Inherited combined immunodeficiency affects both T lymphocytes and B lymphocytes. It is often fatal within the first year of life because there is no resistance to disease or infection. This is a desired part of treatment for disorders such as autoimmune disorders . It is used after organ transplantation to prevent transplant rejection . Malnutrition , particularly with lack of protein , can cause acquired immunodeficiency.
Many cancers can cause immunodeficiency.
Increasing age also reduces the effectiveness of the immune system. There is also reduced lymphocyte number and activity with increasing age. The symptoms vary with the specific disorder. Signs And Tests Persistent or recurrent infections or severe infection by microorganisms that do not usually cause severe infection, may be clues that an immunodeficiency disorder is present. Other tests may be indicated to confirm specific immunodeficiency disorders.