New findings suggest a group of hormones may reduce progressive multiple sclerosis symptoms. The authors evaluated estriol and estradiol as possible treatment protocols through a study using a virus to mimic progressive MS.

MS is believed to occur when the immune system attacks the protective coating of the nerve fibers that transmit electrical impulses throughout the body. The disease occurs more often in women, and those in northern latitudes. About 100,000 of the people in the U.S. with MS have a progressive form of the disease, with symptoms that worsen continuously or after periods of remission. In addition, the progressive form is more prevalent among Black patients. Symptoms include fatigue, numbness or tingling, bladder and bowel problems, and cognitive issues; but difficulty walking and balancing are the most common symptoms — and these are more pronounced in the progressive form of the disease. 

While women are more likely than men to develop MS, once they have the disease and become pregnant, they tend to go into remission. According to Texas A&M University Health Science Center researchers, that’s because during pregnancy — and especially in the third trimester — estradiol and estriol levels are elevated. Even women with MS who are on oral contraceptives experience fewer symptoms and have fewer relapses, so they evaluated how these hormones affect the myelin sheath.

Estrogen is a group of hormones that primarily affect sex drive and reproductive development, especially for women. Estradiol is more potent than estriol and is used for hormone replacement therapy in postmenopausal women. Estriol, on the other hand, is used off-label for a variety of conditions and is FDA-approved only for treating urinary incontinence in dogs.

The researchers found both types of estrogen decreased inflammation in the spinal cord, but only estradiol significantly decreased the damage to the myelin sheath. The researchers believe this could aid in the development of therapeutic interventions for people with progressive MS.

The study was published in the Journal of Neuroimmunology.