Dog erythrocyte antigens 1.1, 1.2, 3, 4, 7, and Dal blood typing and cross-matching by gel column technique

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.

The Indirect Antiglobulin (Coombs') Test Is Specific but Less Sensitive Than the Direct Antiglobulin Test for Detecting Anti-Erythrocytic Autoantibodies and Thereby Immune-Mediated Hemolytic Anemia in Dogs

The immunodiagnostic assessment of dogs suspected of having immune-mediated hemolytic anemia (IMHA) is based on persistent autoagglutination of erythrocytes (after three saline washes), marked spherocytosis, and a positive direct antiglobulin (Coombs') test (DAT). However, the value of using the indirect antiglobulin test (IAT) for the detection of anti-erythrocytic autoantibodies in serum from dogs suspected of having IMHA is unclear. To evaluate the IAT, leftover serum samples from a large cohort of 94 dogs suspected of having IMHA and for which DAT results were known were incubated with DAT- erythrocytes, and five IAT techniques were performed (in part with different reagents and temperatures): microtiter plate (MICRO), microcapillary, laboratory gel column, gel minitube kit (GEL KIT), and immunochromatographic strip kit. Two IAT techniques (MICRO at 37 °C and GEL KIT with rabbit anti-dog polyvalent reagent) detected autoantibodies against erythrocytes in serum from 53% and 57% of DAT+ dogs, respectively, while other IATs performed less well. Moreover, while the analytic specificity of the IAT methods compared to the DAT ranged from 96-100%, the sensitivity range was only 9-57%. Thus, we still recommend DAT for diagnosis and monitoring of IMHA in dogs but conclude that a positive IAT result may aid diagnostically when serum is available, but fresh red blood cells are not.

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.

Canine Blood Group Prevalence and Geographical Distribution around the World: An Updated Systematic Review

In recent years, blood transfusions have been more commonly given to pets. The importance of determining blood groups in dogs and cats is, therefore, well-known for reducing the risk of adverse reactions in the recipient blood caused by a "non-compatible" donor. This systematic review summarizes data from previously published reports and follows the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for systematic reviews. After applying the inclusion and exclusion criteria, we identified 41 eligible studies using different states and blood-typing methods to determine blood groups in dogs. The dog blood groups that were identified between 1999 and 2020 in 17 different countries were combined to yield the DEA (Dog Erythrocyte Antigen), Kai, and Dal groups. These studies were conducted in Europe, America, Africa, and Asia but not in all the countries of these continents. The methods used to determine blood types have also changed over the years. This systematic review highlights gaps in the literature and should advance future studies synthesizing data with methodological rigor.

Identification of 5 novel feline erythrocyte antigens based on the presence of naturally occurring alloantibodies

Background

Since the discovery of the Mik antigen, several studies have described blood incompatibilities unrelated to the AB system in cats.

Objective

To estimate the prevalence of cats with non‐AB incompatibilities associated with naturally occurring alloantibodies (NOAb), and to begin mapping the corresponding feline erythrocyte antigens (FEA).

Animals

Two hundred and fifty‐eight type A cats.

Methods

Prospectively, cats were evaluated for the presence of NOAb by crossmatching in groups of 4‐6 cats. When NOAb were detected in a cat, its plasma was used as reagent to assess for the presence of the corresponding FEA in all cats included thereafter, and agreement observed between results of this extensive blood typing was evaluated.

Results

The chance of detecting incompatibilities by randomly crossmatching 2 cats was 3.9%, which resulted in at least 7% of type A cats having NOAb. Blood typing and agreement analyses performed with 7 newly detected NOAb allowed the identification of 5 presumably distinct FEA. Feline erythrocyte antigens 1 and 5 were most frequent with prevalence of 84% and 96%, respectively. Only FEA 1‐negative status was associated with a higher risk of presenting NOAb; with 16.7% of 42 FEA 1‐negative cats having NOAb compared to 5.1% of 216 FEA 1‐positive cats.

Conclusions and Clinical Importance

This study represents a first step of FEA identification outside the AB system. Because of its prevalence and association with NOAb, FEA 1 might correspond to the Mik antigen.

Accuracy of point-of-care crossmatching methods and crossmatch incompatibility in critically ill dogs

BACKGROUND

The performance of commercial point-of-care crossmatch (CM) tests compared to laboratory tube agglutination CM is unknown. Additionally, there is limited information regarding CM incompatibility in ill dogs.

OBJECTIVES

To determine if point-of-care major CM methods are accurate in detecting compatible and incompatible tests when compared to laboratory CM methods, and to identify factors associated with CM incompatibility in dogs.

ANIMALS

Part 1 (prospective) included 63 client-owned dogs potentially requiring blood transfusion. Part 2 (retrospective) included all dogs from part 1, plus medical records of 141 dogs with major CM results.

METHODS

For part 1, major CM was performed using a tube agglutination assay (LAB-CM), a gel-based point-of-care test (GEL-CM), and an immunochromatographic point-of-care test (IC-CM). For part 2, medical record data were collected to determine rates of and risk factors for CM incompatibility.

RESULTS

Kappa agreement between the LAB-CM and GEL-CM methods could not be calculated due to a relative lack of incompatible results. Kappa agreement between the LAB-CM and IC-CM methods was 0.16 (95% confidence interval [CI] = 0-0.31, P = .007) indicating no agreement. The LAB-CM incompatibility in transfusion-naïve vs dogs that had a transfusion was 25% and 35%, (P = .3).

CONCLUSIONS AND CLINICAL IMPORTANCE

Compared to laboratory methods, point-of-care methods evaluated in our study lacked sensitivity for detecting incompatibilities. Dogs had similar rates of major CM incompatibility regardless of transfusion history. This suggests CM testing prior to transfusion be considered in all dogs however our study did not investigate clinical relevancy of incompatible LAB-CM.

Dal-induced red blood cell incompatibilities in a Doberman Pinscher with von Willebrand factor deficiency and ehrlichiosis

OBJECTIVE

To describe a complex case involving the management of a dog with von Willebrand disease (vWD), active ehrlichiosis infection, nonregenerative anemia, and blood type incompatibility related to the Dal antigen.

CASE SUMMARY

A 13-week-oldintact male Doberman Pinscher weighing 7.2 kg was presented to the emergency service for a previous hemorrhaging event and progressive nonregenerative anemia. The dog had received a fresh whole blood transfusion 8 days prior to presentation due to severe anemia. Upon presentation, the puppy was tachycardic, and his mucous membranes were pale. A CBC revealed a nonregenerative anemia with a PCV of 0.11 L/L (11%). von Willebrand factor deficiency was suspected and later confirmed. The dog's blood type was dog erythrocyte antigen (DEA) 1 positive, but cross-matching to 4 RBC units, both DEA 1 positive and negative, failed to yield any compatible units. Antibody against a possible Dal RBC antigen was suspected, and 11 blood donors (Dalmatians and Dobermans) were cross-matched to find 2 compatible donors. After an uneventful fresh whole blood transfusion, a bone marrow biopsy revealed a hypocellular bone marrow and erythroid hypoplasia. A SNAP4DxPlus test and subsequent polymerase chain reaction (PCR) testing were positive for Ehrlichia ewingii and E. canis. Treatment with doxycycline was started, and the PCV was 0.17 L/L (17%) at discharge. At the 1-week follow-up, the PCV was 0.24 L/L (24%), and the puppy was doing well.

NEW OR UNIQUE INFORMATION PROVIDED

This is a unique case of a dog presenting with several challenging disorders, including vWD resulting in hemorrhage, ehrlichiosis potentially contributing to a nonregenerative anemia, and a blood type incompatibility due to the Dal antigen. Doberman Pinschers have a high prevalence of vWD- and Dal-negative phenotype, which emphasizes the value of cross-matching and the recognition of antigen prevalence in specific breeds.

Small Animal Transfusion Medicine

Transfusion medicine can be a lifesaving intervention. Component therapy has expanded the availability and blood products available. Patient safety and minimizing risk is important and can be accomplished through proper donor screening, collection, storage, compatibility testing, administration, and monitoring. The pros and cons of available products must be considered and tailored to each individual patient. Recent discoveries include new antigens and blood types, microbial effects on blood type, and the association between blood type and disease prevalence.

Prevalence of Dal blood type and dog erythrocyte antigens (DEA) 1, 4, and 7 in canine blood donors in Italy and Spain

BACKGROUND

The aim of this study was to determine the prevalence of Dal, and DEA 1, 4, 7 blood types, in a population of canine blood donors from Italy and Spain. Three hundred and twenty blood donor dogs receiving an annual health evaluation were included in the study. DEA 1 blood type was determined using an immunochromatographic strip technique while Dal, DEA 4 and 7 blood types were determined with polyclonal antisera using agglutination on gel columns.

RESULTS

Out of 320 dogs blood typed 7 (2 Cane Corso and 5 Doberman Pinschers) (2.2%) were Dal negative; 137 (42.8%) were positive for DEA 1; 320 (100%) were positive for DEA 4 and 43 (13.4%) were positive for DEA 7.

CONCLUSION

This study showed a similar prevalence of DEA 1, 7 and 4 to that reported in previous studies in the same, and in different, geographic areas, and provides new data on the prevalence of the Dal blood group in Italy and Spain. There was no significant difference (P = 0.8409) between prevalence of Dal negative blood types found in our population (2.2%) and the prevalence reported in a canine blood donor population from the USA (2.5%). Our study identified Dal negative dogs in a previously tested breed i.e. Doberman Pinschers, but also the Cane Corso breed was found to have Dal negative dogs.

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.

A card agglutination test for dog erythrocyte antigen 1 (DEA 1) blood typing in donor dogs: Determining an appropriate cutoff to detect positivity using a receiver operating characteristic curve

BACKGROUND

The appropriate cutoff to define a positive point-of-care card agglutination (CA) test for dog erythrocyte antigen 1 (DEA 1) blood typing depends on whether the test can be used in the donor or recipient.

OBJECTIVES

By screening for CA test positivity, we aimed to evaluate the best cutoff value for DEA 1 blood typing in canine blood donors using a receiver operator characteristic (ROC) curve.

METHODS

Ethylenediaminetetraacetic acid (EDTA) blood samples from 100 canine blood donors were blood-typed in parallel for DEA 1 using both immunochromatographic (IC) and CA tests. The effect of temperature, storage time, and anticoagulant solutions for both methods was evaluated. Unweighted and weighted Cohen's Kappa (K) statistic was calculated to evaluate the agreement between the two testing methods. The overall performance of the CA test was evaluated by generating a ROC curve using the IC test as the reference method.

RESULTS

Concordant results were obtained for 86% of the samples. Unweighted and weighted K statistics demonstrated good and moderate agreement, respectively. For the CA test, the ROC curve showed an area under the curve (AUC) of 0.910, with the highest sensitivity cutoff values at ≥1+ agglutination. CA- and IC-typed EDTA blood samples stored at room temperature for up to 1 week and refrigerated for up to 1 month were concordant as were the citrate phosphate dextrose adenine 1 (CPDA-1) anticoagulated blood samples stored for up to 1 week at 4 ± 2°C.

CONCLUSIONS

The overall reliability of the CA method seemed to be lower than that of the IC method. When CA is used as a screening test for canine blood donors, the correct cut off is ≥1+ agglutination is recommended to maximize sensitivity.

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.

Modified stall-side crossmatch for transfusions in horses

Background

After‐hours or out‐of‐clinic crossmatches are often limited by the lack of access to specialized material and technical expertise.

Hypothesis/Objectives

The goal was to adapt a stall‐side crossmatch test for pretransfusion evaluation in horses.

Animals

Twelve healthy mares (plasma and blood donors, teaching mares).

Methods

In a prospective study, blood from 12 mares was used to compare the results of 132 crossmatches performed with a rapid gel assay to crossmatches performed with a microgel column assay, and with predicted compatibilities based on blood types and detection of antibodies at a reference laboratory (microplate assay). The rapid gel assay protocol for dogs was adapted to decrease the formation of rouleaux that initially precluded equine erythrocytes migration through the gel.

Results

There was a good agreement between the rapid gel assay and the microgel assay as well as with the predicted compatibilities (κ > .6 for both). Agreement was higher between the microgel assay and the predicted compatibilities (κ = .8). The rapid gel assay failed to detect 6 predicted Aa incompatibilities (agglutinins‐related), 3 of which were also not detected with the microgel assay.

Conclusions and Clinical Importance

Based on these results, the modified rapid gel assay could be useful in settings when access to the microgel assay is not available. Discrepancies between both gel techniques and predicted compatibilities were most often low‐grade agglutination, which warrants further investigation to assess their clinical importance.

Comparison of cross-matching method for detection of DEA 7 blood incompatibility

We compared 3 major cross-match (XM) tests to identify dog erythrocyte antigen (DEA) 7 blood incompatibilities in dogs as a result of anti-DEA 7 antibodies: gel (GEL), standard tube (TUBE) agglutination, and immunochromatography strips (STRIP). Blood samples from 42 dogs were typed for DEA 7; 2 tested DEA 7-positive (DEA 7+). The 40 DEA 7-negative (DEA 7-) plasma samples were cross-matched against the 2 DEA 7+ and 3 DEA 7- red blood cell (RBC) samples by GEL to identify samples with anti-DEA 7 antibodies. Twenty DEA 7- plasma samples without and with anti-DEA 7 antibodies were cross-matched with samples of the 2 DEA 7+ RBCs in a double-blind fashion using the TUBE and STRIP XM methods. GEL results were used as the reference method for comparison. To determine relationships between results, 2 × 2 tables were used. Cohen kappa coefficient (κ) was calculated between results of GEL and the other 2 methods. With GEL, 21 of 40 XM tests were positive and 19 of 40 negative for anti-DEA 7 antibodies. The same results were obtained by TUBE, whereas only 1 of 40 XM tests was positive by STRIP. There was a statistically significant relationship between results of GEL and TUBE ( p < 0.000) with perfect agreement (κ = 1.000), but not between GEL and STRIP results ( p = 1.000) in which agreement was equivalent to chance (κ = 0.0453). The GEL and TUBE XM tests, but not STRIP, are useful methods for identification of DEA 7 incompatibilities caused by anti-DEA 7 antibodies.

Alloimmunisation in transfused patients: serial cross-matching in a population of hospitalised cats

Objectives Cross-matching is currently recommended as part of pre-transfusion testing for repeat transfusions in cats 4 days after having received an initial transfusion. This prospective study determined when and if cats developed positive cross-match (CM) results after having been transfused with AB-compatible blood. Methods Donors were selected according to standard transfusion safety protocols. Twenty-one hospitalised anaemic recipients (blood type A: n = 20; blood type B: n = 1) received 1-4 (median 2) whole blood transfusions (WBTs) over 1-6 days (median 2) in 33 transfusion instances. The tube CM method, including major, minor and recipient control, was employed. Macroscopic and microscopic agglutination reactions were evaluated according to a predetermined scale. CM tests with a positive recipient control could not be evaluated. Results No signs of an acute transfusion reaction were observed. A total of 63 CMs were performed. In one cat with immune-mediated haemolytic anaemia the CM could not be evaluated (positive recipient control). The minor CM was negative in all cases. Fifteen of 20 cats had a negative major CM (MCM) 1-12 days (median 5) after their first transfusion. A positive MCM was observed in five cases after 2-10 days (median 5) post-first WBT. These five cats had received a total of 1-4 (median 2) WBTs. Cats with a negative MCM had received 1-3 (median 2) WBTs. In 51.5% (17/33) of transfusion instances, the cat's haematocrit increased as expected, with cats with a positive MCM at 40% (4/10) vs 56.5% (13/23) if MCM was negative. Conclusions and relevance Twenty-five percent (5/20) of the feline recipients likely developed alloantibodies against erythrocyte antigens outside of the AB system as early as 2 days post-first WBT. This adds data to the recommendation to include cross-matching in pre-transfusion screening tests.

Prevalence of Dog Erythrocyte Antigen 1 in 7,414 Dogs in Italy

The study aim was to establish the prevalence of DEA 1, the most immunogenic and clinically important blood group in canine blood transfusion, in 7,414 dogs from Italy. The potential sensitization risk following a first transfusion and the acute reaction risk following a second transfusion given without a cross-matching and blood typing test were also calculated. Dogs tested were purebred (4,798) and mongrel (2,616); 38.8% were DEA 1 negative and 61.2% were DEA 1 positive. High prevalence for DEA 1 positive blood type was found in Ariegeois and English Setter, whereas German Shepherd and Boxer had higher DEA 1 negative blood type. Breeds with blood type never reported before included French Brittany Spaniel and Pug showing a high prevalence of DEA 1 positive type, while French Bulldog and West Highland White Terrier were more often DEA 1 negative. Just 48.8% of purebred and 13.9% of mongrel dogs were considered as prospective blood donors based upon their blood type. Most of the breeds had a sensitization risk of 20.0–25.0%. Rottweiler and Ariegeois had less risk of sensitization (9.4 and 4.2%) and the minor risk of an acute transfusional reaction (0.9–0.2%). The prevalence of DEA 1 positive and negative dogs in Italy agrees with most of the data already reported in the literature.

Pre- and Post-Transfusion Alloimmunization in Dogs Characterized by 2 Antiglobulin-Enhanced Cross-match Tests

BACKGROUND

When dogs are transfused, blood compatibility testing varies widely but may include dog erythrocyte antigen (DEA) 1 typing and rarely cross-matching.

OBJECTIVES

Prospective study to examine naturally occurring alloantibodies against red blood cells (RBCs) and alloimmunization by transfusion using 2 antiglobulin-enhanced cross-match tests.

ANIMALS

Eighty client-owned anemic, 72 donor, and 7 control dogs.

METHODS

All dogs were typed for DEA 1 and some also for DEA 4 and DEA 7. Major cross-match tests with canine antiglobulin-enhanced immunochromatographic strip and gel columns were performed 26-129 days post-transfusion (median, 39 days); some dogs had an additional early evaluation 11-22 days post-transfusion (median, 16 days). Plasma from alloimmunized recipients was cross-matched against RBCs from 34 donor and control dogs.

RESULTS

The 2 cross-match methods gave entirely concordant results. All 126 pretransfusion cross-match results for the 80 anemic recipients were compatible, but 54 dogs died or were lost to follow up. Among the 26 recipients with follow-up, 1 dog accidently received DEA 1-mismatched blood and became cross-match-incompatible post-transfusion. Eleven of the 25 DEA 1-matched recipients (44%) became incompatible against other RBC antigens. No naturally occurring anti-DEA 7 alloantibodies were detected in DEA 7- dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

The antiglobulin-enhanced immunochromatographic strip cross-match and laboratory gel column techniques identified no naturally occurring alloantibodies against RBC antigens, but a high degree of post-transfusion alloimmunization in dogs. Cross-matching is warranted in any dog that has been previously transfused independent of initial DEA 1 typing and cross-matching results before the first transfusion event.

Kai 1 and Kai 2: Characterization of these dog erythrocyte antigens by monoclonal antibodies

Dog Erythrocyte Antigens (DEA) have thus far been found by sensitizing dogs with canine allogeneic blood and are clinically important regarding blood transfusion incompatibilities, but remain poorly defined. The goals of this study were to discover and characterize two DEAs, named as Kai 1 and Kai 2. The monoclonal antibodies were produced by mouse hybridoma techniques and examined by ELISA isotyping, immunoblotting, and affinity chromatography. Canine blood samples were typed and the development of alloantibodies was examined in transfused dogs. The monoclonal Kai 1 and Kai 2 antibodies were isotyped as IgM kappa and IgG3 lamda, respectively, and identified two different erythrocyte membrane proteins of 200 kDa and 80 kDa in molecular weights, respectively. Either Kai 1 or Kai 2 can be expressed but not both in an individual dog. There were no naturally occurring anti-Kai 1 or Kai 2 alloantibodies. In addition, Kai 1- and/or Kai 2- dogs developed Kai 1 and Kai 2 alloantibodies, respectively, when transfused with mismatched blood. This is the first discovery of canine blood types by screening monoclonal antibodies. Kai 1 and Kai 2 are novel blood types which can induce anti-Kai 1 or anti-Kai 2 alloantibodies when Kai 1- and/or Kai 2- dogs are transfused with Kai 1+ or Kai 2+ blood. These canine blood types may explain some of the blood incompatibilities and transfusion reactions observed in dogs in clinical practice.

Prevalence and Mode of Inheritance of the Dal Blood Group in Dogs in North America

Background

The Dal blood group system was identified a decade ago by the accidental sensitization of a Dal− Dalmatian with a Dal+ blood transfusion. Similar Dal‐related blood incompatibilities have been suspected in other Dalmatians, Doberman Pinschers, and other breeds.

Objectives

To determine the prevalence and mode of inheritance of the Dal antigen expression in dogs.

Animals

A total of 1130 dogs including 128 Dalmatians, 432 Doberman Pinschers, 21 Shih Tzus, and 549 dogs of other breeds including 228 blood donors were recruited from North America between 2008 and 2015.

Methods

Prospectively, dogs were blood typed for Dal applying a gel column technique using polyclonal canine anti‐Dal sera. Pedigrees from 8 typed families were analyzed.

Results

The prevalence of the Dal+ blood type varied between 85.6 and 100% in Dalmatians and 43.3–78.6% in Doberman Pinschers depending on geographical area. Dal− dogs were identified mostly in Dalmatians (15/128; 11.7%), Doberman Pinschers (183/432; 42.4%), and Shih Tzus (12/21; 57.1%), and sporadically in mixed‐breed dogs (3/122; 2.5%), Lhasa Apsos (1/6) and Bichon Frises (1/3). Only 6/245 (2.4%) blood donors were found to be Dal−, including 5 Doberman Pinschers. The mode of inheritance of the Dal+ phenotype was determined to be autosomal dominant.

Conclusions and Clinical Importance

The high percentage of Dal− Doberman Pinchers, Dalmatians and Shih Tzus increases their risk of being sensitized by a blood transfusion from the common Dal+ donor. Extended Dal typing is recommended in those breeds and in dogs when blood incompatibility problems arise after initial transfusions.

Characterization of Anti-Dal Alloantibodies Following Sensitization of Two Dal-Negative Dogs

Since its discovery, the immunogenicity of the Dal blood type has not been further investigated. The aim of this study was to better characterize anti- Dal alloantibodies produced following sensitization of Dal-negative dogs, notably their rate of appearance, the agglutination titer over time, and their immunoglobulin class. A secondary objective was to obtain polyclonal anti- Dal alloantibodies to increase the availability of Dal blood typing. Of 100 healthy laboratory Beagles tested, 2 Dal-negative dogs were identified as recipients. Ten healthy Dal-positive dogs were investigated as potential blood donors. All dogs were extensively blood typed for DEA 1, 3, 4, 5, and 7, as well as for Dal. Then, the recipients were transfused uneventfully with 10 ml/kg of Dal-positive but otherwise compatible packed red blood cells. Posttransfusion blood samples were collected routinely over a minimum of 1 year. Using a gel column technology, anti- Dal alloantibodies were detected as early as 4 days posttransfusion and remained detectable 2 years posttransfusion, with maximum agglutination titers reached at 1 and 2 months posttransfusion. The immunoglobulin class was IgG. The immunogenicity and clinical significance of the Dal blood type were confirmed. The results support the recommendations that previously transfused dogs be crossmatched starting 4 days posttransfusion and for the animal’s lifetime. The polyclonal anti- Dal antibodies produced will allow blood typing of a significant number of dogs, especially transfused dogs facing blood incompatibilities and canine blood donors.

Comparison of Tube, Gel, and Immunochromatographic Strip Methods for Evaluation of Blood Transfusion Compatibility in Horses

Background

Assessment of blood compatibility, typically by tube agglutination (TUBE) and hemolysis crossmatch or, less commonly, by blood typing and alloantibody screening, often is performed before blood transfusion in horses. In contrast, gel column (GEL) and immunochromatographic strip (STRIP) techniques are preferred for compatibility testing in dogs and cats.

Objective

To determine the accuracy of novel and standard crossmatch and typing methods.

Animals

Thirty‐eight healthy horses, previously blood typed and alloantibody screened.

Methods

TUBE and GEL crossmatches were performed on 146 different recipient‐donor pairs with 56 incompatible TUBE crossmatches. Crossmatches were compared by nonparametric area under the curve of receiver operating characteristic (AUC‐ROC) analyses. Horses also were blood typed by the novel immunochromatographic Ca typing STRIP.

Results

Compared to TUBE crossmatch, GEL had excellent accuracy for agglutination (AUC‐ROC = 0.903), but marginal accuracy for hemolysis (AUC‐ROC = 0.639). Compared to macroscopic TUBE, microscopic TUBE had excellent accuracy for agglutination (AUC‐ROC = 0.912). The predicted crossmatch compatibility based on blood type and alloantibody assay showed excellent accuracy compared to TUBE and GEL (AUC‐ROC = 0.843 and 0.897, respectively). However, there were more recipient‐donor pairs identified as incompatible by both TUBE and GEL than predicted by blood type and antibody screen, suggesting the presence of unidentified alloantibodies. A Ca typing STRIP exhibited 100% sensitivity and specificity for the 35 Ca+ and 3 Ca‐ horses tested.

Conclusions and Clinical Relevance

Gel column crossmatch and Ca typing immunochromatographic strip are simple and accurate methods to evaluate clinical blood compatibility.

Activity, specificity, and titer of naturally occurring canine anti–DEA 7 antibodies

The reported prevalence of naturally occurring anti–dog erythrocyte antigen (DEA) 7 antibodies in DEA 7–negative dogs is as high as 50%. Characterization of these antibodies may better define their importance in canine transfusion medicine. We determined in vitro activity, specificity, and titer of anti–DEA 7 antibodies in DEA 7–negative dogs. Plasma samples from 317 DEA 7–negative dogs were cross-matched with DEA 7–positive red blood cells (RBCs) using gel column technology. Agglutination occurred with DEA 7–positive RBCs but not with DEA 7–negative RBCs in 73 samples (23%), which were hence classified as containing anti–DEA 7 antibodies. These samples were evaluated for hemolytic and agglutinating activity, strength of agglutination, and antibody specificity and titers. All samples showed agglutination but none showed hemolysis. Gel agglutination was graded as 1+ for 20 samples (27%), 2+ for 49 samples (67%), 3+ for 4 samples (6%); no samples were graded 4+. The agglutination titer was <1:2 for 51 samples (73%), 1:2 for 13 samples (19%), 1:4 for 4 samples (5%), and 1:8 for 2 samples (3%). Of 16 samples treated with 2-mercaptoethanol, 11 samples (69%) contained only IgM, 4 samples (25%) exhibited only IgG activity, and 1 sample (6%) had both IgG and IgM activity. Low titers of warm, weakly agglutinating, mostly naturally occurring IgM anti–DEA 7 antibodies were found in 23% of DEA 7–negative dogs. The presence of naturally occurring anti–DEA 7 antibodies suggests that cross-matching of canine blood recipients is advisable, even at first transfusion, to minimize delayed transfusion reactions.

Survey of Two New (Kai 1 and Kai 2) and Other Blood Groups in Dogs of North America

Background

Based upon serology, >10 canine blood group systems have been reported.

Objective

We surveyed dogs for dog erythrocyte antigen (DEA) 1 and 2 new blood types (Kai 1 and Kai 2), and some samples also were screened for Dal and DEA 3, 4, and 7.

Methods

Blood samples provided by owners, breeders, animal blood banks, and clinical laboratories were typed for DEA 1 by an immunochromatographic strip technique with a monoclonal antibody and analysis of band intensity. Both new antigens, the Dal and other DEAs (except DEA 7 by tube method), were assessed by a gel column method with either monoclonal or polyclonal antibodies. The same gel column method was applied for alloantibody detection.

Results

Of 503 dogs typed, 59.6% were DEA 1+ with 4% weakly, 10% moderately, and 45.6% strongly DEA 1+. Regarding Kai 1 and Kai 2, 94% were Kai 1+/Kai 2‐, 5% were Kai 1‐/Kai 2‐ and 1% were Kai 1‐/Kai 2+, but none were Kai 1+/Kai 2+. There was no relationship between Kai 1/Kai 2 and other blood types tested. Plasma from DEA 1‐, Kai 1‐, Kai 2‐ dogs, or some combination of these contained no detectable alloantibodies against DEA 1 and Kai 1 or Kai, respectively.

Conclusions and Clinical Importance

The new blood types, called Kai 1 and Kai 2, are unrelated to DEA 1, 3, 4, and 7 and Dal. Kai 1+/Kai 2‐ dogs were most commonly found in North America. The clinical relevance of Kai 1 and Kai 2 in canine transfusion medicine still needs to be elucidated.

Xenotransfusion of anemic cats with blood compatibility issues: pre- and posttransfusion laboratory diagnostic and crossmatching studies

BACKGROUND

Finding compatible feline blood donors can be challenging. Canine blood has been occasionally used when compatible feline blood was not available in emergency situations.

OBJECTIVES

The study goals were to describe the effects of xenotransfusion in 2 anemic cats receiving canine blood because of discordant blood types and acute transfusion reaction, respectively, and to report in vitro heterotyping and crossmatching results between canine and feline blood samples.

MATERIAL AND METHODS

Blood samples from patients and other cats and dogs were typed, crossmatched, and assessed for alloantibodies using gel, card, and immunochromatographic strip techniques.

RESULTS

Cat 1 was found to have type AB blood. Cat 2, which experienced an acute transfusion reaction, had type A blood. Neither had detectable alloantibodies against feline RBC. Both cats transiently improved after transfusion with canine blood; however, acute intravascular hemolysis occurred and the PCV rapidly declined. Blood typing post xenotransfusion with DEA 1 strips revealed a positive control band that was absent in feline blood, thus allowing for the identification of transfused canine RBC. Longitudinal assessment revealed that canine RBC could no longer be detected 4 days after xenotransfusion. Major crossmatching (feline plasma with canine RBC) resulted in both positive and negative reactions, depending on the cat. Minor crossmatching results showed mostly incompatibility.

CONCLUSION

While both cats survived xenotransfusion, the positive control band on the DEA 1 strip revealed that transfused canine RBC were short-lived and intravascular hemolysis occurred. Crossmatch results between cats and dogs showed varied incompatibilities and may not predict transfusion reactions.

Prevalence of Dog Erythrocyte Antigens 1, 4, and 7 in Podenco Ibicenco (Ibizan Hounds) from Ibiza Island

The aims of this study were to evaluate the prevalence of Dog Erythrocyte Antigens (DEA) 1, 4, and 7 in Ibizan hounds, to compare the results with the prevalence of DEA in Spanish greyhounds, and to determine the risk of sensitization following the first transfusion of blood not typed for DEA 1 and the probability of an acute hemolytic reaction following a second incompatible transfusion using untyped DEA 1 blood. DEA 1, 4, and 7 status was determined in 92 Ibizan hounds. Results were compared with the previously reported prevalence in Spanish greyhounds. The risks of sensitization and of a hemolytic transfusion reaction were determined amongst Ibizan hounds and between Ibizan hounds and Spanish greyhounds. The prevalence of DEA 1, 4, and 7 was 75%, 98.9%, and 25%, respectively. There was a significantly higher expression of DEA 1 and 7 in Ibizan hounds than in Spanish greyhounds. The probability of sensitization of a recipient dog to DEA 1 with transfusions amongst Ibizan hounds was 18.5% and between Ibizan hounds and Spanish greyhounds was 13.7%. The probability of an acute hemolytic reaction in each group was 3.5% and 1.9%, respectively. There is a higher prevalence of DEA 1 and 7 in Ibizan hounds than in other sighthounds.

Dog erythrocyte antigen 1: mode of inheritance and initial characterization

BACKGROUND

The dog erythrocyte antigen (DEA) 1 blood group system remains poorly defined.

OBJECTIVES

The purpose of the study was to determine the DEA 1 mode of inheritance and to characterize the DEA 1 antigen and alloantibodies.

ANIMALS

Canine research colony families, clinic canine patients, and DEA 1.2+ blood bank dogs were studied.

METHODS

Canine blood was typed by flow cytometry and immunochromatographic strips using anti-DEA 1 monoclonal antibodies. Gel column experiments with polyclonal and immunoblotting with monoclonal anti-DEA 1 antibodies were performed to analyze select samples. Cross-reactivity of human typing reagents against canine RBC and one monoclonal anti-DEA 1 antibody against human RBC panels was assessed.

RESULTS

Typing of 12 families comprising 144 dogs indicated an autosomal dominant inheritance with ≥ 4 alleles: DEA 1- (0) and DEA 1+ weak (1+), intermediate (2+), and strong (3+ and 4+). Samples from 6 dogs previously typed as DEA 1.2+ were typed as DEA 1+ or DEA 1- using monoclonal antibodies. Human typing reagents produced varied reactions in tube agglutination experiments against DEA 1+ and DEA 1- RBC. Polypeptide bands were not detected on immunoblots using a monoclonal anti-DEA 1 antibody, therefore the anti-DEA 1 antibody may be specific for conformational epitopes lost during processing.

CONCLUSIONS

The autosomal dominant inheritance of DEA 1 with ≥ 4 alleles indicates a complex blood group system; the antigenicity of each DEA 1+ type will need to be determined. The biochemical nature of the DEA 1 antigen(s) appears different from human blood group systems tested.

Prevalence of dog erythrocyte antigens 1, 4, and 7 in galgos (Spanish Greyhounds)

Galgos (Spanish Greyhounds), in common with other sighthounds, have higher hematocrits, hemoglobin concentrations, and red blood cell counts than other breeds. In addition to these hematological characteristics, the physical characteristics of these dogs (medium to large dogs with an easily accessible jugular vein and a good temperament) make galgos ideal blood donors. However, to date, there are only published reports concerning dog erythrocyte antigen (DEA) 1 in this breed. Information on DEAs 4 and 7 would be useful when recruiting blood donors to donation programs, as DEA 1 and 7-negative and DEA 4-positive dogs can be considered universal donors. Ethylenediamine tetra-acetic acid-anticoagulated jugular blood samples were collected from 205 galgos. Dogs were aged between 1 and 10 years, 102 were female (49.8%) and 103 male (50.2%), and all were living in South Madrid, Spain. All 205 blood samples were tested for DEA 1 by card agglutination, and 150 of these samples were tested for DEA 4 and DEA 7 by gel column agglutination using polyclonal anti-DEA antibodies. Of the 205 galgos blood samples typed, 112 out of 205 (54.6%) were positive for DEA 1. Of the 150 blood samples tested, all (150/150, 100%) were positive for DEA 4, and 12 out of 150 (8%) samples tested positive for DEA 7. Of these samples, 70 out of 150 (46.7%) were positive only for DEA 4. There was no relationship between blood types and sex. In addition to the hematological characteristics previously reported and the physical characteristics of these dogs, the relative prevalence of blood types DEA 1, 4, and 7 make galgos good candidates for blood donation in blood donor programs.

Frequency of dog erythrocyte antigen 1.1 in 4 breeds native to different areas in Turkey

BACKGROUND

Dog erythrocyte antigen (DEA) 1.1 is the most important RBC antigen clinically, as it is highly immunogenic and causes acute hemolytic transfusion reactions (HTR) in sensitized dogs.

OBJECTIVES

The aims of this study were to determine the frequency of DEA 1.1 expression in 4 Turkish dog breeds, and to estimate the potential risk of HTR when blood from a DEA 1.1-positive donor is administered to a DEA 1.1-negative recipient following sensitization by a prior mismatched transfusion.

METHODS

EDTA blood samples (n = 178) were typed for DEA 1.1 using a commercial gel-column agglutination test (ID-Gel-Test Canine DEA 1.1). Probabilities of sensitization and risk of an HTR were calculated.

RESULTS

The frequency of positivity for DEA 1.1 among Kars (n = 59), Kangal (n = 53), Akbash (n = 50), and Catalburun (n = 16) breeds was 71.2%, 67.9%, 60.0%, and 50.0%, respectively. Potential risk for occurrence of an HTR after administration of blood from a dog of the same breed ranged from 12.5% to 14.8%, whereas HTR induced by blood of a dog from a different breed ranged from 7.2% to 25.3%.

CONCLUSIONS

The frequency of DEA 1.1-positive dogs among 4 Turkish breeds is high compared with that of most other breeds previously surveyed. The predicted risk of both sensitization and occurrence of DEA 1.1-related HTR following transfusion between dogs of either the same or different Turkish breeds was considerable. Although few dogs are transfused ≥4 days after the first transfusion, we recommend that (1) all donors and recipients be typed for DEA 1.1, (2) DEA 1.1-negative recipients receive only DEA 1.1-negative blood, and (3) blood be cross-matched prior to transfusing any dog ≥4 days after the first transfusion. These guidelines are also applicable to other breeds and countries.

Canine and feline blood transfusions: controversies and recent advances in administration practices

OBJECTIVES

To discuss and review blood transfusion practices in dogs and cats including collection and storage of blood and administration of products. To report new developments, controversial practices, less conventional blood product administration techniques and where applicable, describe the relevance to anaesthetists and anaesthesia.

DATABASES USED

PubMed and Google Scholar using dog, cat, blood transfusion, packed red blood cells and whole blood as keywords.

CONCLUSIONS

Blood transfusions improve oxygen carrying capacity and the clinical signs of anaemia. However there are numerous potential risks and complications possible with transfusions, which may outweigh their benefits. Storage of blood products has improved considerably over time but whilst extended storage times may improve their availability, a phenomenon known as the storage lesion has been identified which affects erythrocyte viability and survival. Leukoreduction involves removing leukocytes and platelets thereby preventing their release of cytokines and bioactive compounds which also contribute to storage lesions and certain transfusion reactions. Newer transfusion techniques are being explored such as cell salvage in surgical patients and subsequent autologous transfusion. Xenotransfusions, using blood and blood products between different species, provide an alternative to conventional blood products.

DEA 1 expression on dog erythrocytes analyzed by immunochromatographic and flow cytometric techniques

Background

The Dog erythrocyte antigen (DEA) 1 blood group system was thought to contain types DEA 1.1 and 1.2 (and possibly 1.3 [A₃]). However, DEA 1.2+ dogs are very rare and newer typing methods reveal varying degrees of DEA 1 positivity.

Objectives

To assess if variation in DEA 1 positivity is because of quantitative differences in surface antigen expression. To determine expression patterns in dogs over time and effects of blood storage (4°C). To evaluate DEA 1.2+ samples by DEA 1 typing methods.

Animals

Anticoagulated blood samples from 66 dogs in a research colony and from a hospital, and 9 previously typed DEA 1.2+ dogs from an animal blood bank.

Methods

Research study: Samples were analyzed by flow cytometry and immunochromatographic strip using a monoclonal anti‐DEA 1 antibody.

Results

Twenty dogs were DEA 1−, whereas 46 dogs were weakly to strongly DEA 1+. Antigen quantification revealed excellent correlation between strip and flow cytometry (r = 0.929). Both methods reclassified DEA 1.2+ samples as weakly to moderately DEA 1+, but they were not retyped with the polyclonal anti‐DEA 1.1/1.X antibodies. Dogs and blood samples retained their relative DEA 1 antigen densities over time.

Conclusions and Clinical Importance

The blood group system DEA 1 is a continuum from negative to strongly positive antigen expression. Previously typed DEA 1.2+ appears to be DEA 1+. These findings further the understanding of the DEA 1 system and suggest that all alleles within the DEA 1 system have a similarly based epitope recognized by the monoclonal antibody.

Transfusion medicine in small animals

This article reviews the use of transfusion medicine in veterinary medicine and discusses current research regarding donor screening and component therapy. Typing and crossmatching methodologies are discussed. Available components, potential uses, and controversies in treatment are also discussed.

Comparison of gel column, card, and cartridge techniques for dog erythrocyte antigen 1.1 blood typing

OBJECTIVE

To compare accuracy and ease of use of a card agglutination assay, an immunochromatographic cartridge method, and a gel-based method for canine blood typing.

SAMPLE

Blood samples from 52 healthy blood donor dogs, 10 dogs with immune-mediated hemolytic anemia (IMHA), and 29 dogs with other diseases.

PROCEDURES

Blood samples were tested in accordance with manufacturer guidelines. Samples with low PCVs were created by the addition of autologous plasma to separately assess the effects of anemia on test results.

RESULTS

Compared with a composite reference standard of agreement between 2 methods, the gel-based method was found to be 100% accurate. The card agglutination assay was 89% to 91% accurate, depending on test interpretation, and the immunochromatographic cartridge method was 93% accurate but 100% specific. Errors were observed more frequently in samples from diseased dogs, particularly those with IMHA. In the presence of persistent autoagglutination, dog erythrocyte antigen (DEA) 1.1 typing was not possible, except with the immunochromatographic cartridge method.

CONCLUSIONS AND CLINICAL RELEVANCE

The card agglutination assay and immunochromatographic cartridge method, performed by trained personnel, were suitable for in-clinic emergency DEA 1.1 blood typing. There may be errors, particularly for samples from dogs with IMHA, and the immunochromatographic cartridge method may have an advantage of allowing typing of samples with persistent autoagglutination. The laboratory gel-based method would be preferred for routine DEA 1.1 typing of donors and patients if it is available and time permits. Current DEA 1.1 typing techniques appear to be appropriately standardized and easy to use.

Coombs' testing and its diagnostic significance in dogs and cats

The Coombs' test can detect both immunoglobulin and complement on the surface of RBCs, and as such can be of value as an aid in the diagnosis of IMHA. Techniques that may improve sensitivity include use of monovalent reagents, increased dilutions of antiglobulin to avoid a prozone effect, and testing at 4°C. These techniques are not without controversy, and positive tests should always be interpreted in the presence of other clinical and hematologic evidence for IMHA. Alternate techniques, such as flow cytometry, can improve detection of RBC-bound immunoglobulin, but require a flow cytometer and further standardization between laboratories.

In vitro lysis and acute transfusion reactions with hemolysis caused by inappropriate storage of canine red blood cell products

BACKGROUND

Transfusion of red blood cell (RBC) products carries considerable risk for adverse reactions, including life-threatening hemolytic reactions.

OBJECTIVE

To report the occurrence and investigation of life-threatening acute transfusion reactions with hemolysis in dogs likely related to inappropriate blood product storage.

ANIMALS

Four dogs with acute transfusion reactions and other recipients of blood products.

METHODS

Medical records were reviewed from 4 dogs with suspected acute hemolytic transfusion reactions after receiving RBC products at a veterinary clinic over a 1-month period. Medical records of other animals receiving blood products in the same time period also were reviewed. Blood compatibility and product quality were assessed, subsequent transfusions were closely monitored, and products were diligently audited.

RESULTS

During or immediately after RBC product transfusion, 4 dogs developed hemolysis, hemoglobinuria, or both. Two dogs died and 1 was euthanized because of progressive clinical signs compatible with an acute hemolytic transfusion reaction. Blood type and blood compatibility were confirmed. RBC units from 2 blood banks were found to be hemolyzed after storage in the clinic's refrigerator; no bacterial contamination was identified. After obtaining a new refrigerator dedicated to blood product storage, the problem of hemolyzed units and acute transfusion reactions with hemolysis completely resolved.

CONCLUSIONS

Acute life-threatening transfusion reactions can be caused by inappropriate storage of RBC products. In addition to infectious disease screening and ensuring blood-type compatibility, quality assessment of blood products, appropriate collection, processing, and storage techniques as well as recipient monitoring are critical to provide safe, effective transfusions.