t cell deficiency t cell deficiency t cell deficiency is a deficiency of t cells, caused by decreased function of individual t cells, it causes an immunodeficiency of cell-mediated immunity. t cells normal function is to help with the human body's immunity, they are one of the two primary types of lymphocytes(the other being b cells). t cell deficiencyhuman t cellspecialtyimmunologysymptomseczematoustypesprimary or secondarydiagnostic methoddelayed hypersensitivity skin test, t cell counttreatmentbone marrow transplant, immunoglobulin replacement symptoms and signs presentations differ among causes, but t cell insufficiency generally manifests as unusually severe common viral infections (respiratory syncytial virus, rotavirus), diarrhea, and eczematous or erythrodermatous rashes. failure to thrive and cachexia are later signs of a t-cell deficiency. mechanism in terms of the normal mechanism of t cell we find that it is a type of white blood cell that has an important role in immunity, and is made from thymocytes. one sees in the partial disorder of t cells that happen due to cell signaling defects, are usually caused by hypomorphic gene defects. generally, (micro)deletion of 22q11.2 is the most often seen. pathogens of concern further information: intracellular pathogen the main pathogens of concern in t cell deficiencies are intracellular pathogens, including herpes simplex virus, mycobacterium and listeria. also, intracellular fungal infections are also more common and severe in t cell deficiencies. other intracellular pathogens of major concern in t cell deficiency are: mycobacterium avium intracellulare salmonella species rhodococcus equi pneumocystis jirovecii toxoplasma gondii cryptosporidium parvum leishmania species herpesviridae (herpes simplex, cytomegalovirus and varicella zoster) cryptococcus neoformans histoplasma capsulatum diagnosis the diagnosis of t cell deficiency can be ascertained in those individuals with this condition via the following: delayed hypersensitivity skin test t cell count detection via culture(infection) types primary or secondary lymphoma primary (or hereditary) immunodeficiencies of t cells include some that cause complete insufficiency of t cells, such as severe combined immunodeficiency (scid), omenn syndrome, and cartilage–hair hypoplasia. secondary causes are more common than primary ones. secondary (or acquired) causes are mainly: aids cancer chemotherapy lymphoma glucocorticoid therapy complete or partial deficiency complete insufficiency of t cell function can result from hereditary conditions (also called primary conditions) such as severe combined immunodeficiency (scid), omenn syndrome, and cartilage–hair hypoplasia. partial insufficiencies of t cell function include acquired immune deficiency syndrome (aids), and hereditary conditions such as digeorge syndrome (dgs), chromosomal breakage syndromes (cbss), and b-cell and t-cell combined disorders such as ataxia-telangiectasia (at) and wiskott–aldrich syndrome (was). treatment harvested bone marrow in preparation for transplant in terms of the management of t cell deficiency for those individuals with this condition the following can be applied: killed vaccines should be used(not live vaccines in t cell deficiency) bone marrow transplant immunoglobulin replacement antiviral therapy supplemental nutrition epidemiology in the u.s. this defect occurs in about 1 in 70,000, with the majority of cases presenting in early life. furthermore, scid has an incidence of approximately 1 in 66,000 in california.