Comparison of five blood-typing methods for the feline AB blood group system

Objective-To compare the ease of use and accuracy of 5 feline AB blood-typing methods: card agglutination (CARD), immunochromatographic cartridge (CHROM), gel-based (GEL), and conventional slide (SLIDE) and tube (TUBE) agglutination assays. Sample Population-490 anticoagulated blood samples from sick and healthy cats submitted to the Transfusion or Clinical Laboratory at the Veterinary Hospital of the University of Pennsylvania. Procedures-Sample selection was purposely biased toward those from anemic, type B, or type AB cats or those with autoagglutination. All blood samples were tested by use of GEL, SLIDE, and TUBE methods. Fifty-eight samples were also tested by use of CARD and CHROM methods. The presence of alloantibodies in all cats expressing the B antigen as detected by use of any method was also assessed. Results-Compared with the historical gold-standard TUBE method, good to excellent agreement was achieved with the other typing tests: CARD, 53 of 58 (91% agreement); CHROM, 55 of 58 (95%); GEL, 487 of 490 (99%); and SLIDE, 482 of 487 (99%; 3 samples were excluded because of autoagglutination). Four of the samples with discordant test results originated from cats with FeLV-related anemia. Conclusions and Clinical Relevance-Current laboratory and in-clinic methods provide simple and accurate typing for the feline AB blood group system with few discrepancies. Retyping after in-clinic typing with the GEL or TUBE laboratory methods is recommended to confirm any type B or AB cats.     

Comparison of various canine blood-typing methods

OBJECTIVE: To compare canine blood-typing results determined by use of the card (CARD), gel (GEL), Michigan State University (MSU), and tube (TUBE) tests. SAMPLE POPULATION: Blood samples from 23 healthy dogs. PROCEDURES: Blood samples anticoagulated with EDTA were screened by use of each blood-typing method according to manufacturers' protocols. RESULTS: Strong RBC agglutination reactions were observed with dog erythrocyte antigen (DEA) 1.1 reagents of the CARD and GEL tests as well as MSU test (only after adding Coombs' reagent) in 9 blood samples. By use of the CARD test, RBCs from 4 additional dogs agglutinated weakly; on the basis of MSU test results, these 4 dogs were classified as DEA 1.2 positive. All blood samples agglutinated with the B antigen reagent of the TUBE test. All but 2 blood samples had strong positive reactions with the DEA 4 reagent of the MSU test. All but 3 blood samples reacted with the E antigen reagent of the TUBE test. Three blood samples agglutinated with the DEA 3 reagent of the MSU test and A antigen reagent of the TUBE test. Five blood samples had strong agglutination reactions with the DEA 5 reagent of the MSU test. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the CARD test allows for rapid identification of DEA 1.1 but may produce weak reactions with blood from DEA 1.2-positive dogs. The GEL test is a reliable and rapid clinical laboratory method for identification of DEA 1.1. The MSU test requires Coombs' reagent for identification of DEA 1.1 and 1.2.     

Frequencies of feline blood types in the Rio de Janeiro area of Brazil

Background: The distribution and frequency of blood types in cat populations vary according to geographic region and breed. Frequencies of feline blood types in Rio de Janeiro city, as well as in other Brazilian areas, are unknown, and the risk of unmatched transfusions and neonatal isoerythrolysis has not been estimated. Objectives: The purpose of this study was to determine the frequency of feline blood types in the area of Rio de Janeiro, Brazil. Methods: EDTA blood samples were obtained from 172 nonpedigreed domestic shorthair (DSH) cats (92 female, 80 male, 3 months-20 years old) in different sites of Rio de Janeiro city. Blood typing was performed by agglutination assays using Triticum vulgaris lectin and feline anti-A serum. The hemagglutination results for type B and AB cats were confirmed by high-performance thin-layer chromatography (HPTLC) of erythrocyte membrane gangliosides. Results: The majority (163/172, 94.8%) of cats were type A, 2.9% were type B, and 2.3% were type AB. High-titer anti-A serum agglutinated RBCs from all cats in type A and type AB blood groups, with 3+ to 4+ agglutination. The probability that a type A cat would receive type B or AB blood in a first random transfusion was calculated as 2.25% and 2.20%, respectively. HPTLC analysis of glycolipids yielded a chromatographic profile characteristic of feline gangliosides for all blood groups. Conclusions: These results indicate a high prevalence of type A cats in Rio de Janeiro, Brazil, and a low frequency of type B and AB cats, consistent with what has been observed for DSH cats in other regions of the world.     

Titres of alloantibodies against A and B blood types in non-pedigree domestic cats in Turkey: assessing the transfusion reaction risk

The severity of a transfusion reaction depends on alloantibody titres within the recipients' blood. Determination of an agglutination titre of naturally occurring alloantibody may help to assess the risk of transfusion reactions following an unmatched transfusion in a cat population. In this group of 312 cats 227 had blood type A, 78 had blood type B, and seven had type AB blood. All type B cats tested showed gross evidence of agglutinating anti-A antibody with plasma titres ranging from 2 to 256. Among the 227 type A domestic cats tested for plasma anti-B alloantibody titres, 70% had gross agglutination with titres ranging from 2 to 16, while 17.6% had microscopic agglutination. The remaining 12.4% of the type A cats were negative for both gross and microscopic agglutination. Based on agglutinating titres, the relative risk of a transfusion reaction when type A or AB blood was given to a type B cat was 6.4% with acute severe reaction, acute mild reactions in 85.9% and premature red cell destruction in 7.7%. On the other hand, transfusion of type AB blood or type B blood to type A cats carries a potential risk of acute mild transfusion reaction in 4.4% and premature red cell destruction in 83.3%. Transfusion of type A or B blood to type AB cats results in no apparent clinical transfusion reactions.     

Frequencies of blood type A, B and AB in non-pedigree domestic cats in Turkey

OBJECTIVES: To determine the distribution of blood types and to estimate the proportion of matings at risk for neonatal isoerythrolysis in non-pedigree domestic cats. METHODS: The present survey determined the frequency of blood types in 301 cats from four distinct regions of Turkey. Ethylenediaminetetraacetic acid-anticoagulated blood samples were typed by simple tube and slide agglutination assays. Serum obtained from type B cats and an anti-B solution, prepared with Triticum vulgaris, were used to determine type A and type B blood, respectively. RESULTS: Of the 301 cats typed, 220 had type A blood, 74 had type B and seven had type AB. There was a significant difference (P<0.01) between the locations of the cats, with fewer type B cats in the eastern than in the western parts of Turkey. Risk for the development of neonatal isoerythrolysis due to A-B mismatch was estimated to be 18.6 per cent. CLINICAL SIGNIFICANCE: The overall type B frequency in Turkish domestic cats is high. Thus, untyped transfusions in these cats carry a high risk of life-threatening acute haemolytic transfusion reactions and neonatal isoerythrolysis. It is therefore strongly recommended that blood typing be performed before breeding or transfusing in order to minimise blood type incompatibility risks.     

Prevalence of feline blood groups in the Montreal area of Quebec,Canada

The feline AB blood group system has clinical significance because type B cats have natural alloimmune anti-A antibodies which can cause isoerythrolysis of the newborn and life-threatening transfusion reactions. In the United States, the prevalence of type B blood is estimated to be 1% to 2%. This study determined the prevalence of feline AB blood groups among 207 potential blood donor cats that included 178 domestic cats, in the Montreal area of Quebec, Canada. Blood typing was performed using a standardized tube technique. Blood types AB and B were confirmed using a backtyping technique. The frequency of blood types among the studied population was as follows: 95.2% type A, 4.4% type B, and 0.48% type AB. Among domestic cats, the frequency was 94.4% for type A, 5% for type B, and 0.6% for type AB. The frequency of type B was higher than expected, which reinforces the recommendation to ensure blood compatibility of the recipient and donor before transfusion through typing and possibly cross-matching as well.     

Titres of naturally occurring alloantibodies against feline blood group antigens in Turkish Van cats

Seventy-eight Turkish Van cats were examined for alloantibody titres, of which 42.3 per cent had type A blood and 57.7 per cent had type B blood. No type AB cats were found. All type B cats (n = 45) showed gross evidence of agglutinating anti-A antibody, with titres ranging from 2 to 256. Sixty-seven per cent of type B cats had anti-A antibody in their plasma, with titres ranging from 8 to 32. However, 13 per cent of type B cats had plasma alloantibody titres of less than 8 and 20 per cent had titres that were higher than 32. A total of 33 type A cats were also tested for anti-B alloantibody titres in their plasma. Among the type A plasma, gross agglutination at titres of 2 and greater than 2 were determined in 24 per cent and 36 per cent of samples, respectively. Microscopic agglutination was seen in an additional 18 per cent of plasma samples. There was no significant association between gender and plasma alloantibody titres of cats (P > 0.05).     

Measurement of titres of naturally occurring alloantibodies against feline blood group antigens in the UK

Measurement of anti-A and anti-B haemagglutinating alloantibody titres was performed on serum samples from both pedigree (n = 61) and non-pedigree (n = 43) cats previously typed using a commercial blood typing kit. All 40 type B cats had anti-A antibody with titres ranging from 4 to 1600. Among the 61 type A sera tested, an anti-B agglutination titre of greater than 2 was recorded in 16.4 per cent. There was no significant association between serum alloantibody titre and cat breed or gender (P > 0.05).     

Comparison of gel column agglutination with monoclonal antibodies and card agglutination methods for assessing the feline AB group system and a frequency study of feline blood types in northern Italy

Background: A new commercial gel column agglutination system is reported to have high sensitivity in detecting cats with blood type AB. Objectives: The aims of this study were to compare gel column agglutination and card agglutination methods for feline blood‐typing and to determine the frequency distribution of feline blood types in northern Italy. Methods: Blood‐typing was performed on 120 cats using both a commercial gel column containing monoclonal antibodies (ID Gel‐Test Micro Typing System) and a card agglutination method (RapidVet‐H Feline). Results were confirmed with back‐typing. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the 2 methods. A second group of 140 Domestic Shorthair (DSH) cats was blood‐typed using the gel column technique to determine the frequency distribution of feline blood types in northern Italy. Results: The card agglutination method demonstrated poor sensitivity in identification of type‐AB cats (61%) and was only 95% specific when identifying type‐B cats. The gel column agglutination technique demonstrated 100% sensitivity and specificity for typing all 3 blood types (A, B, and AB). The frequency distribution study of 140 cats demonstrated that 127 (90.7%) cats were type A, 10 (7.1%) were type B, and 3 (2.1%) were type AB. Conclusion: When blood‐typing cats of breeds with a relatively high frequency of blood types B and AB, methods that use monoclonal antibodies for detection of blood types B and AB are recommended. Alternatively, blood type can be confirmed by more sensitive supplemental testing, such as back‐typing. The high frequency of blood type A in DSH cats in northern Italy was comparable to previously reported frequencies in Italy and world‐wide.     

Blood type A and B frequencies in Turkish Van and Angora cats in Turkey

Blood typing of domestic cats has been performed in domestic and purebred cats in various parts of the world and is important in clinical practice in order to prevent neonatal isoerythrolysis (NI) and acute haemolytic transfusion reactions. Prevalence of blood types vary greatly between breeds of cats. Turkish Van and Angora cats are different breeds that originated in geographically distinct regions of Turkey. The present survey determined the frequency of blood types in these Turkish pedigreed cats in Turkey. Ethylenediaminetetraacetic-acid anti-coagulated blood of a total of 113 Turkish Van and Angora cats were examined for blood typing using a slide and tube agglutination assay. Of the 85 Van cats surveyed, 40% had type A, and 60% had type B blood. Of the 28 Turkish Angora cats, 53.6% had type A, and 46.4% had type B blood. No type AB cats were found between both breeds. There was no significant association between blood types and gender of both Angora and Van cats or eye colours of Van cats (P > 0.05). Although these are limited surveys, the overall prevalence of type B cats in these two breeds was very high compared with the results of previous studies worldwide. It appears likely that blood type incompatibilities responsible for feline NI and transfusion reactions are occurring in these breeds. The risk of transfusion incompatibility in Turkish Angora and Van cats was 46.4 and 60%, respectively. It is therefore strongly recommended to breeders and clinicians that blood typing be performed prior to breeding and transfusing cats.     

Frequency of blood type A, B, and AB in 515 domestic shorthair cats from the Lisbon area

Background: The A, B, and AB feline blood types are recognized worldwide and their frequencies vary geographically and among breeds. Frequencies of feline blood types have been reported previously from northern Portugal; however, they are unknown in other parts of the country. Objectives: This 13‐year retrospective study was undertaken to determine the frequency of feline blood types in domestic shorthair (DSH) cats from the Lisbon area of central Portugal. Methods: Blood samples were obtained at the Veterinary Teaching Hospital of the Technical University of Lisbon and its Veterinary Blood Bank and at several veterinary clinics in the Lisbon area. Blood‐typing was performed by the classical agglutination assay or using a cartridge assay. Results: The study population comprised 515 DSH cats of both sexes and various ages. Frequencies of blood types A, B, and AB were 97.5%, 2.1%, and 0.4%, respectively. Conclusion: As in other parts of the world, this study showed a clear predominance of type‐A cats in the Lisbon area of Portugal.     

A newly recognized blood group in domestic shorthair cats: the Mik red cell antigen

BACKGROUND: Naturally occurring alloantibodies produced against A and B red cell antigens in cats can cause acute hemolytic transfusion reactions. Blood incompatibilities, unrelated to the AB blood group system, have also been suspected after blood transfusions through routine crossmatch testing or as a result of hemolytic transfusion reactions. HYPOTHESIS: Incompatible crossmatch results among AB compatible cats signify the presence of a naturally occurring alloantibody against a newly identified blood antigen in a group of previously never transfused blood donor cats. The associated alloantibody is clinically important based upon a hemolytic transfusion reaction after inadvertent transfusion of red cells expressing this red cell antigen in a feline renal transplant recipient that lacks this red cell antigen. METHODS: Blood donor and nonblood donor cats were evaluated for the presence of auto- and alloantibodies using direct antiglobulin and crossmatch tests, respectively, and were blood typed for AB blood group status. Both standard tube and novel gel column techniques were used. RESULTS: Plasma from 3 of 65 cats and 1 feline renal transplant recipient caused incompatible crossmatch test results with AB compatible erythrocytes indicating these cats formed an alloantibody against a red cell antigen they lack, termed Mik. The 3 donors and the renal transplant recipient were crossmatch-compatible with one another. Tube and gel column crossmatch test results were similar. CONCLUSIONS AND CLINICAL IMPORTANCE: The absence of this novel Mik red cell antigen can be associated with naturally occurring anti-Mik alloantibodies and can elicit an acute hemolytic transfusion reaction after an AB-matched blood transfusion.     

Frequencies of feline blood types in northern Portugal

The frequencies of feline blood types in northern Portugal were studied by surveying 185 pedigreed and nonpedigreed cats. Blood typing was performed by the traditional tube method. As a single group, the majority of cats were type A (90.3%), 3.8% were type B, and 5.9% were type AB. Among pedigreed cats, 19 were Siamese and 7 were Persian; all but 1 were type A. Among nonpedigreed cats, 89.3% were type A, 4.4% were type B, and 6.3% were type AB.     

Determination of the prevalence of feline blood types in the UK

The efficacy and diagnostic accuracy of a new desk-top feline blood typing kit was evaluated by comparing the results of the kit with traditional blood typing methods on 35 feline blood samples. The kit was then used to blood type 139 non-pedigree cats from Scotland and the north of England and 207 pedigree cats from throughout the UK. Of the non-pedigree cats, 87.1 per cent were type A, 7.9 per cent were type B and 5.0 per cent were type AB, while of the pedigree cats, 54.6 per cent were type A, 40.1 per cent were type B and 5.3 per cent were type AB. The majority (121 out of 207) of these pedigree cats were British shorthaired, of which 39.7 per cent were type A, 58.7 per cent were type B and 1.6 per cent were type AB. No cats were identified that failed to express the type A and/or type B antigens. The prevalence of type AB cats appears to be higher in this study than previously reported. The prevalence of blood types within specific pedigree breeds in the UK appears to vary from that reported elsewhere.     

Frequencies of feline blood types in Hungary

Feline blood group determination is done as a routine diagnostic method in numerous countries. Blood transfusion reactions and feline neonatal isoerythrolysis (FNI) can be avoided with the identification of different feline blood groups. The present study is the first investigation in Hungary during which 100 cats have been examined from all over the country. These cats were out of six breeds: European domestic shorthair, Persian mix, Persian, Abyssinian, Siamese and British shorthair. In the Hungarian feline population European domestic shorthair are most common but other breeds also occur. European domestic shorthair, Persian mix, Abyssianian, Siamese and British shorthair individuals all belonged to blood type A (100%). Blood type B was found very rarely and only in Persian cats. One-third of the Persian cats were categorised into blood type B, whilst type AB was not found during the study.     

Distribution of Feline Blood Types Detected in the Copenhagen Area of Denmark

Jensen, A. L., A. B. Olesen and J. Arnbjerg: Distribution of feline blood types detected in the Copenhagen area of Denmark. Acta vet. scand., 1994, 35, 121-124.–The purpose of the present study was to make the first survey of the distribution of feline AB blood types in the Copenhagen area of Denmark. A total of 244 cats (139 purebred cats and 105 Domestic Shorthair cats) were tested. 93% of all tested cats had blood type A. Neither an AB nor an O type cat was detected and thus, the frequency of blood type B among all tested cats was 7%. Most type B cats were purebred cats (Birman, British Shorthair and Persian cats). No association between sex and blood type could be demonstrated among British Shorthair and Persian cats. Thus, the present study indicates that cats in Denmark predominantly have blood type A, and that blood type B cats are rare, except for certain breeds such as Birman and British Shorthair cats.     

Assessment of feline blood for transfusion purposes in the Dublin area of Ireland

The prevalence of A, B and AB blood types and of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection was determined in cats in Ireland, in order to determine risk factors for blood taken for transfusion purposes. EDTA blood samples were available from 137 non-pedigree cats and 39 pedigree cats (91 females and 85 males, aged four months to 15.0 years) in the Dublin area of Ireland. Of the 176 EDTA blood samples obtained, 112 (from 92 healthy cats and 20 sick cats) were tested for the presence of both FIV antibodies and FeLV antigens. Blood typing was performed using an immunochromatographic cartridge (CHROM; Alvedia). Testing for FIV and FeLV was performed by ELISA (SNAP FIV/FeLV Combo Test; Idexx Laboratories). Of the 39 pedigree cats, the majority (38 [97.4 per cent]) was type A, and only one (2.6 per cent) was type B. Of the 137 non-pedigree cats, the majority (116 [84.7 per cent]) was type A, 20 (14.6 per cent) were type B, and one (0.7 per cent) was type AB. Of the 92 healthy cats tested, the prevalence of FIV and FeLV positivity was 4.35 and 1.09 per cent, respectively. None of the 20 sick cats tested was FIV-positive; two (10 per cent) of the 20 sick cats were FeLV-positive.     

Frequencies of feline blood types at a referral hospital in the south east of England

OBJECTIVES: To determine the prevalence of blood types in the feline patients and blood donors of the Queen Mother Hospital for Animals (The Royal Veterinary College, London, UK), that were typed between 2000 and 2004. METHODS: A retrospective study was performed using files of patients and blood donors of the Queen Mother Hospital for Animals seen between January 2000 and November 2004. Commercial blood typing cards were used to determine the blood type. RESULTS: One hundred and fifty-six cats were included in the study; 51 (32.7 per cent) were pedigree and 105 (67.3 per cent) non-pedigree. Of the 51 pedigree cats, the prevalence of blood types was as follows: type A, 42 (82.4 per cent); type B, seven (13.7 per cent) and type AB, two (3.9 per cent). Of the 105 non-pedigree cats, the prevalence of blood types was as follows: type A, 71 (67.6 per cent); type B 32 (30.5 per cent) and type AB two (1.9 per cent). CLINICAL SIGNIFICANCE: The prevalence of type B blood in non-pedigree cats is higher than previously suggested and shows high variability within the UK; because of this, blood typing all feline patients, not only the ones of a breed typically known to have higher prevalence of type B blood before transfusion, is absolutely necessary to avoid a fatal transfusion reaction.     

Frequencies of feline blood groups in the United States

A survey of AB blood group frequencies among cats in the United States was undertaken, using feline blood typing reagents from Australia. We typed blood of 280 cats of both genders and various breeds within the Philadelphia area and 205 cats at 27 veterinary medical teaching hospitals (most cats had been used as blood donors in 1987) throughout the United States. All but 2 cats had type-A blood. A Himalayan cat in Philadelphia and a domestic shorthair cat from Florida, neither of which had been used as a blood donor, had type-B blood. Plasma of the 2 blood-group-Bcats contained strong isoagglutinins (greater than 1:8 titer) against type-A cells, thereby allowing their detection in a major cross-match test. Approximately 30% of tested plasma samples from blood-group-A cats had weak isoagglutinins (1:2 titer) against type-B cells. This limited survey suggests that cats in the United States, including blood donors, predominantly have type-A blood, and that blood-group-B cats are rare.     

The bovine immune response to Brucella abortus IV. Studies with a double immunodiffusion test for antibody against A2.

A double immunodiffusion test for precipitins against Brucella antigen A2 was developed and applied to a variety of samples. The A2 precipitins were produced by a heifer infected with B. abortus strain 2308, cattle vaccinated with killed B. melitensis strain H38 or live B. abortus strain 19 and by a dog infected with B. canis. Precipitins were also detected in the second International Standard for anti-Brucella abortus serum, in several anti-B. canis sera and at low levels in one anti-B. ovis serum tested. Antisera produced in calves against Yersinia enterocolitica serotype 0:9 had no anti-A2 activity despite titers greater than or equal to 1/1024 and greater than or equal to 1/80 in standard Brucella agglutination and CF tests, respectively. The test for A2 precipitins lacked specificity as weak reactions were obtained with five of 295 sera from brucellosis-free herds. This test was relatively insensitive, detecting precipitins in only 16 of 24 sera from infected cattle and 27 of 54 sera positive by complement fixation and enzyme labelled antiglobulin tests performed with whole cell and smooth lipopolysaccharide antigens, respectively. The A2 precipitins were detected in nine sera from five cattle, in two infected herds, which were negative by agglutination and complement fixation tests.