부산대학교 도서관

Background: The treatment for Crohn's disease (CD) has increasingly required the use of biological agents. Safe and affordable tests have led to the active implementation of therapeutic drug monitoring (TDM) in clinical practice, which, although not yet widely available across all health services, has been proven effective. Objective: To analyze serum infliximab (IFX) and antidrug antibody (ADA) levels in CD patients, compare two tests, as well as construct a prediction of neural network using a combination of clinical, epidemiological, and laboratory variables. Design: Cross-sectional observational study. Method: A cross-sectional observational study was conducted on 75 CD patients in the maintenance phase of IFX treatment. The participants were allocated into two groups: CD in activity (CDA) and in remission (CDR). Disease activity was defined by endoscopic or radiological criteria. Serum IFX levels were measured by enzyme-linked immunosorbent assay (ELISA) and rapid lateral flow assay; ADA levels were measured by ELISA. A nonparametric test was used for statistical analysis; p value of ⩽0.05 was considered significant. Differences between ELISA and rapid lateral flow results within the measurement range were assessed by the Wilcoxon test, Passing–Bablok regression, and Bland–Altman method. Prediction models were created using four neural network sets. Neural networks and performance receiver operating characteristic curves were created using the Keras package in Python software. Results: Most participants exhibited supratherapeutic IFX levels (>7 mg/mL). Both tests showed no difference in IFX levels between the CDA and CDR groups (p > 0.05). The use of immunosuppressive therapy did not affect IFX levels (p > 0.05). Only 14.66% of patients had ADA levels >5 AU/mL, and all ADA-positive participants exhibited subtherapeutic IFX levels in both tests. The median results of both tests showed significant differences and moderate agreement (r = −0.6758, p < 0.001). Of the four neural networks developed, two showed excellent performance, with area under the curve (AUCs) of 82–92% and 100%. Conclusion: Most participants exhibited supratherapeutic IFX levels, with no significant serum level difference between the groups. There was moderate agreement between tests. Two neural network sets showed disease activity and the presence of ADA, noninvasively determined in patients using IFX by presenting an AUC of >80%. Plain language summary: Infliximab drug monitoring in Crohn's disease Crohn's disease (CD) is a chronic condition that affects the gastrointestinal tract, with potential effects anywhere between the mouth and the anus. The primary treatment goal is symptom control and disease remission. The objective of this study was to analyze blood levels of infliximab (IFX), a commonly used medication for CD treatment. We also evaluated the level of antibodies that the body can produce against this medication to justify nonresponse to the drug. IFX levels were compared in 75 patients with CD in activity and in remission and using two different tests. The results showed that most patients had serum IFX above the recommended level (> 7 mg/mL). Neither of these tests showed differences in IFX levels when we evaluated disease activity or when the patients used immunosuppressants. Both tests showed antibodies against IFX in 14.66% of patients, all of whom had IFX levels below the therapeutic level. We compared two tests, ELISA and rapid test, and observed a difference between them, with moderate agreement. Normal serum IFX levels were higher with the rapid test than with the ELISA; however, they presented linear relationship. We also created prediction models using neural networks (artificial intelligence), which demonstrated excellent performance in noninvasively predicting disease activity and the presence of antibodies against IFX, achieving an area under the curve between 82% and 100%. [ABSTRACT FROM AUTHOR]