title: Pattern recognition receptor and autophagy gene variants are associated with development of antimicrobial antibodies in Crohn's disease.
abstract: BACKGROUND
  We sought to investigate whether variants in genes involved in bacterial sensing and autophagy (NOD2, TLR5, IRGM, ATG16L1) and the interleukin-23 signaling pathway (IL12B, IL23R, STAT3) were associated with development of antimicrobial antibodies in patients with Crohn's disease (CD).
  
  
  METHODS
  A cohort of 616 CD patients from a tertiary referral hospital (Mount Sinai Hospital, Toronto) was evaluated. DNA was tested for three CD-associated NOD2 variants (3020insC, G908R, R702W), variants in IRGM, ATG16L1, IL12B, IL23R, STAT3, and a TLR5-stop mutation. Serum was analyzed by enzyme-linked immunosorbent assay (ELISA) for anti-Saccharomyces cerevisiae (ASCA) IgG and IgA, anti-outer membrane porin C (anti-ompC), anti-Cbir1 flagellin, and anti-Pseudomonas fluorescens (anti-I2).
  
  
  RESULTS
  NOD2 3020insC was associated with cumulative seroreactivity by quartile sum (P = 0.003) and number of positive antibodies (P = 0.02). NOD2 G908R was also associated with quartile sum (P = 0.05). Increased ASCA seropositivity was associated with NOD2 3020insC (odds ratio [OR] = 1.9, P = 0.02) and G908R (OR = 1.8, P = 0.05), and ATG16L1 T300A (OR = 1.4, P = 0.01) variants; ASCA-positive patients had an increased cumulative number of NOD2 3020insC and ATG16L1 T300A variants (P = 0.007). TLR5-stop mutation abrogated development of anti-flagellin in a dominant-negative fashion (OR = 0.5, P = 0.009). The IRGM CD risk variant was associated with increased anti-flagellin seropositivity (OR = 1.5, P = 0.03). IL12B, IL23R, and STAT3 variants did not contribute to development of antimicrobial antibodies.
  
  
  CONCLUSIONS
  Variants in innate immune genes involved in pattern recognition and autophagy but not the interleukin-23 signaling pathway influence antimicrobial seroreactivity in CD. In particular, the additive effect of NOD2 3020insC and ATG16L1 T300A suggests a role for autophagy in development of ASCA.
authors.affiliation: Division of Gastroenterology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Travis B
authors.initials: TB
authors.lastname: Murdoch
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Stempak
authors.forename: Carol
authors.initials: C
authors.lastname: Landers
authors.forename: Stephan R
authors.initials: SR
authors.lastname: Targan
authors.forename: Jerome I
authors.initials: JI
authors.lastname: Rotter
authors.forename: Mark S
authors.initials: MS
authors.lastname: Silverberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000908:Antibodies, Fungal / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology; D001343:Autophagy; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003424:Crohn Disease / Q000235:genetics* / Q000382:microbiology* / Q000473:pathology; D004247:DNA / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019204:GTP-Binding Proteins / Q000235:genetics; D006801:Humans; D053762:Interleukin-12 Subunit p40 / Q000235:genetics; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D018123:Receptors, Interleukin / Q000235:genetics; D051192:Receptors, Pattern Recognition / Q000235:genetics*; D050796:STAT3 Transcription Factor / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000276:immunology; D062606:Tertiary Care Centers; D051198:Toll-Like Receptor 5 / Q000235:genetics; D055815:Young Adult
chemical_list: C518959:ATG16L1 protein, human; D000907:Antibodies, Bacterial; D000908:Antibodies, Fungal; D000942:Antigens, Bacterial; D000071183:Autophagy-Related Proteins; D002352:Carrier Proteins; C500879:IL12B protein, human; C515500:IL23R protein, human; D053762:Interleukin-12 Subunit p40; C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D018123:Receptors, Interleukin; D051192:Receptors, Pattern Recognition; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C495346:TLR5 protein, human; D051198:Toll-Like Receptor 5; D004247:DNA; D019204:GTP-Binding Proteins; C513539:IRGM protein, human