External Validation of the Newly Developed BETA-2 Scoring System for Pancreatic Islet Graft Function Assessment

Abstract Background BETA-2 score using a single fasting blood sample was developed to estimate beta-cell function after islet transplantation (ITx) and was validated internally by a high ITx volume center (Edmonton). The goal was to validate BETA-2 externally, in our center. Methods Areas under receiver operating characteristic curves (AUROCs) were obtained to see if beta score or BETA-2 would better detect insulin independence and glucose intolerance. Results We analyzed values from 48 mixed meal tolerance tests (MMTTs) in 4 ITx recipients with a long-term follow-up to 140 months (LT group) and from 54 MMTTs in 13 short-term group patients (ST group). AUROC for no need for insulin support was 0.776 (95% confidence interval [CI] 0.539–1, P  = .02) and 0.922 (95% CI 0.848–0.996, P P  = .003) and 0.941 (95% CI 0.86–1, P 76% and specificity, PPV, and NPV > 80% in both groups. Conclusion BETA-2 score was successfully validated externally and is a practical tool allowing for frequent and reliable assessments of islet graft function based on a single fasting blood sample.