Primary Immune-mediated Hemolytic Anemia Research Articles

Point-of-care global coagulation assay parameters in normal dogs and dogs with primary immune-mediated hemolytic anemia.

To compare viscoelastic parameters between healthy control dogs and dogs with primary immune-mediated hemolytic anemia (pIMHA) using a new, point-of-care viscoelastic coagulation monitor (VCM).a DESIGN: Retrospective study from 2017 to 2021. Three regional private referral centers. Eighteen client-owned dogs with pIMHA and 33 healthy control dogs. pIMHA dogs were defined based on established criteria. None. Medical records of dogs with pIMHA and VCM performed at diagnosis from 2017 to 2021 and apparently healthy control dogs voluntarily enrolled in the blood donor program from 2017 to 2018 were reviewed. For the healthy control dogs, consent was obtained to perform VCM in addition to traditional screening. Compared to healthy control dogs, dogs with pIMHA had mean VCM parameters consistent with hypercoagulability, demonstrated by lower mean (SD) clot formation time (108 s [30] vs 233 s [55]; P<0.0001), higher mean alpha angle (62 degrees [6] vs 52 degrees [6]; P<0.0001), higher mean maximum clot formation (49 VCM units [11] vs 32 VCM units [5]; P<0.0001), higher mean amplitude at 10minutes (40 VCM units [11] vs 19 VCM units [3]; P<0.0001), and higher mean amplitude at 20minutes (47 VCM units [11] vs 25 VCM units [4]; P<0.0001). pIMHA dogs also had significantly higher median (interquartile range) lysis index at 30minutes (100% [100-100] vs 98% [90-100]; P<0.0001). When compared to 3 established normal canine reference intervals, dogs with pIMHA had a significantly higher proportion of VCM variables (48%-57%) consistent with hypercoagulability, and a significant percentage of pIMHA dogs (78%-89%) had VCM tracings consistent with hypercoagulability overall, irrespective of the interval utilized for interpretation. This study demonstrates hypercoagulability in dogs with pIMHA when compared to healthy control dogs using VCM. Prospective evaluation is warranted to further characterize these findings as well as to evaluate their clinical impact.

Effectiveness of aspirin vs. clopidogrel in dogs with immune mediated haemolytic anaemia evaluated by serial thromboelastography and platelet mapping

Most dogs with immune mediated haemolytic anaemia (IMHA) are hypercoagulable, as measured by thromboelastography (TEG). Thromboelastography-platelet mapping (TEG-PM) has been used to assess platelet function in human patients treated with aspirin or clopidogrel. The aim of this study was to compare platelet thromboxane A2-receptor inhibition (TXA2-RI) and platelet adenosine diphosphate (ADP)-receptor inhibition (ADP-RI) as measured by TEG-PM in dogs with primary IMHA receiving aspirin or clopidogrel to determine if TEG-PM might be useful to monitor treatment. Eighteen client-owned dogs with IMHA were enroled in a prospective double blinded study. Dogs were randomised to receive aspirin or clopidogrel in addition to standard therapy. Thromboelastography was measured before, and 1 and 4 days after commencing treatment. Thromboelastography-PM was performed on days 1 and 4. Non-responders were defined as < 50 % platelet thromboxane A2-receptor inhibition (TXA2-RI) in the aspirin group and < 50 % platelet adenosine diphosphate (ADP)-receptor inhibition (ADP-RI) in the clopidogrel group, on day 4.Mean platelet TXA2-RI and platelet ADP-RI were not significantly different between groups at any timepoint (P > 0.05). The overall mean percentage inhibition of TXA2-receptor was 25 % (aspirin 33 %, clopidogrel 15 %), and of ADP-receptor was 82 % (aspirin 83 %, clopidogrel 80 %). On day 4, 6/9 dogs (66 %) in the aspirin group and 2/8 dogs (25 %) in the clopidogrel group were non-responders (P = 0.086). Two dogs defined as responders based on TEG-PM developed thromboembolism. Overall, there was no significant difference in efficacy between aspirin and clopidogrel based on measurement of receptor inhibition using TEG-PM (P > 0.05), and routine TEG was not reliable for monitoring treatment response in dogs with IMHA. In some dogs, there was a discrepancy between TEG-PM results and clinical response. Further investigation of TEG-PM use in dogs, including its usefulness to monitor treatment response and adjust treatment in individual dogs and any effect of anaemia, is warranted.

Utility and prognostic significance of leukocyte ratios in dogs withPrimary Immune-Mediated Hemolytic Anemia.

Canine immune-mediated hemolytic anemia (IMHA) is a life-threatening condition that is commonly associated with neutrophilia and monocytosis. Leukocyte ratios have been found to have prognostic value in humans and animals affected by a range of inflammatory, infectious, and neoplastic disorders. We hypothesized that in primary IMHA, neutrophil to lymphocyte (NLR), neutrophil to monocyte (NMR), band neutrophil to segmented neutrophil (BNR) and monocyte to lymphocyte (MLR) ratios would be higher in dogs that did not survive to discharge. Medical records of dogs diagnosed with IMHA at two veterinary teaching hospitals were retrospectively reviewed. Twenty-three of the 72 included dogs did not survive to discharge. NLR, NMR, BNR and MLR ratios were compared between dogs that survived to discharge and dogs that died or were euthanized. None of the ratios were significantly different between survivors and non-survivors (P = 0.14-0.99). Area under the Receiver Operating Characteristic (ROC) curve for prediction of non-survival ranged from 0.5 (95% confidence interval 0.38-0.62) for MLR to 0.61 (0.49-0.72) for NMR and was not significantly different from 0.5 for any ratio (P = 0.29-0.99). After exclusion of 31 dogs that received one or both immunosuppressive medications and blood transfusion before presentation, the area under the ROC curve for prediction of survival was significantly different from 0.5 for MLR (0.78, P = 0.01) and NMR (0.78, P = 0.0002). This study suggests that lower MLR and higher NMR may predict poorer prognosis in untreated dogs with IMHA.

Retrospective evaluation of systemic hypertension in dogs with nonassociative (primary) immune-mediated hemolytic anemia (December 2016 to April 2019): 26 cases.

To report the prevalence of arterial hypertension in a population of dogs with nonassociative immune-mediated hemolytic anemia (IMHA) on presentation and during hospitalization. To determine the relationships of systolic blood pressure (SBP) with mortality and a prognostic indicator, the canine hemolytic anemia objective score. Retrospective observational study (December 2016 to April 2019). University teaching hospital. Twenty-six clinical dogs presenting to the ICU with nonassociative (primary) IMHA and a control group of 23 clinical dogs with idiopathic epilepsy hospitalized in the ICU for seizure treatment or monitoring. None. Hypertension was defined as SBP≥160mm Hg and severe hypertension as SBP≥180mm Hg. Mean SBP was significantly increased in IMHA dogs (161mm Hg, SD=21) compared to ICU control dogs (138mm Hg, SD=14; P<0.005). Hypertension was present in 13 of 26 (50.0%) dogs across the period of hospitalization and was severe in three of 26 (11.5%). During at least 1 day of hospitalization, 18 of 26 (69.2%) dogs were hypertensive and eight of 26 (34.6%) were severely hypertensive. Hypertension was not associated with short-term mortality or canine hemolytic anemia objective score. In this retrospective study, hypertension was more prevalent in dogs with nonassociative IMHA than a control population of ICU-hospitalized dogs. An association between autoimmune conditions and hypertension has been previously reported in people but not within a canine population. Hypertension in dogs may have an inflammatory or autoimmune etiology. SBP should be monitored closely in canine IMHA, in case antihypertensive treatment is required.

Urinary 11-dehydrothromboxane B2 concentrations in 20 dogs with primary immune-mediated hemolytic anemia.

BackgroundThromboembolic disease is a major cause of mortality in dogs with immune‐mediated hemolytic anemia (IMHA). At present, no reliable biomarkers of individual patient thrombotic risk are available. In human medicine, increased urinary thromboxane concentrations have utility as markers of prothrombotic tendency in various situations.Hypothesis/ObjectivesFirst, to determine if urinary 11‐dehydrothromboxane B2 (u11‐dTXB) concentrations are increased in dogs with primary IMHA compared to normal dogs; second, to assess whether u11‐dTXB concentration is associated with survival, known prognostic indicators, or frequency of thrombosis in dogs with IMHA.AnimalsTwenty client‐owned dogs diagnosed with primary IMHA and 17 healthy dogs volunteered by hospital staff.MethodsProspective case‐control study. A previously validated ELISA was used to measure urine 11‐dTXB concentrations, which were normalized to urine creatinine concentration (u11‐dTXB:Cr). Samples were obtained at presentation from patients with primary IMHA. Standard clincopathological data at baseline and survival data were collected. Urinary 11‐dTXB:Cr was compared between outcome subgroups, and correlated with known markers of disease severity.ResultsBaseline u11‐dTXB:Cr was significantly higher in dogs with IMHA than in healthy dogs (median, 3.75; range, 0.83‐25.36 vs 0.65; 0.24‐2.57; P = .003) but did not differ between dogs with IMHA that survived and did not survive to 30 days after presentation, nor between dogs with and without clinical suspicion of thrombotic disease.Conclusions and Clinical ImportanceUrinary 11‐dTXB:Cr is increased in dogs with IMHA compared to healthy controls, consistent with a prothrombotic state. However, in this IMHA population u11‐dTXB:Cr was not associated with survival or suspected thrombosis.

The use of high-dose immunoglobulin M-enriched human immunoglobulin in dogs with immune-mediated hemolytic anemia.

BackgroundThe IV use of human immunoglobulin (hIVIG) in dogs with primary immune‐mediated hemolytic anemia (IMHA) has been described previously, but herein we describe the use of high‐dose IgM‐enriched hIVIG (Pentaglobin).Hypothesis/ObjectivesDogs treated with high‐dose Pentaglobin will experience shorter time to remission and hospital discharge and have decreased transfusion requirements compared to dogs receiving standard treatment alone.AnimalsFourteen client‐owned dogs diagnosed with primary IMHA at specialist referral hospitals in the United Kingdom.MethodsAll prospectively enrolled dogs received prednisolone, dexamethasone or both along with clopidogrel. Patients were randomized to receive Pentaglobin at 1 g/kg on up to 2 occasions, or to serve as controls. No additional immunosuppressive drugs were allowed within the first 7 days of treatment. Remission was defined as stable PCV for 24 hours followed by an increase in PCV.ResultsTen of 11 dogs from the treatment group and 2 of 3 dogs from the control group achieved remission and survived until hospital discharge. Survival and time to remission were not significantly different between groups. The volume of packed red blood cells transfused, normalized for body weight, was not significantly different between groups. Potential adverse reactions to Pentaglobin occurred in 2 dogs, but their clinical signs may have been related to the underlying disease.Conclusions and Clinical ImportanceTreatment with high‐dose Pentaglobin was well tolerated by dogs with primary IMHA but no significant advantage was found in this small study. Additional studies examining larger groups and subpopulations of dogs with primary IMHA associated with a poorer prognosis are warranted.

Immune-Mediated Hemolytic Anemia in a Bitch Triggered by Drugs

Background: Immune-mediated hemolytic anemia (IMHA) is characterized by an autoimmune response with production of auto-antibodies and destruction of erythrocytes resulting in anemia. Primary IMHA is referred to a condition when the cause is unknown (idiopathic), whereas secondary IMHA involves changes in red blood cells caused by the action of drugs, neoplasms, or infectious diseases. The diagnosis can be made through changes in the blood count, usually of a regenerative character, Coombs test, and autoagglutination test. The present study aimed to report a case of drug-induced hemolytic anemia, with emphasis on the clinical signs, diagnostic methods, and treatment, in a female dog.Case: A 9-year-old mixed-breed bitch weighing 29.6 kg was referred to the Veterinary Medical Teaching Hospital (HCV-UFRGS) with a previous diagnosis of gallbladder mucocele that was unresponsive to clinical treatment. After laboratory tests, cholecystectomy was performed, and the procedure required conversion from laparoscopic to open cholecystectomy. Therapy included administration of amoxicillin, dipyrone, tramadol hydrochloride, and meloxicam. Three days after surgery, the dog presented with apathy, lethargy, hyporexia, and a pale and subicteric mucosa. The patient developed hypochromic macrocytic anemia with reticulocytosis, spherocytosis, anisocytosis, and leukocytosis with neutrophilia. The result of the autoagglutination test was positive, confirming the diagnosis. All medications were suspended, and immunosuppressive treatment with dexamethasone was included, with a subsequent switch to prednisolone. After 10 days of treatment, the patient experienced significant improvement, and therapy was discontinued.Discussion: Based on the patient's history, the cause of the IMHA was secondary to drug administration, and it is not possible to distinguish if it was due to one or a combination of drugs, as they were all started and stopped simultaneously. The patient had hypothyroidism, which may have contributed to the production of antibodies against TSH receptors, blocking the hormone's action, thereby causing tissue damage due to T cell-mediated cytotoxicity and the effect of cytokines. The pale and subicteric mucosa, apathy, weakness, lethargy, exercise intolerance, and dyspnea resulted from extravascular hemolysis and bilirubin released from erythrocyte rupture with a subsequent decrease in the number of red blood cells, leading to oxygen transport deficiency. The diagnosis is based on the blood count and results of autoagglutination supported by the response to immunosuppressive therapy. Anemia results in increased production and release of precursor cells from the bone marrow, accompanied by reticulocytosis and increased mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC). The treatment of IMHA consists of supportive care and immunosuppressive therapy with corticosteroids to ensure suppression of the immune system, preventing response against erythrocytes. Initially, tramadol hydrochloride, dipyrone, and amoxicillin with potassium clavulanate were suspended to interrupt the cause of IMHA, and administration of dexamethasone in an immunosuppressive dose was started. Therefore, it is important to include drug-induced IMHA in the differential diagnosis of patients who present with anemia after using medications. Early diagnosis, initiation of therapy, and adequate care were important factors for the recovery of the animal.Título: Anemia hemolítica imunomediada medicamentosa em uma cadelaKeywords: dog, hypochromic macrocytic anemia, erythrocyte, hemoglobin, spherocyte.Descritores: cão, anemia macrocítica hipocrômica, eritrócito, hemoglobina, esferócito.

Serum interleukin 17 concentrations in dogs with immune-mediated hemolytic anemia.

BackgroundIncreased serum interleukin 17 (IL‐17) concentration has been associated with the immunopathogenesis of autoimmune hemolytic anemia in humans. No data are available about IL‐17 in immune‐mediated hemolytic anemia (IMHA) of dogs.ObjectivesMonitor changes in serum IL‐17 concentration during the acute stages of IMHA in dogs, compared with results in healthy dogs, and its relationship with outcome.AnimalsThirty‐one client‐owned dogs with primary IMHA and 27 healthy dogs.MethodsQuantification of serum IL‐17 concentration using a commercially available ELISA kit at the time of admission (D0), after 48 hours (D2) and after 96 hours (D4) as compared to concentration in healthy dogs. The IMHA dogs were classified as survivors if discharged from hospital, or nonsurvivors for any cause of in‐hospital mortality.ResultsMean serum IL‐17 concentration was higher in dogs with IMHA on admission compared with healthy dogs (D0), but this difference was not significant (mean, 19.52 pg/mL vs 10.52 pg/mL, respectively, P = .17). Throughout hospitalization, serum IL‐17 concentration significantly decreased in survivors. Serum IL‐17 concentration at D0 was not different between survivors and nonsurvivors, but surviving dogs had significantly lower serum IL‐17 concentration at D2 and D4 (P = .04 and P = .004, respectively) compared with nonsurviving dogs. No correlation was found between serum IL‐17 concentration and serum total bilirubin or lactate concentrations or CBC parameters.Conclusion and Clinical ImportanceSerum IL‐17 concentration remained significantly higher in nonsurviving IMHA dogs whereas it significantly decreased during hospitalization in survivors, making serum IL‐17 concentration a potential biomarker for severity and response to treatment in IMHA.

RNA sequencing of whole blood in dogs with primary immune-mediated hemolytic anemia (IMHA) reveals novel insights into disease pathogenesis.

Immune-mediated hemolytic anemia (IMHA) is a life-threatening autoimmune disorder characterized by a self-mediated attack on circulating red blood cells. The disease occurs naturally in both dogs and humans, but is significantly more prevalent in dogs. Because of its shared features across species, dogs offer a naturally occurring model for studying IMHA in people. In this study, we used RNA sequencing of whole blood from treatment-naïve dogs to study transcriptome-wide changes in gene expression in newly diagnosed animals compared to healthy controls. We found many overexpressed genes in pathways related to neutrophil function, coagulation, and hematopoiesis. In particular, the most highly overexpressed gene in cases was a phospholipase scramblase, which mediates the externalization of phosphatidylserine from the inner to the outer leaflet of cell membranes. This family of genes has been shown to be critically important for programmed cell death of erythrocytes as well as the initiation of the clotting cascade. Unexpectedly, we found marked underexpression of many genes related to lymphocyte function. We also identified groups of genes that are highly associated with the inflammatory response and red blood cell regeneration in affected dogs. We did not find any genes that distinguished dogs that lived vs. those that died at 30 days following diagnosis, nor did we find any relevant genomic signatures of microbial organisms in the blood of affected animals. Future studies are warranted to validate these findings and assess their implication in developing novel therapeutic approaches for dogs and humans with IMHA.

Primary immune-mediated haemolytic anaemia: a retrospective long-term study in 61 dogs.

The objective of this study is to describe the course of disease of dogs with primary immune-mediated haemolytic anaemia (pIMHA) with an observation period longer than 90 days in regard to clinical signs, laboratory results and treatment response. Clinical records between January 2003 and December 2011 were reviewed. Diagnosis of pIMHA was based on the presence of haemolytic anaemia with a packed cell volume of <0.35 L/L, a positive Coombs' test and/or erythrocyte agglutination, spherocytosis and exclusion of an underlying disease. Included were dogs which could be monitored for more than 90 days after initial presentation. Sixty-one dogs with pIMHA were included. The initial packed cell volume ranged from 0.08 to 0.30 L/L (median 0.16). Immunosuppressive treatment included prednisolone in all the cases; 32 dogs successively received cyclosporine (28), cyclophosphamide (5), leflunomide (2) or human intravenous immunoglobulins (2) in addition. In 33/61 dogs, the drugs were discontinued 67-3372 days (median 334) after beginning of therapy; in 28 dogs, the drug dosage was reduced, but not discontinued until the end of the study. Three dogs developed immune-mediated thrombocytopenia (days 132, 156 and 680). The observation period ranged from 96 to 4147 days (median 628). A total of 22.9% (14/61) of the dogs developed a relapse after 94-3972 days (median 517). Five dogs were euthanased due to a relapse after 96-1188 days (median 628). Long-term prognosis in dogs with pIMHA is favourable. However, a relapse can occur after many years. Relapse was the most common cause of death in dogs with pIMHA that survive more than 90 days.

Thrombocyte indices and plateletcrit in dogs with primary immune-mediated hemolytic anemia

Primary immune-mediated hemolytic anemia (IMHA) is one of the most common autoimmune disorders in dogs. Platelet indices in dogs with IMHA have not been commonly used in daily clinical practice. The purpose of this study was to evaluate trombocyte indices, including platelet count (PLT), mean platelet volume (MPW), platelet size deviation width (PDW), and plateletcrit (PCT) in dogs with primary IMHA and to compare them with the corresponding values in a control series of healthy dogs. This study was performed on 21 dogs diagnosed with primary IMHA and 11 healthy dogs. The inclusion criteria were the presence of a positive Coombs’ test, true agglutination, anemia with HCT &lt;35 %, hyperbilirubinemia, bilirubinuria, hemoglobinemia, hemoglobinuria, and spherocytosis. MPV and PDW were significantly higher in the dogs with IMHA compared to the reference population. No significant differences were found in PLT and PCT between the groups. The use of MPV and PDW values in evaluating the bone marrow response would be helpful in dogs with primary IMHA.

Vaccination and Associated Adverse Events in Dogs Previously Treated for Primary Immune-Mediated Hemolytic Anemia

This study described the rate of vaccine reactions in a population of dogs receiving vaccines after diagnosis of primary immune-mediated hemolytic anemia (IMHA). A secondary objective was to describe the time elapsed between vaccination and initial diagnosis of IMHA. A medical record search identified cases meeting criteria for primary IMHA. Owners and referring veterinarians were surveyed regarding vaccination of the dog following diagnosis. Referring veterinarians were surveyed regarding vaccination prior to diagnosis of IMHA. A completed survey was returned in 44 cases. Twenty-two dogs received vaccinations after diagnosis, and 22 dogs did not. The median time elapsed between vaccination and initial diagnosis was 280 days. No dog was vaccinated within 30 days of diagnosis. Two of the following possible reactions were noted out of 22 dogs vaccinated: vomiting and urticarial eruption in a dog administered a rabies and canine distemper vaccine, and recurrent anemia in a dog administered a rabies vaccine. The rate of vaccine reactions was higher than previously reported, although the time period evaluated was longer than in previous studies. The relationship between initial vaccination and development of IMHA, and between vaccination and vaccine reaction, in this population is uncertain and may reflect coincidence or differences in susceptibility.

Influence of immune-mediated hemolytic anemia on flow velocities in the portal vein and caudal vena cava measured by use of pulsed-wave Doppler ultrasonography in dogs.

OBJECTIVE To compare blood flow velocities of the portal vein (PV) and caudal vena cava (CVC) measured by use of pulsed-wave Doppler ultrasonography in clinically normal dogs and dogs with primary immune-mediated hemolytic anemia (IMHA). ANIMALS 11 client-owned dogs admitted to a veterinary teaching hospital for management of primary IMHA and 21 staff- or student-owned clinically normal dogs. PROCEDURES Flow velocities in the PV and CVC at the porta hepatis were evaluated in conscious unsedated dogs with concurrent ECG monitoring; evaluations were performed before dogs with IMHA received heparin or blood transfusions. Three measurements of peak velocity at end expiration were obtained for each vessel, and the mean was calculated. Results were compared between IMHA and control groups. RESULTS Mean ± SD blood flow velocity in the CVC differed between control (63.0 ± 18.6 cm/s) and IMHA (104 ± 36.9 cm/s) groups. Variance in dogs with IMHA was significantly greater than that for the clinically normal dogs. No significant difference in blood flow velocity in the PV was detected between IMHA and control dogs. CONCLUSIONS AND CLINICAL RELEVANCE Higher blood flow velocities were detected by use of pulsed-wave Doppler ultrasonography in the CVC of dogs with naturally occurring IMHA and may be used to predict anemia in patients suspected of having IMHA.

Evaluation of the delta neutrophil index from an automated blood cell analyser in septic dogs

Immature granulocytes (IG) are a marker of severe inflammatory states in human beings and animals, and have been linked to a diagnosis of sepsis and poor prognosis. The delta neutrophil index (DNI), automatically calculated by a haematological analyser, provides an estimate of circulating IG. In particular, an increased DNI value has been associated with the severity of sepsis, and mortality, in critically ill human beings. The aims of this study were to determine the DNI reference interval (RI) in healthy dogs, and to evaluate its diagnostic and prognostic significance in dogs with sepsis. A total of 118 dogs with sepsis undergoing a complete blood cell count (CBC) at the time of hospital admission were included retrospectively. Dogs with sepsis were compared to 20 dogs with primary immune-mediated haemolytic anaemia (IMHA) and 99 healthy controls. The DNI RI was set from 0 to 9.2%. The DNI was significantly higher in dogs with sepsis compared to dogs with IMHA and healthy dogs (P<0.001), and significantly higher in dogs with septic shock compared to septic dogs without circulatory failure (P<0.03). No differences were detected between survivors (78/118) and non-survivors (40/118). Septic dogs with a DNI above the RI had significantly higher frequencies of IG and toxic neutrophil changes on manual blood smear evaluation (P=0.03 and P<0.001, respectively). The DNI had a fair performance in identifying dogs with sepsis in this population and predicted septic shock. Larger prospective studies are needed to validate DNI measurement in dogs and to test its clinical utility.

Serum Thymidine Kinase 1, Canine-C-Reactive Protein, Haptoglobin, and Vitamin D Concentrations in Dogs with Immune-Mediated Hemolytic Anemia, Thrombocytopenia, and Polyarthropathy.

BackgroundRelapses of immune‐mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthropathy (IMPA) occur despite normal hematologic and cytologic parameters. Thymidine kinase 1 (TK1), canine C‐reactive protein (c‐CRP), haptoglobin (HPT), and 25‐Hydroxyvitamin‐D (25(OH)D) might be adjunct to current monitoring strategies.Hypothesis/ObjectivesCompare serum concentrations of TK1, c‐CRP, HPT, and 25(OH)D in dogs with well‐ and poorly controlled primary IMHA, ITP, or IMPA.AnimalsThirty‐eight client‐owned dogs.MethodsProspective descriptive study. Dogs diagnosed with IMHA, ITP, or IMPA had serum biomarker concentrations measured commercially. Disease control was assessed by hematocrit/PCV and reticulocyte count, platelet count, and synovial fluid cytology for IMHA, ITP, and IMPA, respectively. Statistical analysis performed by Mann‐Whitney rank‐sum tests and receiver operating characteristic curves.Results TK1 and c‐CRP, but not HPT significantly decreased with well‐ versus poorly controlled IMHA (P = 0.047, P = 0.028, P = 0.37). C‐CRP, but not TK or HPT was significantly lower with well‐ versus poorly controlled IMPA (P = 0.05, P = 0.28, P = 0.84). Sensitivity and specificity of TK and c‐CRP (simultaneously) for detecting dogs with poorly controlled IMHA were 88 and 100%, respectively. Sensitivity and specificity of c‐CRP for detecting poorly controlled dogs with IMPA were 13 and 100%, respectively. 92% of dogs were vitamin D insufficient (<100 ng/mL) regardless of disease control.Conclusions and Clinical ImportanceCombining TK1 and c‐CRP might act markers of disease control in dogs with IMHA. Canine‐CRP cannot be recommended as an independent marker of disease control in IMPA. 25(OH)D insufficiency in immune‐mediated disorders might benefit from further study to determine if supplementation could improve therapeutic response or reduce disease risk.

Anemia hemolítica imunomediada em cadela da raça teckel – relato de caso

Immune-mediated hemolytic anemia leads to the premature removal of erythrocytes. It is a type 2 hypersensitivity reaction in which erythrocytes are covered by antibodies or complement and are phagocytized in the spleen or lysed within the blood vessels. It is considered of primary origin when the causes of the onset of the disease are unknown, or regarded as secondary when resulting from external antigens. The diagnosis may be therapeutic or based on the direct positive Coombs test in conjunction with laboratory findings, such as moderate to severe variable regeneration anemia, polychromasia, spherocytosis, red blood cell agglutination, hyperbilirubinemia, and hemoglobinuria. Treatment is based on immunosuppressive doses of steroidal anti-inflammatory drugs such as prednisone. This paper reports the case of an acute onset in a dog diagnosed with primary immune-mediated hemolytic anemia, presenting apathy, dyspnea, pain upon abdominal palpation, splenomegaly and pale mucous membranes. Coombs direct test was positive. Treatment started with prednisone, but as the response was not favorable, other drugs were associated to it. Evolution was unfavorable and the owner opted for euthanasia due to poor prognosis.

Characterisation of the Immunophenotype of Dogs with Primary Immune-Mediated Haemolytic Anaemia

BackgroundImmune-mediated haemolytic anaemia (IMHA) is reported to be the most common autoimmune disease of dogs, resulting in significant morbidity and mortality in affected animals. Haemolysis is caused by the action of autoantibodies, but the immunological changes that result in their production have not been elucidated.AimsTo investigate the frequency of regulatory T cells (Tregs) and other lymphocyte subsets and to measure serum concentrations of cytokines and peripheral blood mononuclear cell expression of cytokine genes in dogs with IMHA, healthy dogs and dogs with inflammatory diseases.Animals19 dogs with primary IMHA, 22 dogs with inflammatory diseases and 32 healthy control dogs.MethodsResidual EDTA-anti-coagulated blood samples were stained with fluorophore-conjugated monoclonal antibodies and analysed by flow cytometry to identify Tregs and other lymphocyte subsets. Total RNA was also extracted from peripheral blood mononuclear cells to investigate cytokine gene expression, and concentrations of serum cytokines (interleukins 2, 6 10, CXCL-8 and tumour necrosis factor α) were measured using enhanced chemiluminescent assays. Principal component analysis was used to investigate latent variables that might explain variability in the entire dataset.ResultsThere was no difference in the frequency or absolute numbers of Tregs among groups, nor in the proportions of other lymphocyte subsets. The concentrations of pro-inflammatory cytokines were greater in dogs with IMHA compared to healthy controls, but the concentration of IL-10 and the expression of cytokine genes did not differ between groups. Principal component analysis identified four components that explained the majority of the variability in the dataset, which seemed to correspond to different aspects of the immune response.ConclusionsThe immunophenotype of dogs with IMHA differed from that of dogs with inflammatory diseases and from healthy control dogs; some of these changes could suggest abnormalities in peripheral tolerance that permit development of autoimmune disease. The frequency of Tregs did not differ between groups, suggesting that deficiency in the number of these cells is not responsible for development of IMHA.

Hemolytic Anemia Imunne-mediated in dogs

Due to the reduction in the number of red blood cells, caused by the immune system, the immune-mediated hemolytic anemia (IMHA) is the most common disease among the hemolytic anemias and occurs more frequently in dogs (Nelson & Couto, 2010), wherein the most affected breeds are Cocker Spaniel, Poodle, Doberman and Collie (ETTINGER; FELDMAN 2004; THRALL et al 2007.). There is no pathognomonic sign for the diagnosis of the immune-mediated hemolytic anemia; however, laboratory findings show regenerative anemia, spherocytosis, positive results in Coombs' test and rarely, monocytes with hemosiderin or erythrocytes phagocytosis, but even with these findings, the primary and secondary IMHA can not be differentiate from each other. Differentiation can only be achieved when there is a deep investigation into the cause of the anemia. The IMHA therapeutics starts with the support treatment and follows with an immunosuppressive therapy. In relation to IMHA Mortality rates, the numbers range from 25% to 50% (Thrall, 2007), or above 70% (CARR; Panciera; Kidd, 2002).

Evaluation of the safety and tolerability of rivaroxaban in dogs with presumed primary immune-mediated hemolytic anemia.

To evaluate the safety and tolerability of rivaroxaban (RIV), an oral direct factor Xa inhibitory drug, in dogs with presumed primary immune-mediated hemolytic anemia (pIMHA). Prospective, multicenter, positive-controlled, unblinded clinical trial. Client-owned dogs were enrolled between October 2012 and March 2014. Private referral centers. Twenty-four client-owned dogs with pIMHA. Enrolled dogs were randomized in 2 treatment groups to receive by mouth RIV or clopidogrel (CL) and low-dose aspirin (LDA). All dogs were monitored for 90 days from the enrollment in the study. Enrolled dogs were given a standardized immunosuppressive protocol and RIV or CL and LDA. There was no identifiable adverse drug reaction, evidence of hemorrhage, significant prolongation of prothrombin time or activated partial thromboplastin time, or increase in transfusion requirements associated with RIV therapy compared to CL and LDA in dogs with pIMHA. There was no significant difference between treatment groups with respect to thrombotic events, survival rates to discharge, at 1 month and 3 months from diagnosis. This study suggests that RIV at a median dose of 0.89 mg/kg by mouth once daily was safe and well tolerated in a small group of dogs with presumed pIMHA able to tolerate oral medications and treated with a standardized immunosuppressive treatment protocol. Conclusions regarding the relative efficacy of RIV as compared to CL and LDA cannot be made due to the small size of the treatment groups and because pharmacodynamic effects were not assessed.

Demographic Characteristics, Survival and Prognostic Factors for Mortality in Cats with Primary Immune-Mediated Hemolytic Anemia.

BackgroundImmune‐mediated hemolytic anemia (IMHA) is uncommon in cats, but may result in severe disease. Demographic predispositions for development of the disease and prognostic factors for mortality have not been investigated previously.Hypothesis/ObjectivesTo explore possible demographic predispositions for development of primary IMHA in cats and to investigate possible prognostic factors for mortality.Animals107 client‐owned cats with IMHA, of which 72 had primary IMHA and 35 had secondary IMHA, and 9,194 control cats.MethodsData were collected retrospectively from records of cats with IMHA, defined by the presence of anemia and concurrent autoagglutination, ghost cells without oxidative damage on fresh blood smear, positive titer in a direct antiglobulin test, or evidence of phagocytosis of erythroid precursors in bone marrow. Odds ratios were calculated to assess the risk of development of primary IMHA in different demographic groups and Cox proportional hazards analysis was conducted to evaluate prognostic factors.ResultsNo sex or breed predisposition was identified for the development of primary IMHA in comparison to the control cats, but cats in the age range 2.1–5.9 years were predisposed. Higher total bilirubin concentration and age were significant negative prognostic factors and higher lymphocyte numbers and serum globulin concentration were positive prognostic factors in a multivariable model.Conclusions and Clinical ImportanceYoung adult cats were more likely to develop primary IMHA than other groups, but no apparent male predisposition was identified in this study, contrary to previous reports. Several prognostic factors were identified, which may be helpful in guiding clinical practice in the future.