Infliximab is emerging as the first-line therapy for Crohn's disease (CD); however, the rate of secondary loss of response (SLR) can exceed 50%. This study aimed to construct a nomogram based on bioelectrical impedance analysis (BIA) indexes and laboratory markers to predict SLR to infliximab in biologically naïve CD patients.
Data of 136 biologically naïve CD patients treated between September 2019 and March 2021 were retrospectively retrieved. BIA-based body composition parameters and laboratory markers were obtained before the infliximab therapy. Predictor selection was conducted using the least absolute shrinkage and selection operator (LASSO) and univariate logistic regression. The nomogram was developed using multivariable logistic regression, and internal validation was made by ten-fold cross-validation.
SLR occurred in 51% of the CD patients during 54 weeks. The nomogram predictors included hemoglobin, albumin, serum iron, and BIA scores. The nomogram showed significant discrimination (area under the curve [AUC], 0.920; 95% confidence interval, 0.873-0.967) and calibration (mean error = 0.012). Decision curve analysis (DCA) indicated that the nomogram provided net clinical benefit when the risk probability was between 2% and 83%. Internal validation assessment of the nomogram robustness found an AUC of 0.904 and an accuracy of 0.841.
This BIA-based body composition parameters- and laboratory markers-based novel nomogram could act as a predictive tool to evaluate SLR to infliximab therapy, crucial for optimizing treatment strategies and switching biologics in CD.