Production of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor by carcinomas in a dog and a cat with paraneoplastic leukocytosis.

A dog with a pulmonary papillary carcinoma and a cat with a dermal tubular adenocarcinoma had profound paraneoplastic neutrophilic leukocytosis with no clinically detectable inflammatory foci. To investigate the mechanism of the leukocytosis, oligonucleotide primers were designed from the cDNA sequences of granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) of dogs. Reverse transcription polymerase chain reaction was performed on tumor tissues, and specific amplification of G-CSF and GM-CSF was obtained with the tumor RNA in the dog. The tumor RNA in the cat demonstrated specific amplification of G-CSF but not GM-CSF. These findings are consistent with the production of G-CSF and/or GM-CSF by neoplasms as a mechanism for paraneoplastic leukocytosis in small animals.