title: Low immunoglobulin M memory B-cell percentage in patients with heterotaxy syndrome correlates with the risk of severe bacterial infection.
abstract: BACKGROUND
  Patients with heterotaxy syndrome, commonly associated with complex congenital heart disease (CHD), exhibit a higher risk of severe bacterial infection (SBI). We sought to define the change of a novel immunologic marker, the immunoglobulin M (IgM) memory B-cell percentage, and its association with SBI.
  
  
  METHODS
  We enrolled 46 (M/F 29/17) heterotaxy syndrome patients (42 right atrial isomerism (RAI) and 4 left atrial isomerism (LAI)) aged > 1 y during the period 2010-2012 in a tertiary care center. We analyzed IgM(+)CD27(+) memory B-cell percentages. Patients with simple and complex CHD served as controls.
  
  
  RESULTS
  The mean IgM memory B-cell percentages were the lowest in the heterotaxy syndrome group, compared with those in complex and simple CHD groups (1.8 ± 2.1 vs. 3.9 ± 3.2 vs. 5.1 ± 4.7, P < 0.001). In the heterotaxy syndrome group, 41.3% had low IgM memory B-cell percentages (<1% of B cells). Seven had a history of community-acquired SBI and 85.7% of these had low IgM memory B-cell percentages, which was the only significant factors related to community-acquired SBI (P = 0.028).
  
  
  CONCLUSIONS
  The memory B cell and IgM memory B-cell percentages are low in patients with heterotaxy syndrome, and the presence of IgM memory B-cell percentage < 1% correlates with community-acquired SBI.
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Shuenn-Nan
authors.initials: SN
authors.lastname: Chiu
authors.affiliation: Department of Laboratory Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu City, Taiwan.|Department of Pediatrics, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu City, Taiwan.
authors.forename: Pei-Lan
authors.initials: PL
authors.lastname: Shao
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Jou-Kou
authors.initials: JK
authors.lastname: Wang
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Hui-Wen
authors.initials: HW
authors.lastname: Hsu
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Ming-Tai
authors.initials: MT
authors.lastname: Lin
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Luan-Yin
authors.initials: LY
authors.lastname: Chang
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Chun-Yi
authors.identifier: http://orcid.org/0000-0002-5240-2808
authors.initials: CY
authors.lastname: Lu
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Ping-Ing
authors.initials: PI
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, National Taiwan University Hospital and Medical College, National Taiwan University, Taipei, Taiwan.
authors.forename: Mei-Hwan
authors.initials: MH
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D001402:B-Lymphocytes / Q000276:immunology*; D001424:Bacterial Infections / Q000175:diagnosis / Q000276:immunology* / Q000382:microbiology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D059446:Heterotaxy Syndrome / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D016867:Immunocompromised Host; D007075:Immunoglobulin M / Q000276:immunology*; D007156:Immunologic Memory; D016130:Immunophenotyping / Q000379:methods; D007223:Infant; D018655:Lymphocyte Count; D008297:Male; D009894:Opportunistic Infections / Q000175:diagnosis / Q000276:immunology* / Q000382:microbiology; D010641:Phenotype; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D062606:Tertiary Care Centers
chemical_list: D007075:Immunoglobulin M