salivary immunoglobulin A

An immunoglobulin present in saliva. Salivary immunoglobulin A may help protect the upper respiratory tract from infection. Very intense exercise is associated with a drop in salivary immunoglobulinA concentration, but the level usually returns to normal a few hours after the exercise has stopped. However, overtraining can prolong the effect, resulting in a chronic state of immunosuppression that makes the overtrained athlete particularly vulnerable to viral infections.