Role of human leukocyte antigen-G 14-base pair polymorphism in kidney transplantation outcomes

BACKGROUND: Both the membrane-bound and soluble forms of human leukocyte antigen-G (HLA-G) molecules exhibit a multitude of immunomodulatory properties that can potentially obviate or delay graft rejection. The 14-base pair (14-bp) polymorphism in the 3'-untranslated region of the HLA-G gene is thought to have a role in soluble HLA-G (sHLA-G) expression. METHODS: In this study, we retrospectively investigated a large cohort of 418 kidney transplant recipients with the aim of establishing whether the HLA-G 14-bp insertion/deletion polymorphism could serve as an effective genetic risk marker for acute and/or chronic deterioration of transplanted kidney function. RESULTS: A statistically significant higher incidence of chronic kidney dysfunction leading to allograft loss was observed in transplant recipients homozygous for the HLA-G 14-bp deletion polymorphism. This difference increased over time and was confirmed by progressive decline in the glomerular filtration rate. CONCLUSIONS: These results suggest that alongside other factors previously consolidated in clinical practice, recipient HLA-G 14-bp genotype may serve as an adjuvant independent predictor of long-term outcome of kidney transplantation.