Incidence of acute haemolysis in cats receiving canine packed red blood cells (xenotransfusions).

OBJECTIVES: The aim of this study was to report the incidence of transfusion reactions in cats, including acute haemolysis (AH), occurring within 24 h of receiving a xenotransfusion. An additional aim was to determine whether cases with AH could be classified as having an acute haemolytic transfusion reaction (AHTR) as per the definition provided by the Association of Veterinary Haematology and Transfusion Medicine's Transfusion Reaction Small Animal Consensus Statement. METHODS: Medical records of cats that received canine packed red blood cells (PRBCs) between July 2018 and September 2020 at a veterinary hospital were reviewed. The incidence of AH, AHTRs, febrile non-haemolytic transfusion reactions (FNHTRs), transfusion-associated circulatory overload and septic transfusion reactions were recorded. RESULTS: The medical records of 53 cats were retrospectively evaluated. Twenty-three (43%) cats had transfusion reactions. Thirteen (25%) cats had AH; however, only four (8%) met the definition of an AHTR. Ten (19%) cats were determined to have FNHTRs. Survival to discharge of cats affected by AH was 50% (25% for cases that met the definition of an AHTR). Survival to discharge of cats not suffering from AHTR was 40%. CONCLUSIONS AND RELEVANCE: This report indicates that a higher proportion of cats undergo AH (25%) when administered canine PRBCs than previously reported, although many could not be classed as having an AHTR due to an apparently adequate packed cell volume rise. Challenges with sourcing feline blood in emergency situations occasionally necessitates the use of xenotransfusion in transfusion medicine. Clinicians should be aware that haemolysis after xenotransfusion can occur within 24 h and that a repeat feline transfusion may be required sooner than anticipated in some cases.

2021 ISFM Consensus Guidelines on the Collection and Administration of Blood and Blood Products in Cats.

PRACTICAL RELEVANCE: Blood and blood products are increasingly available for practitioners to use in the management of haematological conditions, and can be lifesaving and therapeutically useful for patients with anaemia and/or coagulopathies. It is important for feline healthcare that donors are selected appropriately, and transfusions of blood or blood products are given to recipients that will benefit from them. Complications can occur, but can be largely avoided with careful donor management and recipient selection, understanding of blood type compatibility, and transfusion monitoring. CLINICAL CHALLENGES: Feline blood transfusion, while potentially a lifesaving procedure, can also be detrimental to donor and recipient without precautions. Cats have naturally occurring alloantibodies to red cell antigens and severe reactions can occur with type-mismatched transfusions. Blood transfusions can also transmit infectious agents to the recipient, so donor testing is essential. Finally, donors must be in good health, and sedated as appropriate, with blood collected in a safe and sterile fashion to optimise the benefit to recipients. Transfusion reactions are possible and can be mild to severe in nature. Autologous blood transfusions and xenotransfusions may be considered in certain situations. EVIDENCE BASE: These Guidelines have been created by a panel of authors convened by the International Society of Feline Medicine (ISFM), based on available literature. They are aimed at general practitioners to provide a practical guide to blood typing, cross-matching, and blood collection and administration.

Clinical, hematological, blood gasometric and electrolytic changes in dogs receiving whole blood transfusions

Blood transfusion is a tool capable of saving lives. Patients undergoing blood transfusion usually present several alterations in the acid-base and electrolyte balance, aggravating the condition of critically ill patients. Some studies have demonstrated haematological alterations in certain species that received whole blood transfusions, however, few studies have evaluated acid base and electrolyte changes in dogs undergoing whole blood haemotherapy. The aim of this study was to analyze clinical, hematological, blood gas and electrolyte changes in anemic dogs after whole blood transfusion. Twenty nine dogs transfused due to anemia were enrolled in the study. Donors blood was collected in a transfusion bag containing citrate phosphate adenine dextrose and stored up to 24 h. Blood collections and evaluations were made before and 24 h after the transfusion. Data distribution normality was tested by the Shapiro Wilk Test. The means of the variables were compared by paired t-test. It was observed an increase in diastolic blood pressure and a reduction in heart rate (P < 0.05). There was a not significant increase in systolic blood pressure, temperature, and a reduction in respiratory rate per minute. Erythrocyte, haemoglobin and haematocrit averages were significantly increased after blood transfusion (P < 0.05). It was observed a reduction in the mean values of pH (P < 0.05), potassium (P > 0.05) and ionized calcium (P > 0.05) and an increase in the mean partial pressure of carbon dioxide (pCO2 ) (P < 0.001), bicarbonate (P > 0.05) and sodium (P < 0.05). The probable cause of anemia was monocytic ehrlichiosis (14/29), visceral leishmaniasis (1/29), babesiosis (1/29), co-infection of Ehrlichia canis and Leishmania infantum (2/29), co-infection of E. canis and Babesia vogeli (1/29). It was not possible to determine the etiology of the anemia in ten dogs. Heart rate significantly reduced after transfusion, probably because of the increase in hematocrit, hemoglobin and erythrocyte values. It may be justified by the displacement of extravascular fluid to the intravascular space. Mean values of systolic blood pressure were slightly elevated before transfusion and remained elevated afterwards, while diastolic and mean arterial pressure increased significantly after transfusion. These changes may be due to the morbid condition and may be influenced by many other factors. Haematocrit, haemoglobin and erythrocyte values increased significantly after transfusion, according to what was observed in other studies. The significant reduction in pH and increase in pCO2 reflects the compensatory mechanism for metabolic acidosis to increase ventilation, leading to pCO2 reduction and changes in pH. The reduction in pH due to the contact of the collected blood with conservative solutions is one of the main changes thar occurs during blood storage. It was described significantly lower pH in dogs' whole blood samples stored for more than 24 h in vacutainer plastic containing CPDA-1. We may assume there was no intense pH reduction in the present study because the bags were stored for up to 24 h. Although not statistically significant, the increase of pO2 mean reflects the improvement of tissue oxygen perfusion. It was observed a significant increase in sodium ions. The mean sodium ion concentration before transfusion was very close to the maximum reference value. Hyperkalaemia was not observed, nor was there significant reduction of potassium ions after transfusion. Several studies report hyperkalaemia and transfusion-associated cardiac arrests in humans, associated with infusion of large volumes of blood. Whole blood transfusion increased erythrogram values and did not negatively affect the electrolyte or acid-base status, representing a safe and useful tool in the intensive care of small animals.(AU)

Xenotransfusion of canine blood to cats: a review of 49 cases and their outcome.

OBJECTIVES: To describe the use of a xenotransfusion protocol, the outcome of xenotransfusion in recipient cats and to assess owner memory of the xenotransfusion. MATERIALS AND METHODS: Cats administered xenotransfusions in two hospitals between January 2016 and July 2018 were included. Adherence to xenotransfusion protocol, cause of anaemia, blood type, packed cell volume (PCV), transfusion volume, transfusion reactions, PCV 12 hours after transfusion and survival to discharge were recorded. Owners of surviving cats were questioned to assess if they remembered that a xenotransfusion had been performed. RESULTS: Forty-nine cats underwent the xenotransfusion protocol. The most common causes of anaemia were surgical blood loss (n = 17), immune-mediated haemolytic anaemia (n = 14) and neoplasia (n = 14). Median PCV before transfusion was 10%. Six cats (12%) had febrile non-haemolytic transfusion reactions. Median PCV 12 hours after transfusion was 25%. Ten cats (20%) died or were euthanased within 24 hours of xenotransfusion. A delayed haemolytic transfusion reaction occurred in 25 of 39 (64%) cats manifesting as icterus in 15 cats after a median of 1.9 days and haemolytic serum in 19 cats after a median of 2 days. Of the 18 cats alive at 1 week after discharge, 15 (83%) were still alive at a median of 173 days after xenotransfusion. All owners contacted remembered that their cats had received a xenotransfusion. CLINICAL SIGNIFICANCE: Xenotransfusion of canine packed red blood cells to cats is possible but haemolysis should be expected between 1 and 6 days after transfusion.

Retrospective evaluation of the indications, safety and effects of fresh frozen plasma transfusions in 36 cats (2014-2018).

OBJECTIVES: The goals of this study were to classify the indications, risks, effects on coagulation times and outcomes of cats receiving fresh frozen plasma (FFP) transfusions in clinical practice. METHODS: This was a retrospective study of FFP transfusions administered in two referral hospitals from 2014 to 2018. Transfusion administration forms and medical records were reviewed. Information was collected on indication, underlying condition, coagulation times and signs of transfusion reactions. Seven-day outcomes after FFP administration were also evaluated when available. RESULTS: Thirty-six cats received 54 FFP transfusions. Ninety-four percent of cats were administered FFP for treatment of a coagulopathy. Twenty cats had paired coagulation testing before and after FFP administration. Eighteen of these cats had improved coagulation times after receiving 1-3 units of FFP. Eight of the 36 cats had probable transfusion reactions (14.8% of 54 FFP transfusions). These reactions included respiratory signs (n = 4), fever (n = 2) and gastrointestinal signs (n = 2). Five of the eight cats with probable reactions had received packed red blood cells contemporaneously. Overall mortality rate during hospitalization was 29.7%, with 52.8% (n = 19/36) of cats confirmed to be alive 7 days after discharge. CONCLUSIONS AND RELEVANCE: This retrospective study shows that FFP transfusions improve coagulation times in cats. Transfusion reactions are a risk, and risk-benefit ratios must be measured prior to administration and possible reactions monitored. In the study cats, the FFP transfusions appeared to be a tolerable risk given the benefit to prolonged coagulation times.

DEA 1. 1 blood group frequency in dogs attended at the veterinary hospital of UFMT (Sinop/MT), risk of DEA 1 negative dog sensitization and occurrence of hemolytic transfusion reaction in a second blood transfusion / Frequência do grupo sanguíneo DEA 1. 1 em cães atendidos no Hospital Veterinário da UFMT (Sinop/MT), risco de sensibilização de cães DEA 1 negativos e da ocorrência de reação transfusional hemolítica por ocasião de uma segunda transfusão de sangue

The goal of this research was to identify the frequency of the DEA 1.1 blood group in dogs from Sinop, Mato Grosso, Brazil, to help in the recruitment of compatible blood donors and recipients, and to assess the risk of transfusion reactions in previously sensitized dogs. Also, from the obtained results, to pick potential blood donors to compose a data bank. 195 adult dogs (1 to 4 years old), males and females, mongrel and purebred dogs were screened at the Veterinary Hospital of the University of Mato Grosso. The DEA 1.1 blood typing was performed using commercially available immunochromatographic strip for DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, France). The results showed a general frequency of 65% for DEA 1.1 positive dogs (n = 126) and 35% for DEA 1 negative dogs (n = 69). The general risk of sensitization of a DEA 1 negative dog following a first transfusion with DEA 1.1 positive blood was 23%, while the risk of this sensitized recipient to receive DEA 1.1 positive blood in a second transfusion and to develop an acute hemolytic reaction was calculated to be 5%. The blood typing of the dogs allowed their classification as DEA 1 typed blood donors, in a preliminary data bank, and also ensured the safety of blood transfusions.

Objetivou-se identificar a frequência do grupo sanguíneo DEA 1.1 em cães de Sinop, Mato Grosso, Brasil, para auxiliar a seleção de doadores e receptores de sangue compatíveis e, adicionalmente, avaliar o risco de reações transfusionais em cães sensibilizados. Além disso, a partir dos resultados obtidos, selecionar potenciais doadores de sangue para compor um banco de dados. Um total de 195 cães adultos (de 1 a 4 anos de idade), machos e fêmeas, mestiços e puros, que nunca haviam recebido transfusões de sangue, foram triados no Hospital Veterinário da Universidade do Mato Grosso. A tipagem sanguínea DEA 1.1 foi realizada utilizando-se ensaio imunocromatográfico comercialmente disponível para DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, França). Os resultados demonstraram uma frequência geral de 65% para cães DEA 1.1 positivos (n = 126) e 35% para cães DEA 1 negativos (n = 69). O risco geral de sensibilização de cães DEA 1 negativos após uma primeira transfusão com sangue DEA 1.1 positivo foi calculado em 23%, enquanto o risco deste receptor sensibilizado receber sangue DEA 1.1 positivo em uma segunda transfusão e desenvolver uma reação hemolítica aguda foi calculado em 5%. A tipagem sanguínea dos cães permitiu sua inserção como doadores de sangue tipados para o grupo DEA 1 em um banco de dados preliminar e garantiu a segurança das transfusões de sangue.

Frequência do grupo sanguíneo DEA 1.1 em cães atendidos no Hospital Veterinário da UFMT (Sinop/MT), risco de sensibilização de cães DEA 1 negativos e da ocorrência de reação transfusional hemolítica por ocasião de uma segunda transfusão de sangue / DEA 1.1 blood group frequency in dogs attended at the veterinary hospital of UFMT (Sinop/MT), risk of DEA 1 negative dog sensitization and occurrence of hemolytic transfusion reaction in a second blood transfusion

Objetivou-se identificar a frequência do grupo sanguíneo DEA 1.1 em cães de Sinop, Mato Grosso, Brasil, para auxiliar a seleção de doadores e receptores de sangue compatíveis e, adicionalmente, avaliar o risco de reações transfusionais em cães sensibilizados. Além disso, a partir dos resultados obtidos, selecionar potenciais doadores de sangue para compor um banco de dados. Um total de 195 cães adultos (de 1 a 4 anos de idade), machos e fêmeas, mestiços e puros, que nunca haviam recebido transfusões de sangue, foram triados no Hospital Veterinário da Universidade do Mato Grosso. A tipagem sanguínea DEA 1.1 foi realizada utilizando-se ensaio imunocromatográfico comercialmente disponível para DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, França). Os resultados demonstraram uma frequência geral de 65% para cães DEA 1.1 positivos (n = 126) e 35% para cães DEA 1 negativos (n = 69). O risco geral de sensibilização de cães DEA 1 negativos após uma primeira transfusão com sangue DEA 1.1 positivo foi calculado em 23%, enquanto o risco deste receptor sensibilizado receber sangue DEA 1.1 positivo em uma segunda transfusão e desenvolver uma reação hemolítica aguda foi calculado em 5%. A tipagem sanguínea dos cães permitiu sua inserção como doadores de sangue tipados para o grupo DEA 1 em um banco de dados preliminar e garantiu a segurança das transfusões de sangue.

The goal of this research was to identify the frequency of the DEA 1.1 blood group in dogs from Sinop, Mato Grosso, Brazil, to help in the recruitment of compatible blood donors and recipients, and to assess the risk of transfusion reactions in previously sensitized dogs. Also, from the obtained results, to pick potential blood donors to compose a data bank. 195 adult dogs (1 to 4 years old), males and females, mongrel and purebred dogs were screened at the Veterinary Hospital of the University of Mato Grosso. The DEA 1.1 blood typing was performed using commercially available immunochromatographic strip for DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, France). The results showed a general frequency of 65% for DEA 1.1 positive dogs (n = 126) and 35% for DEA 1 negative dogs (n = 69). The general risk of sensitization of a DEA 1 negative dog following a first transfusion with DEA 1.1 positive blood was 23%, while the risk of this sensitized recipient to receive DEA 1.1 positive blood in a second transfusion and to develop an acute hemolytic reaction was calculated to be 5%. The blood typing of the dogs allowed their classification as DEA 1 typed blood donors, in a preliminary data bank, and also ensured the safety of blood transfusions.

Detection of canine anti-DEA 1 antibodies using flow cytometry in dogs following DEA 1-positive blood transfusion / Detecção de anticorpos caninos anti-AEC 1 por citometria de fluxo em cães pós-transfundidos com sangue AEC 1 positivo

The shortage of dog blood donors in veterinary emergencies can lead to blood transfusions between animals whose blood type has not been identified. The antibody profile serves as a warning sign for animals that require a second blood transfusion, which is only advisable from compatible donor dogs. This article focuses on determination of anti-DEA 1 antibodies using the flow cytometry technique in dogs that have undergone a transfusion using DEA 1-positive blood, compared to results obtained from crossmatching. Blood from 18 DEA 1-positive donors ranked according to the chromatographic technique was used to transfuse thirty-three animals with unknown blood types and which demonstrated negative crossmatching to donors. On post-transfusion days 7, 14, 21 and 28, 45% and 27% of the animals tested positive for the anti-DEA 1 antibody, through crossmatching and flow cytometry, respectively. Detecting antibodies using the flow cytometric technique has high specificity and sensitivity, while crossmatching methods are highly sensitive but manifest low specificity. Following blood transfusion, animals that did not present as positive through crossmatching or flow cytometry were considered different from all other DEA 1-positive blood groups.(AU)

A escassez de cães doadores de sangue em situações de emergência na Medicina Veterinária pode levar a realização de transfusões de sangue entre animais que não tiveram seu tipo sanguíneo previamente determinado. O padrão de anticorpos serve como um sinal de alerta para animais que serão submetidos a uma segunda transfusão sanguínea, sendo essa somente recomendável a partir de cães doadores compatíveis. Este artigo aborda a pesquisa de anticorpos anti-AEC 1 pela técnica de citometria de fluxo em cães que receberam uma transfusão utilizando sangue do grupo AEC 1 positivo, comparando os resultados com aqueles obtidos a partir de reação cruzada. Foi utilizado sangue de 18 animais doadores do tipo AEC 1 positivo classificados por técnica cromatográfica para transfundir trinta e três animais com tipos sanguíneos desconhecidos, os quais mostraram reação cruzada negativa aos doadores. Nos dias 7, 14, 21 e 28 pós-transfusão, 45% e 27% dos animais mostraram-se positivos para os anticorpos anti-AEC 1, respectivamente, pela reação cruzada e através de citometria de fluxo. A pesquisa de anticorpos com o emprego da técnica de citometria de fluxo tem alta especificidade e sensibilidade, enquanto a reação cruzada, altamente sensível, tem baixa especificidade. Animais que não apresentaram positividade após a transfusão de sangue na reação cruzada e na citometria de fluxo concomitantemente foram considerados de qualquer outro grupo sanguíneo diferente do grupo sanguíneo AEC 1 positivo.(AU)

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.

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.

Effects of four additive solutions on canine leukoreduced red cell concentrate quality during storage.

BACKGROUND: Additive solutions (AS) and prestorage leukoreduction (LR) are important tools used to maintain erythrocyte viability during storage and avoid transfusion reactions in recipients, respectively. OBJECTIVES: The purpose of the study was to determine the efficacy of a WBC filter (Immugard IIIRC) and compare the effect of 4 AS (phosphate-adenine-glucose-guanosine-gluconate-mannitol [PAGGGM], saline-adenine-glucose-mannitol [SAGM], Adsol, Optisol) on the in vitro quality of canine leukoreduced packed RBC units (pRBC) stored for 41 days. METHODS: Five hundred milliliters of blood were collected from 8 healthy dogs each into 70 mL of citrate-phosphate-dextrose (CPD) solution, and were leukoreduced by a polyurethane filter. pRBC of each dog were divided equally into 4 bags containing a different AS. Bags were stored for 41 days at 4°C and evaluated every 10 days. Variables analyzed included pH, PCV, and% hemolysis, and lactate, glucose, potassium, sodium, ATP, and 2,3-diphosphoglycerate (2,3-DPG) concentrations. RESULTS: The LR resulted in residual WBC counts comparable to human standards. During storage, pH, and glucose, 2,3-DPG, and ATP concentrations decreased, and hemolysis, and lactate, sodium, and potassium concentrations increased (P < .05). Significant differences between AS were seen in the glucose and sodium concentrations, due to the composition of AS. Also, the pH maintained by PAGGGM at day 21 was significantly higher than that seen with SAGM or Adsol. CONCLUSIONS: All AS used gave satisfactory results during the first 21 days of storage based on the degree of hemolysis, and on ATP and 2,3-DPG concentrations. When compared with day 1 values, significant changes were seen in these variables by day 31 with all AS.