Alloimmunization of a dog erythrocyte antigen 1- dog transfused with weakly dog erythrocyte antigen 1+ blood

Evaluation of post-transfusion RBC alloimmunization in dogs using a gel-column crossmatch with and without anti-canine globulin enhancement

A blood crossmatch is essential to ensure RBC compatibility for previously transfused dogs. There is no gold standard crossmatch method for dogs, although the standards used most commonly by academic institutions and reference laboratories are the tube and gel-column crossmatches. Addition of anti-canine globulin (ACG) has been suggested to increase detection of RBC incompatibilities. Our objective was to determine if there is a correlation between results of a standard and an ACG-enhanced gel-column crossmatch in detecting post-transfusion RBC alloimmunization. Pre- and post-transfusion serum or plasma samples were obtained from 33 dogs for major crossmatches to 1-6 (median: 3) blood donors. Crossmatches were performed with (n = 202) and without (n = 202) ACG, with results scored by 4 observers, 3 of whom were anonymized. Ten of 33 (30%) dogs had major crossmatch incompatibilities post-transfusion. RBC incompatibilities (2-4+ agglutination) were detected only with ACG in 4 dogs, only without ACG in 3 dogs, and with both methods in 3 dogs. There was fair correlation between crossmatch methods for determination of compatibility (ρ = 0.34; p < 0.001) and incompatibility (ρ = 0.35; p < 0.001) scores. Among 4 observers, there was near-perfect agreement in determining compatibility (κ = 0.97; p < 0.001) and substantial agreement in overall scoring of incompatibility (κ = 0.77; p < 0.001). Our results suggest that detection of RBC incompatibilities in dogs can be maximized by performing a gel-column crossmatch both with and without ACG enhancement.

Effect of donor blood storage on gel column crossmatch in dogs

BACKGROUND

Compared with fresh blood, stored equine donor blood results in spurious tube crossmatch incompatibilities. Interpretation of blood crossmatch results is considered subjective.

OBJECTIVES

We aimed to determine if the duration of canine donor blood storage impacts compatibility testing using a standard gel column crossmatch and evaluate interobserver variation in the interpretation of crossmatch results.

METHODS

Observational study. Whole blood segments were obtained from 23 canine packed red blood cell (RBC) units for use in crossmatches after storage for 0, 7, 14, 21, 28, and 35 days. Major and minor crossmatches were performed using serum and RBCs, respectively, from two to three healthy "recipient" dogs per unit. All crossmatch results were interpreted by four observers, of whom three were blinded.

RESULTS

All major crossmatches (n = 61) were compatible on day 0 and remained compatible through day 35 of storage. All minor crossmatches (n = 69) were compatible at all time points, except for five donor pairs with 1 to 3+ agglutination. Repeat testing of these five donor pairs confirmed crossmatch incompatibilities on days 0 through 35, with no change in the degree of incompatibility over time. There was substantial agreement among four observers in determining compatibility (κ = 0.94) and scoring incompatibility (κ = 0.76).

CONCLUSIONS

The current practice of performing canine crossmatches with whole blood segments stored for up to 35 days is acceptable, with no spurious changes in compatibility expected over time. The substantial interobserver agreement suggests that the gel column is suitable for performing canine crossmatches in a laboratory setting with multiple personnel.

Validation of a cage-side agglutination card for Dal blood typing in dogs

BACKGROUND

Although 98% of the canine population is Dal-positive, Dal-negative dogs are more common in some breeds such as Doberman Pinschers (42.4%) and Dalmatians (11.7%), and finding compatible blood for these breeds may be challenging, given limited access to Dal blood typing.

OBJECTIVES

To validate a cage-side agglutination card for Dal blood typing and determine the lowest packed cell volume (PCV threshold) at which interpretation remains accurate.

ANIMALS

One-hundred fifty dogs, including 38 blood donors, 52 Doberman Pinschers, 23 Dalmatians and 37 anemic dogs. Three additional Dal-positive canine blood donors were included to establish the PCV threshold.

METHODS

Dal blood typing was performed on blood samples preserved in ethylenediaminetetraacetic acid (EDTA) <48 hours using the cage-side agglutination card and a gel column technique (gold standard). The PCV threshold was determined using plasma-diluted blood samples. All results were read by 2 observers, blinded to each other's interpretation and to the sample's origin.

RESULTS

Interobserver agreement was 98% and 100% using the card and gel column assays, respectively. Overall, the sensitivity and specificity of the cards were 86%-87.6% and 96.6%-100%, respectively, depending on the observer. However, 18 samples were mistyped using the agglutination cards (15/18 by both observers): 1 false-positive (Doberman Pinscher), and 17 false-negative samples including 13 anemic dogs (PCV range, 5%-24%; median, 13%). The PCV threshold allowing reliable interpretation was determined to be >20%.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dal agglutination cards are reliable as a cage-side test, but results should be interpreted cautiously in severely anemic patients.

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

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.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

The dog erythrocyte antigen 1 blood group in nondomesticated canids and compatibility testing between domestic dog and nondomesticated canid blood

Background

The dog erythrocyte antigen (DEA) 1 blood group is considered as the most immunogenic and clinically important in dogs. Little is known in nondomesticated canids.

Objectives

To type DEA 1 in nondomesticated captive canids and to evaluate potential interspecific blood transfusions between domestic and nondomestic canids.

Animals

One hundred forty captive nondomesticated canids belonging to 13 species from 19 French zoos, and 63 domestic dogs.

Methods

Prospective study. Blood samples were typed for DEA 1 using immunochromatographic and flow cytometric techniques. A neutral gel column test was used for crossmatching.

Results

Of 140 nondomesticated canids, 72.9% were DEA 1+ and 27.1% were DEA 1− using immunochromatographic technique and 74.3% were DEA 1+ and 25.7% were DEA 1− by flow cytometric technique.

Crossmatch (XM) between 140 nondomesticated canid red blood cells (RBCs) and plasma from a previously DEA 1+ sensitized DEA 1− dog revealed 112 incompatibilities (80%). Crossmatches between 130 nondomesticated canid serum and 1 or up to 8 donor dogs' RBCs revealed 99 of 130 (76%) compatibilities. Crossmatches between 115 nondomesticated canid RBCs and donor dogs' serum revealed 59 of 115 (51%) compatibilities.

Conclusions and Clinical Importance

Dog erythrocyte antigen 1 blood type is present in nondomesticated canids with variable prevalence depending on species. The majority of tested nondomesticated canids appear to have no naturally occurring alloantibodies against domestic dogs' RBCs. Therefore xenotransfusion of blood from domestic dogs can be considered when species specific blood is not available. Cross matching is essential before xenotransfusion.

Survey of Blood Groups DEA 1, DEA 4, DEA 5, Dal, and Kai 1/Kai 2 in Different Canine Breeds From a Diagnostic Laboratory in Germany

More than twelve blood group systems have been described in dogs, but little is known about their distribution frequencies within breed populations. Here, we report on an extensive typing survey carried out using available reagents and either established or new clinical kits in purebred dogs from Germany. Leftover anticoagulated blood samples were examined using an immunochromatographic strip method for DEA 1, a gel column technique for Dal and Kai 1/2, and new card agglutination tests for DEA 4 and DEA 5 (which were partially compared with the gel column technique). Monoclonal antibodies were used for DEA 1 and Kai 1/2 typing, and polyclonal antibodies were used for all other types. Among the 206 dogs, 59.2% were DEA 1+, 100% DEA 4+, 9% (Card)/11% (Gel) DEA 5+, 89.3% Dal+, 96.6% Kai 1+, and 2.9% Kai 2+. None of the dogs were Kai 1+/2+, and only one was Kai 1-/2-. Dal- dogs were found in several breeds. Erythrocytes from most DEA 1+ dogs bound strongly on the strips. The agglutination reactions for DEA 5 on the new card tests were generally less than those on the gel column. The blood group pattern DEA 4+, DEA 5-, Dal+, Kai 1+/2- and either DEA 1+ or DEA 1- was found among 80% of the dogs. In this first extensive blood typing survey of purebred dogs from Europe, the proportions of positive and negative blood types were similar to those found in the United States and, for DEA 1, were also similar to those from other European countries, with considerable breed variation in blood types. The newer typing techniques seem to work well and will likely be useful for detecting and preventing specific blood type incompatibilities in the clinic.

Alloimmunization of a dog erythrocyte antigen 1- dog transfused with weakly dog erythrocyte antigen 1+ blood

BACKGROUND

Acute hemolytic transfusion reactions because of dog erythrocyte antigen (DEA) 1 sensitization after mismatched transfusions are serious complications. Dog erythrocyte antigen 1 expression varies from negative to weakly to strongly positive.

OBJECTIVES

To assess alloimmunization after transfusion of weakly DEA 1+ blood to a DEA 1- dog.

ANIMALS

One DEA 1- recipient and 1 weakly DEA 1+ donor, and 106 control dogs.

METHODS

Long-term follow-up study. Matched for DEA 3, 4, 5, and 7, Dal, and Kai 1 and 2, weakly DEA 1+ donor packed red blood cells (RBCs) were transfused 3 times (0.45 mL/kg at Day 0, 16, and 37) to a DEA 1- recipient. Alloantibodies against RBCs from donor and 106 controls were determined in recipient's plasma samples using a commercial antiglobulin-enhanced immunochromatographic strip and gel tube crossmatches. Alloantibody titers were determined.

RESULTS

The DEA 1- recipient was sensitized after 16 days to ≥1657 days after transfusion to weakly DEA 1+ and otherwise matched RBCs. Strong to moderate crossmatch incompatibilities were observed between recipient's plasma and all 61 DEA 1+ crossmatched controls. Moderate to weak incompatibilities were also observed to DEA 1- controls. Anti-DEA 1 and other alloantibodies were detected over the 4.5 year observation period.

CONCLUSIONS AND CLINICAL IMPORTANCE

Blood from a weakly DEA 1+ donor induces a strong and durable alloimmunization in a DEA 1- recipient dog. Additional alloantibodies developed against yet to be defined RBC antigens. Those results support the recommendation of typing dogs against DEA 1, considering weakly DEA 1+ as immunogenic, and crossmatching all previously transfused dogs.