Copy number variation in CCL3L1 gene is associated with susceptibility to acute rejection in patients after liver transplantation.

Copy number variation (CNV) in gene was a novel type of genetic diversity in human that affect the pathogenesis, progress, and prognosis of disease. The aim of this study was to determine the associations between CNV in CCL3L1 gene and the rejection risk in liver-transplant recipients. The 266 Han-Chinese patients and 135 volunteers were enrolled in this study. Genomic DNA and mRNA samples were obtained from the whole peripheral blood; a quantitative real-time PCR-based assay was carried out to determine the copy number of CCL3L1, and real-time PCR was carried out to calculate the CCL3L1/CCL3 mRNA ratio. The CNV distributions in patients and health controls had no significant differences. Copy number in acute rejection group (AR) shifted to higher number compared with non-acute rejection group (4.74±1.87 vs. 3.88±2.13, p=0.017). Moreover, patients with higher CCL3L1 copies (≥3 copies) had a significantly higher rejection risk than patients lower copies CCL3L1 (OR=3.85, 95% CI, 1.14-13.04; p=0.021). No association was found between CNV and rejection grades. In conclusion, liver transplant recipients with high copy number of CCL3L1 gene had a significant higher risk of AR. CNV might be a novel genetic diversity that correlated with allograft rejection.