, 39% (131 of 335) among CCR5-Delta32 heterozygote children, and 40% (1408 of 3526) among wild-type CCR5 homozygote children. Compared with wild-type homozygotes, the random effects risk ratio for heterozygotes was 1.04 (95% confidence interval [CI], 0.92-1.17) among all children (N = 3861) and 1.03 (95% CI, 0.90-1.17) among those of European descent (n = 2890). Results were similar when adjusted for the available data on the CCR2-641 polymorphism (n = 1542). The meta-analysis clarifies that perinatal infection is not significantly altered by heterozygosity for CCR5-Delta32 in the child.

Characterization of high-risk HIV-1 seronegative hemophiliacs.

Mechanisms that protect most high-risk HIV-1 seronegative (HRSN) persons are not well understood. Among hemophiliacs from the Multicenter Hemophilia Cohort Study who remained HIV-1 seronegative despite a high (94%) risk for acquisition of HIV-1 infection, only 7/43 were homozygous for the protective CCR5 Delta32 polymorphism. Among the remainder, neither CCR5 density nor beta-chemokine production, nor in vitro susceptibility to infection with the HIV-1 isolate JR-FL could distinguish HRSN hemophiliacs from healthy controls. When compared to lymphocytes of healthy controls not at risk for HIV-1 infection, diminished spontaneous lymphocyte proliferation was seen in lymphocytes of HRSN hemophiliacs as well as in lymphocytes of hemophiliacs not at risk for HIV-1 infection. Surprisingly sera/plasmas obtained from high-risk HIV-1 seropositve hemophiliacs prior to seroconversion more often contained alloreactive antibodies than date-matched sera/plasmas obtained from HRSN hemophiliacs. Thus alloreactivity may predispose to acquisition of HIV-1 infection after parenteral exposure.

Delta 32 deletion of CCR5 gene and association with asthma or atopy

The CCR5-delta32 deletion polymorphism (CCR5-delta32) was investigated for linkage and association to asthma and atopy using two panels of nuclear families containing 1284 individuals. No statistically significant linkage to asthma/wheeze or atopy was observed in either of the two panels of families. Multiallelic transmission disequilibrium tests (TDT) of the combined data found no significant association for atopy (52 independent alleles transmitted, 51 non-transmitted) or asthma/wheeze (39 transmitted, 44 non-transmitted). Although functional evidence might suggest that CCR5 is a good candidate gene for atopic asthma, this study provides no genetic evidence from CCR5-delta32 polymorphism to support this hypothesis.