Hookworm Treatment for Relapsing Multiple Sclerosis: A Randomized Double-Blinded Placebo-Controlled Trial.

Area of Science:

• Immunology
• Neuroscience
• Infectious Disease

Background:

• Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system.
• Gut worms (helminths) are known to modulate immune responses, potentially offering therapeutic benefits for autoimmune conditions.
• Previous research suggests helminth infections may protect against MS, but controlled trials are lacking.

Purpose of the Study:

• To evaluate the efficacy of hookworm (Necator americanus) treatment in reducing magnetic resonance imaging (MRI) activity in relapsing-MS patients.
• To assess the impact of hookworm treatment on T regulatory cell populations in individuals with relapsing MS.

Main Methods:

• A 9-month, double-blind, randomized, placebo-controlled trial involving 71 patients with relapsing MS.
• Participants received either 25 Necator americanus larvae or a placebo transcutaneously.
• MRI scans and peripheral blood analysis for regulatory T cells (CD4+CD25highCD127neg) were conducted monthly.

Main Results:

• No significant difference in cumulative MRI lesions between hookworm and placebo groups, potentially due to low disease activity.
• A significant increase in regulatory T cells was observed in the hookworm group compared to placebo (P=.01).
• Hookworm treatment was safe and well-tolerated, with no serious adverse events. Relapse rates were lower in the hookworm group (14.3%) versus placebo (30.6%).

Conclusions:

• Hookworm treatment is a safe and viable option for patients with relapsing MS.
• The observed increase in regulatory T cells indicates an immunobiological effect of hookworm infection.
• Helminthic interventions may induce immunoregulatory changes relevant to managing MS disease activity.