FTO rs9939609 Gene Polymorphism and Obesity: Lack of Association in Kidney Transplantation

The fat mass and obesity-associated (FTO) gene is one of the most important obesity susceptibility genes. Some FTO gene polymorphisms have been associated with obesity, diabetes, and hypertension, all conditions for which, after transplant, there is increased susceptibility, due to effects of immunosuppressive regimens. To evaluate whether FTO could be a candidate for targeted preventive intervention in the transplant setting, we investigated whether the common genetic variation, FTO rs9939609T>A, could affect weight gain and risk of cardiovascular complications in kidney transplantation.

METHODS

In 198 kidney transplant recipients, FTO rs9939609 was investigated in association with body mass index (BMI)/obesity and with other clinical markers of posttransplant risk, then monitored up to 5 years after transplantation. Genotyping was performed using an allelic discrimination method on a real-time polymerase chain (PCR) system. Associations were analyzed using the chi-square test; differences between genotypes were examined with analysis of variance or Kruskal-Wallis test; tests for repeated measures and a general linear model analysis controlling for age and gender were also utilized.

RESULTS

Allele and genotype frequencies of FTO rs9939609 in recipients (T/T, 29.8%; T/A, 49.0%; A/A, 21.2%; A, 45.7%; T, 54.3%) reflect those present in healthy Caucasian populations. In the face of pre-/posttransplant differences in total cholesterol, triglycerides, or fasting glucose, results did not show significant changes in these factors among genotypes either before or after transplantation.

CONCLUSION

This study highlights a lack of association of FTO rs9939609T>A genotypes and posttransplant weight gain, plasma lipids, and fasting blood glucose in kidney transplantation.

Kidney Transplantation, Polymorphisms of IL-18, and Other Pro-Inflammatory Genes and Late Post-Transplant Outcome

BACKGROUND

Functional polymorphisms of molecules involved in immune-mediated mechanisms of allograft rejection could be predictive of increased risk for early and late post-transplant complications. In the past years, the challenge for long-term graft survival in kidney recipients is the implementation of personalized approaches. In this study, effects of interleukin (IL)-18-137G/C (rs187238), -607C/A (rs1946518), and other pro-inflammatory cytokine gene polymorphisms (tumor necrosis factor [TNF]-α-308G/A, rs1800629, IL-6-174G/C, rs1800795, and interferon [IFN]-γ+874A/T, rs2430561) on the main post-transplant risk parameters and diseases (metabolic, cardiovascular, infective, and chronic allograft rejection) were assessed in kidney-transplanted patients.

METHODS

One hundred seventy-nine transplanted patients were retrospectively analyzed for clinical and biochemical parameters and onset of post-transplant complications. Taqman allelic discrimination and PCR-SSP (polymerase chain reaction-sequence specific primers) techniques were used for genotyping.

RESULTS

No predictive effects of allele and genotypes of IL-18-607C/A, TNF-α-308G/A, IL-6-174G/C, and IFN-γ+874A/T gene polymorphisms and onset of risk factors and late complications were evidenced. However, Kaplan-Meier analysis evidenced a weak effect of IL-18-137G/C genotypes on graft survival.

CONCLUSIONS

Analyzing associations between some pro-inflammatory cytokine gene polymorphisms and onset of the most relevant risk factors and late complications of kidney transplant, results suggested a possible impact of IL-18-137G/C genotypes on graft survival, which deserves further studies.