Trough level of infliximab is useful for assessing mucosal healing in Crohn's disease: a prospective cohort study

BACKGROUND/AIMS: Decreased trough levels of infliximab (TLI) and antibodies to infliximab (ATI) are associated with loss of response (LOR) in Crohn's disease. Two prospective studies were conducted to determine whether TLI or ATI better correlates with LOR (Study 1), and whether TLI could become a predictor of mucosal healing (MH) (Study 2). METHODS: Study 1 was conducted in 108 patients, including those with LOR and remission to compare ATI and TLI in discriminating the 2 conditions based on receiver operating characteristic (ROC) curve analyses. Study 2 involved 35 patients who were evaluated endoscopically. RESULTS: In Study 1, there were no differences between the 2 assays in ROC curve analyses; the TLI cutoff value for LOR was 2.6 µg/mL (sensitivity, 70.9%; specificity, 79.2%), and the ATI cutoff value was 4.9 µg/mL (sensitivity, 65.5%; specificity, 67.9%). The AUROC (area under the ROC curve) of TLI was greater than that of ATI. AUROC was useful for discriminating between the 2 conditions. In Study 2, the TLI was significantly higher in the colonic MH group than in the non-MH group (2.7 µg/mL vs. 0.5 µg/mL, P=0.032). CONCLUSIONS: TLI is better than ATI for clinically diagnosing LOR, and a correlation was observed between TLI and colonic MH.

Comparison of Glucose Area Under the Curve Measured Using Minimally Invasive Interstitial Fluid Extraction Technology with Continuous Glucose Monitoring System in Diabetic Patients

BACKGROUND: Continuous glucose monitoring (CGM) is reported to be a useful technique, but difficult or inconvenient for some patients and institutions. We are developing a glucose area under the curve (AUC) monitoring system without blood sampling using a minimally invasive interstitial fluid extraction technology (MIET). Here we evaluated the accuracy of interstitial fluid glucose (IG) AUC measured by MIET in patients with diabetes for an extended time interval and the potency of detecting hyperglycemia using CGM data as a reference. METHODS: Thirty-eight inpatients with diabetes undergoing CGM were enrolled. MIET comprised a pretreatment step using a plastic microneedle array and glucose accumulation step with a hydrogel patch, which was placed on two sites from 9:00 AM to 5:00 PM or from 10:00 PM to 6:00 AM. IG AUC was calculated by accumulated glucose extracted by hydrogel patches using sodium ion as standard. RESULTS: A significant correlation was observed between the predicted AUC by MIET and CGM in daytime (r=0.76) and nighttime (r=0.82). The optimal cutoff for the IG AUC value of MIET to predict hyperglycemia over 200 mg/dL measured by CGM for 8 hours was 1,067.3 mg·hr/dL with 88.2% sensitivity and 81.5% specificity. CONCLUSION: We showed that 8-hour IG AUC levels using MIET were valuable in estimating the blood glucose AUC without blood sampling. The results also supported the concept of using this technique for evaluating glucose excursion and for screening hyperglycemia during 8 hours in patients with diabetes at any time of day.