Identification of ICAM-1 polymorphism that is associated with protection from transplant associated vasculopathy after cardiac transplantation

Transplant associated coronary disease (TxCAD) is the main cause of late gr aft loss following cardiac transplantation. It is a multifactorial disease with immunologic and nonimmunologic components involved. This study was und ertaken to analyze the gene polymorphism in adhesion molecules in donors an d recipients and to investigate its potential association with the developm ent of TxCAD. A coral of 82 cardiac transplant patients, 96 donors and 101 UR controls, were genotyped retro-specetively. Nine nucleotide polymorphism s in L-selectin, E-selectin, ICAM-1, and PECAM were analyzed using allele-s pecific PCR-SSP assay. Recipients were selected on the basis of the develop ment of TxCAD: patients who had developed TxCAD within 2 years after transp lantation, and patients who did not have TxCAD within 4.5-5 years after tra nsplantation. All recipients received CyA and azathioprine as a primary imm unosuppression. Associations were assessed by using Fisher's exact rest. No association was found between E-selectin, L-selectin, and PECAM allele or genotype frequencies and TxCAD. However, the donors whose recipients did no r develop TxCAD at first 2 years had a significant increase of ICAM-1 E-469 allele compared with donors, whose recipients developed TxCAD (63.8% vs 46 .4%,p = 0.042) and to UK controls (63.8% vs 47%,p = 0.04). Moreover, we fou nd that the decreased frequency of ICAM E469 allele was associated with the increased number of rejection episodes. The 469 E/K polymorphism is in exo n 6 and results in a change from glutamic acid to lysine in Ig-like domain 5 of ICAM-1, which is thought to affect interactions with LFA-1 and adhesio n of B-cells. Our data suggest the presence of allele E469 ICAM-1 in either donor or recipient is protective against allograft rejection in a transpla nt setting. Human Immunology 62, 247-255 (2001). (C) American Society for H istocompatibility and Immunogenetics, 2001. Published by Elsevier Science I nc.