Nanoscale flow cytometry to distinguish subpopulations of prostate extracellular vesicles in patient plasma.

OBJECTIVE: To determine if prostate-derived extracellular vesicles (EVs) present in patient plasma samples are of exocytotic origin (exosomes) or released by the cell membrane (microparticles/microvesicles). Both malignant and normal prostate cells release two types of EVs into the circulation, exosomes, and microparticles/microvesicles which differ in size, origin, and mode of release. Determining what proportion of prostate-derived EVs are of exosomal versus microparticle/microvesicle EV subtype is of potential diagnostic significance. MATERIALS AND METHODS: Multi-parametric analytical platforms such as nanoscale flow cytometry (nFC) were used to analyze prostate derived extracellular vesicles. Plasmas from prostate cancer (PCa) patient plasmas representing benign prostatic hyperplasia (BPH), low grade prostate cancer (Gleason Score 3 + 3) and high grade prostate cancer (Gleason Score ≥4 + 4) were analyzed for various exosome markers (CD9, CD63, CD81) and a prostate specific tissue marker (prostate specific membrane antigen/PSMA). RESULTS: By using nanoscale flow cytometry, we determine that prostate derived EVs are primarily of cell membrane origin, microparticles/microvesicles, and not all PSMA expressing EVs co-express exosomal markers such as CD9, CD63, and CD81. CD9 was the most abundant exosomal marker on prostate derived EVs (12-19%). There was no trend observed in terms of more PSMA + CD9 or PSMA + CD63 co-expressing EVs versus increasing grade of prostate cancer. CONCLUSION: The majority of prostate derived EVs present in plasmas are from the cell membrane as evidenced by their size and most importantly, lack of co-expression of exosomal markers such as CD9/CD63/CD81. In fact, CD81 was not present on any prostate derived EVs in patient plasmas whereas CD9 was present on a minority of prostate derived EVs. The addition of an exosomal marker for detection of prostate-derived EVs does not provide greater clarity in distinguishing EVs released by the prostate.

Long- versus short-duration systemic corticosteroid regimens for acute exacerbations of COPD: A systematic review and meta-analysis of randomized trials and cohort studies.

While systemic corticosteroids quicken patient recovery during acute exacerbations of COPD, they also have many adverse effects. The optimal duration of corticosteroid administration remains uncertain. We performed a systematic review and meta-analysis to compare patient outcomes between short- (≤7 days) and long- (>7 days) corticosteroid regimens in adults with acute exacerbations of COPD. MEDLINE, EMBASE, CENTRAL, and hand searches were used to identify eligible studies. Risk of bias was assessed using the Cochrane RoB 2.0 tool and ROBINS-I. Data were summarized as ORs (odds ratios) or MDs (mean differences) whenever possible and qualitatively described otherwise. A total of 11532 participants from eight RCTs and three retrospective cohort studies were included, with 1296 from seven RCTs and two cohort studies eligible for meta-analyses. Heterogeneity was present in the methodology and settings of the studies. The OR (using short duration as the treatment arm) for mortality was 0.76 (95% CI = 0.40-1.44, n = 1055). The MD for hospital length-of-stay was -0.91 days (95% CI = -1.81--0.02 days, n = 421). The OR for re-exacerbations was 1.31 (95% CI = 0.90-1.90, n = 552). The OR for hyperglycemia was 0.90 (95% CI = 0.60-1.33, n = 423). The OR for infection incidence was 0.96 (95% CI = 0.59-1.156, n = 389). The MD for one-second forced expiratory volume change was -18.40 mL (95% CI = -111.80-75.01 mL, n = 161). The RCTs generally had low or unclear risks of bias, while the cohort studies had serious or moderate risks of bias. Our meta-analyses were affected by imprecision due to insufficient data. Some heterogeneity was present in the results, suggesting population, setting, and treatment details are potential prognostic factors. Our evidence suggests that short-duration treatments are not worse than long-duration treatments in moderate/severe exacerbations and may lead to considerably better outcomes in milder exacerbations. This supports the current GOLD guidelines. Trial registration: Our protocol is registered in PROSPERO: CRD42023374410.