Proteomic analysis of plasma extracellular vesicles for predicting acute kidney injury following laparoscopic radical nephrectomy.

Acute kidney injury (AKI) is a common complication following laparoscopic radical nephrectomy (LRN). Emerging evidence implicates extracellular vesicles (EVs) as promising candidates for diagnostic biomarkers in disease surveillance, therapeutic efficacy evaluation, and prognostic stratification. Currently, there is a lack of research on preoperative plasma EVs protein markers for predicting AKI after LRN. Plasma samples were obtained prior to the induction of anesthesia. Plasma-derived EVs were isolated using combinatorial chromatography and analyzed proteomically through off-label quantification (4D-DIA) from 5 patients with postoperative AKI and 5 patients without. Subsequently, plasma samples from an additional cohort comprising 28 AKI patients and 24 no_AKI patients were collected to validate differential protein expression in EVs. A total of 43 differential proteins were identified in EVs extracted from plasma samples, including 1 up-regulated protein and 42 down-regulated proteins. Subsequent validation demonstrated that the mean levels of Poly(rC)-binding protein 2 (PCBP2) and Profilin 1 (Pfn1) were significantly lower in AKI patients compared to no_AKI patients, yielding an AUC of 0.893 and 0.923 (95% CI: 0.776 -0.962; 0.814 -0.978), a sensitivity of 92.9% and 89.3%, and a specificity of 83.3% and 87.5%, respectively. This study employed 4D-DIA proteomic analysis and identified 43 differentially expressed proteins, among which PCBP2 and Pfn1 in plasma EVs were significantly downregulated in AKI patients and demonstrated good predictive ability for AKI. Moreover, preoperative risk stratification based on their optimal cutoff values showed high consistency with the postoperative KDIGO clinical diagnostic criteria.