Spurious capillary zone electrophoresis pattern in hypercholesterolemic dogs

Capillary zone electrophoresis (CZE) is a relatively new serum protein electrophoresis method with higher resolution than other electrophoretic techniques. Hypercholesterolemic dogs exhibit a peculiar CZE pattern. Specifically, they have a shoulder or peak immediately next to the albumin peak. We investigated the prevalence of this spurious peak in hypercholesterolemic dogs and its correlation with the serum cholesterol concentration. Moreover, possible discrepancies between the CZE and spectrophotometric (bromocresol green [BCG] method) albumin concentrations in those animals were evaluated, as well as the accuracy in measuring albumin by a different CZE fractionation system. We retrospectively enrolled 500 hypercholesterolemic and normotriglyceridemic dogs. Each electrophoretic curve was inspected visually to identify a spurious peak (prevalence of 68.8%). We chose 120 dogs to further investigate the albumin concentration; CZE albumin was significantly higher than measured using the BCG method. A weak but significant correlation (r = 0.412; p <0.0001) was observed between the magnitude of the spurious peak and the serum cholesterol concentration. Finally, the significant difference between CZE and BCG albumin measurement disappeared (p = 0.92) when the spurious peak was considered as α1-globulins instead of albumin.

Computed tomographic findings in dogs with multiple myeloma

BACKGROUND

Computed tomography (CT) is considered the first-line imaging modality for human patients with suspected multiple myeloma (MM). Recently the diagnostic criteria for human MM have been updated.

OBJECTIVES

To describe and provide a baseline of the CT features and distribution of osseous lesions in dogs diagnosed with MM and to describe the change of initial osseous lesions after the start of treatment in a subset of dogs.

METHODS

Single-centre, retrospective, descriptive, case series. Dogs were included when they met the updated MM criteria and if a staging CT was performed at the time of diagnosis and prior to initiation of treatment. When available, change of osseous lesions was assessed on serial imaging studies.

RESULTS

Thirteen dogs met the inclusion criteria. All dogs had involvement of the axial skeleton and 9/13 (69%) had concurrent involvement of the appendicular skeleton. Large (≥1 cm), lytic, 'punched out' or expansile bony lesions and regions of permeative lysis were most common and mainly affected the vertebral column. Discrete intramedullary soft tissue attenuating lesions of the proximal appendicular skeleton were observed in 8/13 dogs (61%) and bilateral involvement of both humeri and femurs was seen in 4/9 dogs (44%). A subset of dogs underwent serial imaging and progressive replacement of the contrast-enhancing lesions with fat attenuating tissue was observed for all dogs, corresponding with clinical improvement.

CONCLUSIONS

This case series provides a baseline knowledge of the initial and follow-up CT features in dogs diagnosed with MM based on updated criteria.

Ein Update zur Leishmaniose des Hundes: Diagnostik, Therapie und Monitoring

Aufgrund von steigenden Importzahlen von Hunden aus dem Ausland, zunehmendem Reiseverkehr sowie den Veränderungen klimatischer Bedingungen in Europa gewinnen Infektionen mit Leishmania (L.) infantum bei Hunden in Deutschland zunehmend an Bedeutung. Daher sollten auch Hunde aus dem Ausland, die keine klinischen Symptome zeigen, direkt nach Import sowie erneut 6 Monate später auf vektorübertragene Infektionserreger getestet werden. Bei Hunden mit klinischer Symptomatik, die hinweisend auf eine Leishmaniose sind, werden direkte und indirekte Nachweisverfahren sowie eine hämatologische und biochemische Untersuchung unter Einbezug von Serumeiweißelektrophorese sowie Bestimmung des C-reaktiven Proteins empfohlen. Als Leitfaden für die Therapie sowie das Monitoring stehen die LeishVet-Guidelines zur Verfügung. Es stehen leishmanizide und leishmaniostatische Wirkstoffe zur Verfügung, die in first-line, second-line und third-line unterschieden werden. Zur Anpassung der Allopurinol-Dosierung wird der Stufenplan empfohlen. Aufgrund der Veränderung der klimatischen Bedingungen kommt es zu einer Ausbreitung der Habitate von Sandmücken, die als Vektoren der Leishmaniose bekannt sind. Als weitere Infektionsquellen sind Deckakte, transplazentare Infektionen, Bisswunden und Bluttransfusionen beschrieben. Leishmania infantum hat zoonotisches Potential und ist daher auch in Hinblick auf den „One-Health“-Gedanken bedeutend.

Erythrophagocytic multiple myeloma in a dog

A 5-y-old spayed female Golden Retriever dog was referred because of severe normocytic normochromic nonregenerative anemia and thrombocytopenia. Serum analysis revealed hyperproteinemia and monoclonal or oligoclonal gammopathy. Fine-needle aspiration of the spleen revealed a highly erythrophagocytic population of neoplastic round cells, morphologically suggestive of plasma cells. After euthanasia, histologic assessment of the spleen and liver revealed an erythrophagocytic round cell tumor. Immunohistochemical analysis of the tumor population was positive for MUM1p and negative for CD3, CD20, and Iba-1, confirming the plasma cell origin of the tumor. Erythrophagocytic multiple myeloma is a very rare neoplastic condition in dogs.

Diagnostic performance of routine electrophoresis and immunofixation for the detection of immunoglobulin paraproteins (M-Proteins) in dogs with multiple myeloma and related disorders: Part 1 - Current performance

BACKGROUND

Routine electrophoresis [agarose gel electrophoresis (AGE) and capillary zone electrophoresis (CZE)] and species-specific immunofixation (IF) can be used alone or in combination to detect immunoglobulin paraprotein (M-protein) and diagnose secretory myeloma-related disorders (sMRD).

OBJECTIVE

We aimed to evaluate the performance of AGE, CZE, CZE plus IF (CZE-IF), and AGE plus IF (AGE-IF) for detecting canine serum M-proteins.

METHODS

One hundred canine cases that had AGE, CZE, and routine IF performed on serum, and where B-cell lineage neoplasia (such as B-cell lymphoma and plasma cell tumors) had been diagnosed or excluded, were evaluated. Routine IF protocols targeted IgG-FC, IgA, and IgM heavy chains and light chains. IgG4 IF and free light chain IF were also performed. B-cell lineage neoplasms with an M-protein detected, using any available method, were classified as sMRD. Datasets from AGE, CZE, IF, CZE-IF, and AGE-IF (electrophoretograms, gel images, and fraction concentrations) were composed and reviewed. The sensitivity, specificity, and Youden's index for M-protein detection were determined for each dataset.

RESULTS

The combination of AGE-IF or CZE-IF was more sensitive (82.9%) than CZE alone (72.0%) or AGE alone (64.6%) and more specific (66.1%, 48.3%, 51.7%, respectively). Immunofixation could be used alone to detect M-proteins (sensitivity 82.9%, specificity 61.9%), but there were technical challenges that complicated the performance and evaluation of the test. Myeloma with free light chains only was found in 5/41 cases of sMRD.

CONCLUSIONS

Adding routine IF to routine electrophoresis increases the ability to accurately identify M-proteins; however, there is still room for further diagnostic performance improvements.

Protein characterization using electrophoresis and immunofixation; a case-based review of dogs and cats

Protein electrophoresis and immunotyping can be a useful adjunct to the standard biochemical techniques for characterizing serum and urine proteins. This paper reviews currently available and commonly used methods for diagnostic protein electrophoresis, including both agarose gel and capillary zone electrophoretic techniques and total protein assessments. Immunofixation and immunosubtraction methods for identification of immunoglobulin location and class are also presented. Practical application of quality assurance and quality control strategies in compliance with American Society of Veterinary Clinical Pathology (ASVCP) best practices are discussed. Commonly encountered serum and urine electrophoretic diagnostic patterns, including electrophoretically normal, acute-phase protein responses, polyclonal gammopathies, restricted polyclonal/oligoclonal gammopathies, paraproteinemias (monoclonal or biclonal gammopathies), and Bence-Jones proteinurias are also reviewed using relevant case material. Cases in which immunofixation electrophoresis are particularly useful are highlighted, and methodologies to more accurately quantify serum monoclonal proteins (M-proteins), monitoring tests commonly used in human medicine, are discussed.

Laboratory tests for diagnosing and monitoring canine leishmaniasis

Although several reviews on canine leishmaniasis have been published, none thoroughly described clinicopathologic abnormalities and their clinical usefulness. The aim of this review was to provide information concerning current diagnostic tests relevant for clinical pathologists and from a practical perspective. Specifically, in canine leishmaniasis, nonregenerative normocytic normochromic anemia, thrombocytopenia, or leukogram changes may be present. Clinical chemistry and urinalysis may indicate renal dysfunction (azotemia, decreased urine specific gravity, proteinuria) and an inflammatory/immune response (increased acute phase proteins [APP] or α₂ - and/or γ-globulins). Although a potential gammopathy is usually polyclonal, it may also appear oligo- or monoclonal, especially in dogs coinfected by other vector-borne pathogens. When lesions are accessible to fine-needle aspiration (lymphoadenomegaly, nodular lesions, joint swelling), cytology is strongly advised, as the presence of Leishmania amastigotes in a pattern of pyogranulomatous inflammation or lymphoplasmacytic hyperplasia is diagnostic. If the cytologic pattern is inconclusive, the parasite should be identified by histology/immunohistochemistry or PCR on surgical biopsies. Alternatively, cytology and PCR may be performed on bone marrow samples where amastigotes, along with erythroid hypoplasia, myeloid hyperplasia, plasmacytosis, or secondary dysmyelopoiesis can be observed. Dogs with overt leishmaniasis generally have high antibody titers, while low titers predominate in immunologically resistant infected dogs or in exposed dogs with no parasite confirmation. Quantitative serology is recommended in clinically suspect dogs as high-titer antibodies titers may confirm the clinical diagnosis. In confirmed and treated dogs, renal function and inflammatory/immune response variables should be periodically monitored.