BETHESDA, MD (Reuters Health) Mar 28 - A drug known for both its antidepressive and anti-inflammatory properties appears to be a promising treatment for autoimmune diseases, especially in patients who are also depressed, Dr. Roland Martin said Tuesday at a conference on mind-body medicine, held here at the National Institutes of Health.
Dr. Martin, acting chief of the cellular immunology section at the National Institute of Neurological Disorders and Stroke, said he has been working with rolipram to see if it would be useful in the treatment of multiple sclerosis, irritable bowel syndrome, and other autoimmune diseases in which some patients also exhibit psychiatric disorders.
"It is well-known that depression and the rate of suicide are elevated in many autoimmune diseases," Dr. Martin said. "This is a promising treatment approach for hyperactivity of the T-cell system and depression."
Rolipram appears to work by inhibiting the expression of phosphodiesterase-4 (PDE-4), an enzyme that is crucial to both the brain and the lymph system. In the brain, PDE enzymes regulate the degradation of cyclic adenosine monophosphate (cAMP), and "they are the only mechanism by which cAMP can be degraded," Dr. Martin said. "Although several PDE enzymes are present in the brain, PDE-4 is most abundant."
In the immune system, PDE-4 works to modulate the T-cell receptor signal, Dr. Martin continued. "So these molecules are very important in tuning the response of our immune system and brain to external stimuli." As a result, a drug that inhibits this particular enzyme can affect both brain and immune system function.
Although it is possible that patients with autoimmune diseases have "situational depression," researchers think there is more to it than that because not all autoimmune patients become depressed, Dr. Martin told Reuters Health.
"Only a certain percentage of individuals have depression," he said. "It is poorly understood why depression levels are high in autoimmune diseases; is it the chronic stress of the disease, or a genetic change in the regulation of glucocorticoids?"
Dr. Martin said that
although rolipram has been tested as an antidepressant, no one has used
it to treat patients with autoimmune disease. He and his colleagues are
planning to begin the first tests of rolipram in multiple sclerosis patients
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