Circulating microRNAs as non-invasive diagnostic biomarkers for community-acquired pneumonia

Community-acquired pneumonia (CAP) remains a major cause of morbidity and mortality worldwide, while timely and accurate diagnosis remains challenging. Circulating microRNAs (miRNAs) have emerged as promising non-invasive biomarkers; however, their diagnostic accuracy for CAP has not been systematically quantified. PubMed, Web of Science, Cochrane Library, and Embase were searched from inception to April 14, 2026. Study selection and data extraction were independently performed by two investigators, and study quality was assessed using QUADAS-2. A bivariate random-effects model was used to estimate pooled sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and area under the curve (AUC). Exploratory subgroup and sensitivity analyses were performed, and publication bias was assessed. Fourteen studies involving 2,177 participants were included. The pooled sensitivity and specificity were 0.81 (95% CI: 0.74–0.86) and 0.88 (95% CI: 0.85–0.91), respectively. The pooled positive and negative likelihood ratios were 6.93 (95% CI: 5.31–9.04) and 0.22 (95% CI: 0.16–0.30), respectively, with a pooled DOR of 31.98 and an AUC of 0.92 (95% CI: 0.89–0.94). Exploratory subgroup analyses suggested differences in diagnostic performance according to miRNA expression direction. Deeks’ test indicated potential publication bias ( P = 0.01), while sensitivity analyses showed that the pooled estimates remained robust. Circulating miRNAs demonstrate promising diagnostic potential as non-invasive biomarkers for CAP. Future large-scale, multicenter prospective studies are needed to validate their diagnostic performance and clinical applicability.