ORIGINAL CONTRIBUTION Identification of Genetic Loci Associated With Helicobacter pylori Serologic Status Julia Mayerle, MD Importance Helicobacter pylori is a major cause of gastritis and gastroduodenal ul- Caroline M. den Hoed, MD cer disease and can cause cancer. H pylori prevalence is as high as 90% in some de- Claudia Schurmann, MSc veloping countries but 10% of a given population is never colonized, regardless of exposure. Genetic factors are hypothesized to confer H pylori susceptibility. Lisette Stolk, PhD Objective To identify genetic loci associated with H pylori seroprevalence in 2 in- Georg Homuth, PhD dependent population-based cohorts and to determine their putative pathophysiologi- Marjolein J. Peters, MD, PhD cal role by whole-blood RNA gene expression profiling. Lisette G. Capelle, MD Design, Setting, and Participants Two independent genome-wide association studies (GWASs) and a subsequent meta-analysis were conducted for anti-H pylori Kathrin Zimmermann, MD IgG serology in the Study of Health in Pomerania (SHIP) (recruitment, 1997-2001 Fernando Rivadeneira, MD, PhD [n =3830]) as well as the Rotterdam Study (RS-I) (recruitment, 1990-1993) and RS-II Sybille Gruska, PhD (recruitment, 2000-2001 [n=7108]) populations. Whole-blood RNA gene expression profiles were analyzed in RS-III (recruitment, 2006-2008 [n=762]) and SHIP-TREND Henry Vo¨lzke, MD (recruitment, 2008-2012 [n=991]), and fecal H pylori antigen in SHIP-TREND (n=961). Annemarie C. de Vries, PhD Main Outcomes and Measures H pylori seroprevalence. Uwe Vo¨lker, PhD Results Of 10 938 participants, 6160 (56.3%) were seropositive for H pylori. GWASs Alexander Teumer, PhD identified the toll-like receptor (TLR) locus (4p14; top-ranked single-nucleotide poly- morphism (SNP), rs10004195; P=1.4ϫ10Ϫ18; odds ratio, 0.70 [95% CI, 0.65 to 0.76]) Joyce B. J. van Meurs, PhD and the FCGR2A locus (1q23.3; top-ranked SNP, rs368433; P=2.1ϫ10Ϫ8; odds Ivo Steinmetz, MD ratio, 0.73 [95% CI, 0.65 to 0.81]) as associated with H pylori seroprevalence. Among the 3 TLR genes at 4p14, only TLR1 was differentially expressed per copy number Matthias Nauck, MD of the minor rs10004195-A allele (␤=Ϫ0.23 [95% CI, Ϫ0.34 to Ϫ0.11]; P=2.1ϫ10Ϫ4). Florian Ernst, PhD Individuals with high fecal H pylori antigen titers (optical density Ͼ1) also exhibited ␹2 Frank-Ulrich Weiss, PhD the highest 25% of TLR1 expression levels (P=.01 by test). Furthermore, TLR1 ex- hibited an Asn248Ser substitution in the extracellular domain strongly linked to the Albert Hofman, MD, PhD rs10004195 SNP. Martin Zenker, MD Conclusions and Relevance GWAS meta-analysis identified an association be- Heyo K. Kroemer, PhD tween TLR1 and H pylori seroprevalence, a finding that requires replication in non- white populations. If confirmed, genetic variations in TLR1 may help explain some of Holger Prokisch, PhD the observed variation in individual risk for H pylori infection. Andre G. Uitterlinden, MD, PhD JAMA. 2013;309(18):1912-1920 www.jama.com Markus M. Lerch, MD, FRCP Author Affiliations: Department of Medicine A (Drs Erasmus University Medical Center, Rotterdam, the Ernst J. Kuipers, MD, PhD Mayerle, Gruska, Weiss, and Lerch), Interfaculty Insti- Netherlands; Netherlands Consortium for Healthy Aging, tute for Genetics and Functional Genomics (Drs Homuth, Rotterdam, Leiden, the Netherlands (Drs Stolk, Peters, HE GRAM-NEGATIVE PATHOGEN Vo¨lker, Teumer, and Ernst and Ms Schurmann), Fried- Rivadeneira, van Meurs, Hofman, and Uitterlinden); Insti- rich Loeffler Institute of Medical Microbiology (Drs Zim- tute of Human Genetics, Otto-von-Guericke Univer- Helicobacter pylori is specifi- mermann and Steinmetz), Institutes for Community sity, Magdeburg, Germany (Dr Zenker); Helmholtz cally adapted to colonize the Medicine (Dr Vo¨lzke) and Clinical Chemistry and Labo- Zentrum Mu¨nchen, German Research Center for Envi- mucus layer covering the gas- ratory Medicine (Dr Nauck), and Department of Phar- ronmental Health, Institut fu¨r Humangenetik, Neuher- macology, Center of Drug Absorption and Transport berg, Germany (Dr Prokisch); and Technische Univer- Ttric mucosa, with little invasion of the (CDAT) (Dr Kroemer), University Medicine Greifs- sita¨tMu¨nchen, Institut fu¨r Humangenetik, Munich, gastric glands.1,2 It is the major cause wald, Greifswald, Germany; Departments of Gastro- Germany (Dr Prokisch). enterology and Hepatology (Drs den Hoed, Capelle, Corresponding Author: Markus M. Lerch, MD, FRCP, de Vries, and Kuipers), Internal Medicine (Drs Stolk, Department of Medicine A, University Medicine For editorial comment see p 1939. Peters, Rivadeneira, van Meurs, Uitterlinden, and Kui- Greifswald, Ferdinand-Sauerbruchstrasse, 17475 pers), and Epidemiology (Drs Hofman and Uitterlinden), Greifswald, Germany ([email protected]). 1912 JAMA, May 8, 2013—Vol 309, No. 18 ©2013 American Medical Association. All rights reserved. Corrected on June 4, 2013 Downloaded From: https://jamanetwork.com/ on 09/25/2021 GWAS OF H PYLORI INFECTION SUSCEPTIBILITY of gastritis (80%) and gastroduodenal sequent whole-blood transcriptome Written informed consent was ob- ulcer disease (15%-20%) and the only analyses were conducted in the inde- tained from all participants, and the bacterial pathogen believed to cause pendent SHIP-TREND and RS-III popu- medical ethics committee of the Eras- cancer (IARC Working Group 1994).3,4 lations. mus Medical Center Rotterdam and Prevalence of infection with H pylori University Medicine Greifswald ap- varies from less than 10% in asymp- METHODS proved the study. tomatic children in Western countries Study Cohorts to approximately 90% in some devel- The SHIP study consists of 2 indepen- Phenotype Determination: oping countries. Most infections oc- dent prospectively collected population- Seroprevalence and Bacterial Load cur during childhood, whereas the H based cohorts in Northeastern Ger- Anti–H pylori serum IgG antibody ti- pylori status of adults remains stable.5,6 many, SHIP and SHIP-TREND. The ters were measured using commercial Furthermore, although there are wide study design of SHIP has been previ- enzyme immunoassays (Pyloriset interindividual variations in the level ously described in detail.17 The first pa- EIA-G III ELISA; Orion). Seropreva- of gastritis as well as in the inflamma- tient for the SHIP study was recruited lence, an indicator for current or pre- tory response to H pylori, the intrain- in October 1997 and the last in May vious infection, was defined as an an- dividual gastritis pattern is constant 2001. SHIP-TREND is an additional in- ti–H pylori IgG titer equal to or greater over time.7 dependent cohort from the same re- than 20 U/mL, according to the manu- Approximately 5% to 10% of a popu- gion, with individuals newly recruited facturer’s recommendation.21 In com- lation is never infected with H pylori, between September 2008 and summer parison with culture or CLO (Campy- even in the presence of high exposure 2012; for details of SHIP-TREND, lobacter-like organism) testing (rapid rates.8 A contribution of genetic fac- see the eAppendix available at http: urease activity testing), using this cut- tors to H pylori susceptibility is sup- //www.jama.com. off value should detect H pylori infec- ported by differences in H pylori sus- The SHIP study has 2 main objec- tion with a sensitivity of 97.8%, a speci- ceptibility between African Americans tives: to assess prevalence and inci- ficity of 58.0%, and an accuracy of and US residents of European ances- dence of common risk factors, subclini- 78.7%. The positive predictive value for try after adjusting for socioeconomic cal disorders, and clinical diseases; and the Pyloriset EIA-G III ELISA immu- status, age, and living conditions.9 Sig- to investigate the complex associa- noassay is reported as 71.5% and the nificantly higher concordance for H py- tions among risk factors, subclinical dis- negative predictive value as 96.2%.22 In- lori infection in monozygotic com- orders, and clinical diseases. A particu- dividuals with the lowest 75% of the IgG pared with dizygotic twins, or for lar characteristic of SHIP is that it does titer distribution comprised the con- household members who are siblings not specifically address a single se- trol group. Infection was defined in ac- rather than unrelated persons,10 also ar- lected disease; rather, it attempts to de- cordance with international conven- gues for a genetic influence, with a heri- scribe health-related conditions with the tion when H pylori was detected by fecal tability estimate in twins of 57%.10 widest focus possible. H pylori antigen testing.23 A signifi- The key pathophysiological event in The Rotterdam Study is a large, cant correlation between titer levels and H pylori infection is the initiation of an population-based prospective study of actual infection has been reported.22 To inflammatory response. This response elderly individuals of European ances- investigate the association of gene ex- is triggered by bacterial membrane com- try consisting of 3 cohorts (RS-I, RS- pression levels and the fecal H pylori an- ponents, namely, lipopolysaccharides II, RS-III) of individuals residing in a tigen titer, individuals with high bac- and lipid A, as well as cytotoxins and suburb of Rotterdam, the Nether- terial load (based on fecal H pylori H pylori urease activity.11 So far, few lands, and has been described in de- antigen titer, optical density [OD]Ͼ1; candidate gene studies have analyzed tail.18-20 The study targets cardiovascu- see below) were studied to determine human host genetic factors for suscep- lar, endocrine, hepatic, neurologic, if they also exhibited the highest 25% tibility to H pylori infection and per- ophthalmic, psychiatric, and respira- of gene expression levels of the respec- sistence.12-14 Several studies have dem- tory diseases. Baseline recruitment and tive 4p14-region genes. onstrated that genetic variations, eg, in measurements for the RS-I study were The H pylori antigen ELISA kit (Im- IL1B, modulate the susceptibility for obtained between 1990 and 1993.