Vitiligo forecast: Future treatments to target immune system

June 1, 2008

Future vitiligo treatments will largely target the immune system as well as promote the growth of melanocytes, according to the director of the Vitiligo and Pigmentation Institute of Southern California.

Key Points

"The new research suggests that vitiligo is a T cell-mediated disease," says Dr. Pearl Grimes, M.D., clinical professor in the department of dermatology at the University of California, Los Angeles.

"It may very well be that vitiligo is a T cell-mediated disease driven by cytotoxic CD8+ lymphocytes that migrate into the skin to destroy melanocytes," Dr. Grimes tells Dermatology Times.

Other research suggests that oxidative stress that generates an increase in free radicals in the skin can play a role in the destruction of melanocytes.

Dr. Grimes cites a study that found patients who were treated with phototherapy using narrow-band ultraviolet B (UVB) and systemic antioxidants experienced a better response than those who were subject to monotherapy with narrow-band UVB.

Antioxidant therapies can take the form of high-potency compopunds that contain vitamins and other substances, such as C, E, B complex, folic acid, alpha lipoic acid and coenzyme Q10, Dr. Grimes says.

Epidemiological and natural history data indicate that, on average, 20 percent to 30 percent of patients with vitiligo will have another family member who suffers from the condition.

Environmental factors

Indeed, genetics and the environment can trigger the disease.

"There are a host of phenolic compounds that are ubiquitous in the environment," Dr. Grimes says.

Candidate genes, such as the NALP1 gene located on chromosome 17p13 and the autoimmune susceptibility (AIS) 1 gene, are being investigated and show highly significant linkage, suggesting that they are major susceptibility loci in Caucasians. Most studies suggest a polygenic multifactorial inheritance, Dr. Grimes says.

The principle in treating vitiligo is to stabilize the patient, as well as repigment the skin as much as possible.

Clinicians are turning to calcineurin inhibitors like tacrolimus to manage the condition, despite the agents not being approved for the treatment of vitiligo.

Patients with limited involvement may be candidates for targeted light treatment such as the excimer laser, while patients with more disseminated disease would be candidates for a combination therapy consisting of topical steroids and phototherapy in the form of narrow-band UVB.

"You want to ideally minimize any scarring associated with the procedure or cobblestoning associated with the procedure," she says.

Patients with vitiligo often have diminished quality of life and experience low self-esteem because of their appearance, Dr. Grimes says. "We live in a society that is driven by aesthetics."