Objective To investigate the value of serum Apelin-13 and Omentin-1 in early prediction of acute renal injury after renal transplantation.

Methods A total of 89 renal transplantation patients were included in the renal transplantation group, and were divided into renal injury group (21 cases) and non-renal injury group (68 cases) according to whether acute renal injury occurred within one month after renal transplantation. At the same time, 87 healthy people were randomly selected as the control group. Serum Apelin-13 and Omentin-1 levels were detected by enzyme-linked immunosorbent assay (ELISA); the Cystatin C levels were determined by particle enhanced transmission immunoturbidimetry; serum creatinine level was determined by enzyme method; the blood urea nitrogen level was determined by UV-glutamate deaminase method; the levels of β₂-microglobulin and 24 h urinary protein were measured by turbidimetry. The eMDRD equations were corrected and estimated glomerular filtration rate (eGFR) was calculated. Pearson method was used to analyze the correlations of serum Apelin-13 and Omentin-1 levels with renal function indexes in renal transplantation patients with postoperative renal function injury; receiver operating characteristic (ROC) curve was used to analyze the predictive value of serum Apelin-13 and Omentin-1 levels on postoperative renal function injury in renal transplantation patients; Logistic regression analysis was used to analyze the influencing factors of renal function injury after renal transplantation.

Results The levels of serum creatinine, blood urea nitrogen, cystatin C, β₂-microglobulin and 24 h urinary protein in the renal transplantation group were significantly higher, and the levels of Apelin-13, Omentin-1 and eGFR were significantly lower than those in the control group (P < 0.05). The levels of serum creatinine, blood urea nitrogen, cystatin C, β₂-microglobulin and 24 h urinary protein in the renal injury group were significantly higher, and the levels of Apelin-13, Omentin-1 and eGFR were significantly lower than those in the non-renal injury group (P < 0.05). Serum Apelin-13 and Omentin-1 levels were negatively correlated with creatinine, blood urea nitrogen, cystatin C, β₂-microglobulin and 24 h urinary protein, and positively correlated with eGFR in renal transplantation patients with postoperative renal injury (P < 0.05). The area under the curve (AUC) of Apelin-13 and Omentin-1 alone and their combination to predict postoperative renal injury were 0.784, 0.773 and 0.841, respectively. Apelin-13 and Omentin-1 were protective factors for renal function injury after renal transplantation (P < 0.05).

Conclusion Serum Apelin-13 and Omentin-1 are low in patients with renal injury after renal transplantation, which may be an early predictor.