HLA-G 14-bp insertion/deletion polymorphism in kidney transplant patients with metabolic complications.

HLA-G, a nonclassical HLA molecule with limited polymorphism has immunomodulating/tolerogenic properties. The most common polymorphism of HLA-G is a deletion/insertion of 14 bp, located at the 3'UTR region of the gene (exon 8). This polymorphism is associated with modifications of mRNA stability that can lead to variations of membrane versus soluble HLA-G expression. HLA-G may be involved in the clinical outcomes of transplantation, as evidenced by studies in hematopoietic cell transplantation. We evaluated the possible prognostic importance of 14-bp polymorphisms of HLA-G among kidney transplantation patients. Using polymerase chain reaction amplification we genotyped 124 patients (mean organ survival: 878.95 +/- 595.12 days; range = 1-2565) and 98 control individuals representative of the Italian population. Products were visualized by electrophoresis on agarose gels. The results showed no differences between patients and controls. Twenty-nine patients with acute or chronic rejection or in whom clinical conditions required the use of steroid bolus treatments also showed no association with HLA-G 14-bp genotypes or alleles. The subset of patients with dyslipidemia during follow-up showed a significant decrease among the HLA-G-14/-14 genotype, compared with heterozygous (+14/-14) and nondeleted homozygous (+14/+14) genotype patients (P(c) = .03). These preliminary data showed that HLA-G 14-bp genotypes, although not predictive of rejection, may be useful to identify individuals at risk for the development of posttransplant complications.