Intrinsic factor antibodies means the proteins produced by the immune system that are associated with pernicious anemia. This laboratory test helps in identification of intrinsic factor antibody (IgG antibody) circulating in blood in human body. Intrinsic factor means protein in human body produced by a type of specialized cells that can be found in line the stomach wall called parietal cells. The deficiency of intrinsic factor can result in the malabsorption of vitamin B12 and subsequently anemia. Autoantibodies are also formed directly countering the parietal cells which identically results in inadequate intrinsic factor activity and vitamin B12 lacking.