title: Confirmation of positive antibody screens by solid-phase red cell adherence assay using a tube technique method with polyethylene glycol enhancement.
abstract: Our blood bank routinely screens donors for antibodies using a solid-phase red cell adherence (SPRCA) assay. Positive results are then confirmed using a tube technique with polyethylene glycol (PEG) enhancement due to reported higher specificity than with SPRCA. Over a 5-month period, 49,084 donor serum or plasma samples were tested using the SPRCA assay. Further identification of positive samples was performed using a PEG enhancement method. Testing was performed with strict adherence to the manufacturers' inserts. Of 49,084 samples, 313 (0.64%) were positive by the SPRCA assay. Of these, 99 (31.6%) samples remained positive when tested with PEG enhancement. The remaining 214 (68.4%) were negative, giving specificity for the SPRCA assay of 99.6 percent (48,985/ 49,199). We report a high specificity for antibody screening using the SPRCA assay. However, it is cost effective to perform a confirmatory tube test with PEG enhancement because 214 SPRCA assay samples were interpreted as having a negative antibody screen, thus allowing the release of valuable blood components for transfusion.
authors.affiliation: South Florida Blood Banks, Inc., 933 45th Street, West Palm Beach, Florida 33407, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Gammon
authors.forename: M
authors.initials: M
authors.lastname: Lake
authors.forename: N
authors.initials: N
authors.lastname: Velasquez
authors.forename: A
authors.initials: A
authors.lastname: Prichard