The drug is azathioprine, an immunosuppressive agent that is well tolerated, easy to administer and monitor, and has been used for many years in the treatment of transplant rejections and autoimmune diseases. Azathioprine reduces relapse rates in MS patients, but its effects on the frequency and accumulation of new brain inflammatory lesions has not been studied in MS, according to background information in the article. MS is a disease of the central nervous system, marked by numbness, weakness, loss of muscle coordination, and problems with vision, speech, and bladder control.
Luca Massacesi, M.D., and colleagues at the University of Florence, Italy, conducted an open-label treatment study to evaluate the effect of azathioprine therapy on new brain lesion suppression in MS. They used magnetic resonance imaging (MRI) to evaluate brain lesions of 14 patients with relapse-remitting MS (RRMS) of short duration. RRMS is a form of the disease characterized by relapses, when new symptoms can appear and old ones resurface or worsen, followed by periods of remission, when the person fully or partially recovers from the deficits acquired during the relapse. The patients were evaluated for six months before and six months during treatment with azathioprine, and new lesions were evaluated during the same periods and after an additional six months.
"The results of this study show, for the first time, that the immunosuppressive agent azathioprine suppresses new brain lesions evaluated using MRI in patients with RRMS," the authors report.
"Indeed, the treatment induces remarkable new brain lesion reduction, stable for 12 months," they write. "This activity was obtained at doses that can be well tolerated and that are associated with low circulating lymphocyte numbers."
Adverse events were observed in six patients, mainly at the beginning of the evaluation period, but they were transient or reversed after dose reduction and no patient interrupted therapy. Neurologic disability was stable, and the relapse rate decreased consistently with the new brain lesion rate.
"If considered in the context of previous clinical trials, the present study indicates that azathioprine may represent an alternative to immunomodulatory medications specifically approved for RRMS," the authors conclude.
(Arch Neurol. 2005;62:1843-1847. Available pre-embargo to the media at www.jamamedia.org.) Editor's Note: This study was supported by the Multiple Sclerosis Project of the Italian Istituto Superiore di Sanità and by the Florence University Magnetic Resonance Imaging Centre.
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