Interferon Therapy for Keloid Scars
Interferons are proteins produced by immune cells. They have been used to treat a number of diseases, primarily viral infections (e.g., hepatitis) and as an anti-tumor drug in cancers (e.g., skin cancer and Kaposi sarcoma). After it was discovered (in 1989) that interferons decreased collagen production in the lab, researchers theorized it could help prevent and treat keloids and hypertrophic scars in patients.32
How do they work?
Interferons are known to inhibit collagen and fibrotic scar tissue production.5 One of the ways it does this is by stimulating activity of an enzyme that breaks down collagen.32
Evidence of Benefit
Results from clinical studies are mixed. Some show that injections of interferon alfa-2b are more effective in both reducing keloid size and preventing recurrence after surgical removal than corticosteroid injections.17 An injection of interferon where the surgical wound is stitched also appears to prevent recurrences in some cases.3 And when administered at higher dosage levels after carbon dioxide laser removal of keloids, less than 35% of keloids reappeared after three years after treatment.3
Others, including a prospective clinical trial, demonstrated the opposite. Injections of the corticosteroid triamcinolone after surgical excision of keloids showed a 15% recurrence rate compared to over 50% recurrence in an interferon alfa-2b treated group of patients, and no benefit was seen with injection alone compared to placebo.32 Lower doses used of interferon alpha-2b used by itself and a higher-dosage administered during surgery and then once after surgery failed to show improvement or block reappearance of the keloid.3
Additionally, the cost may be prohibitive and the treatments are painful and can have severe flu-like symptom side effects, so researchers are looking into topical applications of the immunomodulator.2,5