Breed predispositions, clinical findings, and prognostic factors for death in dogs with nonregenerative immune-mediated anemia

Clinical findings, treatment and outcome in cats diagnosed with precursor-targeted immune-mediated anaemia in a referral hospital in the UK: 30 cases (2010-2021)

Aims

This retrospective study aimed to report clinical findings, treatment response and survival in cats diagnosed with precursor-targeted immune-mediated anaemia (PIMA) in a referral hospital in the UK.

Methods

Feline cases diagnosed with presumed PIMA between January 2010 and February 2021 were retrospectively recruited. Signalment, clinical signs, diagnostic tests, treatment and outcome were recorded. Descriptive analytics were performed. Outcomes were documented according to survival to discharge, 30-day survival, total survival time, response to immunosuppressive treatment and frequency of relapses.

Results

Thirty cats met the inclusion criteria. A higher prevalence of females (19/30) was identified (p = 0.001). Most cats (25/30) presented with haematocrit below 0.15 L/L. Concurrent cytopenias occurred in 18 of 30 cats. Bone marrow diagnosis was erythroid hyperplasia in 24 of 30 cases. Survival to discharge was documented in 26 of 30 cats, of which 23 survived more than 30 days since diagnosis. Initial treatment included blood products (26/30) and prednisolone (26/30) or prednisolone with ciclosporin (3/30); 18 of 30 cats responded to treatment, with a normal haematocrit at a mean of 28 days. The initial haematocrit and the presence of concurrent cytopenia were not statistically different between responders and non-responders. The median survival time was 140 days (range 1-3930 days).

Conclusions and relevance

The treatment response rate of feline PIMA was high (60%), with a mortality rate of 23% over the 30 days following diagnosis. Relapses occur frequently (77%) but the response rate after treatment modification was high (76%) and therefore ongoing treatment may be justified at that point. Long survival times (up to 3930 days) can be achieved.

Transcriptome and proteome analysis of dogs with precursor targeted immune-mediated anemia treated with splenectomy

Precursor-targeted immune-mediated anemia (PIMA) in dogs is characterized by persistent non-regenerative anemia and ineffective erythropoiesis, and it is suspected to be an immune-mediated disease. Most affected dogs respond to immunosuppressive therapies; however, some are resistant. In this study, we carried out splenectomy as an alternative therapy for refractory PIMA in dogs, and analyzed gene expression levels in the spleen of dogs with or without PIMA and in serum before and after splenectomy. A total of 1,385 genes were found to express differentially in the spleens from dogs with PIMA compared with healthy dogs by transcriptome analysis, of which 707 genes were up-regulated, including S100A12, S100A8, and S100A9 that are linked directly to the innate immune system and have been characterized as endogenous damage-associated molecular patterns. Furthermore, immunohistochemistry confirmed that S100A8/A9 protein expression levels were significantly higher in dogs with PIMA compared with those in healthy dogs. A total of 22 proteins were found to express differentially between the serum samples collected before and after splenectomy by proteome analysis, of which 12 proteins were up-regulated in the samples before. The lectin pathway of complement activation was identified by pathway analysis in pre-splenectomy samples. We speculated that S100A8/9 expression may be increased in the spleen of dogs with PIMA, resulting in activation of the lectin pathway before splenectomy. These findings further our understanding of the pathology and mechanisms of splenectomy for PIMA.

Improvement of anemia in five dogs with nonregenerative anemia treated with allogeneic adipose-derived stem cells

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Five canine cases with nonregenerative anemia were included in this study.

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All were treated with allogeneic adipose-derived stem cells (ADSCs).

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All cases showed improvement of anemia by ADSCs treatment.

Background

Objectives

Methods

Results

Conclusions

Comparative study of immunohematological tests with canine blood samples submitted for a direct antiglobulin (Coombs') test

BACKGROUND

A 2019 ACVIM consensus statement on diagnostics for immune-mediated hemolytic anemia (IMHA) in dogs made testing recommendations. As data on the performance of immunohematological tests was lacking, we undertook a comparative analysis.

MATERIAL AND METHODS

Anticoagulated blood samples from 126 dogs suspected of having IMHA submitted to a diagnostic veterinary laboratory for a routine direct antiglobulin test (DAT) and from 28 healthy control dogs were evaluated for spherocytosis and autoagglutination before and after three saline washes. Samples were also subjected to different DATs: a gel minitube and an immunochromatographic strip kit used in clinics; neutral gel column cards, microtiter plates (at 4°, 22°, and 37°C), capillary tubes, and flow cytometry used in laboratories.

RESULTS

Samples from healthy dogs yielded negative results with all immunodiagnostic tests. Among the 126 samples submitted for DAT 67 were positive by a DAT utilizing microtiter plates with goat anti-dog antiglobulin DAT at 22°C. Notably, DAT results were comparable and consistent across all evaluated methods regardless of antiglobulin and temperature used. DAT+ dogs were more severely anemic and more likely to have erythroid regeneration compared to DAT- dogs. Macroscopic agglutination in tubes or on slides was observed in 48 samples after 1:1 and 1:4 blood to saline dilution, but only persisted in four samples after washing. Among the DAT+ samples, 57% had agglutination, 87% had spherocytosis, and 45% had both. There was good correlation between spherocytosis and DAT results from the six DAT techniques, but the correlation with autoagglutination was only fair. Clinical follow-up was available for 42 dogs. Of the sample from 12 DAT+ dogs collected during treatment, 10 remained DAT+ when tested 1-24 weeks after initial assessment.

CONCLUSIONS

Based upon this comparative prospective survey, all in-clinic and laboratory DAT techniques produced similar results when performed by trained personnel and can therefore be recommended for detection of antibody-coated erythrocytes and immunohematological diagnosis. In addition, use of these tests for monitoring response of IMHA dogs to treatment might be valuable.