Immunological aspects in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive motor neuron death, leading to muscle atrophy, paralysis, and death usually within 3 to 5 years after diagnosis. Most cases are sporadic, with still undefined etiopathogenesis. Both the innate and adaptive immune systems are involved in ALS, with special participation of T lymphocytes and microglia. Inflammation plays a dual role in the disease, protective and T regulatory cell rich in the early stages and deleterious as disease progresses. Attempts to modulate immune/inflammatory system response are reported in the literature, and while beneficial effects are achieved in ALS animal models, results of most clinical trials have been disappointing. The impaired blood-brain barrier is an important feature in the pathogenesis of ALS and likely affects the immune system response. The present review describes the role of the immune system in ALS pathogenesis and the tight coupling of immunity and central nervous system barrier function.