CD3-CD4-CD8 lymphocyte subpopulation

Mature T lymphocytes are defined by the expression of the markers CD3 and CD4 on helper lymphocytes or CD3 and CD8 on suppressor/cytotoxic T lymphocytes. The test involves the determination of the relative and absolute number of mature human T lymphocytes (CD3+) and their subpopulations - cytotoxic/supressor T lymphocytes (CD3+CD8+) and helper/inducer T lymphocytes (CD3+CD4+). The test is used to assess and monitor certain immunodeficiency syndromes, such as severe combined immunodeficiency (SCID) - a group of rare monogenic primary immunodeficiencies characterised by a lack of active peripheral T lymphocytes, resulting in severe respiratory tract infections. CD3-CD4-CD8 lymphocyte subpopulation acquired immunodeficiency syndrome (AIDS) and autoimmune diseases.