Folate receptor autoantibodies are antibodies produced by the immune system that target folate receptor alpha in the body. Folate receptors are proteins located on the surface of cells and are responsible for facilitating the transport and uptake of folate (vitamin B9) into cells. When the immune system malfunctions and produces autoantibodies, they can mistakenly target these folate receptors.
The presence of autoantibodies to the folate receptor alpha can have several implications:
- Interference with Folate Uptake: Autoantibodies may interfere with the normal function of folate receptors, disrupting the cellular uptake of folate. This interference can lead to reduced levels of folate inside cells, affecting processes that depend on this vitamin.
- Potential Folate Deficiency: The disruption of folate uptake by autoantibodies can contribute to a state of folate deficiency. Folate deficiency can have various health consequences, including anemia, neurological issues, complications during pregnancy, autism spectrum disorders, and cerebral folate deficiency syndrome.
It is important to screen for folate receptor autoantibodies as they have the potential to compromise proper folate transport. Folate is an essential nutrient for various cellular functions, including DNA synthesis and repair. It is particularly important during periods of rapid cell division and growth, such as during pregnancy and infancy. Additionally, folate is crucial for normal neurological function. This vitamin is involved in the synthesis of neurotransmitters (chemical messengers in the brain) and supports overall brain health.
Interestingly, a large number of children with autism spectrum disorder have tested positive for folate receptor autoantibodies. This would suggest that in such cases not enough folate is being delivered into the brain and across the choroid plexus, ultimately affecting neurological function.
One emerging therapeutic strategy involves administering active folates, such as folinic acid, to help improve folate availability to the neurons. Folinic acid is a type of folate, also known as vitamin B9. Folates, in general, are types of Vitamin B9 and are necessary for many of our basic systems in the body to function properly. The most commonly known form of folate, folic acid, is an oxidized form, and is found in prenatal vitamins, over-the-counter vitamins and is readily supplied in some of the foods that we eat (breads, cereals, pasta, rice) via mandatory fortification. Because it is in an oxidized form, it requires several steps to be converted into a biological useable form. Folinic acid, also known as leucovorin in some instances, is one of the active forms of folate that can be readily used by the body without the need for conversion and does not require the same enzymatic conversion to become bioactive. This makes folinic acid a more direct and readily available source of folate. In the case with those that have folate receptor autoantibodies, folinic acid can enter the brain via a different channel (reduced folate carrier) and work around the blocked folate receptor alpha.
This approach has been well-documented through various studies. For example, in a 2016 publication by Frye et al. which shows results of a double-blinded placebo-controlled study, the response to folinic acid was several fold better in children with ASD who had autoantibodies to the folate receptor alpha, compared to children who were negative for the antibodies. Additional studies have evidenced similar findings. In many cases, children with ASD that have tested positive for folate receptor autoantibodies have improved with folinic acid. As with any medical situation, a physician’s assessment and guidance is absolutely necessary.
Folate receptor autoantibodies may be screened using the FRAT® test. Please consult your medical provider. It is important for healthcare professionals to be aware of the presence of folate receptor autoantibodies in certain individuals, as this knowledge can be relevant for managing and addressing health conditions associated with folate deficiency.