Vitamin A Ineffective in Patients with Emphysema

Retinoids may provide little clinical benefit for patients with emphysema, according to a new study.

Researchers from the David Geffen School of Medicine at the University of California Los Angeles (UCLA, CA, USA) and other facilities enrolled 148 patients with moderate-to-severe chronic obstructive pulmonary disease (COPD)--with a primary component of emphysema--in a study called FORTE (feasibility of retinoids for the treatment of emphysema). The patients received all-trans retinoic acid (ATRA) at either a low or high dose, 13-cis retinoic acid (13-cRA), or placebo for six months followed by a three-month crossover period.

At the end of six months, no treatment was associated with an overall improvement in pulmonary function, computerized tomography (CT) density mask score, or health-related quality of life (HRQL). Retinoid-related side effects were common but generally mild. However, time- and dose-dependent changes in diffusing capacity, CT density mask score, and HRQL were observed in patients treated with ATRA, suggesting the possibility of exposure-related biologic activity that the researchers suggest warrants further investigation. The study was published in the November 2006 issue of Chest.

"Administration of ATRA and 13-cRA resulted in frequent, although usually minor, side effects and no overall improvement in pulmonary function or CT imaging. These results do not support the use of retinoids as a clinical treatment for emphysema at this time,” concluded lead author Michael D. Roth, M.D., and colleagues.

ATRA is a derivative of vitamin A and has similar side-effects (e.g. benign intracranial hypertension). ATRA's success in treating acute promyelocytic leukemia (APML) by causing the immature promyelocytes to differentiate to normal mature blood cells was a major breakthrough in the treatment of this type of leukemia.



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