Open AccessSpurious laboratory results associated with immunoglobulin M gammopathy in a dog with multiple myeloma
Author(s) -
Loane Samantha C.,
Castillo Daniel A.,
Peschard AnneLorraine D. M.,
Hall Harriet R.,
Kortum Andre J.
Publication year - 2022
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.16540
Subject(s) - medicine , paraproteinemia , azotemia , serum protein electrophoresis , pathology , multiple myeloma , plasma cell dyscrasia , serology , gastroenterology , immunology , antibody , monoclonal , monoclonal antibody , renal function , immunoglobulin light chain
An 11 year old female‐neutered Labrador presented for facial swelling. Clinicopathological abnormalities included hyperglobulinemia, azotemia, hypercalcemia, nonregenerative anemia, thrombocytopenia, and spurious hypoglycemia. Normoglycemia was subsequently confirmed using a cage‐side analyzer (AlphaTRAK, Zoetis, UK). Serum and urine protein electrophoresis documented monoclonal (immunoglobulin M) gammopathy with Bence‐Jones proteinuria. Computed tomography imaging revealed a monostotic osteolytic bone‐lesion, and bone marrow cytology and histopathology documented plasmacytosis with multiple myeloma oncogene 1 / interferon regulatory factor 4 positivity, consistent with multiple myeloma. Infectious disease testing initially indicated seropositivity for Leishmania , Borrelia , and Anaplasma spp.; however, Leishmania PCR (splenic and bone marrow aspirates), and paired serological titers for Borrelia and Anaplasma were negative. Consequently, initial serological results were considered to be false positive because of paraproteinemia‐associated assay interference. Chemotherapy (prednisolone and melphalan combination therapy) was initiated, but the dog was euthanased 30 days later because of the development of pericardial effusion. This is a report of spurious serological (and other laboratory) results occurring secondary to monoclonal gammopathy in a dog.