Leucovorin (also called folinic acid) is a derivative of vitamin B9 being studied and used as a treatment to improve certain symptoms in some children with autism spectrum disorder (ASD). It is primarily used to address a condition called cerebral folate deficiency (CFD), where folate (vitamin B9) levels in the brain are abnormally low despite normal blood levels. This deficiency is often due to folate receptor autoantibodies that block folate transport into the brain, which can contribute to developmental problems in autism. Leucovorin works by bypassing the blocked folate receptor pathway, entering the brain through an alternative folate carrier to restore folate levels in the central nervous system. Clinical trials indicate that leucovorin can significantly improve language, communication, and cognitive abilities for a subset of children with autism, especially those positive for folate receptor autoantibodies. It is given in high doses, often up to 2 mg/kg per day, and has shown safety and efficacy in randomized controlled trials. While leucovorin is not a cure for autism overall, it represents an important therapeutic option for children with specific folate metabolism disruptions associated with autism symptoms.
Key Points about Leucovorin and Autism
- Leucovorin treats cerebral folate deficiency (CFD) by restoring brain folate levels.
- CFD occurs when folate receptor autoantibodies block folate entry into the brain.
- High-dose leucovorin is used to bypass this blockade through an alternate transport path.
- Clinical trials show improvements in speech, language, and core autism symptoms.
- It is most effective in children with ASD who test positive for folate receptor autoantibodies.
- Leucovorin requires a prescription and dosing is typically weight-based.
- It is not a cure but a promising treatment targeting a specific biological subset of autism.
This treatment has gained attention recently with regulatory moves to approve leucovorin calcium tablets for autism symptoms, highlighting its emerging role in autism therapeutics.