Immunodeficiency Disease and Malignancy

Patients with immunodeficiency have a markedly increased incidence of malignancy. Defects in cellular and circulating immunity common to these patients are caused by various pathophysiological mechanisms. Some have developmental disorders in their ability to synthesize lymphocytes and immunoglobulins, the effectors of immunity. Others have defects in antigen processing and recognition, an abnormality of the afferent limb of immunity. A third group of patients with increased malignancy has immunodeficiency due to shortened survival of effectors of immunity. Ataxia-telangiectasia, Wiskott-Aldrich syndrome, and intestinal lymphangiectasia are discussed as examples of these three categories of immunodeficiency. The association of malignancy with these immunologic disorders supports the concept that the immune system normally plays an important role in control of malignant disease, by surveillance and elimination of exogenous oncogenic viruses and tumor cells that possess new surface antigens and perhaps in preventing activation of latent viral genomes within the reticuloendothelial system.