Evaluation of point‐of‐care versus laboratory antiglobulin‐enhanced major crossmatch testing in cats

OBJECTIVES: It is recommended that all cats, regardless of transfusion history, undergo major crossmatch prior to blood product administration to decrease the likelihood of immunological transfusion reactions. A reliable and user-friendly point-of-care crossmatch test would help make crossmatch testing more accessible. The primary objective of this study was to assess agreement between two antiglobulin-enhanced major crossmatch test methods, a laboratory-based tube crossmatch method and a point-of-care gel column crossmatch method, in cats in need of blood transfusion. MATERIALS AND METHODS: Cats that had the potential to require blood transfusion were prospectively recruited. Each cat underwent major crossmatch using two methods concurrently: a laboratory-based tube crossmatch method performed by a reference laboratory, and a gel column crossmatch method performed in the clinic by a clinician and interpreted using guidelines supplied by the manufacturer. RESULTS: A total of 95 unique donor-recipient pairings were evaluated with both major crossmatch methods. Of the 95 pairings, 21 were incompatible using the laboratory-based tube crossmatch test while 18 were incompatible on the gel column crossmatch test; 13 pairings were incompatible on both methods. Kappa agreement between the laboratory-based tube crossmatch and gel column crossmatch methods was 0.581 (95% confidence interval: 0.378 to 0.785), showing significant agreement. The overall percent agreement between the tests was 86.3%; positive percent agreement was 93.2%, while negative percent agreement was 61.9%. CLINICAL SIGNIFICANCE: The commercial antiglobulin-enhanced, point-of-care gel major crossmatch test had moderate agreement with the antiglobulin-enhanced tube crossmatch performed at a reference laboratory. Inclusion of larger numbers of incompatible pairings would help further evaluate the agreement between the two test methods.