Evaluation of Plasma Levels of Soluble HLA-G and HLA-G Genotypes in Kidney Transplant Recipients

• Published in: Transplantation proceedings Vol. 52; no. 5; pp. 1559 - 1561
• Main Authors: Piancatelli, Daniela, Maccarone, Daniela, Colanardi, Alessia, Sebastiani, Pierluigi, D’Anselmi, Fabrizio, Iesari, Samuele, Binda, Barbara, Pisani, Francesco
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2020
• ISSN: 0041-1345; 1873-2623
• DOI: 10.1016/j.transproceed.2020.02.044

In the field of transplantation, expression of HLA-G, a nonclassical HLA molecule with immunosuppressive functions and limited gene polymorphism, is considered beneficial for graft acceptance; various studies have aimed to demonstrate this role in transplantation. Recently, in other clinical conditions, it has been observed that insulin resistance was associated with HLA-G14bpins/del polymorphism, the most studied regulatory polymorphism of this molecule. In the present study, plasma levels of the soluble form of HLA-G (sHLA-G) were analyzed in kidney transplant recipients (n = 103) with different HLA-G14bpins/del genotypes. In a group of 26 recipients, sHLA-G was detected before and after transplantation (1 year) to evaluate early variations. In 77 recipients, sHLA-G was detected after transplantation (3-24 years) and correlated with occurrence of long-term post-transplant morbidity (diabetes mellitus, hyperlipidemia, hypertension, obesity, etc.). Levels of sHLA-G were measured in plasma with an enzyme-linked immunosorbent assay; HLA-G14bpins/del and HLA-G+3142C>G genotypes were assessed using direct polymerase chain reaction. Plasma levels of sHLA-G significantly decreased during the first year after transplantation (P = .019); no significant correlations were found with genotypes or early post-transplant events. Lower levels of sHLA-G were found in recipients with post-transplant diabetes mellitus or obesity carrying the HLA-G14bpins/ins (P = .006 and P = .003, respectively) or HLA-G+3142G/G genotypes. A complex modulation of HLA-G, which includes both immunologic and metabolic effects, could affect the risk for long-term post-transplant morbidity in kidney transplant recipients. Associations of HLA-G, diabetes, and obesity deserve to be investigated by deeply exploring HLA-G regulatory variants.