Signalment and blood types in cats being evaluated as blood donors at two italian university blood banks

Do Blood Phenotypes of Feline AB Blood Group System Affect the SARS-CoV-2 Antibody Serostatus in Cats?

Cats are susceptible to coronavirus infections, including infection by human severe acute respiratory syndrome coronavirus (SARS-CoV). In human ABO system blood groups, alloantibodies can play a direct role in resistance to infectious diseases. Individuals with the AB blood type were over-represented in the SARS-CoV-2 infection group. Blood type AB individuals lack both anti-A and anti-B antibodies, and therefore lack the protective effect against SARS-CoV-2 infection given by these antibodies. Starting from this knowledge, this pilot preliminary study evaluated a possible association between feline blood phenotypes A, B, and AB and serostatus for SARS-CoV-2 antibodies in cats. We also investigated selected risk or protective factors associated with seropositivity for this coronavirus. A feline population of 215 cats was analysed for AB group system blood phenotypes and antibodies against the nucleocapsid (N-protein) SARS-CoV-2 antigen using a double antigen ELISA. SARS-CoV-2 seropositive samples were confirmed using a surrogate virus neutralization test (sVNT). Origin (stray colony/shelter/owned cat), breed (DSH/non DSH), gender (male/female), reproductive status (neutered/intact), age class (kitten/young adult/mature adult/senior), retroviruses status (seropositive/seronegative), and blood phenotype (A, B, and AB) were evaluated as protective or risk factors for SARS-CoV-2 seropositivity. Seropositivity for antibodies against the SARS-CoV-2 N-protein was recorded in eight cats, but only four of these tested positive with sVNT. Of these four SARS-CoV-2 seropositive cats, three were blood phenotype A and one was phenotype AB. Young adult age (1-6 years), FeLV seropositivity and blood type AB were significantly associated with SARS-CoV-2 seropositivity according to a univariate analysis, but only blood type AB (p = 0.0344, OR = 15.4, 95%CI: 1.22-194.39) and FeLV seropositivity (p = 0.0444, OR = 13.2, 95%CI: 1.06-163.63) were significant associated risk factors according to a logistic regression. Blood phenotype AB might be associated with seropositivity for SARS-CoV-2 antibodies. This could be due, as in people, to the protective effect of naturally occurring alloantibodies to blood type antigens which are lacking in type AB cats. The results of this pilot study should be considered very preliminary, and we suggest the need for further research to assess this potential relationship.

Evaluation of Association between Blood Phenotypes A, B and AB and Feline Coronavirus Infection in Cats

Cats are susceptible to feline coronavirus (FCoV), a highly contagious virus with fecal–oral transmission. In people, susceptibility to coronavirus infection, such as SARS-CoV infection, has been associated with the ABO blood group, with individuals with blood group O having significantly lower risk of SARS-CoV infection. This study evaluated a possible association between feline blood group phenotypes A, B and AB and serostatus for antibodies against FCoV. We also investigated risk or protective factors associated with seropositivity for FCoV in the investigated population. Feline populations were surveyed for AB group system blood types and for presence of antibodies against FCoV. Blood phenotype, origin, breed, gender, reproductive status and age of cats were evaluated as protective or risk factors for coronavirus infection. No blood type was associated with FCoV seropositivity, for which being a colony stray cat (p = 0.0002, OR = 0.2, 95% CI: 0.14–0.54) or a domestic shorthair cat (p = 0.0075, OR = 0.2, 95% CI = 0.09–0.69) were protective factors. Based on results of this study, feline blood phenotypes A, B or AB do not seem to predispose cats to seropositivity for FCoV. Future studies on other feline blood types and other infections could clarify whether feline blood types could play a role in predisposing to, or protecting against, feline infections.

Wild Felids Blood Group System

Wild felids and domestic cats share the AB blood group. However, there have been few studies regarding the characterization and prevalence of the different blood types in wild animals. The erythrocyte membrane glycolipids of the wild cats correspond to the major disialoganglioside patterns observed in domestic cats. Like in domestic cats, type A blood seems to be the most common, although wild felid species seem to exhibit one single blood type. Of the species studied, the wild domestic cats, and the Panthera and ocelot lineages, all had type A blood; the Puma lineage showed almost exclusively type B blood. The prevalence of wild felids blood types show that there seems to be variation between species, but not within species, and no evidence of geographical variation has yet been found, showing apparently no genetic variability. The presence of alloantibodies has also been demonstrated, so the risk of life-threatening transfusion reactions due to mismatched transfusions and neonatal isoerythrolysis is a possibility. Like in other species, the recognition of wild felids blood groups is clinically relevant, as it can also be important in establishing phylogenetic relationships within the Felidae family. We will review the current knowledge on this topic and give insights into the wild felids blood groups potential for zoo transfusion medicine and phylogenetic studies in order to help support reintroduction projects and to preserve genetic diversity.

Feline Blood Groups: A Systematic Review of Phylogenetic and Geographical Origin

Simple Summary

Numerous breeds have been identified in the domestic cat, grouped according to their phylogenetic or geographical origin. In the cat, the AB blood group system is the most important feline system, and the determination of the blood group by specific methods is an essential step to avoid or reduce the risk of an adverse reaction in the recipient patient. Many studies have been published on the distribution and prevalence of blood types in pedigree and non-pedigree cats, but the information has never been collated in a systematic manner.

Abstract

Domestic cats descended from the African wildcat several thousand years ago. Cats have spread to all parts of the world, probably along routes between civilizations or geographical boundaries, leading to the movement of species, from Asia to the African continent through the Mediterranean basin, and finally to the American continent, Australia, and New Zealand. Currently, 73 cat breeds are recognized by the International Cat Association. With the increasing interest in the selection of breeds, the determination of blood groups in cats has acquired importance over time. The AB blood group system is the most important blood system in cats, in which A, B, and AB or C blood groups are identified. This systematic review describes data from previously published reports about cat blood types and cat breeds. After applying specific criteria, 28 eligible studies were identified in which the prevalence percentages for each blood group in correlation with specific cat breeds were reported. The breeds were, in turn, divided into four groups according to their geographic and phylogenetic origins as follows: Asian cat breeds, American cat breeds, European cat breeds, and breeds from Oceania. Although numerous studies were carried out before 2021, gaps in the literature on the AB system and, in particular, the Mik group are highlighted.

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.

Frequency of Blood Types A, B and AB in a Population of Non-Pedigree Domestic Cats from Central Italy

Simple Summary

This study aimed to evaluate the frequency of AB blood groups in non-pedigree domestic cats in Central Italy. The presence of natural alloantibodies in the feline blood group system can cause life-threatening transfusion reactions due to mismatched transfusion and, depending on the parents’ blood type, can also account for hemolytic reactions in newborn kittens. Based on the frequency of the AB blood groups found in the 483 cats studied, a potential risk (6.5%) of acute hemolytic transfusion or neonatal reactions was calculated. Therefore, determining the blood group in non-pedigree domestic cats from Central Italy before transfusion is strongly recommended, as has been reported for other geographical areas. Moreover, particular attention should be paid to the mating of non-purebred cats.

Abstract

Blood transfusion reactions and neonatal isoerythrolysis are common events in the feline population due to the presence of natural alloantibodies in the AB blood group system. It is known that the frequency of feline blood types varies according to the geographic region and breed. Therefore, the aims of this study were to investigate the frequency of AB blood groups in non-pedigree domestic cats in Central Italy and estimate the risk of a life-threatening transfusion reaction and neonatal isoerythrolysis, caused by mismatched transfusion or incompatible random mating, respectively. The AB blood group was determined on non-pedigree domestic feline patients and potential blood donors submitted at the Veterinary Teaching Hospitals of the Universities of Teramo (Abruzzo Region, Teramo, Italy) and Perugia (Umbria Region, Teramo, Italy), and visited at veterinary practitioners in Rome (Lazio Region, Teramo, Italy) using commercial immunochromatographic cartridges and commercial agglutination cards. There were four hundred and eighty-three cats included in the study. The frequencies of the blood types were: 89.9% type A, 7.0% type B, and 3.1% type AB. The probability of an acute hemolytic transfusion reaction or a neonatal isoerythrolysis was 6.5%. Although the frequency of type B in non-pedigree domestic cats living in Central Italy was relatively low, to reduce the risk of fatal transfusion reactions, blood group typing is recommended before each transfusion.

Hematological and Biochemical Reference Intervals for 5 Adult Hunting Dog Breeds Using a Blood Donor Database

Simple Summary

Hematological and biochemical profiles are essential in the diagnosis and monitoring of disease in veterinary medicine, requiring optimal Reference Intervals (RIs) for accurate interpretation. The aim of this study is to determine hematobiochemical RIs for 5 hunting dog breeds from a blood donor database and to compare them with laboratory established and published RIs to identify possible breed and attitude-related differences. A total of 445 healthy adult hunting dogs (156 Ariégeois, A; 52 Bleu de Gascogne, B; 64 Bracco italiano, C; 123 Segugio italiano, D; 50 Briquet Griffon Vandeen, E) were included in the study. Significant differences in 12 hematologic and serum biochemical analytes, for which a breed-specific variation appears to be the most plausible explanation, were detected, and new RIs for these parameters are provided.

Abstract

Numerous studies have shown the importance of breed-related differences between hematological and biochemical results in veterinary medicine. The aim of this study is to determine hematologic and biochemical Reference Intervals (RIs) for 5 hunting dog breeds from a blood donor database, adopting an indirect sampling method, and to compare them with laboratory established and published RIs to identify possible breed and attitude-related differences. The study analyzed the blood parameters of 445 adults (222 females and 223 male, with age ranging from 2 to 8 years, mean age 5.3 years), client-owned, clinically healthy blood donor dogs of 5 breeds: 156 Ariégeois, 52 Bleu de Gascogne, 64 Bracco italiano, 123 Segugio italiano, and 50 Briquet Griffon Vandeen. Statistical analysis was performed as recommended by the American Society of Veterinary Clinical Pathology (ASVCP) guidelines. RIs for red blood cells (RBC), hematocrit (HCT), hemoglobin (HB), main corpuscular volume (MCV), main corpuscular hemoglobin (MCH), main corpuscular hemoglobin concentration (MCHC), red distribution widht (RDW), white blood cells (WBC), and differential leukocytes count, PLT, Albumin, Total Protein, Urea, Creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) for each of the 5 breeds were performed, and significant differences with the established RIs were detected. We found significant differences in 12 hematologic and serum biochemical analytes for which a breed-specific variation appears to be the most plausible explanation. New RIs for HCT, MCH, MCHC, RDW, PLT, Monocytes, Eosinophils, Albumin, Urea, Creatinine, AST, and ALT are provided for at least 1 breed. Breed-specific RIs for adult hunting dogs will help avoid misinterpretation of laboratory results in these breeds.

Prevalence of Blood Types and Alloantibodies of the AB Blood Group System in Non-Pedigree Cats from Northern (Lombardy) and Southern (Sicily) Italy

Simple Summary

The most important blood group system in cats is the AB, in which cats are classified as type-A, B or AB. Cats have antibodies against the blood type they do not possess, called alloantibodies. The aims of this study were to update blood type prevalence in cats from Northern Italy and study for the first time the blood type in cats from an insular region of Southern Italy, Sicily; to detect alloantibodies in these feline populations; to compare results with previous studies performed in Italy and between regions in Northern and Southern Italy. Cats from Southern Italy had the highest prevalence of type-B and type-AB, and the lowest prevalence of type-A blood in Italy. In particular, type-AB prevalence was higher than all previous reports in non-pedigree cats in Europe and the Italian prevalence of anti-type-B alloantibodies in type-A cats was the lowest reported worldwide. These results highlight the usefulness of regional studies to report different prevalences in feline blood types. Compatibility tests such as blood typing and cross matching must be considered fundamental in cats of any origin to ensure safe and efficient blood transfusion and to prevent neonatal isoerythrolysis.

Abstract

The aims of this study were to determine the prevalence of A, B and AB blood types and alloantibodies in non-pedigree cats from two regions, one in Northern and one in Southern Italy (Lombardy and Sicily, respectively). A total of 448 samples (52.0% from Northern and 48.0% from Southern Italy) were blood typed. The prevalence of A, B and AB blood types in northern and southern cats were 91.0%, 5.2%, 3.8%, and 77.2%, 12.1% and 10.7%, respectively. The prevalence of type-A blood in southern cats was significantly lower (p = 0.0001) than in northern cats, while type-B and AB blood were significantly higher (p = 0.0085 and p = 0.0051, respectively) in Southern compared to Northern Italian cats. Alloantibodies against type-A blood were found in 94.1% of type-B cats, 11.2% of type-A cats had alloantibodies against type-B blood, while no type-AB cats had alloantibodies with no significant difference between the two Italian populations. Type-AB prevalence in non-pedigree cats in Southern Italy was the highest reported in Europe. Italian type-A cats had the lowest worldwide prevalence of alloantibodies against type-B blood. These results highlight the usefulness of regional studies to report different prevalences in feline blood types and reinforce the importance of blood typing cats before transfusions and mating.

CMAH genotyping survey for blood types A, B and C (AB) in purpose-bred cats

In domestic cats, the AB blood group system consists of the three types A, B and C (also called AB). Mismatches can cause acute hemolytic transfusion reactions and hemolysis of the newborn (neonatal isoerythrolysis, NI). As blood types B and C are inherited recessively to A, breeders need to know the genotype to predict blood types in offspring and avoid NI. Several CMAH variants have been described as being associated with the b and a^c alleles, and different genotyping schemes exist. Here, we genotyped 2145 cats with the original SNV panel, including SNVs c.142G>A and ∆-53, and our new scheme, with SNVs c.179G>T, c.268T>A and c.1322delT, to differentiate types A and B and added the SNV for the common a^c (c.364C>T). Based upon the new scheme, all samples were assigned the correct genotype. No discordances appeared for the A allele, and new breed-specific SNVs (c.179G>T, c.1322delT) for the b allele were discovered. Furthermore, the genotypes A/a^c (type A), a^c /a^c (C) and a^c /b (C) could be detected. We found the variant c.179G>T in additional breeds: Ragdoll, Siberian, Scottish Fold, Chartreux, Neva Masquerade, British Shorthair and Highlander. Also, the variant c.364C>T was detected in additional breeds: Bengal, British Shorthair, Maine Coon, and Scottish Fold. We conclude that our new SNV panel is superior in genotyping cats than the original SNV panel and assures correct assignments of types A, B and C to assist veterinary clinicians and breeders to recognize, confirm and avoid blood incompatibilities such as acute hemolytic transfusion reactions and NI.

Comparison of three blood transfusion guidelines applied to 31 feline donors to minimise the risk of transfusion-transmissible infections

Objectives The increased demand for animal blood transfusions creates the need for an adequate number of donors. At the same time, a high level of blood safety must be guaranteed and different guidelines (GLs) deal with this topic. The aim of this study was to evaluate the appropriateness of different GLs in preventing transfusion-transmissible infections (TTI) in Italian feline blood donors. Methods Blood samples were collected from 31 cats enrolled as blood donors by the owners' voluntary choice over a period of approximately 1 year. Possible risk factors for TTI were recorded. Based on Italian, European and American GLs, specific TTI, including haemoplasmas, feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), Anaplasma phagocytophilum, Ehrlichia species, Bartonella species, Babesia species, Theileria species, Cytauxzoon species, Leishmania donovani sensu lato and feline coronavirus (FCoV), were screened. Rapid antigen and serological tests and biomolecular investigations (PCR) were used. Several PCR protocols for haemoplasma and FeLV DNA were compared. Results The presence of at least one recognised risk factor for TTI was reported in all cats. Results for FIV and FeLV infections were negative using rapid tests, whereas five (16.1%) cats were positive for FCoV antibodies. Four (12.9%) cats were PCR positive for haemoplasma DNA and one (3.2%) for FeLV provirus, the latter being positive only using the most sensitive PCR protocol applied. Other TTI were not detected using PCR. Conclusions and relevance Blood safety increases by combining the recommendations of different GLs. To reduce the risk of TTI, sensitive tests are needed and the choice of the best protocol is a critical step in improving blood safety. The cost and time of the screening procedures may be reduced if appropriate tests are selected. To this end, the GLs should include appropriate recruitment protocols and questionnaire-based risk profiles to identify suitable donors.

Distribution of feline AB blood types: a review of frequencies and its implications in the Iberian Peninsula

Objectives

The objective of this study was to document the prevalence of feline blood types in the Iberian Peninsula and to determine the potential risk of incompatibility-related transfusion reactions in unmatched transfusions and the potential risk of neonatal isoerythrolysis (NI) in kittens born to parents of unknown blood type.

Methods

Blood samples were obtained from blood donors of the Animal Blood Bank (BSA-Banco de Sangue Animal). Blood typing was performed using a card method (RapidVet-H Feline Blood Typing; MDS).

Results

The studied population comprised 1070 purebred and non-purebred cats from Portugal and Spain aged between 1 and 8 years. Overall, frequencies of blood types A and B were 96.5% and 3.5%, respectively. No AB cats were found. Based on these data, the potential risks of NI and transfusion reactions in unmatched transfusions were calculated to be 6.8% and 2.8%, respectively.

Conclusions and relevance

Unlike previous studies, no type AB cats were found in this study. Although the calculated potential risks of transfusion reaction in unmatched transfusions and neonatal isoerythrolysis were low, blood typing prior to blood transfusion and blood typing of cats for breeding purposes are highly recommended.

Molecular Characterization of the Cytidine Monophosphate-N-Acetylneuraminic Acid Hydroxylase (CMAH) Gene Associated with the Feline AB Blood Group System

Cat’s AB blood group system (blood types A, B, and AB) is of major importance in feline transfusion medicine. Type A and type B antigens are Neu5Gc and Neu5Ac, respectively, and the enzyme CMAH participating in the synthesis of Neu5Gc from Neu5Ac is associated with this cat blood group system. Rare type AB erythrocytes express both Neu5Gc and Neu5Ac. Cat serum contains naturally occurring antibodies against antigens occurring in the other blood types. To understand the molecular genetic basis of this blood group system, we investigated the distribution of AB blood group antigens, CMAH gene structure, mutation, diplotypes, and haplotypes of the cat CMAH genes. Blood-typing revealed that 734 of the cats analyzed type A (95.1%), 38 cats were type B (4.9%), and none were type AB. A family of three Ragdoll cats including two type AB cats and one type A was also used in this study. CMAH sequence analyses showed that the CMAH protein was generated from two mRNA isoforms differing in exon 1. Analyses of the nucleotide sequences of the 16 exons including the coding region of CMAH examined in the 34 type B cats and in the family of type AB cats carried the CMAH variants, and revealed multiple novel diplotypes comprising several polymorphisms. Haplotype inference, which was focused on non-synonymous SNPs revealed that eight haplotypes carried one to four mutations in CMAH, and all cats with type B (n = 34) and AB (n = 2) blood carried two alleles derived from the mutated CMAH gene. These results suggested that double haploids selected from multiple recessive alleles in the cat CMAH loci were highly associated with the expression of the Neu5Ac on erythrocyte membrane in types B and AB of the feline AB blood group system.

Haematological and biochemical reference intervals in adult Maine Coon cat blood donors

OBJECTIVES

The objectives of this study were to derive Maine Coon haematological and biochemical reference intervals (RIs) from adult healthy blood donors, to validate (or reject) the use of published RIs for the general feline population in this breed, and to evaluate the effects of age, sex and weight on the haematological and biochemical results.

METHODS

Haematological and biochemical data were retrieved retrospectively from a database of 81 healthy adult Maine Coon cat blood donors and were analysed to generate normal RIs. RIs were determined and compared with established non-breed-specific feline RIs according to the Clinical and Laboratory Standards Institute guidelines and the American Society of Veterinary Clinical Pathology guidelines using Reference Value-Advisor (version 2.1) software.

RESULTS

The age of the cats ranged from 1-8 years (mean 4.4 years), 42 were female and 39 were male, and weights ranged from 4.9-8.5 kg (mean 6.7 kg). New Maine Coon RIs were proposed for red blood cell count, mean corpuscular volume, mean corpuscular haemoglobin concentration, reticulocyte count and percentage. Haematocrit was higher in male cats (mean HCT 42.9% vs 41% in females; P = 0.001) and in heavier cats (P = 0.003; slope 1.0, regression equation HCT = 35.1 + 1.0 × weight). New biochemical RIs were proposed for urea, aspartate aminotransferase, γ-glutamyl transpeptidase (GGT), alkaline phosphatase, total protein and albumin in Maine Coons. Females had higher GGT (median GGT value in females 4.0 vs 3.0 in males; P = 0.011) and albumin values (mean albumin value 3.3 in females vs 3.1 in males; P = 0.013).

CONCLUSIONS AND RELEVANCE

Currently published RIs for some haematological and biochemical parameters are not appropriate for use in adult Maine Coon cats. A breed-specific variation could be a plausible explanation for the new haematological and serum biochemical analytes proposed in this study. Breed-specific RIs for Maine Coon cats will help prevent misinterpretation of laboratory results in diagnosis and in the selection of ideal blood donors.