A patient with cerebellar problems and spider angiomas is diagnosed with a combined T-cell and B-cell deficiency known as ataxia- telangiectasia. In addition to a defect in this patient's DNA repair enzymes, which immunoglobulin is the primary antibody in saliva, tears, and intestinal and genital secretions, and is also deficient in this illness?
High-Yield Explanation
IgA antibody is involved in local immunity at the level of the mucous membrane. It also arises early in disease, is short lived, and will disappear similarly as IgM.