Non-specific red cell reactivity in an obstetric population.

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.

Duke Scholars

Author Jessica Lynne Poisson Pathology