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 para-neoplastic 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.