Limitations of Polybrene to detect ABO incompatibility

The ability of the manual Polybrene test to detect ABO incompatibility was assessed since the anti-human globulin phase of the crossmatch is no longer mandated under many circumstances by the Standards of the American Association of Blood Banks, while the ability of the crossmatch to detect ABO incompatibility remains a requirement. 10,084 randomly selected patient samples (from approximately 6,000 different patients) were entered into a double-blind study. Sera from 97 different patients gave unexpectedly negative reactions with A2 and/or B cells in the manual Polybrene test. 94 of these sera reacted as expected in saline (87 after an immediate-spin examination). The manual Polybrene test does not provide adequate assurance of ABO compatibility.