At one point, immunoglobulin G (IgG) was studied as a potential therapy for Alzheimer’s disease and the results were not what researchers had hoped to achieve. Michael Steinitz, from Hebrew University in Jerusalem, focused on  immunoglobulin M (IgM) as a treatment for Alzheimer’s disease, but the problem with IgM is that scientists did not believe it was possible for IgM to pass the blood-brain barrier because it is 5 times larger than IgG.

The blood-brain barrier keeps foreign substances out of the brain and is a gauntlet to researchers because it filters out many of the solutions researchers have devised for Alzheimer’s.

What surprised the researchers is that IgM passed through the blood-brain barrier despite its relatively large size. In studies with mice that have an animal version of Alzheimer’s disease, IgM was able to reverse learning problems. IgM grabs onto the amyloid beta protein in the brain and prevents it from changing into the toxic substance believed to cause Alzheimer’s disease.

It is a major thing that scientists have been trying to accomplish—getting antibodies into the brain in the right amount to treat illnesses and IgM does that! Further research is needed, but IgM could lead to a new approach in the fight against Alzheimer’s disease.