Alloimmunization in dogs after transfusion: A serial cross‐match study

Abstract

Background Cross‐matching is performed to determine the serological compatibility of donor and recipient blood. Current guidelines recommend that cross‐matching should be performed in dogs when an initial transfusion was performed more than 4 days ago or when the transfusion history is unknown. Hypothesis Determination at what time point alloantibodies are detected in dogs after transfusion. The hypothesis was that dogs would form alloantibodies within 4 days after a transfusion. Animals Twenty‐one anemic dogs were transfused and monitored for at least 4 subsequent days. Exclusion criteria were persistent red blood cell (RBC) agglutination and a previous transfusion. Methods Prospective observational study. Cross‐matching was performed before the initial DEA 1‐compatible transfusion and on days 1, 2, 3, and 4 and if possible, between day 5 and 28, using the tube method without enhancement (major cross‐match, recipient controls); recipients were monitored for transfusion reactions. Results In 12/21 dogs a positive cross‐match (microscopic degree of agglutination [AD] 1+ to 2+) was observed within 4 days after the transfusion. In a nonlinear regression model, no significant association was detected between type of anemia (P = .41), RBC storage time (P = .44), immunosuppressive treatment (P = .75) nor transfusion volume (P = .70) and the occurrence of positive cross‐matches within 4 days after transfusion. Another 4 dogs developed a positive cross‐match (microscopic AD 1+ to 2+) after 6 to 13 days. Conclusions and Clinical Importance Because production of alloantibodies was detected as early as 1 day after transfusion, cross‐matching should be performed before every subsequent transfusion.

Crossmatch: Alloimmunization versus unspecific agglutination reactions?

“…Based on these data, they claim that alloantibodies developed within hours to days posttransfusion and recommend that all dogs requiring transfusion should be crossmatched at day 1, instead of the current practice of crossmatching 4 days posttransfusion. 1 Based upon longstanding principles in basic immunology and transfusion medicine and my own experience with blood typing, crossmatching, and alloimmunization in companion animals over the past decades, I would like to comment on the authors' claims and recommendations for the following reasons:…”

“…• Neither in vitro nor in vivo immunological data were presented by Kohn et al 1 to recommend routine crossmatching before or on day 1 after the first transfusion in dogs requiring a second transfusion.…”

“…• Interpretation of the authors' tube crossmatch test is difficult, particularly when they only found "very weak" and only microscopic agglutination. 1 Crossmatch gel column techniques for laboratory use and in-clinic immunochromatographic strip and gel minitube kits are available in animal blood banking and veterinary transfusion medicine and easier to perform and grade. The authors' observed microscopic agglutination reactions of 1+ to 2+ could easily be unspecific because tube agglutination tests can be affected by many factors including disease state, inferior quality of transfused red blood cells, immediate inflammatory responses in recipients, 5 condition of donor blood aliquoted in a tube not approved for long-term storage of blood, and testing methods., 5,6,7 • When finding incompatibilities with antiglobulin-enhanced crossmatch tests in humans, blood group antibody screening with a panel of erythrocytes with different blood types is used to assess alloantibody specificity.…”

“…Dr Barbara Kohn's group at the Clinic for Small Animals of the Freie University Berlin, Germany, recently reported on crossmatch results in (pre‐) transfused dogs in JVIM . 1 These authors used a tube crossmatch method without canine antiglobulins to assess the potential appearance of alloantibodies posttransfusion. They reported that a subset of 21 transfused tested dogs was exhibiting “very weak” microscopic agglutination reactions before and within hours to days after transfusion.…”

“…Based on these data, they claim that alloantibodies developed within hours to days posttransfusion and recommend that all dogs requiring transfusion should be crossmatched at day 1, instead of the current practice of crossmatching 4 days posttransfusion. 1 …”