The β-glucosidase assay: a new diagnostic tool for necrotizing enterocolitis. Sensitivity, specificity, and predictive values.

UNLABELLED: We aimed to establish the utility of serum cytosolic β-glycosidase (CBG) assay as a NEC diagnosis tool. CBG activity has been compared in 192 NEC-free (NEC(-)) and 13 NEC-affected (NEC(+)) neonates, with modified Bell's stages II/III, born at Reina Sofia University Hospital; additional blood hematology, microbiology, and biochemical parameters have been assayed. NEC(+) neonates have higher serum CBG activity, 26.4 ± 12.4 mU/mg; 95 % CI (18.8-33.9), than NEC(-) infants, 11.0 ± 6.6 mU/mg; 95 % CI (10.1-11.9) (p < 0.0001). The CBG cutoff value in the ROC curve, 15.6 mU/mg, discriminates NEC(+)/NEC(-) infants with 84.6 % sensitivity, 85.9 % specificity, 37.9 positive predictive value and 98.2 negative predictive value, 6.11 positive likelihood ratio and 0.18 negative likelihood ratio, 33.61 DOR, and 0.89 AUC. A combined panel [CBG + aspartate aminotransferase + C-reactive protein] shows a 0.90 AUC value in multiple linear regressions.

CONCLUSIONS

The serum CBG level is a good NEC diagnosis test and a novel NEC biomarker which may become a screening tool.

WHAT IS KNOWN: •NEC affects ∼2.5 % of infants at NICU, ∼90 % of them weighing <1500 g. •NEC requires a careful differential diagnosis, being lethal if not diagnosed and treated. What is new: •CBG assay will be useful to determine infants without NEC and preventing unnecessary treatment. •CBG assay could discriminate NEC better than other gut-specific sera protein biomarkers.