RESUMEN
OBJECTIVE: To evaluate the clinical potential of urine prostatic exosomal protein (PSEP) as a diagnostic biomarker of chronic prostatitis (CP). Materials andmethods: Using an enzyme-linked immunosorbent assay kit, urine PSEP levels were detected in 103 control cases as well as 283 cases of CP, with 82 cases fulfilling the definition of the USA National Institutes of Health category II (NIH-II), 108 cases of NIH-IIIa and 93 cases of NIH-IIIb. The values of age, body mass index, prostate volume, serum prostatic specific antigen (PSA) urine PSEP levels, and seminal parameters were analyzed. RESULTS: The PSEP levels were significantly higher in patients of NIH-II (2.09 [2.35] ng/mL), NIH-IIIa (1.80 [2.95] ng/mL) and NIH-IIIb (1.64 [2.48] ng/mL) compared to the value of 0.24 (0.76) ng/mL in the controls. ROC identified a cutoff value of 1.387 ng/mL, with a sensitivity of 59.0% and specificity of 94.2%. The area under the ROC curve was 0.833. PSEP levels positively correlated with serum PSA levels in the NIH-IIIb group, and with EPS WBC count in the NIH-IIIa group, and with semen WBC count in each CP subgroups but negatively correlated with sperm motility in both the NIH-IIIa group and the NIH-IIIb group. CONCLUSION: Urine PSEP could be a potential biomarker for CP.
Asunto(s)
Complejo Multienzimático de Ribonucleasas del Exosoma/orina , Prostatitis/diagnóstico , Prostatitis/orina , Proteínas de Unión al ARN/orina , Adulto , Enfermedad Crónica , Humanos , MasculinoRESUMEN
Urinary exosomes are 40-100 nm vesicles containing protein, mRNA, and microRNA that may serve as biomarkers of renal dysfunction and structural injury. Currently, there is a need for more sensitive and specific biomarkers of renal injury and disease progression. Here we sought to identify the best exosome isolation methods for both proteomic analysis and RNA profiling as a first step for biomarker discovery. We used six different protocols; three were based on ultracentrifugation, one used a nanomembrane concentrator-based approach, and two utilized a commercial exosome precipitation reagent. The highest yield of exosomes was obtained using a modified exosome precipitation protocol, which also yielded the highest quantities of microRNA and mRNA and, therefore, is ideal for subsequent RNA profiling. This method is likewise suitable for downstream proteomic analyses if an ultracentrifuge is not available and/or a large number of samples are to be processed. Two of the ultracentrifugation methods, however, are better options for exosome isolation if an ultracentrifuge is available and few samples will be processed for proteomic analysis. Thus, our modified exosome precipitation method is a simple, fast, highly scalable, and effective alternative for the isolation of exosomes, and may facilitate the identification of exosomal biomarkers from urine.