Comparison of a commercial immunochromatographic strip crossmatch kit and standard laboratory crossmatch methods for blood transfusion compatibility in dogs.

Abstract

OBJECTIVE: To evaluate agreement between 2 standard laboratory (SL) methods and an immunochromatographic strip (ICS) method to crossmatch dogs receiving RBC transfusions.&#xa0;A second objective was to evaluate uninterpretable SL crossmatch results as compared to ICS in the presence of autoagglutination. DESIGN: Prospective observational study (September 2018 to October 2019). SETTING: University teaching hospital. ANIMALS: Forty anemic dogs receiving RBC transfusions. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: All dogs received DEA 1-negative packed RBCs. Three crossmatch methods were evaluated against the same unit transfused to each dog: SL method performed at institutional laboratory (SL-I), SL method sent to a commercial laboratory (SL-C), and a commercially available point-of-care ICS method. Major and minor crossmatches were incompatible for 2.5%/7.5% of ICS tests, 82.5%/52.5% of SL-I tests, and 52.5%/27.5% of SL-C tests.&#xa0;Agreement between ICS and SL-C major (&#x3ba;&#xa0;=&#xa0;0.05) and minor (&#x3ba;&#xa0;=&#xa0;0.02) crossmatches and between ICS and SL-I major (&#x3ba;&#xa0;=&#xa0;0.009) and minor (&#x3ba;&#xa0;=&#xa0;0.03) crossmatches was slight. Agreement between SL-C and SL-I major (&#x3ba;&#xa0;=&#xa0;-0.06) and minor (&#x3ba;&#xa0;=&#xa0;-0.12) crossmatches was poor. Results of major and minor crossmatches were uninterpretable due to autoagglutination in 38%/38% for SL-I and 29%/18% for SL-C crossmatches. ICS method was interpretable for 93% (major) and 98% (minor) crossmatches. After exclusion of uninterpretable SL pairings, agreement still remained poor to slight between all tests. Only 1 of 40 dogs (2.5%; 95% confidence interval:&#xa0;<1.0%-13.2%) had an immediate immunological transfusion reaction. CONCLUSIONS: Lack of agreement between all methodologies was noted. The high level of incompatibility predicted by SL methods despite lack of clinically relevant reactions suggests a high false incompatibility rate as compared to the ICS test. ICS testing was also able to give results more frequently in the face of autoagglutination.&#xa0;Further work is needed to investigate the ICS method's ability to predict clinically significant transfusion reactions.