Anti‐Erythrocyte Antibodies and Disease Associations in Anemic and Nonanemic Dogs

Abstract

Background: Flow cytometry has been used to detect anti-red blood cell (RBC) antibodies in dogs with immune-mediated hemolytic anemia (IMHA), but the prevalence of anti-RBC antibodies in anemic and nonanemic dogs with a variety of different diseases has not been assessed previously.Hypothesis: We hypothesized that anti-RBC antibodies would be more common in anemic dogs and in dogs with immunemediated disorders and cancer.Animals: Blood samples from 292 dogs were analyzed prospectively by flow cytometry for anti-RBC antibodies.Methods: Blood samples from 147 anemic and 145 nonanemic dogs were evaluated by flow cytometry to detect surfacebound immunoglobulin (Ig) G and IgM antibodies on RBC. Disease associations with RBC antibodies were determined, as was the correlation between disease status and the percentage of Ig 1 RBC. The specificity and sensitivity of flow cytometry and clinical variables for the diagnosis of IMHA were compared by Bayesian analysis.Results: Anemic dogs were significantly more likely to be positive for anti-RBC antibodies (IgG, IgM, or both) than nonanemic dogs. Anemic dogs also had significantly higher percentages of Ig 1 RBC than nonanemic dogs, whereas dogs with IMHA had significantly higher percentages of Ig 1 RBC than dogs with all other diseases. Dogs with IMHA, infectious diseases, and immune-mediated thrombocytopenia were significantly more likely to have anti-RBC antibodies than dogs with other medical or surgical diseases.Conclusions: Anemic dogs with immune-mediated diseases and infectious diseases were at the highest risk for the development of anti-RBC antibodies, and flow cytometry for the detection of IgG on RBC was highly sensitive and specific for the diagnosis of IMHA.

Canine idiopathic immune-mediated haemolytic anaemia: a review with recommendations for future research

“…The subset of dogs with IMHA with a low mortality risk score is perfectly suited to the study of immunomodulating therapies that have an expected onset of action after 2 weeks, such as azathioprine and cyclosporine. The duration, dosing, and efficacy of (Keller 1992;Morley et al 2008) in a university hospital population; a point estimate of 4% was used. Estimates for the prevalence of IMHA in a population of anaemic dogs range from 10% to 30%, and for the calculation above an intermediate estimate of 25% was chosen.…”

“…The direct Coombs' test is still the main method used to demonstrate anti-erythrocyte antibodies, alternative methods, however, include flow cytometry (Morley et al 2008), enzyme-linked immunosorbent assay (Jones et al 1987), and a gel test (Lapierre et al 1990), although these tests are not routinely available in veterinary practice. The diagnostic performance of the direct Coombs' test depends on many factors, such as use of polyspecific instead of monospecific Coombs reagents, a one-dilution only tube test instead of multititre plates, and incubation at 37 C only versus additional incubation at 4 C (Wardrop 2005).…”

<b>Caracterização da anemia em cadelas com piometra</b>

“…Entretanto, outros mecanismos poderiam se encontrar na gênese da anemia, como citam Morley et al (2008) e Tizard (2008. De acordo com esses autores, a anemia hemolítica causada pelos processos infecciosos, pode se desenvolver como consequência da deposição de imunocomplexos na superfície das hemácias ou da produção de anticorpos anti-eritrocitários, o que resulta na destruição eritrocitária precoce.…”

“…A porcentagem de hemácias com imunoglobulinas na superfície pode ser determinada por Citometria de Fluxo (QUIGLEY et al, 2001;MORLEY et al, 2008).…”

“…Ela pode ocorrer como um evento primário ou secundário a uma grande variedade de doenças infecciosas ou neoplásicas (BARKER, 2000). Segundo Morley et al (2008), em um estudo prospectivo com 292 cães, a utilização da citometria de fluxo para a detecção de imunoglobulinas na superfície de eritrócitos foi de alta sensibilidade e especificidade para o diagnóstico de AHIM.…”