Clinical and Genomic Correlates of Neutrophil Reactive Oxygen Species Production in Pediatric Patients With Crohn's Disease

• Type of Material: Article
• Authors: Lee A. Denson, University of Cincinnati; Ingrid Jurickova, University of Cincinnati; Rebekah Karns, University of Cincinnati; Kelly A. Shaw, Emory University; David J Cutler, Emory University; David Okou, Emory University; Anne Dodd, Emory University; Kathryn Quinn, Cincinnati Children's Hospital Medical Center; Kajari Mondal, Emory University; Bruce J. Aronow, Cincinnati Children's Hospital Medical Center; Yael Haberman, University of Cincinnati; Aaron Linn, University of Cincinnati; Adam Price, University of Cincinnati; Ramona Bezold, University of Cincinnati; Kathleen Lake, University of Cincinnati; Kimberly Jackson, University of Cincinnati; Thomas D. Walters, University of Toronto; Anne Griffiths, University of Toronto; Michael Zwick, Emory University; Subramaniam Kugathasan, Emory University
• Language: English
• Date: 2018-06-01
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018 AGA Institute
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1053/j.gastro.2018.02.016
• Title of Journal or Parent Work: Gastroenterology
• ISSN: 0016-5085
• Volume: 154
• Issue: 8
• Start Page: 2097
• End Page: 2110
• Grant/Funding Information: This work was supported by the Gene Analysis and Flow Cytometry cores of the National Institutes of Health (NIH)-supported Cincinnati Children’s Hospital Research Foundation Digestive Health Center (1P30DK078392-01); the Crohn’s and Colitis Foundation (LAD & SK); and NIH grant R01 DK098231 (LAD & SK) and P30 DK043351 (RJK).
• Keywords: NADPH OXIDASE; Science & Technology; GENE-EXPRESSION; Neutrophil Oxidative Burst; FEATURES; WES; AUTOPHAGY; CANDIDATE GENE; IBD; WIDE ASSOCIATION; CYBA; Life Sciences & Biomedicine; POLYMORPHISMS; Gastroenterology & Hepatology; Genetic Variant; CHRONIC GRANULOMATOUS-DISEASE; SUSCEPTIBILITY LOCI
• Research Categories: Health Sciences, Medicine and Surgery; Biology, Genetics

Abstract

Background & Aims: Individuals with monogenic disorders of phagocyte function develop chronic colitis that resembles Crohn's disease (CD). We tested for associations between mutations in genes encoding reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, neutrophil function, and phenotypes of CD in pediatric patients. Methods: We performed whole-exome sequence analysis to identify mutations in genes encoding NADPH oxidases (such as CYBA, CYBB, NCF1, NCF2, NCF4, RAC1, and RAC2) using DNA from 543 pediatric patients with inflammatory bowel diseases. Blood samples were collected from an additional 129 pediatric patients with CD and 26 children without IBD (controls); we performed assays for neutrophil activation, reactive oxygen species (ROS) production, and bacteria uptake and killing. Whole-exome sequence analysis was performed using DNA from 46 of the children with CD to examine associations with NADPH gene mutations; RNA sequence analyses were performed using blood cells from 46 children with CD to test for variations in neutrophil gene expression associated with ROS production. Results: We identified 26 missense mutations in CYBA, CYBB, NCF1, NCF2, and NCF4. Patients with CD who carried mutations in these genes were 3-fold more likely to have perianal disease (P =.0008) and stricturing complications (P =.002) than children with CD without these mutations. Among patients with CD with none of these mutations, 9% had undergone abdominal surgery; among patients with mutations in these NADPH oxidase genes, 31% had undergone abdominal surgery (P =.0004). A higher proportion of neutrophils from children with CD had low ROS production (47%) than from controls (15%) among the 129 patients tested for ROS (P =.002). Minor alleles of the NADPH genes were detected in 7% of children with CD whose neutrophils produced normal levels of ROS vs 38% of children whose neutrophils produced low levels of ROS (P =.009). Neutrophils that produced low levels of ROS had specific alterations in genes that regulate glucose metabolism and antimicrobial responses. Conclusions: We identified missense mutations in genes that encode NADPH oxidases in children with CD; these were associated with a more aggressive disease course and reduced ROS production by neutrophils from the patients.