Sarcoids—those unsightly tumors on horses’ skin—seem to have some things in common with human cervical cancer: Researchers have known for years that both diseases are related to a papilloma virus, but researchers from Switzerland recently showed that, like cervical cancer, sarcoid tumors appear to be affected by the number of “Tregs” present.

T-regulatory cells, or Tregs, are special white blood cells known as lymphocytes that play a central role in regulating immune responses. In cervical cancer patients, the higher the Treg count, the poorer the prognosis.

Results from the new Swiss study reveal that high Treg counts in equine sarcoid patients are present in sarcoids' microenvironment, explained Kathrin Mählmann, DrMedVet, of the Swiss Equine Medicine Institute, Agroscope, and Vetsuisse Faculty of the University of Bern. Mählmann presented her work at the 2014 Swiss Equine Research Day held April 10 in Avenches.

Whereas human cervical cancer is caused by the human papillomavirus, equine sarcoids are caused by the bovine papillomavirus. In 2011 medical researchers discovered the link between Tregs and cervical cancer prognosis, Mählmann said. In follow-up studies scientists observed an increase in Tregs at elevated malignancy and reduced Tregs in patients with milder lesions and spontaneous regression