The suitability of hemolyzed specimens for compatibility testing using automated technology

Blood banks have historically rejected hemolyzed specimens for ABO type and antibody screen based on concerns of artifactual interference with test performance or the detection of incompatibility. Samples from emergency departments (EDs) are commonly discarded due to hemolysis or mislabeling.

This study investigated whether hemolysis produced via experimental mechanical stress has a threshold for introducing discrepancy in ABO-Rh typing and antibody screening using an automated gel testing system (ProVue, Ortho-Clinical Diagnostics, Inc.).

Twenty-three samples from healthy subjects were shown to have threshold supernatant hemoglobin (Hb) levels producing discrepancy in the results for both ABO reverse type and antibody screen at 75 and 125 mg per dL, respectively. Above these levels of Hb, both tests became uninterpretable and reported as "no result determined." Twenty of 31 positive antibody screens became uninterpretable after experimental hemolysis without any threshold supernatant Hb being evident, likely explained by the duration of specimen storage before experimental hemolysis. No false-positive or false-negative samples were observed in the antibody screen of the hemolyzed specimens.

Properly collected hemolyzed specimens present an opportunity for ABO-Rh forward typing, and a significant proportion of such specimens give valid (concordant) results for reverse type and antibody screen. Our data, although device-specific, are adequate to suggest that sample discard and recollection due to hemolysis in blood bank specimens should be reconsidered with potential benefits for patient safety and efficiency.