Association between Angiotensin I-Converting Enzyme Insertion/Deletion Polymorphism and Prognosis of Kidney Transplantation: A Meta-Analysis

The Role of Angiotensin-Converting Enzyme (ACE) Polymorphisms in the Risk of Development and Treatment of Diabetic Nephropathy

BACKGROUND

Angiotensin-converting enzyme (ACE) is responsible for the production of angiotensin II, and increased production of angiotensin II is observed in diabetes. What is more, ACE polymorphisms may play a role in the development of diabetic nephropathy. The aim of this study was to assess the role of selected ACE polymorphisms (rs4343 and rs4646994) in the risk of development of diabetic nephropathy and in the likelihood of renal replacement therapy.

METHODS

ACE polymorphisms were analyzed in a group of 225 patients who were divided into three subgroups. The rs4343 polymorphism was determined using the PCR-RFLP, and the rs4646994 polymorphism was determined using the PCR. Molecular docking between domains of ACE and its ligands was performed by using AutoDock Vina.

RESULTS

The G/G genotype of rs4343 polymorphism is associated with increased odds of developing diabetic nephropathy. The G allele is also associated with a higher risk of this disease. Similar results were obtained in patients who had already had a kidney transplant as a result of diabetic nephropathy.

CONCLUSIONS

The presence of G/G and G/A genotypes, and the G allele increases the likelihood of developing diabetic nephropathy. This may also be a risk factor for renal replacement therapy.

Update on Treatment of Hypertension After Renal Transplantation

PURPOSE OF REVIEW

To incorporate novel findings on pathophysiology and treatment of posttransplant hypertension.

RECENT FINDINGS

(1) The sodium retaining effects of CNIs are mediated by stimulation of the thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubule and in this regard chlorthalidone was proven to be an effective antihypertensive drug in renal transplantation. (2) Local and not systemic activation of the renin-angiotensin-aldosterone system plays a crucial role in the pathogenesis of posttransplant hypertension. (3) Recent randomized controlled trials failed to prove the presumed superiority of renin-angiotensin blockers in kidney transplantation. (4) Steroid-free and mammalian target of rapamycin-based immunosuppressive drug combinations did not show favorable effects on blood pressure control. (5) In a recent report the risk of non-melanoma skin cancer was higher with thiazide diuretics. But the increased cancer risk in transplant recipients is mainly attributed to comorbidities, such as diabetes and hypertension and of course to the transplantation condition itself or the obligatory application of immunosuppression, and has little to do with the antihypertensive medication Actual recommendations about BP targets in adult renal transplant recipients are coming from a post hoc analysis of a large randomized trial with another primary endpoint. Unless convincing studies on treatment of hypertension after renal transplantation are available, the ESC/ESH Guidelines 2018 should apply for these patients.

Correlation between gene polymorphism and blood concentration of calcineurin inhibitors in renal transplant recipients: An overview of systematic reviews

BACKGROUND

To provide an overview of systematic reviews and meta-analyses (SRs/MAs) of the correlation between genetic polymorphisms and blood concentrations of calcineurin inhibitors (CNIs) in recipients of renal transplant.

METHODS

Databases including Medline, EMBase, The Cochrane Library (Issue 7, 2016), the Chinese Biomedical Literature Database, the China National Knowledge Infrastructure, the China Science and Technology Journal Database, and the Wan Fang Database were searched for SRs/MAs of the correlation between genetic polymorphisms and blood concentrations of CNIs in renal transplant recipients from inception to July 2016. Two reviewers independently screened the literatures and extracted data, then the AMSTAR measurement tool was used to assess the methodological quality of SRs/Mas included in the overview.

RESULTS

Fourteen SRs/MAs met the inclusion criteria. The most commonly reported genotype was CYP3A53/3, which was strongly associated with cyclosporine A (CsA) and tacrolimus (FK506). MDR1 C3435T CC was also associated with CNI use, especially with CsA therapy. Other less commonly reported genotypes such as CYP3A41B, MDR1 C1236T CC, and MDR1 G2677T/A GG also affected the blood concentrations of CNIs.

CONCLUSIONS

Our overview showed that polymorphisms influence the blood concentrations of CNIs, which suggests the necessity to monitor these concentrations in patients with genotypes that affect dose-adjusted trough concentrations (C0/D) or dose-adjusted peak concentrations (C2/D) to regulate the dosage for individual administration. Because of the limited number of included studies, these findings should be verified in more high-quality studies.

Genetics of acute rejection after kidney transplantation

Treatment of acute rejection (AR) following kidney transplantation has improved in recent years, but there are still limitations to successful outcomes. This review article covers literature in regard to recipient and donor genetics of AR kidney and secondarily of liver allografts. Many candidate gene and some genome-wide association studies (GWASs) have been conducted for AR in kidney transplantation. Genetic associations with AR in kidney and liver are mostly weak, and in most cases, the associations have not been reproducible. A limitation in the study of AR is the lack of sufficiently large populations that account for population stratification to study the AR phenotype which in this era occurs in <10% of transplants. Furthermore, the AR phenotype has been difficult to define and the definitions of classifications have evolved over time. Literature related to the pharmacogenomics of tacrolimus is robust and has been validated in many studies. Associations between gene expression and AR are emerging as markers of outcomes and AR classification. In the future, combinations of pretransplant genotype for AR risk prediction, genotype-based immune suppressant dosing, and pharmacogenomic markers to select AR maintenance or treatment and expression markers from biopsies may provide valuable clinical tools for guiding treatment.