Alopecia areata is a disease characterized by the loss of hair from some or all areas of the body. This condition originates from an abnormal activity of T-cells, immune cells that start infiltrating into hair follicles and damaging them.

Raphael Clynes, Columbia University, New York, USA, and colleagues discovered that alopecia can be treated using pharmacological inhibitors of Janus kinases (JAK), a family of tyrosine kinases. The researchers demonstrated that FDA-approved JAK inhibitors such as ruxolitinib prevent the pathological infiltration of T-cells into hair follicles. As a consequence, when orally administered to three patients suffering from alopecia, ruxolitinib induced a nearly complete hair regrowth within five months of treatment.

JAK inhibitors may thus be useful tools to treat alopecia.

• Alopecia areata is driven by cytotoxic T lymphocytes and is reversed by JAK inhibition,
  Luzhou Xing, Zhenpeng Dai, Ali Jabbari, Jane E. Cerise, Claire A. Higgins, Weijuan Gong, Annemieke de Jong, Sivan Harel, Gina M. DeStefano, Lisa Rothman, Pallavi Singh, Lynn Petukhova, Julian Mackay-Wiggan, Angela M. Christiano, Raphael Clynes,
  Nat. Med. 2014.
  DOI: 10.1038/nm.3645