Highly active relapsing multiple sclerosis (MS)

Multiple sclerosis, or MS, is a long-term disease of the brain and spinal cord. The immune system, which normally fights germs, attacks myelin. Myelin is the protective coating around nerve fibers. When it is damaged, messages between the brain and body slow down or get blocked. The damaged areas show up on MRI scans as spots called lesions.

Most people are first diagnosed with relapsing-remitting MS. They have flare-ups of new or worse symptoms, called relapses, followed by times of partial or full recovery. “Highly active” means the disease keeps flaring or making new lesions even with treatment, or disability is building up quickly.

MS is an autoimmune disease, which means the body’s defenses turn on its own tissue. No one knows exactly what starts it. Researchers think it comes from a mix of genes and things in a person’s life and surroundings.

Epstein-Barr virus, the virus that causes mono, is the infection most consistently linked to MS. Smoking raises the risk, while sun exposure and higher vitamin D levels are linked to a lower risk. None of these explains why one particular person got MS.

MS is not passed down in a simple way. Common differences in or near hundreds of genes probably add to a person’s risk. Having a parent, brother or sister with MS raises the chance of getting it, but MS itself is not an inherited disorder.

Symptoms depend on where the damage is. Early signs can include vision problems, numbness or tingling, muscle weakness, dizziness, trouble with balance and bladder problems. MS can also cause fatigue, mood changes and problems with thinking or memory.

MS usually starts between ages 20 and 40 and is more common in women. When the disease stays active, damage can add up and cause lasting disability. Some people later move into a progressive phase, where problems slowly get worse with or without relapses.

MS care usually lasts for life. It includes regular neurology visits and MRI scans, rehabilitation, and help with fatigue, bladder problems, mood and mobility. MS organizations can help people find support for work, school and daily life.

A transplant is a major treatment. The chemotherapy, the return of the cells and early recovery usually mean about a month in the hospital. After an uncomplicated transplant, new treatment-related problems are rare after about six months. Risks include infections, bleeding, loss of fertility and other autoimmune problems later on. Deaths from the treatment have become much less common than in earlier years, but the risk is not zero.

Experts say aHSCT should be done only at experienced centers, with a neurologist and a transplant team working together. In the United States, NMDP reports that the American Society for Transplantation and Cellular Therapy (ASTCT) recommends considering own-cell transplant as “standard of care, clinical evidence available” for relapsing MS that stays active despite treatment.

No donor is needed. The transplant used for MS is autologous, which means it uses the person’s own blood-forming stem cells, usually collected from the bloodstream. There is no registry search and no need for a family match.

A transplant using cells from another person is not a standard MS treatment. European transplant guidance (EBMT, 2025) generally does not recommend an unrelated-donor transplant for MS, and newer cell therapies such as CAR-T are still being studied. Registry donors help patients with blood cancers and other conditions who need healthy blood-forming cells from someone else.