Immunoglobulin A

Immunoglobulin A (IgA) is a type of antibody that plays a key role in the immune system by defending the body's mucous membranes, such as those in the nose, throat, lungs, digestive tract, and other areas exposed to the environment. It helps prevent harmful germs like bacteria and viruses from attaching and entering the body’s tissues. IgA is primarily found in secretions like saliva, tears, mucus, and breast milk, providing localized protection and supporting immune defense at these surfaces, which are common entry points for infections.