Evaluation of dysmyelopoiesis in cats: 34 cases (1996–2005)

Peripheral blood cells of native pig (Zovawk) of Mizoram, India: Light and scanning electron microscopy analysis

The literature on the blood cells of Zovawk pigs is scanty; thus, this study was designed to elaborate the light microscopy (LM) and scanning electron microscopy (SEM) characterization of blood cells of Zovawk pigs by LM and SEM. Twelve different blood samples were aseptically obtained from adult healthy Zovawk pigs, irrespective of sex. To determine the cytomorphological and cytochemical structures of the many produced constituents of blood, blood smears were stained with various stains. The blood samples were treated with various substrates for cytoenzymatic research, and the alterations were noted. A 1000× magnification Olympus Trinocular Research microscope was used to examine the smears. The blood samples were prepared for electron microscopy according to the standard procedure. The prepared samples were delivered to the Sophisticated Analytical Instrumentation Facility (SAIF), All India Institute of Medical Sciences (AIIMS), New Delhi, for SEM imaging. On LM, pig erythrocytes were spherical and nonnucleated. The cytoplasm of the neutrophils was spherical and included cytoplasmic granules. The eosinophils had prominent cytoplasmic granules and were round. Basophils were infrequently present and had cytoplasmic granules that were clear blue. The sizes of small, medium and large lymphocytes were noted. The monocytes were oval or circular. The platelets ranged in form from asymmetric to round. The blood samples were stained for cytochemical analyses using acid ferrocyanide stain for iron, Sudan black blue stain for lipids, toluidine blue stain for mucopolysaccharides, and periodic acid Schiff's stain for glycogen. The cytoenzymatic characteristics were evaluated and compared with substrates treated with acid phosphatase, alkaline phosphatase, peroxidase, arylsulfatase, cytochrome oxidase, beta-glucuronidase, and succinate dehydrogenase. Erythrocytes appeared as biconcave disks under SEM. Two forms of leukocytes were observed, having a rough and pointed cell surface like a flower. It can be concluded that the LM and SEM morphology of blood cells of Zovawk pigs resembled other domestic animals, however, few differences were observed among the discussed animals.

Molecular basis of essential thrombocythaemia in humans and dogs – a review

<b>A potential cause of essential thrombocythaemia can be seen as the V617F point mutation within Janus kinase 2. This mutation occurs in 60-70% of patients with this disease and is located in the domain acting as an inhibitor. It increases the enzymatic activity of JAK2 kinase and induces intensified sensitivity of cells to cytokines. Identification of mutations in the JAK2 gene has made it possible to describe the molecular pathogenesis of myeloproliferative syndromes, which has enabled more accurate diagnosis and assisted in effective treatment. The significant similarity of the clinical, laboratory and morphological features of myeloproliferative syndromes (including essential thrombocythaemia) in animals and humans suggests that common signalling pathways within the JAK2 gene may be involved in the development of these diseases.</b>

Feline non-regenerative anemia: Diagnostic and treatment recommendations

PRACTICAL RELEVANCE

Non-regenerative anemia, or anemia with reticulocytopenia, is a daily diagnosis in feline practice.

CLINICAL CHALLENGES

The disease processes underlying non-regenerative anemia are many and diverse. A major diagnostic evaluation may be required to correctly diagnose and treat the underlying cause.

AUDIENCE

All veterinarians caring for cats will face the diagnostic and therapeutic challenge of non-regenerative anemia. Readers will benefit from the review of diagnostic testing and therapeutic options for non-regenerative anemia.

EVIDENCE BASE

This review summarizes the currently available literature informing diagnostic and treatment recommendations related to non-regenerative anemia. The evidence available to support the recommendations in this review is graded as low and includes predominantly expert opinion, case reports and cases series, on which the authors' interpretation/consensus is based.

Development of canine X-chromosome inactivation pattern analysis for the detection of cell clonality by incorporating the examination of the SLIT and NTRK-like family member 4 (SLITRK4) gene

X-chromosome inactivation pattern (XCIP) analysis can be used to assess the clonality of cell populations of various origin by distinguishing the methylated X chromosome from the unmethylated X chromosome. In this study, the utility of XCIP analysis was improved by incorporating the examination of AC dinucleotide repeats in SLIT and NTRK-like family member 4 (SLITRK4) gene into the previously reported CAG repeat examination of androgen receptor (AR) gene in dogs. The rate of heterozygosity when both genes were analysed (125/150, 83.3%) was higher than AR gene examination alone (86/150, 57.3%). Blood samples from heterozygous dogs in either AC-1 or AC-2 of SLITRK4 gene were examined for the corrected inactivation allele ratio (CIAR), resulting in the determination of a reference range of CIAR <3.8 in non-neoplastic cell/tissue samples. Using this analytical method, 49% (21/43) of neoplastic tissue samples from dogs showed a CIAR >3.8, indicating the presence of a clonal population. Through the present study, the availability of canine XCIP analysis was improved by incorporating the examination of the SLITRK4 gene, providing a highly useful laboratory examination system for the detection of the clonality of various cell/tissue samples in dogs.

Retrospective study of 152 feline cytological bone marrow examinations: preliminary classification and ranges

Objectives

Cytological assessment of the bone marrow is an essential tool for understanding and investigating haematological abnormalities. Sometimes it represents the only way to reach a definitive diagnosis. The purpose of this study was to provide a general overview regarding the prevalence of feline bone marrow disorders encountered in a private European laboratory setting, to classify them and to assess the differential cell counts related to such disorders.

Methods

In total, 152 bone marrow samples were classified using cytological and numerical criteria. The bone marrow cytological examinations were performed after the identification of haematological alterations, such as cytopenias, increased number of cells or suspicion of malignant blood disorders.

Results

Of the 152 bone marrow samples evaluated, 71 (46.7%) were classified as hyperplastic, primarily granulocytic and erythroid hyperplasia (50.7% and 45.1%, respectively, of the total hyperplasia); 23 (15.1%) showed dysmyelopoiesis, mainly in the form of myelodysplastic syndrome (39.1% of the total dysmyelopoiesis); 21 (13.8%) had no cytological abnormalities; 17 (11.2%) were malignant blood disorders; 15 (9.9%) had hypoplastic conditions; and two (1.3%) were miscellaneous diseases. Metastatic disease was detected in only two cases (1.3%). Differential cell counts and myeloid-to-erythroid (M:E) ratios were reported for normal, erythroid hypoplastic, erythroid and granulocytic hyperplastic and dysplastic conditions.

Conclusions and relevance

This study provides a general overview of the prevalence and incidence of feline bone marrow disorders together with ranges for differential nucleated cell counts and M:E ratios for the various conditions reported.

Suspected myelodysplastic/myeloproliferative neoplasm in a feline leukemia virus-negative cat

A 10-year-old castrated Domestic Short-Haired cat was presented to a primary care veterinarian for a wellness examination and laboratory examination for monitoring of diabetes mellitus. The CBC revealed marked thrombocytosis, leukopenia and macrocytic, normochromic anemia. The cat tested negative for FeLV and feline immunodeficiency virus, but was positive for Mycoplasma haemominutum by PCR. Hematologic abnormalities were not responsive to therapy, so a repeat CBC and a bone marrow aspiration for cytology were performed. Additional blood smear findings included anisocytosis with megaloblastic erythroid precursors, large platelets, eosinophilic myelocytes and metamyelocytes, and rare unidentified blasts. The bone marrow smear was highly cellular, and the cytologic pattern was consistent with myelodysplastic syndrome with an erythroid predominance. At that time, 15% blasts were present. The cat was treated with a vitamin K₂ analog, doxycycline, and prednisolone, but without a clinical response. Within 3 months, euthanasia was elected due to declining quality of life, and a necropsy was performed. Postmortem bone marrow smears were highly cellular and dominated by monomorphic blasts of unknown line of origin (52%), persistent marked erythroid and megakaryocytic dysplasia, and ineffective erythropoiesis and granulopoiesis. Immunohistochemical, immunocytochemical, and cytochemical stains resulted in a diagnosis of acute myeloid leukemia of unclassified type. Additional histologic findings included mixed hepatitis with trematode infestation and lymphoplasmacytic interstitial nephritis with fibrosis. The marked thrombocytosis with myelodysplastic syndrome and the FeLV-negative status of this cat were unusual. The difficulty in classifying the myelodysplasia and subsequent leukemia highlights a need for further reporting and characterization of these types of disease.

A retrospective study of 180 anaemic cats: features, aetiologies and survival data

The study comprised 180 anaemic cats. Descriptive and survival data were obtained. Cats were classified by aetiology of anaemia development and degenerative, anomalous, metabolic, miscellaneous, neoplastic, infectious, inflammatory, immune-mediated, toxic, traumatic or vascular disease (DAMNITV) classification and anaemia severity. Sixty-four (35.6%) cats had mild [packed cell volume (PCV)/haematocrit (HCT) 20-24.9%], 58 (32.2%) moderate (14-19.9%), 23 (12.8%) severe (11-13.9%) and 35 (19.4%) very severe (<10.9%) anaemia. By aetiology of anaemia development, bone marrow (BM) abnormalities were more common (95, 52.8%) than haemorrhage (37, 20.6%) or haemolysis (19, 10.6%). By DAMNITV classification, infectious diseases were more common (39, 21.7%) than neoplasia (36, 20%), metabolic (21, 11.7%), trauma (15, 8.3%), miscellaneous (14, 7.8%), inflammatory (11, 6.1%), immune-mediated (11, 6.1%), anomalous (8, 4.4%), toxic (2, 1.1%) or vascular disease (1, 0.6%). BM abnormalities were significantly associated with more severe anaemia (P = 0.003). Most cats (112, 62.2%) survived to discharge whereas 55 (30.6%) were euthanased and 13 (7.2%) died. Survival to discharge was not associated with anaemia severity but was associated significantly with aetiology of anaemia development (P = 0.046), as cats with haemolysis were more likely to survive to discharge than cats with BM abnormalities. Survival to discharge was also associated significantly with DAMNITV classification (P = 0.010), with cats with neoplasia being less likely, and cats with immune-mediated disease more likely, to survive to discharge. Cox regression analysis found that survival was not associated with anaemia severity, but was associated with DAMNITV classification (P = 0.011) and age (P = 0.082), with cats with immune-mediated disease and younger cats more likely to survive.

Diagnostic accuracy of using erythrocyte indices and polychromasia to identify regenerative anemia in dogs

OBJECTIVE

To determine diagnostic accuracy of using erythrocyte indices and polychromasia to identify regenerative anemia in dogs.

DESIGN

Retrospective and prospective cross-sectional study.

ANIMALS

4,521 anemic dogs.

PROCEDURES

CBC results obtained between July 2002 and July 2008 by use of an automated laser-based flow cytometric hematology analyzer from dogs with Hct values ≤ 35% were retrieved. Sensitivity, specificity, accuracy, and predictive values of using erythrocyte indices and polychromasia to identify regeneration were determined, with a reticulocyte count > 65,000 reticulocytes/μL considered the gold standard. Similarly, 134 blood samples from anemic dogs were analyzed prospectively with an in-house electrical impedance analyzer.

RESULTS

Of 4,387 dogs with samples analyzed retrospectively, 1,426 (32.5%) had regenerative anemia. Of these, 168 (11.8%) had macrocytic hypochromic anemia. High mean cell volume and low mean cell hemoglobin concentration had low sensitivity (11%), high specificity (98%), and moderate accuracy (70%) when used to identify regenerative anemia. Use of polychromasia alone had an accuracy of 77%, and use of polychromasia combined with a high RBC distribution width (RDW) had an accuracy of 79%. Results obtained with the in-house analyzer were similar.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that most regenerative anemias in dogs were not macrocytic hypochromic. Polychromasia, with or without high RDW, was a more accurate indicator than other erythrocyte indices of regenerative anemia. To avoid a false diagnosis of nonregenerative anemia, a blood smear should be evaluated in anemic dogs when a reticulocyte count is not available.

Prognostic markers for myeloid neoplasms: a comparative review of the literature and goals for future investigation

Myeloid neoplasms include cancers associated with both rapid (acute myeloid leukemias) and gradual (myelodysplastic syndromes and myeloproliferative neoplasms) disease progression. Percentage of blast cells in marrow is used to separate acute (rapid) from chronic (gradual) and is the most consistently applied prognostic marker in veterinary medicine. However, since there is marked variation in tumor progression within groups, there is a need for more complex schemes to stratify animals into specific risk groups. In people with acute myeloid leukemia (AML), pretreatment karyotyping and molecular genetic analysis have greater utility as prognostic markers than morphologic and immunologic phenotypes. Karyotyping is not available as a prognostic marker for AML in dogs and cats, but progress in molecular genetics has created optimism about the eventual ability of veterinarians to discern conditions potentially responsive to medical intervention. In people with myelodysplastic syndromes (MDS), detailed prognostic scoring systems have been devised that use various combinations of blast cell percentage, hematocrit, platelet counts, unilineal versus multilineal cytopenias and dysplasia, karyotype, gender, age, immunophenotype, transfusion dependence, and colony-forming assays. Predictors of outcome for animals with MDS have been limited to blast cell percentage, anemia versus multilineal cytopenias, and morphologic phenotype. Prognostic markers for myeloproliferative neoplasms (eg, polycythemia vera, essential thrombocythemia) include clinical and hematological factors and in people also include cytogenetics and molecular genetics. Validation of prognostic markers for myeloid neoplasms in animals has been thwarted by the lack of a large case series that requires cooperation across institutions and veterinary specialties. Future progress requires overcoming these barriers.

Immune-mediated erythroid and megakaryocytic aplasia in a cat

CASE DESCRIPTION

A 6-month-old domestic shorthair cat was evaluated because of acute lethargy.

CLINICAL FINDINGS

Severe nonregenerative anemia and thrombocytopenia were identified. Cytologic examination of a bone marrow aspirate revealed selective erythroid and mega-karyocytic aplasia and a high number of apparently normal small lymphocytes. Infectious agents implicated in feline hematologic disorders were excluded on the basis of serologic tests or PCR amplification, including FeLV, Ehrlichia canis, Anaplasma phagocytophilum, Mycoplasma haemofelis, Candidatus Mycoplasma haemominutum, and Candidatus Myco-plasma turicensis.

TREATMENT AND OUTCOME

A 10-day course of prednisolone administration did not improve the hematologic disorder. Administration of human polyclonal immunoglobulins preceded increased reticulocyte count by 3 days. A second bone marrow examination confirmed restoration of erythroblasts and megakaryocytes. After 1 relapse, the disease was successfully controlled with prednisolone for > 3 years.

CLINICAL RELEVANCE

Immune-mediated bone marrow aplasia is rare in cats and usually affects only erythrocyte progenitors. Concomitant involvement of erythroid and megakaryocytic cell lines can be successfully treated via immunosuppressive therapy. Human immunoglobulins seem to be well tolerated in cats; however, proof of a beneficial effect requires further study.