Serum MicroRNA-99a Helps Detect Acute Rejection in Renal Transplantation

MicroRNAs (miRNAs) are short, single-stranded, non-coding RNAs, and they are becoming increasingly known as potential biomarkers for a variety of pathologies. However, the significance of circulating miRNAs in renal transplantation patients needs further studies.

An miRNA array was used to profile the serum miRNAs of stable transplantation patients and transplantation patients with acute rejection (AR). We performed quantitative real-time polymerase chain reaction with the serum samples from 12 patients with AR, 11 control transplantation patients without rejection, and 15 transplantation patients with delayed graft function (DGF) for validation. Receiver operator characteristic analysis was used to assess the diagnostic capacity of serum miRNA.

The miR-99a, miR-100, miR-151a, let-7a, let-7c, and let-7f were deregulated in the serum of the patients with AR. In the validation set, only miR-99a and miR-100 were upregulated in the AR group. We further evaluated the expression levels of miR-99a and miR-100 in the DGF group. Only miR-99a was observed with the potent diagnostic value in discriminating AR patients from stable patients (area under the curve [AUC] = 0.750, 95% confidence interval [CI] = 0.529-0.971, P = .042) and DGF patients (AUC = 0.811, 95% CI = 0.600-1.000, P = .006).

Serum miR-99a may serve as a biomarker of AR in renal transplantation patients. Further studies are required to confirm the results.