Clinical performance of an infliximab rapid quantification assay. (September 2017)

• Record Type: Journal Article
• Authors: Magro, Fernando; Afonso, Joana; Lopes, Susana; Coelho, Rosa; Gonçalves, Raquel; Caldeira, Paulo; Lago, Paula; de Sousa, Helena Tavares; Ramos, Jaime; Gonçalves, Ana Rita; Ministro, Paula; Rosa, Isadora; Meira, Tânia; Andrade, Patrícia; Soares, João-Bruno; Carvalho, Diana; Sousa, Paula; Vieira, Ana Isabel; Lopes, Joanne; Dias, Cláudia Camila; Geboes, Karel; Carneiro, Fátima
• Is Part Of: Therapeutic advances in gastroenterology. Volume 10:Number 9(2017)
• Page Start: 651
• Page End: 660
• Publication Date: 2017-09
• Subjects: infliximab -- ulcerative colitis -- therapeutic window; Gastroenterology -- Periodicals; Digestive organs -- Diseases -- Treatment -- Periodicals; Gastrointestinal system -- Diseases -- Treatment -- Periodicals; Liver -- Diseases -- Treatment -- Periodicals; Pharmacology -- Periodicals; Gastroenterology -- Periodicals; Gastrointestinal Diseases -- therapy -- Periodicals; Liver Diseases -- therapy -- Periodicals; Pharmacology -- Periodicals; Gastroentérologie -- Périodiques; Appareil digestif -- Maladies -- Traitement -- Périodiques; Tractus gastro-intestinal -- Maladies -- Traitement -- Périodiques; Hépatologie -- Périodiques; Foie -- Maladies -- Périodiques; Pharmacologie -- Périodiques; 616.3005
• DOI: 10.1177/1756283X17722916
• Languages: English
• ISSNs: 1756-283X

Abstract

Background: Therapeutic drug monitoring (TDM)-based algorithms can be used to guide infliximab (IFX) adjustments in inflammatory bowel disease (IBD) patients. This study aimed to explore a rapid IFX-quantification test from a clinical perspective. Methods: This manuscript describes a prospective cohort study involving 110 ulcerative colitis (UC) patients on the maintenance phase of IFX. IFX trough levels were quantified using a rapid quantification assay and a commonly-used reference kit. Results: Irrespective of the assay used to measure IFX, its through levels were statistically different between patients with and without endoscopic remission (Mayo endoscopic score = 0), as well as between patients stratified by their faecal calprotectin (FC) levels. Despite the fact that the two methods correlated well with each other [Spearman's rank correlation coefficient = 0.843, p < 0.001; intraclass correlation coefficients = 0.857, 95% confidence interval (CI): 0.791–0.903], there was a discernible systematic variation; values obtained with the reference kit were on average 2.62 units higher than those obtained with the rapid assay. Notwithstanding, 3 µg/ml was shown to be an acceptable cut-off to assess endoscopic status and inflammatory burden levels using both assays. The percentage of patients that had a positive outcome when the IFX concentration measured by the rapid assay ranked above 3 µg/ml was 88% both for a Mayo endoscopic score ⩽ 1 and for an FC concentration <250 µg/g. Conclusions: Based on this study, we concluded that using the rapid IFX assessment system with a 3 µg/ml threshold is a reliable alternative to the time-consuming enzyme-linked immunosorbent assays in patients on the maintenance phase of IFX.