In a study published in the journal Science Translational Medicine, the researchers detail how low doses of the drug interleukin-2 (IL-2) can alleviate chronic graft-versus-host disease (GVHD), a debilitating condition that often occurs in patients who have received a stem cell transplant. In patients with chronic GVHD, donor immune cells launch an attack on healthy tissue. IL-2 is so versatile at restoring immune system balance, the researchers found, that it may eventually become a primary treatment for chronic GVHD and may even hold promise for treating autoimmune diseases, such as rheumatoid arthritis and lupus, which result from a misguided immune system attack on otherwise healthy organs and tissues.

"We found that low doses of IL-2 work through several independent mechanisms to restrain the aggressive immune response that can lead to chronic GVHD," said John Koreth, MBBS, DPhil, who co-led the study with Dana-Farber colleagues Ken-ichi Matsuoka, MD, PhD, and Haesook Kim, PhD. "The effect of low-dose IL-2 is so robust that it may have application for a variety of conditions associated with an overactive immune system."

The new study grew out of a much-discussed paper from 2011. In a phase I clinical trial, Koreth and his colleagues found that half of patients with chronic GVHD experienced a marked improvement in symptoms after receiving daily, low-dose injections of IL-2. The finding may well have caused double takes across the cancer research world. "Because of its ability to stimulate the immune system, IL-2 was previously approved by the Food and Drug Administration for the treatment of advanced melanoma and renal cell cancer," said Robert Soiffer, MD, of Dana-Farber, a co-author of the new study. "Since IL-2 is an immune system stimulant – revving up the immune system's attack on tissue – it might initially have been expected to exacerbate GVHD, not relieve it."

Health Canal