Multiple Sclerosis (MS) is an autoimmune disease that affects the central nervous system by attacking the myelin sheath – the protective layer that surrounds nerve cells. People can live with MS for many years, but some individuals have a more severe and disabling progression than others.
Women, those with other autoimmune diseases, and those who have a family member with MS, are all at increased risk. Living in colder climates also appears to be a factor (think Vitamin D deficiency). Early signs and symptoms include muscle weakness, difficulty with balance, fatigue, vision problems, and numbness and tingling. Unfortunately, MS is the most common neurological condition (of its kind) among young adults. It is also one of the most costly medical conditions to treat. In fact, cost is one of the reasons this recent finding on the drug Minocycline is turning heads.
What is Minocycline?
Minocycline is a common antibiotic in the tetracycline class, often used to treat acne or bacterial infections. The drug has been around for 40 years and despite being contraindicated in pregnancy and children, is generally considered safe with only mild side effects reported. While minocycline works to help prevent the growth and spread of bacteria, it also appears to have anti-inflammatory and neuroprotective properties as well as immune-modulating abilities. Immune-modulating activities include preventing leukocytes from crossing the blood-brain barrier and inhibiting microglia. These additional mechanisms may explain the findings of a study published this year in the New England Journal of Medicine, which explored the effects of minocycline on the subsequent development of MS following a clinically isolated syndrome of MS (also referred to as a first demyelinating event).
Dr. Luanne Metz, lead researcher on this study, reported it to be the first phase 3 trial showing benefits of an antibiotic in the treatment of MS. Participants were divided into a treatment group and a placebo group and followed for (up to) 24 months following a clinically isolated syndrome (CIS). Only those who had experienced a CIS within 180 days were chosen. They also needed to have at least two T2 hyperintense brain lesions present. Using cranial MRI and the McDonald criteria of 2005, participants were assessed at baseline and at regular intervals throughout the trial to determine whether or not their symptoms had progressed to full-blown MS. The treatment group was given 100 mg of minocycline twice daily. After 6 months, participants in the treatment group had a 27.4% less chance of progressing to a full-blown MS diagnosis. Results became insignificant by 24 months, but researchers attributed this to small sample size, as some participants had dropped out by that point in the study. These benefits appear to be similar to those found in other already approved MS medications. This is significant considering that minocycline would be easier to prescribe than other MS meds, allowing patient to get treatment more quickly. It is also more cost-effective.
Side Effects & Other Considerations
Since the sample size in this study was small, more research is needed. While the results are encouraging, it may take several more years to get minocycline approved for use in MS. It is also worth noting that some participants reported mild, but undesirable side effects including digestive disturbances, rash, dizziness, fungal infections, and teeth discoloration. In recent years, the effects of antibiotics on gut bacteria has gained much attention. Research has shown that one round of minocycline can disturb beneficial gut bacteria for 1 month, but does appear to repopulate in healthy individuals. However, it is also worth noting that the drug was used for an extended period of time in this study, so there is no way of knowing at this point what effects it might have on the microbiome when used in this manner. This is an important consideration since we now know that much of the immune system is housed in the gut. Nevertheless, these findings will at the very least give more insight into the mechanisms involved in the pathogenesis of a disease that afflicts so many people in the prime of their lives and will hopefully will lead to better and more accessible treatments.