Pulmonary surfactant is a surface-active lipoprotein complex (phospholipoprotein) formed by type II alveolar cells. The proteins and lipids that make up the surfactant have both hydrophilic and hydrophobic regions.
Antibody deficiencies, also called immunoglobulin deficiency syndromes, are immune system disorders that are characterized by low or absent levels of immunoglobulin in the blood.Immunoglobulins (Ig) are antibodies that play an essential role in the body's immune system.he antibodies are present in the bloodstream or bound to the outer surfaces of B-cells or plasma cells. There are five classes of immunoglobulins: IgA, IgD, IgE, IgG, and IgM. Patients who have antibody deficiencies may have reduced or absent levels of one or more types of immunoglobulin.
An intrinsic factor antibody (IF antibody) test may be used to help determine the cause of a vitamin B12 deficiency and to confirm a diagnosis of pernicious anemia. Pernicious anemia is caused by vitamin B12 deficiency due to a lack of intrinsic factor. This condition occurs primarily when the body's immune system targets its own tissues and develops antibodies directed against the parietal cells and/or the intrinsic factor.