Sivelestat is widely used in treating acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), although the clinical efficacy of sivelestat remains controversial. This study aimed to evaluate the impact of sivelestat in patients with ALI/ARDS. Electronic databases, PubMed, Embase, and the Cochrane Library, were searched to identify trials through April 2017. Randomized controlled trials (RCTs) were included irrespective of blinding or language that compared patients with and without sivelestat therapy in ALI/ARDS. A random-effects model was used to process the data, and the relative risk (RR) and standard mean difference (SMD) with corresponding 95% confidence intervals (CIs) were used to evaluate the effect of sivelestat. Six RCTs reporting data on 804 patients with ALI/ARDS were included. Overall, no significant difference was found between sivelestat and control for the risk of 28–30 days mortality (RR: 0.94; 95% CI: 0.71–1.23; P = 0.718). Sivelestat therapy had no significant effect on ventilation days (SMD: 0.05; 95% CI: −0.27 to 0.38; P = 0.748), arterial oxygen partial pressure (PaO2)/fractional inspired oxygen (FiO2) level (SMD: 0.48; 95% CI: −0.45 to 1.41; P = 0.315), and intensive care unit (ICU) stays (SMD: −9.87; 95% CI: −24.30 to 4.56; P = 0.180). The results of sensitivity analysis indicated that sivelestat therapy might affect the PaO2/FiO2 level in patients with ALI/ARDS (SMD: 0.87; 95% CI: 0.39 to 1.35; P < 0.001). Sivelestat therapy might increase the PaO2/FiO2 level, while it had little or no effect on 28–30 days mortality, ventilation days, and ICU stays. These findings need to be verified in large-scale trials.

Extracellular vesicles (EVs) are nano-sized vesicles secreted by living cells and ubiquitously present in body fluids. They carry molecular cargo-including proteins, nucleic acids, and lipids-that accurately mirrors the physiological and pathological state of their parent cells, offering a highly promising novel source of biomarkers for liquid biopsy. This review systematically summarizes the progress in biomarker discovery and application of EVs in major diseases such as cancer, neurological disorders, and cardiovascular diseases. It provides an in-depth analysis of the key technical bottlenecks in current EV isolation, characterization, and detection methodologies, and discusses the challenges related to standardization and clinical translation. Finally, the review outlines the broad future prospects in this field, including integrated multi-omics analysis based on EVs, and their potential for early diagnosis, real-time therapeutic monitoring, and prognostic assessment.