Observational Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. May 6, 2017; 8(2): 127-130
Published online May 6, 2017. doi: 10.4292/wjgpt.v8.i2.127
Correlation of rapid point-of-care vs send-out fecal calprotectin monitoring in pediatric inflammatory bowel disease
Alexis Rodriguez, Lauren Yokomizo, Megan Christofferson, Danielle Barnes, Nasim Khavari, K T Park
Alexis Rodriguez, Lauren Yokomizo, Megan Christofferson, Danielle Barnes, Nasim Khavari, K T Park, Stanford University School of Medicine, Stanford University, Palo Alto, CA 94304, United States
Alexis Rodriguez, Megan Christofferson, Danielle Barnes, Nasim Khavari, K T Park, Division of Gastroenterology, Department of Pediatrics, Stanford University, Palo Alto, CA 94304, United States
Author contributions: Rodriguez A and Yokomizo L contributed equally to this work; Park KT conceptualized the study; Rodriguez A, Yokomizo L, Christofferson M, Barnes D, Khavari N and Park KT participated in sample analysis and assisted in the logistics of the study; Rodriguez A, Yokomizo L and Park KT participated in the statistical analysis, wrote the manuscript and approved the final manuscript draft; Christofferson M, Barnes D and Khavari N edited and approved the final manuscript draft.
Institutional review board statement: This study had IRB approval from Stanford University.
Informed consent statement: Informed consent and assent forms were obtained prior to patient enrollment.
Conflict-of-interest statement: KT Park has served as consultant for Inova Diagnostics and received research support from BUHL MANN Laboratories.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: K T Park, MD, MS, Division of Gastroenterology, Department of Pediatrics, Stanford University, 750 Welch Road, Ste 116, Stanford, Palo Alto, CA 94304, United States. ktpark@stanford.edu
Telephone: +1-650-7235070 Fax: +1-650-4985608
Received: May 25, 2016
Peer-review started: May 27, 2016
First decision: July 22, 2016
Revised: December 21, 2016
Accepted: January 16, 2017
Article in press: January 18, 2017
Published online: May 6, 2017
Processing time: 344 Days and 0.1 Hours
Abstract
AIM

To assess the correlation between the send-out enzyme-linked immuno sorbent assay (ELISA) and the point-of-care (POC) calprotectin test in pediatric inflammatory bowel disease (IBD) patients.

METHODS

We prospectively collected stool samples in pediatric IBD patients for concomitant send-out ELISA analysis and POC calprotectin testing using the Quantum Blue® (QB) Extended immunoassay. Continuous results between 17 to 1000 μg/g were considered for comparison. Agreement between the two tests was measured by a Bland-Altman plot and statistical significance was determined using Pitman’s test.

RESULTS

Forty-nine stool samples were collected from 31 pediatric IBD patients. The overall means for the rapid and ELISA tests were 580.5 and 522.87 μg/g respectively. Among the 49 samples, 18 (37.5%) had POC calprotectin levels of ≤ 250 μg/g and 31 (62.5%) had levels > 250 μg/g. Calprotectin levels ≤ 250 μg/g show good correlation between the two assays. Less correlation was observed at quantitatively higher calprotectin levels.

CONCLUSION

In pediatric IBD patients, there is better correlation of between ELISA and POC calprotectin measurements at clinically meaningful, low-range levels. Future adoption of POC calprotectin testing in the United States may have utility for guiding clinical decision making in real time.

Keywords: Calprotectin; Stool biomarker; Inflammatory bowel disease; Crohn’s disease; Ulcerative colitis; Point-of-care test

Core tip: Quantitative fecal calprotectin (FC) measurements, particularly in children affected by inflammatory bowel disease (IBD), is an important element of disease monitoring in a patient population vulnerable to repeated endoscopic confirmation of mucosal healing. In the United States, rapid FC assays are not yet Food and Drug Administration approved, and send-out FC assays require processing delay, preventing point-of-care usefulness. The significance of our findings in this study reiterate the clinical utility of the point-of-care FC testing in children with IBD, who are at-risk for subclinical mucosal-level inflammation. Our study confirms good correlation between the send-out and rapid point-of-care FC tests at the clinically-meaningful target range (≤ 250 μg/g) associated with endoscopic remission.