title: Clinical disorders associated with T cell subset abnormalities.
abstract: Monoclonal antibodies have been used to enumerate T cell subsets in many different diseases, only a portion of which have been reviewed here. These studies have increased our understanding of T cell immunoregulation in these diseases. In the future, other diseases will similarly be analyzed regarding their immunoregulatory T cell defects. That different investigators have reported conflicting results regarding the same disease is not unexpected. Different patients at different stages of the same disease may not always have the same T cell abnormalities. Patient subgroups with different etiologies and prognoses may well have different T cell subsets. Many of the diseases described in this chapter with decreased T suppressor-cytotoxic cell number and function are associated with autoimmune or autocytotoxic disorders. The lack of T cell suppressor activity may result in a lack of regulation of both autoantibody production and autocytotoxic activity. Increased T cell suppressor-cytotoxic cell numbers have been found in certain viral infections, such as EBV, CMV, and HBV. Other viral agents may produce similar changes in T cell subsets as the immune system attempts to clear and combat these agents. These virus-induced changes in the immune system may be responsible for the transient immunosuppression observed in several of these illnesses. Decreased T helper cell number has been observed in transient hypogammaglobulinemia of infancy. This common pediatric problem seems to result from an immature or delayed development of T helper cell activity. The disease is a transient one, and return to normal gammaglobulin synthesis occurs with the return of normal T helper cell numbers. Increased T helper cell number seems to occur in diseases with excessive immune activity, such as sarcoidosis and granuloma annulare. This excessive activity of T helper cells may be responsible for the disease manifestations. In the future, one can expect more studies regarding T cell subset abnormalities in a wide variety of diseases. Cure and therapy of many diseases may be monitored in the future by T cell subset abnormalities. This will be a most exciting area in the future for pediatrics.
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D001327:Autoimmune Diseases / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000276:immunology; D004700:Endocrine System Diseases / Q000276:immunology; D006801:Humans; D007154:Immune System Diseases / Q000276:immunology*; D007136:Immunoglobulins / Q000378:metabolism; D007223:Infant; D007231:Infant, Newborn; D007958:Leukocyte Count; D009103:Multiple Sclerosis / Q000276:immunology; D009157:Myasthenia Gravis / Q000276:immunology; D009369:Neoplasms / Q000276:immunology; D012216:Rheumatic Diseases / Q000276:immunology; D012871:Skin Diseases / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D007136:Immunoglobulins