Transforming growth factor-β1-gene polymorphism in the development of kidney disease after liver transplantation.

BACKGROUND

The development of kidney dysfunction is one of the most important after liver transplantation (LT). Genetic variants of pathogenetically relevant cytokines may influence the development and course of the disease. The aim of our study was to evaluate the role of transforming growth factor-β1 (TGF-β1) polymorphism in this context.

METHODS

Four hundred eighty-six liver graft recipients were genotyped for TGF-β1 codon 25 (guanine → cytosine, G → C) by polymerase chain reaction. Renal function before and after LT was characterized by estimation of glomerular filtration rate (GFR) using four-parameter-modification of diet in renal disease formula on defined dates. GFR was compared among TGF-β1-genotype groups of the entire cohort within the median observation period of 7 years. For the assessment of renal function recovery after LT, patients were divided into three groups by GFR difference (ΔGFR = ± 10 mL/min).

RESULTS

Mean pretransplant GFR differed significantly among TGF-β1-genotype groups (GG: 85.0 mL/min vs. GC/CC: 75.3 mL/min; P=0.016). The significance disappeared in the follow-up period. Although GG genotype demonstrated higher mean GFR levels, patients with GC/CC genotype tended to improve kidney function compared with GG genotype (P=0.013). Interestingly, lower mean GFR rates were observed among female compared with male recipients before (P=0.002), separately at all dates and cumulatively after LT (P<0.001).

CONCLUSIONS

Genetic variants of one of the most important cytokine TGF-β1 at codon 25 may have an impact on kidney function, suggesting an unfavorable effect of C allele in pretransplant setting and serve as marker for the recovery of renal function after LT. The identification of further confounders seems to be promising.