Influence of angiotensin converting enzyme (ACE) gene rs4362 polymorphism on the progression of kidney failure in patients with autosomal dominant polycystic kidney disease (ADPKD)

Background & objectives: Autosomal dominant polycystic kidney disease (ADPKD) is an inherited systemic disorder, characterized by the fluid filled cysts in the kidneys leading to end stage renal failure in later years of life. Hypertension is one of the major factors independently contributing to the chronic kidney disease (CKD) progression. The renin-angiotensin aldosterone system (RAAS) genes have been extensively studied as hypertension candidate genes. The aim of the present study was to investigate the role of angiotensin converting enzyme tagging - single nucleotide polymorphisms (ACE tag-SNPs) in progression of CKD in patients with ADPKD. m0 ethods: In the present study six ACE tagSNPs (angiotensin converting enzyme tag single nucleotide polymorphisms) and insertion/deletion (I/D) in 102 ADPKD patients and 106 control subjects were investigated. The tagSNPs were genotyped using FRET-based KASPar method and ACE ID by polymerase chain reaction (PCR) and electrophoresis. Genotypes and haplotypes were compared between ADPKD patients and controls. Univariate and multivariate logistic regression analyses were performed to assess the effect of genotypes and hypertension on CKD advancement. Mantel-Haenszel (M-H) stratified analysis was performed to study the relationship between different CKD stages and hypertension and their interaction. Results: All loci were polymorphic and except rs4293 SNP the remaining loci followed Hardy-Weinberg equilibrium. Distribution of ACE genotypes and haplotypes in controls and ADPKD patients was not significant. A significant linkage disequilibrium (LD) was observed between SNPs forming two LD blocks. The univariate analysis revealed that the age, hypertension, family history of diabetes and ACE rs4362 contributed to the advancement of CKD. Interpretation & conclusions: The results suggest that the ACE genotypes are effect modifiers of the relationship between hypertension and CKD advancement among the ADPKD patients

Aldosterone synthase gene is not a major susceptibility gene for progression of chronic kidney disease in patients with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common heritable kidney disease and is characterized by bilateral renal cysts. Hypertension is a frequent cause of chronic kidney disease (CKD) and mortality in patients with ADPKD. The aldosterone synthase gene polymorphisms of the renin-angiotensin-aldosterone system have been extensively studied as hypertension candidate genes. The present study is aimed to investigate the potential modifier effect of CYP11B2 gene on the progression of CKD in ADPKD. One hundred and two ADPKD patients and 106 healthy controls were recruited based on Ravine inclusion and exclusion criteria. The three tag-SNPs within CYP11B2 gene (rs3802230, rs4543, and rs4544) were genotyped using FRET-based KASPar method. Cochran-Armitage trend test was used to assess the potential associations between these polymorphisms and CKD stages. Mantel- Haenszel stratified analysis was used to explore confounding and interaction effects of these polymorphisms. Of the three tag-SNPs genotyped, rs4544 polymorphism was monomorphic and rs3802230 deviated Hardy-Weinberg equilibrium. The CYP11B2 tag-SNPs did not show significant association with ADPKD or CKD. Further, these polymorphisms did not exhibit confounding effect on the relationship between CKD progression and hypertension. Our results suggest that aldosterone synthase gene is not a major susceptibility gene for progression of CKD in South Indian ADPKD patients

Physical Activity and Quality of Life after Renal Transplantation

Background: The survival rate after renal transplantation (RT) has improved across the world. Physical activity (PA) remains a way to sustain health benefits after successful RT. But, the PA and quality of life (QOL) after renal transplantation remains underexplored. Methods: This cross-sectional study was done on 63 eligible, consented RT recipients who underwent transplant between 2010 and 2014. The Blood urea, serum creatinine, Physical Activity level (IPAQ) and QOL (RAND 36) were assessed. Results: The PA was found to be low, moderate and high respectively among 28, 24 and 11 subjects. The mean score of PA, physical health (QOL) was 932 ±720, 73.68±10.85 respectively. Physical health QOL positively correlated with PA, negatively with Post RT duration (p<0.05). Conclusions: The PA and QOL remained low with time than the recommendation. The significant correlation between the PA, duration of transplantation and QOL warrants tailored interventions in post renal transplantation patients

Endothelin 1 gene is not a major modifier of chronic kidney disease advancement among the autosomal dominant polycystic kidney disease patients

Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the presence of numerous cysts in the kidney and manifest with various renal and extra-renal complications leading to ESRD. Endothelin may contribute to various renal and extra-renal manifestations pointing to genetic and environmental modifying factors that alter the risk of developing chronic kidney disease (CKD) in ADPKD. In the present study we investigated six genes coding for endothelin 1 (EDN1) tagging-single nucleotide polymorphisms (tag-SNPs) to unravel the EDN1 gene modifier effect for renal disease progression in ADPKD. Materials and Methods: The tag-SNPs were genotyped using FRET-based KASPar method in 108 ADPKD patients and 119 healthy subjects. Cochran-Armitage trend test was used to determine the association between ADPKD and EDN1 tag-SNPs. Multivariate logistic regression analysis was performed to assess the effect of tag-SNPs on CKD progression. The relationship between different CKD stages and hypertension and their interaction Mantel-Haenszel stratified analysis was performed. Results: All loci are polymorphic and followed Hardy-Weinberg equilibrium. Distribution of EDN1 genotypes and haplotypes in control and ADPKD is not statistically significant. Five SNPs covering 3.4 kb forming single LD block, but the LD was not strong between SNPs. The EDN1 genotypes are not contributing to the CKD advancement among the ADPKD patients. Conclusion: These results suggest that the EDN1 gene is not a major modifier of CKD advancement among ADPKD patients

Additional file 1: Table S1. of Renin gene rs1464816 polymorphism contributes to chronic kidney disease progression in ADPKD

Primers used for genotyping REN tag-SNPs. (DOCX 13 kb