Objective  To observe the expression level of plasma exosomal microRNA-202-5p (miR-202-5p) in patients with severe traumatic brain injury (sTBI) and its value in predicting prognosis.

Methods  A total of 78 patients with sTBI were selected as study objects, and were divided into poor prognosis group and good prognosis group according to Glasgow Prognosis Scale (GOS) score, and 50 normal people in the same period were selected as control group. The plasma exosomes were extracted, and the expression level of miR-202-5p was detected. Logistic regression analysis was used to explore the factors associated with poor prognosis, and receiver operating characteristic (ROC) curve was used to analyze the prognostic value of miR-202-5p.

Results  The expression level of plasma exosomal miR-202-5p of STBI patients was (0.84±0.09), which was lower than (3.72±0.16) of the normal subjects (t=12.235, P < 0.01); the Glasgow Coma Scale (GCS) score, miR-202-5p level and Rotterdam CT score of patients with poor prognosis were lower than those of patients with good prognosis, and the Acute Physiology and Chronic Health Status Ⅱ (APACHE Ⅱ) score was higher than that of patients with good prognosis (P < 0.05). GCS score, miR-202-5p level, APACHE Ⅱ score and Rotterdam CT score were independent risk factors affecting the prognosis of patients. The level of miR-202-5p was positively correlated with Rotterdam CT score and GCS score (r= 0.703, 0.711, P < 0.01), and negatively correlated with APACHE Ⅱscore (r=-0.693, P < 0.01). The effect of area under ROC curve (AUC) of miR-202-5p in predicting prognosis of patients was better than that of APACHE Ⅱ score, Rotterdam CT score and GCS score.

Conclusion  The low expression of plasma exosomal miR-202-5p of sTBI patients can reflect the prognosis of the disease.