title: Non-specific red cell reactivity in an obstetric population.
abstract: OBJECTIVE
  To examine non-specific red cell reactivity (NSR) on antibody (Ab) screening of obstetric inpatients.
  
  
  METHODS
  Observational study of 5438 obstetric inpatients (2009-2013). Ab-positive patients were identified and their records reviewed for NSR, other antibodies, transfusion reactions or hemolytic disease of the fetus/newborn (HDFN). Evaluation of NSR frequency by test era assessed the impact of an institutional change to solid-phase screening in 2011.
  
  
  RESULTS
  Of obstetric inpatients, 5.3% had at least one positive Ab screen; 1.6% had NSR. Of NSR-positive patients, 16.7% had identifiable Abs that pre-dated NSR; 25% had concurrent Abs and 8.5% had subsequent Ab identification. In 49.1%, NSR resolved during follow-up. The frequency of NSR was higher after the change to solid-phase Ab screening, but specific Ab frequency was similar in both testing periods. No transfusion reactions or cases of HDFN were noted in this cohort.
  
  
  CONCLUSIONS
  NSR is found in 1-2% of obstetrical inpatients at our institution, and has more than doubled since the initiation of solid-phase screening. Although likely clinically insignificant by itself, NSR is commonly found in relation to other red cell Abs and may precede their development.
authors.affiliation: a Department of Obstetrics and Gynecology , Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California , Los Angeles , CA , USA .
authors.forename: Kristi R
authors.initials: KR
authors.lastname: Van Winden
authors.affiliation: b Department of Pathology , Division of Clinical Services, Duke University School of Medicine , Durham , NC , USA .
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Poisson
authors.affiliation: a Department of Obstetrics and Gynecology , Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California , Los Angeles , CA , USA .
authors.forename: Richard H
authors.initials: RH
authors.lastname: Lee
authors.affiliation: c Keck School of Medicine, University of Southern California , Los Angeles , CA , USA , and.
authors.forename: Ravi
authors.initials: R
authors.lastname: Agarwal
authors.affiliation: a Department of Obstetrics and Gynecology , Division of Maternal-Fetal Medicine, Keck School of Medicine, University of Southern California , Los Angeles , CA , USA .
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Ouzounian
authors.affiliation: d Department of Pathology and Transfusion Medicine , Keck School of Medicine, University of Southern California , Los Angeles , CA , USA.
authors.forename: Ira A
authors.initials: IA
authors.lastname: Shulman
mesh_terms: D004899:Erythroblastosis, Fetal / Q000209:etiology*; D004912:Erythrocytes / Q000276:immunology*; D005260:Female; D006801:Humans; D007159:Immunologic Tests / Q000379:methods*; D011247:Pregnancy / Q000276:immunology*
keywords: Antibody screen; blood bank; hemolytic disease; phototherapy; pregnancy; transfusion