CCR5Delta32 genotype is associated with outcome in type 2 diabetes mellitus

Prevalence of CCR5 Delta 32 Genetic Variant in the Turkmen Population of Golestan Province, Northeast of Iran

The 32 bp deletion in the chemokine receptor (C-C motif) 5 gene (CCR5Δ32) is a natural loss of function polymorphism that prevents the protein from locating on the cell surface. This genetic variation acts as a double-edge sword in the pathogenesis/defense mechanism of different health conditions, such as viral infections, autoimmune diseases, and cancers. Here, we evaluated the prevalence of the CCR5Δ32 polymorphism in the Turkmen population of Golestan province, northeast of Iran. Blood samples were collected from 400 randomly selected Turkmen populations (199 women and 201 men), and genomic DNA was extracted. Characterization of CCR5Δ32 genotypes was performed by PCR using primers flanking the 32-nucleotide deletion in the CCR5 gene. The amplified DNA fragments were visualized on 2% agarose gel electrophoresis with cybergreen staining under UV light. All individuals were of Turkmen ethnicity and lived in the Golestan province, northeast of Iran. The mean age of all participants was 35.46 years, with a 20-45 year range. All the studied subjects were healthy without any severe conditions such as autoimmune disease and viral infections. All individuals had no history of HIV infection. The PCR product visualization showed that all the samples are at the 330 bp size, which means the CCR5Δ32 allele was utterly absent from the study population. The presence of the CCR5Δ32 allele among Turkmens may be attributed to the admixture with European descent people. We conclude that the CCR5Δ32 polymorphism may be absent in the Iranian Turkmen population, and further studies with a large population are needed.

Comprehensive Network Analysis Reveals the Targets and Potential Multitarget Drugs of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a metabolic disease with increasing prevalence and mortality year by year. The purpose of this study was to explore new therapeutic targets and candidate drugs for multitargets by single-cell RNA expression profile analysis, network pharmacology, and molecular docking. Single-cell RNA expression profiling of islet β cell samples between T2DM patients and nondiabetic controls was conducted to identify important subpopulations and the marker genes. The potential therapeutic targets of T2DM were identified by the overlap analysis of insulin-related genes and diabetes-related genes, the construction of protein-protein interaction network, and the molecular complex detection (MCODE) algorithm. The network distance method was employed to determine the potential drugs of the target. Molecular docking and molecular dynamic simulations were carried out using AutoDock Vina and Gromacs2019, respectively. Eleven cell clusters were identified by single-cell RNA sequencing (scRNA-seq) data, and three of them (C2, C8, and C10) showed significant differences between T2DM samples and normal samples. Eight genes from differential cell clusters were found from differential cell clusters to be associated with insulin activity and T2DM. The MCODE algorithm built six key subnetworks, with five of them correlating with inflammatory pathways and immune cell infiltration. Importantly, CCR5 was a gene within the key subnetworks and was differentially expressed between normal samples and T2DM samples, with the highest area under the ROC curve (AUC) of 82.5% for the diagnosis model. A total of 49 CCR5-related genes were screened, and DB05494 was identified as the most potential drug with the shortest distance to CCR5-related genes. Molecular docking illustrated that DB05494 stably bound with CCR5 (-8.0 kcal/mol) through multiple hydrogen bonds (LYS26, TYR37, TYR89, CYS178, and GLN280) and hydrophobic bonds (TRP86, PHE112, ILE198, TRP248, and TYR251). This study identified CCR5 as a potential therapeutic target and screened DB05494 as a potential drug for T2DM treatment.

Macrophage-derived cytokines in pneumonia: Linking cellular immunology and genetics

Macrophages represent the first line of anti-pathogen defense - they encounter invading pathogens to perform the phagocytic activity, to deliver the plethora of pro- and anti-inflammatory cytokines, and to shape the tissue microenvironment. Throughout pneumonia course, alveolar macrophages and infiltrated blood monocytes produce increasing cytokine amounts, which activates the antiviral/antibacterial immunity but can also provoke the risk of the so-called cytokine "storm" and normal tissue damage. Subsequently, the question of how the cytokine spectrum is shaped and balanced in the pneumonia context remains a hot topic in medical immunology, particularly in the COVID19 pandemic era. The diversity in cytokine profiles, involved in pneumonia pathogenesis, is determined by the variations in cytokine-receptor interactions, which may lead to severe cytokine storm and functional decline of particular tissues and organs, for example, cardiovascular and respiratory systems. Cytokines and their receptors form unique profiles in individual patients, depending on the (a) microenvironmental context (comorbidities and associated treatment), (b) lung monocyte heterogeneity, and (c) genetic variations. These multidisciplinary strategies can be proactively considered beforehand and during the pneumonia course and potentially allow the new age of personalized immunotherapy.

Chemokine receptors on peripheral blood T lymphocytes in children on peritoneal dialysis

BACKGROUND

Immune cell dysfunction is listed among complications resulting from chronic kidney disease (CKD). It could be associated with T-cells, which play a role in the lymphocytic migration and infiltration. However, the data on chemokine receptors expression on T-cells in patients with CKD particularly treated with peritoneal dialysis (PD) are still limited.

METHODS

The study aimed at multiparameter flow-cytometric analysis of the absolute numbers and percentage of T-cell subsets with surface chemokine receptors (CCR4, CCR5, CCR7, CXCR3, and CXCR4) or receptors' combinations in 47 children treated with PD.

RESULTS

We found lower absolute numbers of total T lymphocytes, lymphocytes with surface CCR5, CXCR4⁺CCR5, CXCR3⁺CCR5 antigens and T-cells with CCR4, CCR4⁺CD4, CXCR3, CXCR3⁺CD4, and CD8 receptors. Lymphocytes T with CD4, CCR7, CD28⁺CCR7, CXCR3⁺CD8 antigens showed higher percentage in children on PD as compared to healthy children and opposite percentage values of CCR4⁺, CCR4⁺CD4⁺, CXCR3⁺ T lymphocytes were diminished. Mean fluorescent intensity for CCR7⁺, CCR7⁺CD45RO⁺, CCR7⁺CD28⁺, CXCR4⁺CD4⁺, CCR5⁺CD4⁺, CCR4⁺, CCR4⁺CD4⁺ T-cells was lower in the PD group than in healthy children. The analysis of correlation between T lymphocyte subpopulations with chemokine receptors and other parameters revealed positive correlation of CCR7⁺ and CCR7⁺CD28⁺ T-cells and weekly creatinine clearance, negative correlation between the percentage of CD45RO⁺CCR7 antigen positive T-cells and KT/V_urea.

SUMMARY

In conclusion, we could not confirm the phenomenon of earlier senescence of T-cells in children with CKD on PD treatment. This still requires further investigation. The higher percentage of T-cells with CCR7 surface receptor could be responsible for the increase of proliferation activity in this group of children.

The Role of Chemokines and Chemokine Receptors in Diabetic Nephropathy

Kidney function decline is one of the complications of diabetes mellitus and may be indicated as diabetic nephropathy (DN). DN is a chronic inflammatory disease featuring proteinuria and a decreasing glomerular filtration rate. Despite several therapeutic options being currently available, DN is still the major cause of end-stage renal disease. Accordingly, widespread innovation is needed to improve outcomes in patients with DN. Chemokines and their receptors are critically involved in the inflammatory progression in the development of DN. Although recent studies have shown multiple pathways related to the chemokine system, the specific and direct effects of chemokines and their receptors remain unclear. In this review, we provide an overview of the potential role and mechanism of chemokine systems in DN proposed in recent years. Chemokine system-related mechanisms may provide potential therapeutic targets in DN.

It Takes Two to Tango: The Role of Dysregulated Metabolism and Inflammation in Kidney Disease Development

Acute kidney injury is a major contributor of chronic kidney disease development. The pathogenesis of acute kidney injury and chronic kidney disease shows significant similarities. Both conditions are associated with a defect in cellular metabolism, such as fatty acid oxidation and mitochondrial oxidative phosphorylation in kidney tubule cells and a marked increase in infiltrating immune cells. Here, we discuss how inflammatory cytokines and macrophages contribute to epithelial injury and metabolic defects. In addition, we discuss the role of mitochondrial damage and cytosolic leakage of the mitochondrial DNA activating the innate immune pathway such as cyclic guanosine monophosphate-adenosine monophosphate synthase/stimulator of interferon genes. The interplay between inflammation and metabolism appears to be critical for kidney disease development.

Metabolomics as an Approach to Characterise the Contrasting Roles of CCR5 in the Presence and Absence of Disease

Chemokine receptors such as C-C chemokine receptor 5 (CCR5) are activated through interaction with their ligands and are well known for their role in chemotaxis and signal transduction. While serving these roles, cellular responses are effected, hence the immune function of these molecules is established. Given the role of CCR5 in immune function and that the immune and metabolic systems are interlinked, subsequent immune-directed changes should be measurable at a metabolic level. Numerous investigations have reported on metabolic changes associated with CCR5 status in the presence of disease, so as to understand whether specific CCR5 genotypes, frequency and/or levels offer protection to the host or not. However, these metabolic changes were recorded using older conventional techniques. Depending on certain factors such as the disease model, the geography of the samples and/or the ethnic group under study, the role of CCR5 in disease differs. In addition, little is known about CCR5's role in the absence of an enhanced inflammatory state, such as when infection persists. Metabolomics is defined as the study of metabolites and informs on metabolic changes within living organisms as induced by various stimuli, such as the interaction of CCR5 with its ligand. Since metabolomics reflects the underlying biochemical activity and state of cells/tissues, this review proposes it as a tool to clarify the contrasting roles of CCR5.

STAT3 activation in circulating myeloid-derived cells contributes to retinal microvascular dysfunction in diabetes

Background

Leukostasis is a key patho-physiological event responsible for capillary occlusion in diabetic retinopathy. Circulating monocytes are the main cell type entrapped in retinal vessels in diabetes. In this study, we investigated the role of the signal transducer and activator of transcription 3 (STAT3) pathway in diabetes-induced immune cell activation and its contribution to retinal microvascular degeneration.

Methods

Forty-one patients with type 1 diabetes (T1D) [mild non-proliferative diabetic retinopathy (mNPDR) (n = 13), active proliferative DR (aPDR) (n = 14), inactive PDR (iPDR) (n = 14)] and 13 age- and gender-matched healthy controls were recruited to the study. C57BL/6 J WT mice, SOCS3^fl/fl and LysM^Cre/+SOCS3^fl/fl mice were rendered diabetic by Streptozotocin injection. The expression of the phosphorylated human and mouse STAT3 (pSTAT3), mouse LFA-1, CD62L, CD11b and MHC-II in circulating immune cells was evaluated by flow cytometry. The expression of suppressor of cytokine signalling 3 (SOCS3) was examined by real-time RT-PCR. Mouse plasma levels of cytokines were measured by Cytometric Beads Array assay. Retinal leukostasis was examined following FITC-Concanavalin A perfusion and acellular capillary was examined following Isolectin B4 and Collagen IV staining.

Results

Compared to healthy controls, the expression of pSTAT3 in circulating leukocytes was statistically significantly higher in mNPDR but not aPDR and was negatively correlated with diabetes duration. The expression of pSTAT3 and its inhibitor SOCS3 was also significantly increased in leukocytes from diabetic mice. Diabetic mice had higher plasma levels of IL6 and CCL2 compared with control mice. LysM^Cre/+SOCS3^fl/fl mice and SOCS3^fl/fl mice developed comparative levels of diabetes, but leukocyte activation, retinal leukostasis and number of acellular capillaries were statistically significantly increased in LysM^Cre/+SOCS3^fl/fl diabetic mice.

Conclusion

STAT3 activation in circulating immune cells appears to contribute to retinal microvascular degeneration and may be involved in DR initiation in T1D.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1533-1) contains supplementary material, which is available to authorized users.

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.

Effect of PF-04634817, an Oral CCR2/5 Chemokine Receptor Antagonist, on Albuminuria in Adults with Overt Diabetic Nephropathy

Introduction

Inflammatory cell recruitment, which is potentially mediated by the monocyte chemoattractant protein 1/C-C chemokine receptor type 2 (CCR2) system and by C-C chemokine receptor type 5 (CCR5) activity, may play a role in the development and progression of diabetic nephropathy. PF-04634817 is a dual chemokine CCR2/5 receptor antagonist that is being developed for the treatment of diabetic nephropathy.

Methods

We evaluated the efficacy of PF-04634817 compared with matching placebo for reduction of albuminuria after 12 weeks of treatment in subjects with type 2 diabetes who received standard of care (SOC; angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy), in a randomized, double-blind, placebo-controlled, parallel-group phase 2 study.

Results

A total of 226 subjects who received SOC with baseline estimated glomerular filtration rates between 20 and 75 ml/min per 1.73 m² and a baseline urinary albumin-to-creatinine ratio (UACR) of ≥300 mg/g were randomly assigned 3:1 to receive PF-04634817 (150 or 200 mg orally, once daily) or placebo. The primary analysis was Bayesian, with an informative prior for placebo response (equivalent to including an additional 80 subjects in the placebo arm). We observed a placebo-adjusted reduction in UACR of 8.2% (ratio 0.918; 95% credible interval: 0.75–1.09) at week 12 in the PF-04634817 arm. PF-04634817 appeared to be safe and well-tolerated.

Conclusion

Despite the good safety profile shown by PF-04634817, clinical development for this indication was discontinued in light of the modest efficacy observed.

CCR5-Δ32 gene polymorphism is associated with retinopathy in patients with type 1 diabetes

AIM

The aim of the study was to assess the relationship between the CCR5-Δ32 polymorphism and the risk of diabetic retinopathy (DR) in patients with DM1.

METHODS

We examined 420 patients and 350 healthy controls. The analysis concerned CCR5-Δ32 polymorphism as well as levels of serum inflammatory markers (CRP, TNF-α), adhesion molecules (VCAM, ICAM-1, ICAM-3) and CCR5 ligand (MCP-1).

RESULTS

We found a negative association between DM1 and Δ32 allele. Moreover, the frequency of Δ32 allele was higher in a group with DR in comparison to control subjects without this complication. We also found that Δ32 carriers had the highest levels of: HbA1c, inflammatory markers, adhesion molecules and CCR5 ligand.

CONCLUSIONS

The findings of our studies suggest that the CCR5-Δ32 polymorphism is associated with DM1 such that the Δ32 allele protects against the development of DM1 and increases the risk of DR in patients who have already developed the disease.

Emerging role of chemokine CC motif ligand 4 related mechanisms in diabetes mellitus and cardiovascular disease: friends or foes?

Chemokines are critical components in pathology. The roles of chemokine CC motif ligand 4 (CCL4) and its receptor are associated with diabetes mellitus (DM) and atherosclerosis cardiovascular diseases. However, due to the complexity of these diseases, the specific effects of CCL4 remain unclear, although recent reports have suggested that multiple pathways are related to CCL4. In this review, we provide an overview of the role and potential mechanisms of CCL4 and one of its major receptors, fifth CC chemokine receptor (CCR5), in DM and cardiovascular diseases. CCL4-related mechanisms, including CCL4 and CCR5, might provide potential therapeutic targets in DM and/or atherosclerosis cardiovascular diseases.

Is the CCR5 Δ 32 mutation associated with immune system-related diseases?

Hypersensitivity and autoimmunity are the main features of immune system-related diseases such as type 2 diabetes (T2D), multiple sclerosis (MS), and asthma. It has been established that chemokines play key roles in the activation and regulation of immune cell migration which is important in the pathogenesis of the diseases mentioned. CC chemokines receptor 5 or CCR5 is a receptor for RANTES, MIP-1α, and MIP-1β and is expressed by several immune cells including NK cells, T lymphocytes, and macrophages. It plays key roles in the regulation of migration and activation of the immune cells during immune responses against microbe and self-antigens during autoimmunity and hypersensitivity disorders. Therefore, any alteration in the sequence of CCR5 gene or in its expression could be associated with immune system-related diseases. Previous studies revealed that a 32-base pair deletion (Δ 32) in exon 1 of the CCR5 gene led to downregulation of the gene. Previous studies demonstrated that not only CCR5 expression was altered in autoimmune and hypersensitivity disorders, but also that the mutation is associated with the diseases. This review addresses the recent information regarding the association of the CCR5 Δ 32 mutation in immune-related diseases including T2D with and without nephropathy, MS, and asthma. Based on the collected data, it seems that the CCR5 Δ 32 mutation can be considered as a risk factor for MS, but not asthma and T2D with and without nephropathy.

CC chemokine receptors and chronic inflammation--therapeutic opportunities and pharmacological challenges

Chemokines are a family of low molecular weight proteins with an essential role in leukocyte trafficking during both homeostasis and inflammation. The CC class of chemokines consists of at least 28 members (CCL1-28) that signal through 10 known chemokine receptors (CCR1-10). CC chemokine receptors are expressed predominantly by T cells and monocyte-macrophages, cell types associated predominantly with chronic inflammation occurring over weeks or years. Chronic inflammatory diseases including rheumatoid arthritis, atherosclerosis, and metabolic syndrome are characterized by continued leukocyte infiltration into the inflammatory site, driven in large part by excessive chemokine production. Over years or decades, persistent inflammation may lead to loss of tissue architecture and function, causing severe disability or, in the case of atherosclerosis, fatal outcomes such as myocardial infarction or stroke. Despite the existence of several clinical strategies for targeting chronic inflammation, these diseases remain significant causes of morbidity and mortality globally, with a concomitant economic impact. Thus, the development of novel therapeutic agents for the treatment of chronic inflammatory disease continues to be a priority. In this review we introduce CC chemokine receptors as critical mediators of chronic inflammatory responses and explore their potential role as pharmacological targets. We discuss functions of individual CC chemokine receptors based on in vitro pharmacological data as well as transgenic animal studies. Focusing on three key forms of chronic inflammation--rheumatoid arthritis, atherosclerosis, and metabolic syndrome--we describe the pathologic function of CC chemokine receptors and their possible relevance as therapeutic targets.

CD11b+ bone marrow-derived monocytes are the major leukocyte subset responsible for retinal capillary leukostasis in experimental diabetes in mouse and express high levels of CCR5 in the circulation

We investigated the phenotype of cells involved in leukostasis in the early stages of streptozotocin-induced diabetes in mice by direct observation and by adoptive transfer of calcein-AM-labeled bone marrow-derived leukocytes from syngeneic mice. Retinal whole mounts, confocal microscopy, and flow cytometry ex vivo and scanning laser ophthalmoscopy in vivo were used. Leukostasis in vivo and ex vivo in retinal capillaries was increased after 2 weeks of diabetes (Hb A(1c), 14.2 ± 1.2) when either donor or recipient mice were diabetic. Maximum leukostasis occurred when both donor and recipient were diabetic. CD11b(+), but not Gr1(+), cells were preferentially entrapped in retinal vessels (fivefold increase compared with nondiabetic mice). In diabetic mice, circulating CD11b(+) cells expressed high levels of CCR5 (P = 0.04), whereas spleen (P = 0.0001) and retinal (P = 0.05) cells expressed increased levels of the fractalkine chemokine receptor. Rosuvastatin treatment prevented leukostasis when both recipient and donor were treated but not when donor mice only were treated. This effect was blocked by treatment with mevalonate. We conclude that leukostasis in early diabetic retinopathy involves activated CCR5(+)CD11b(+) myeloid cells (presumed monocytes). However, leukostasis also requires diabetes-induced changes in the endothelium, because statin therapy prevented leukostasis only when recipient mice were treated. The up-regulation of the HMG-CoA reductase pathway in the endothelium is the major metabolic dysregulation promoting leukostasis.

CCR5Δ32 genotype leads to a Th2 type directed immune response in ESRD patients

Background

In patients with end stage renal disease (ESRD) we observed protection from inflammation-associated mortality in CCR5Δ32 carriers, leading to CCR5 deficiency, suggesting impact of CCR5Δ32 on inflammatory processes. Animal studies have shown that CCR5 deficiency is associated with a more pronounced Th2 type immune response, suggesting that in human CCR5Δ32 carriers the immune response may be more Th2 type directed. So, in the present study we determined the Th1-Th2 type directed immune response in ESRD patients carrying and not carrying the CCR5Δ32 genetic variant after stimulation.

Methodology/Principal Findings

We tested this hypothesis by determining the levels of IFN-γ and IL-4 and the distribution of Th1, Th2 and Th17 directed circulating CD4+ and CD8+ T cells and regulatory T cells (Tregs) after stimulation in ESRD patients with (n = 10) and without (n = 9) the CCR5Δ32 genotype. The extracellular levels of IFN-γ and IL-4 did not differ between CCR5Δ32 carriers and non carriers. However, based on their intracellular cytokine profile the percentages IL-4 secreting CD4+ and CD8+ T cells carrying the CCR5Δ32 genotype were significantly increased (p = 0.02, respectively p = 0.02) compared to non carriers, indicating a more Th2 type directed response. Based on their intracellular cytokine profile the percentages IFN-γ and IL-17 secreting T cells did not differ between carriers and non-carriers nor did the percentage Tregs, indicating that the Th1, Th17 and T regulatory response was not affected by the CCR5Δ32 genotype.

Conclusions/Significance

This first, functional human study shows a more pronounced Th2 type immune response in CCR5Δ32 carriers compared to non carriers. These differences may be involved in the previously observed protection from inflammation-associated mortality in ESRD patients carrying CCR5Δ32.

Chemotactic cytokine receptor 5 gene polymorphism: relevance to microvascular complications in type 2 diabetes

We investigated the involvement of chemotactic cytokine receptor 5 (CCR5) gene polymorphism in microvascular complications of T2DM. All subjects were genotyped with the 59029 SNP in the CCR5 gene. The genotype/allele frequencies did not differ between T2DM patients and controls. Genotype distribution was compared in patients with and without complications (nephropathy, retinopathy and neuropathy). The frequency of A allele was significantly higher in patients with complications (OR for A allele 3.07, 95% CI 2.49-3.77). The A allele carriage was associated with diabetic nephropathy (OR 6.17, 95% CI 3.28-11.6). An association was observed between 59029 polymorphism and age at T2DM onset. The A allele was more frequent in early onset than in late onset patients. For AA homozygotes OR was 2.38 (1.19-4.76) and 2.26 (1.12-4.58) in complicated and uncomplicated subgroups, respectively. These results suggest that CCR5 gene polymorphism is associated with diabetic nephropathy in T2DM.

The predictive value of IL28B gene polymorphism for spontaneous clearance in a single source outbreak cohort is limited in patients carrying the CCR5Δ32 mutation

BACKGROUND & AIMS

The CCR5Δ32 mutation has been suspected to adversely affect outcomes of HCV infection, although reports have remained controversial. Here, we investigated the relative genetic contributions of the CCR5Δ32 deletion and the IL28B rs12979860 polymorphisms to spontaneous clearance of hepatitis C in a single-source outbreak.

METHODS

We retrieved 396 Caucasian women (119 women with spontaneous HCV clearance) who had been infected with HCV genotype 1-contaminated anti-D immunoglobulin in 1978, and determined their IL28B and CCR5 alleles.

RESULTS

IL28B CC, CT, and TT genotypes were found in 35.4%, 50%, and 14.6% of patients and corresponded to spontaneous clearance rates of 50%, 21.2%, and 12.1% (Chi(2)=38.7, p=5.0×10(-10)), respectively. CCR5 WT/WT, WT/Δ32, and Δ32/Δ32 genotypes were observed in 76%, 22.7%, and 1.3% of patients and corresponded to clearance rates of 33.2%, 21.2%, and 0% (Chi(2)=6.9, p=0.009), respectively. In a stepwise forward-conditional multivariate regression model both CCR5 (OR 2.1, p=0.01 for WT/WT) and IL28B genetic variants (OR 4.3, p=4.6×10(-10) for the C/C genotype) were identified as independent predictors of spontaneous HCV clearance. Importantly, favorable response rates were associated with the IL28B CC genotype only in CCR5 wild-type homozygous women, while HCV clearance in CCR5Δ32 carriers remained poor even in patients with the rs12979860 CC genotype.

CONCLUSIONS

Both IL28B rs1297860 and CCR5Δ32 allelic variants are independent genetic determinants of spontaneous HCV clearance. The variable relative distribution between IL28B rs1297860 and CCR5Δ32 allelic variants in different populations may have masked the role of the CCR5Δ32 mutation in some studies.

Using a genetic, observational study as a strategy to estimate the potential cost-effectiveness of pharmacological CCR5 blockade in dialysis patients

BACKGROUND AND OBJECTIVE

Randomized clinical trials are expensive and time consuming. Therefore, strategies are needed to prioritise tracks for drug development. Genetic association studies may provide such a strategy by considering the differences between genotypes as a proxy for a natural, lifelong, randomized at conception, clinical trial. Previously an association with better survival was found in dialysis patients with systemic inflammation carrying a deletion variant of the CC-chemokine receptor 5 (CCR5). We hypothesized that in an analogous manner, pharmacological CCR5 blockade could protect against inflammation-driven mortality and estimated if such a treatment would be cost-effective.

METHODS

A genetic screen and treat strategy was modelled using a decision-analytic Markov model, in which patients were screened for the CCR5 deletion 32 polymorphism and those with the wild type and systemic inflammation were treated with pharmacological CCR5 blockers. Kidney transplantation and mortality rates were calculated using patient level data. Extensive sensitivity analyses were performed.

RESULTS

The cost-effectiveness of the genetic screen and treat strategy was &OV0556;18 557 per life year gained and &OV0556;21 896 per quality-adjusted life years gained. Concordance between the genetic association and pharmacological effectiveness was a main driver of cost-effectiveness. Sensitivity analyses showed that even a modest effectiveness of pharmacological CCR5 blockade would result in a treatment strategy that is good value for money.

CONCLUSION

Pharmacological blockade of the CCR5 receptor in inflamed dialysis patients can be incorporated in a potentially cost-effective screen and treat programme. These findings provide formal rationale for clinical studies. This study illustrates the potential of genetic association studies for drug development, as a source of Mendelian randomized evidence from an observational setting.

CD14++CD16+ monocytes and cardiovascular outcome in patients with chronic kidney disease

AIMS

Patients with chronic kidney disease (CKD) pose a worldwide growing burden to health care systems due to accelerated atherosclerosis and subsequent high cardiovascular (CV) morbidity. Atherogenesis is prominently driven by monocytes and monocyte-derived macrophages. The expression of CD14 and CD16 characterizes three monocyte subsets: CD14(++)CD16(-), CD14(++)CD16(+), and CD14((+))CD16(+) cells; the latter two are often denoted as 'proinflammatory' CD16(+) monocytes. Despite an association between CD16(+) monocyte counts and higher CV risk in cross-sectional cohorts, the prognostic impact of elevated CD16(+) monocyte counts is poorly understood.

METHODS AND RESULTS

We assessed monocyte heterogeneity using flow cytometry in 119 patients with non-dialysis CKD, who were prospectively followed for a median of 4.9 (inter-quartile range 4.8-5.0) years for the occurrence of CV events. In addition, we assessed expression of chemokine receptors on monocyte subsets. CD14(++)CD16(+) monocyte were independently associated with CV events [hazard ratio (for an increase of 10 cells/μL) 1.26 (confidence interval: 1.04-1.52; P = 0.018)] after adjustment for variables that significantly affected CD14(++)CD16(+) cell counts at baseline. Across the spectrum of CKD, CD14(++)CD16(+) monocytes selectively expressed CCR5.

CONCLUSION

We found that CD14(++)CD16(+) monocytes were independently associated with CV events in non-dialysis CKD patients. Our results support the notion that CD16(+) monocytes rather than CD16(-) monocytes are involved in human atherosclerosis.

TNF-α levels are not increased in inflamed patients carrying the CCR5 deletion 32

BACKGROUND AND AIMS

Recently we reported on a genetically predisposed protection from C-reactive protein (CRP) related mortality in dialysis patients carrying the functional CC-chemokine receptor 5 deletion 32 allele (CCR5Δ32) mutation. Since CCR5Δ32 is associated with a less pro-inflammatory immune response in mice, we hypothesized that the observed protection is (in part) due to a less pro-inflammatory cytokine profile.

METHODS

Cross-sectional observational study including 263 incident dialysis patients aged 18-70years, without clinical signs of infection and/or acute vasculitis. TNF-α, IL-6, IL-10 and hsCRP levels were determined and studied in relation to the CCR5 genotype.

RESULTS

In the presence of elevated hsCRP, IL-6 concentration was higher irrespective of the CCR5 genotype. However, in patients with the CCR5 deletion, TNF-α did not differ in the presence/absence of elevated hsCRP and was not correlated with hsCRP levels in carriers of the CCR5Δ32 polymorphism.

CONCLUSIONS

A possible underlying mechanism of the impact of CCR5Δ32 genotype on inflammation driven mortality in dialysis patients could be a reduced Th1 immune response as represented by decreased TNF-α levels.