Characterization of clinical and genetic risk factors associated with dyslipidemia after kidney transplantation

Managing dyslipidemia in solid organ transplant patients

Solid organ transplant recipients face an increased risk of dyslipidemia, which contributes to cardiovascular complications. Commonly used drugs such as ciclosporin and tacrolimus can aggravate and cause dyslipidemia. Immunosuppressive drugs particularly ciclosporin and tacrolimus are also known to worsen dyslipidemia in transplant recipients. Mammalian target of rapamycin (mTOR) inhibitors like sirolimus and everolimus also alter lipid metabolism. Lifestyle and dietary modifications should be encouraged. Careful consideration of immunosuppressant choices is also vital to control dyslipidemia. Statins are recommended as first-line agents for lipid-lowering therapy, with consideration for potential drug interactions. Other options, such as ezetimibe and nicotinic acid, may be considered as alternatives. The management of dyslipidemia in renal transplant patients mainly involves statin therapy, although the clinical effectiveness in this population is not well-documented. Lifestyle modifications, careful drug selection, and statin therapy are key components in managing dyslipidemia in solid organ transplant patients.

Genetic polymorphisms of glucocorticoid receptor and their association with new-onset diabetes mellitus in kidney transplant recipients

INTRODUCTION

The variability in developing New-onset Diabetes Mellitus After Transplantation (NODAT), together with previously well-established interindividual variation in glucocorticoid sensitivity, led us to hypothesize that polymorphisms in the NR3C1 gene encoding glucocorticoid receptor may alter glucose balance in kidney transplant recipients. This study aimed to evaluate the association of three functional polymorphisms, BclI, N363S, and ER22/23EK, on the NR3C1 gene with NODAT in kidney allograft recipients.

METHODS

From Jun 2020 to July 2022 in Shiraz, 52 patients with NODAT (case group) and 52 non-diabetic kidney transplant recipients (control group) were randomly screened and recruited in this case-control study. The PCR-RFLP technique determined the genotypes of BclI, N363S, and ER22/23EK polymorphisms.

RESULTS

The allelic frequencies of the mutant alleles of BclI, N363S, and ER22/23EK polymorphisms in all patients were 0.36, 0.03, and 0.009, respectively. BclI mutant genotypes (CG and GG) were significantly associated with an increased risk of NODAT (P = 0.016), while the two other polymorphisms disclosed no significant association with NODAT development. In the case group, no significant association was detected between the onset time of NODAT and studied polymorphisms, including BclI (P = 0.43), N363S (P = 0.30), and ER22/23EK. P value was not reported for the last polymorphism because all patients with NODAT had the wild-type genotype (GG/GG) and performing statistical analysis was not feasible. Among studied demographic/clinical/paraclinical variables, factors such as higher mean trough level of tacrolimus during the first month after transplantation and higher mean daily dose of prednisolone significantly linked with NODAT development.

CONCLUSION

Our data suggested that BclI polymorphism significantly affects NODAT development among Iranian kidney allograft recipients.

Dyslipidemia in Transplant Patients: Which Therapy?

Cardiovascular disease is the most important cause of death worldwide in recent years; an increasing trend is also shown in organ transplant patients subjected to immunosuppressive therapies, in which cardiovascular diseases represent one of the most frequent causes of long-term mortality. This is also linked to immunosuppressant-induced dyslipidemia, which occurs in 27 to 71% of organ transplant recipients. The aim of this review is to clarify the pathophysiological mechanisms underlying dyslipidemia in patients treated with immunosuppressants to identify immunosuppressive therapies which do not cause dyslipidemia or therapeutic pathways effective in reducing hypercholesterolemia, hypertriglyceridemia, or both, without further adverse events.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors Use for Atherogenic Dyslipidemia in Solid Organ Transplant Patients

Dyslipidemia is a widespread risk factor in solid organ transplant patients, due to many reasons, such as the use of immunosuppressive drugs, with a consequent increase in cardiovascular diseases in this population. PCSK9 is an enzyme mainly known for its role in altering LDL levels, consequently increasing cardiovascular risk. Monoclonal antibody PCSK9 inhibitors demonstrated remarkable efficacy in the general population in reducing LDL cholesterol levels and preventing cardiovascular disease. In transplant patients, these drugs are still poorly used, despite having comparable efficacy to the general population and giving fewer drug interactions with immunosuppressants. Furthermore, there is enough evidence that PCSK9 also plays a role in other pathways, such as inflammation, which is particularly dangerous for graft survival. In this review, the current evidence on the function of PCSK9 and the use of its inhibitors will be discussed, particularly in transplant patients, in which they may provide additional benefits.

Association between the Three Polymorphisms of the Glucocorticoid Receptor Gene and the Early Clinical Outcome in Kidney Transplantation Patients

Background:

Glucocorticoids are pivotal components of immunosuppressive regimens in solid organ transplantations. This study aimed to assess the possible association between the ER22/23EK, N363S, and Bcl1 polymorphisms, and short-term clinical outcomes, including acute rejection and delayed graft function (DGF), in kidney transplantation recipients.

Methods:

A case-control study was conducted in a two-year period on adults with transplanted kidneys, comprised of subjects without rejection (n=50, control) and those with documented rejection within one year after transplantation (n=50, case), between April 2017 and September 2018, in Shiraz, Iran. Demographic characteristics and clinical and paraclinical findings were gathered. The genotyping of the ER22/23EK, N363S, and Bcl1 polymorphisms was carried out via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The association between the genotypes and DGF as well as rejection types was evaluated using either the Chi square test or Fisher exact test. A stepwise logistic regression analysis was conducted to determine the independent factors of acute rejection within the first year after transplantation.

Results:

The study population consisted of 64 men and 36 women. The frequency of mutated alleles was 0.32 for G (Bcl1), 0.02 for S (N363S), and 0.065 for A (ER22/23EK). There was no significant association either between the studied polymorphisms and acute rejection or between the Bcl1 (P=0.17), N363S (P=0.99), and ER22/23EK (P=0.99) genotypes and DGF. The length of hospital stay after kidney transplantation was slightly more in N363N and ER22/23EK wild allele carriers. However, this difference was not statistically significant.

Conclusion:

Our data suggested no statistically significant association between the genotypes of the studied polymorphisms and early clinical outcomes after kidney transplantation.

Low-dose Rituximab and Thymoglobulin Induction With Steroid-free Maintenance Immunosuppression and Protocol Biopsies Improves Long-term Patient and Graft Survival After Kidney Transplantation: Survival and Safety Outcomes in More Than 1100 Patients From a Single Center

BACKGROUND

Steroid-free maintenance immunosuppression after kidney transplantation provides acceptable patient and graft survival and minimizes steroid-associated side effects among recipients with a low immunological risk. However, the long-term outcomes of such protocols, incorporating low-dose rituximab and thymoglobulin induction along with protocol biopsies, in non-European populations remains underreported.

METHODS

We retrospectively analyzed 1142 consecutive kidney transplantations conducted at our center from July 2005 to October 2017. Immunosuppression protocol included induction with thymoglobulin and low-dose preoperative rituximab. Maintenance immunosuppression consisted of tacrolimus and mycophenolate mofetil; prednisolone was discontinued on postoperative day 5. Protocol biopsies were carried out at 3 months and at 1, 5, and 10 years after transplantation-in addition to the indicated biopsies. The 12-year patient and graft survival and posttransplantation complications were studied.

RESULTS

The analysis of outcomes was conducted for 1111 transplant recipients. Patients (70.59%) remained steroid-free at 12 years after transplantation. The patient survival rates at 1, 5, and 12 years were 97.7%, 94.8%, and 92.4%, respectively. The corresponding graft survival rates were 97.2%, 90.9%, and 86.1%, respectively. Biopsy-proven acute rejection occurred in 12.7% of recipients, including 3.5% subclinical rejections. The cumulative incidence of graft loss was 6.56% at 12.3 years. The overall incidence of death was 5.3%.

CONCLUSIONS

Steroid-free maintenance immunosuppression was associated with excellent long-term patient and graft survival rates and reduced incidence of prednisolone-related side effects, despite acceptable rejection rates. Low-dose rituximab with thymoglobulin induction with immediate steroid withdrawal and surveillance biopsies resulted in excellent long-term outcomes in our single-center experience.