Concentration of lipocalin region of collagen XXVII alpha 1 in the serum of dogs with hemangiosarcoma.

BACKGROUND

Hemangiosarcoma (HSA) is a common malignancy of dogs with characteristic early, aggressive metastasis. Diagnosis of HSA is challenging because of lack of sensitive and specific diagnostic tests.

HYPOTHESIS

Specific proteins that are increased in serum of dogs with HSA might represent useful biomarkers of the disease.

ANIMALS

Thirty-four dogs with HSA and 42 healthy dogs from the Ontario Veterinary College Teaching Hospital.

METHODS

This case-control study compared serum proteins in dogs with HSA and healthy dogs. Proteins were separated by 2-dimensional difference gel electrophoresis and identified by liquid chromatography and tandem mass spectrometry.

RESULTS

Western blot analysis showed that serum collagen XXVII peptide concentration in serum of dogs with large metastatic HSA burdens (1,488, 231-3,754 DU; median, minimum-maximum); was, on average, 9.5-fold higher than in healthy dogs (156; 46-2,101 DU). While concentrations for dogs with osteosarcomas (678; 124-3,251 DU), lymphomas (423; 92-2,777 DU), carcinomas (1,022; 177-3,448 DU), and inflammatory disease were also increased, values were consistently lower than those for HSA. Receiver operating characteristic curves revealed an estimated area under the curve of 83% for HSA cases whereas areas for other neoplastic and nonneoplastic diseases were nondiscriminatory. Serum collagen XXVII peptide concentration before splenectomy (1,350; 1,156-1,929 DU) was reduced after tumor removal (529; 452-562 DU) and chemotherapy but increased in 2 dogs with tumor recurrence (511-945 DU; 493-650 DU).

CONCLUSIONS AND CLINICAL IMPORTANCE

Collagen XXVII peptide might be useful for diagnosis and monitoring of advanced HSA.