Leukemia drug kills cancerous T-cells in blood but spares immunity

Doctors at Brigham and Women’s Hospital in Boston, Mass. have found that a leukemia drug previously thought harmful to patients’ immune systems actually spares normal immunity. Low-dose Campath does not kill all T-cells and B-cells in the body, but only those that enter the bloodstream. In those with Leukemic cutaneous T-cell lymphoma, this means eliminating cancer cells while maintaining the ability to fight off infections. Researchers discovered that patients taking Campath were not getting sick because there are protective T-cells in the tissue of several areas of the body.  "We used to believe that most T-cells responsible for protecting against infection were in the bloodstream. But we now realize that highly protective T-cells also inhabit tissues such as the skin, lungs and gastrointestinal tract. It is these tissue resident T-cells that are critical in protecting us from infection on a day-to-day basis,” explains Rachael Clark, an associate dermatologist who worked on the study.