Establishing the blood reference interval of pancreatic elastase-1: A prospective study.

BACKGROUND AND AIM: Pancreatic elastase-1 (PE-1) has been investigated in pancreatic disorders. However, the reference interval (RI) of PE-1 in blood remains unconfirmed. We aimed to establish the blood RI of PE-1 in an adult population. METHODS: In this prospective cross-sectional study, we enrolled 400 adults who had received the whole-body physical check-up program between May 1, 2019 and November 20, 2019. The serum and plasma PE-1 levels were measured by latex turbidimetric immunoassay in different storage conditions (fresh, refrigerated, and frozen). The 95% and 99% RI of PE-1 were calculated according to the Clinical & Laboratory Standards Institute guidelines. The correlations between PE-1 and other parameters were analyzed using multivariable regression models. Ultimately, 38 patients with acute pancreatitis were prospectively recruited as the validation cohort. RESULTS: The PE-1 levels in fresh serum were highly correlated with those in refrigerated (R2  = 0.998) or frozen (R2  = 0.942) samples; however, plasma should not be suggested in frozen conditions (plasma vs serum: R2  = 0.185). In the RI study population (202 male & 198 female participants), the median age was 52.6 (25-75% interquartile range: 43.1-61.0). The 95% and 99% RIs of PE-1 were 30.0-221.0 and 22.0-359.0 ng/dL, respectively. Triglycerides (ß = 0.106, P = 0.033), lipase (ß = 0.154, P = 0.007), and CA19-9 (ß = 0.130, P = 0.008) were independent factors associated with PE-1. In the pancreatitis validation cohort, with a cut-off value of 359.0 ng/dL, the sensitivity and specificity were 100% and 99.8%, respectively. CONCLUSION: The RI of PE-1 established in this study can be used for further applications. Serum is the suggested form for frozen sample storage.

Cessation of Nucleos(t)ide Analogue Therapy in Non-Cirrhotic Hepatitis B Patients with Prior Severe Acute Exacerbation.

Chronic hepatitis B (CHB) with severe acute exacerbation (SAE) is an urgent problem requiring nucleos(t)ide analogue (NA) therapy. We aim to evaluate the clinical relapse (CR) risk after discontinuing NA in patients with prior SAE. METHODS: In this retrospective cohort study, CHB patients who discontinued NA therapy were screened between October, 2003 and January, 2019. A total of 78 non-cirrhotic patients who had received NA therapy for CHB with SAE, i.e., bilirubin ≥ 2 mg/dL and/or prothrombin time prolongation ≥3 s, (SAE group) were matched 1:2 with 156 controls without SAE (non-SAE group) by means of propensity scores (age, gender, NA categories, NA therapy duration, and HBeAg status). RESULTS: The 5-year cumulative incidences of severe CR, i.e., ALT > 10X ULN, (42.78%, 95% CI: 27.84-57.73% vs. 25.42%, 95% CI: 16.26-34.58%; p = 0.045) and SAE recurrence (25.91%, 95% CI: 10.91-40.91% vs. 1.04%, 95% CI: 0-3.07%; p < 0.001) were significantly higher in the SAE group. Prior SAE history (HR 1.79, 95% CI: 1.04-3.06) was an independent factor for severe CR. The 5-year cumulative incidence of HBsAg seroclearance was significantly higher in the SAE group than that in the non-SAE group (16.82%, 95% CI: 2.34-31.30% vs. 6.02%, 95% CI: 0-13.23%; p = 0.049). CONCLUSIONS: Even though it creates a greater chance of HBsAg seroclearance, NA therapy cessation may result in a high risk of severe CR in non-cirrhotic CHB patients with prior SAE.