Biclonal gammopathy associated with immunoglobulin A in a dog with multiple myeloma

Manifestations of systemic disease in the retina and fundus of cats and dogs

The fundus is unique in that it is the only part of the body that allows for a noninvasive and uninterrupted view of vasculature and nervous tissue. Utilization of this can be a powerful tool in uncovering salient incidental findings which point to underlying systemic diseases, and for monitoring response to therapy. Retinal venules and arterioles allow the clinician to assess changes in vascular color, diameter, outline, and tortuosity. The retina and optic nerve may exhibit changes associated with increased or decreased thickness, inflammatory infiltrates, hemorrhages, and detachments. While some retinal manifestations of systemic disease may be nonspecific, others are pathognomonic, and may be the presenting sign for a systemic illness. The examination of the fundus is an essential part of the comprehensive physical examination. Systemic diseases which may present with retinal abnormalities include a variety of disease classifications, as represented by the DAMNIT-V acronym, for Degenerative/Developmental, Anomalous, Metabolic, Neoplastic, Nutritional, Inflammatory (Infectious/Immune-mediated/ischemic), Toxic, Traumatic and Vascular. This review details systemic illnesses or syndromes that have been reported to manifest in the fundus of companion animals and discusses key aspects in differentiating their underlying cause. Normal variations in retinal anatomy and morphology are also considered.

Multiple myeloma, a quintessential malignant disease of aging: a geroscience perspective on pathogenesis and treatment

Multiple myeloma (MM) is an incurable plasma cell malignancy, which is predominantly a disease of older adults (the median age at diagnosis is 70 years). The slow progression from asymptomatic stages and the late-onset of MM suggest fundamental differences compared to many other hematopoietic system-related malignancies. The concept discussed in this review is that age-related changes at the level of terminally differentiated plasma cells act as the main risk factors for the development of MM. Epigenetic and genetic changes that characterize both MM development and normal aging are highlighted. The relationships between cellular aging processes, genetic mosaicism in plasma cells, and risk for MM and the stochastic processes contributing to clonal selection and expansion of mutated plasma cells are investigated. In line with the DNA damage accumulation theory of aging, in this review, the evolution of monoclonal gammopathy to symptomatic MM is considered. Therapeutic consequences of age-dependent comorbidities that lead to frailty and have fundamental influence on treatment outcome are described. The importance of considering geriatric states when planning the life-long treatment course of an elderly MM patient in order to achieve maximal therapeutic benefit is emphasized.

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.

Hypoglobulinemia in a dog with disseminated plasma cell neoplasia: Case report and review of the diagnostic criteria

This is the first reported case of hypoglobulinemia in a dog with disseminated plasma cell neoplasia. A 6-year-old male intact Rottweiler was referred to the U-Vet Animal Hospital (Werribee, Vic, Australia) for weight loss, hyporexia, lethargy, vomiting, and soft stools. Examination of a buffy coat preparation and splenic and liver aspirates revealed a monomorphic population of plasmacytoid cells, and the same cells comprised approximately 90% of bone marrow samples submitted for cytologic and histologic evaluation. Biochemistry revealed a hypoglobulinemia, and the presence of an M-protein was not supported by serum and urine protein electrophoresis or serum immunofixation. Immunohistochemistry demonstrated strong nuclear labeling for MUM-1.

Retrospective evaluation of the use of the International Myeloma Working Group response criteria in dogs with secretory multiple myeloma

BACKGROUND

Current recommendations for monitoring disease progression and response to treatment in humans with multiple myeloma include evaluation of serum paraprotein (M-protein) concentration. Densitometry, species-specific radial immunodiffusion (RID) and ELISA methods can be used to quantify M-proteins.

OBJECTIVE

Retrospectively evaluate use of the International Myeloma Working Group (IMWG) response criteria for humans in dogs with multiple myeloma.

ANIMALS

Sixteen dogs with a diagnosis of multiple myeloma, M-protein documented by serum protein electrophoresis (SPE) and immunofixation (IF) in an initial sample and subsequent electrophoretic evaluation of serial samples.

METHODS

Retrospectively, densitometric M-proteins, RID and globulins were measured and characterized according to IMWG criteria. Available clinical history was reviewed. Overall survival time (OST) was calculated from initial electrophoretic evaluation to death or last contact.

RESULTS

All cases received some form of nonstandardized chemotherapy. Complete response (CR), a lack of detectable M-protein by SPE and IF, was documented in 1 case. Median survival was longer for dogs that attained ≥90% densitometric M-protein reduction (630 days) than for those that did not attain at least 50% reduction in densitometric M-protein (284 days; log rank P = .006). Five dogs were defined as having progressive disease (M-protein increase of >25% and at least 0.5 g/dL from nadir), which correlated with concurrent or subsequent clinical deterioration. Response criteria categorized by serum globulins or RID was not correlated with OST or clinical findings.

CONCLUSIONS AND CLINICAL IMPORTANCE

Densitometric M-protein characterized using IMWG response criteria correlated with OST and clinical findings. Densitometric M-protein detection should be used to monitor dogs with multiple myeloma.

Identification of canine IgG and its subclasses, IgG1, IgG2, IgG3 and IgG4, by immunofixation and commercially available antisera

Immunofixation is a diagnostic and research tool used for characterizing the electrophoretic location of immunoglobulin fractions in serum and urine. Commercially available polyclonal antisera which discriminate two IgG subclasses (IgG1 and IgG2) are available and commonly used. More recently, four IgG subclasses have been defined in the dog based on cDNA data. Archived serum from 16 dogs with naturally occurring monoclonal or biclonal gammopathies were characterized using routine serum protein electrophoresis, routine immunofixation and LCMS/MS as 3 IgA, 3 IgM, 2 IgG2, 7 IgG3 and 2 IgG4 heavy chain predominant cases. Immunofixation reactivity of a panel of commercially available antisera to these cases was characterized. The anti-human IgG antisera was the only tested antisera which bound all canine IgG restricted bands without also labelling IgA or IgM heavy chains or light chains. The tested polyclonal antisera labeled as reacting with canine IgG2 bound canine IgG2, IgG3, IgA and IgM and may label IgG1. The tested polyclonal antisera labeled as reacting with canine IgG1 bound the canine IgG4 bands but not those identified as IgA, IgM, IgG2 or IgG3 and likely did not bind IgG1. This data suggests that commercially available polyclonal IgG1 antisera (Bethyl A40 - 120A and Bio-Rad AHP947) can be used to positively but possibly not selectively identify canine IgG4 by immunofixation.

Validation and method comparison of the use of densitometry to quantify monoclonal proteins in canine sera

BACKGROUND

Densitometric quantitation using serum protein electrophoresis (SPE) is used to monitor monoclonal proteins (M-proteins) in human patients but has not been validated in the dog. Serum globulin concentrations, species-specific radial immunodiffusion (RID), and ELISAs are currently used in veterinary medicine.

OBJECTIVE

We aimed to compare four methods that quantify M-proteins using densitometry and biuret protein (dM-protein) measurements. We also validated the best performing method and compared it with the RID and ELISA methods for measuring canine serum M-protein.

METHOD

Serum from six normal dogs and 83 serum samples from 46 dogs with confirmed monoclonal gammopathies were used. A spike and recovery experiment with purified monoclonal IgG and IgM, inter-run and intra-run variability, linearity under dilution, and lower limit of detection were performed. Results of commercial canine RID and ELISA kits for total class-specific immunoglobulin were compared with dM-proteins.

RESULTS

The corrected perpendicular drop gating method had <20% error for IgG/γ-globulin and IgM/β-globulin M-protein quantifications. Linearity (r > .99), intra-run CV (1.1%-2.3%), and inter-run CVs (2.0%-3.5%) were acceptable. Correlation between the RID and densitometry results ranged from r = .25 to r = .88, depending on the class. The RID result was greater than that of the biuret total protein in 26/63 (41%) IgA cases. A panel of IgG, IgA, and IgM RIDs failed to correctly identify an IgM paraproteinemia in 6/6 (100%) cases. Densitometry was not comparable with any other tested method.

CONCLUSION

Densitometric quantitation is a valid technique for measuring M-proteins in the β- and γ-globulin regions. Immunotyping via RID using the tested kit does not appear to detect IgM. Densitometry is recommended for measuring M-proteins in canine patients.

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.

Application of native agarose gel electrophoresis of serum proteins in veterinary diagnostics

Electrophoretic techniques, used to separate mixtures of electrically charged particles, are widely used in science. One of these techniques, native protein electrophoresis in an agarose gel, is applied in human and veterinary medicine. Changes in the proportions of individual protein fractions correspond to significant changes in the physiology of the body. Although the pattern obtained by electrophoretic separation rarely indicates a specific disease, it provides valuable information for the differential diagnosis. Decades of research on the types of patterns obtained in the case of particular diseases have led to the accumulation of substantial knowledge. The paper presents the available information on this topic. Serum protein electrophoresis is recommended in cases of increased levels of total protein in order to reveal the nature of the process. The basic information which can be obtained from electrophoretic separation includes the immune status of the organism. Both increased antigenic stimulation and immunodeficiency are clearly visible in electropherograms. Moreover, the level of heterogeneity of the corresponding protein fractions can help to distinguish between infectious diseases and cancer - multiple myeloma - the latter producing a homogeneous immunoglobulin fraction. Analysis of other protein fractions helps to detect or confirm an ongoing inflammatory process and provides information regarding liver function. Even when the concentration of total protein is within the reference range, this analysis can be recommended as a basic laboratory test.

Bimodal immunoglobulin A gammopathy in a cat with feline myeloma-related disorders

A 10-year-old female spayed mixed breed cat with a subcutaneous mass on the right hind limb was revealed with bimodal monoclonal gammopathy composed of IgA by immunoelectrophoresis and immunofixation. Approximately 1 month after referral, the cat died due to renal failure. Postmortem immunohistopathologic evaluation of the subcutaneous mass revealed neoplastic cell proliferation of plasma cells and giant myeloma cells. Neoplastic cells were also present in the liver and spleen. These results led to the diagnosis of a rare case of feline myeloma-related disorders with extramedullary plasmacytoma infiltrating in multiple locations. This report emphasizes the necessity to accumulate cases with similar clinicopathologic findings in the future.

Clinical pathology of Greyhounds and other sighthounds

Owing to the development of Greyhounds as racing sighthounds, these dogs have acquired unique physiologic adaptations that distinguish them from other breeds. Reference intervals for many analytes in retired racing Greyhounds (RRGs) differ from those of other breeds; most of the hematologic differences have also been described in other sighthounds. In this review, we provide a survey of the literature on clinical pathology of Greyhounds and other sighthounds and results of laboratory testing, including analysis of CBCs, biochemical profiles, coagulation tests, and blood gases, in RRGs at The Ohio State University. Major clinicopathologic differences in this breed include higher RBC mass, creatinine concentration, glomerular filtration rate, activities of hepatic enzymes, and concentration of cardiac troponin, as well as lower WBC, neutrophil, and platelet counts, thromboelastographic values, and concentrations of serum haptoglobin, total globulins, and T4.

Monoclonal gammopathy associated with multiple myeloma and visceral leishmaniasis in the dog: a comparison of two cases

The term monoclonal gammopathy (MG) suggests the presence of clonal immunoglobulins in blood serum that are recognized as narrow spikes in the beta and/or gamma region of the electrophoretic pattern of serum. In the dog, MG is rare and is associated with a heterogeneous group of diseases that include multiple myeloma (the most common source of MG) as well as infectious and chronic inflammatory diseases such as Leishmaniasis. In this paper, two cases of MG are described: the first case is associated with multiple myeloma of monoclonal component type IgA/lambda, with the latter rare in dogs, and the second case involves MG that developed 3 years after an initial diagnosis of Leishmaniasis.

First cases of animal diseases published since 2000. 1. Dogs

In this first article of a series of papers listing first case reports of animal diseases published since 2000, the following 19 cases of dog diseases are discussed: Blastomycotic granuloma involving the cranial vena cava. Congenital myocardial hamartoma. Discospondylitis: three cases caused respectively by Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus epidermidis. Dystrophin deficient muscular dystrophy in a Labrador Retriever. Emphysematous prostatitis. Erythema multiforme major caused by a Parvovirus infection of keratinocytes. Hemochromatosis due to repeated blood transfusions. Intraspinal synovial cyst. Juvenile nephropathy in the Collie and the Irish Wolfhound. Primary cerebellar cortical degeneration (abiotrophy) in a Scottish terrier. Primary pulmonary artery chondrosarcoma. Renal dysplasia in a Bull Mastiff. Rhabdomyosarcoma (botryoid sarcoma) of the urinary bladder in a Maltese. Spinal mast cell tumor. Spongiform degeneration of the white matter in the central nervous system of Australian Cattle dog. Systemic pasteurellosis caused by Pasteurella canis. Thymic hemorrhage caused by dicumarol intoxication. Undimerized biclonal gammopathy with a single heavy chain class IgA in a dog with multiple myeloma. After a short introduction, the bibliographical data and the abstract of the author(s) and mostly some additional information derived from the article are given. The article will be regularly updated adding overlooked as well as new first reports.