immunology allergic disorders
Leukocyte Adhesion Deficiency
Introduction
Leukocyte adhesion deficiency results from an adhesion molecule defect that causes granulocyte and lymphocyte dysfunction and recurrent soft-tissue infections. (See also Overview of Immunodeficiency Disorders and Leukocyte adhesion deficiency is a Primary Immunodeficiencies that involves Leukocyte adhesion deficiency is caused by deficiency of adhesive glycoproteins (eg, integrins, selectins) on the surfaces of white blood cells (WBCs); these glycoproteins facilitate cellular interactions, cell attachment to blood vessel walls, cell movement, and interaction with complement fragments. Deficiencies impair the ability of granulocytes (and lymphocytes) to migrate out of the intravascular compartment, to engage in cytotoxic reactions, and to phagocytose bacteria. Severity of disease correlates with degree of deficiency. Three different types of syndromes have been identified: Leukocyte adhesion deficiency 1: Deficient or defective beta-2 integrin family Leukocyte adhesion deficiency 2: Absent fucosylated carbohydrate ligands for selectins Leukocyte adhesion deficiency 3: Defective activation of all beta integrins (1, 2, and 3) Type 1 results from mutations in the integrin beta-2 gene (ITGB2), encoding CD18 beta-2 integrins. Type 2 results from mutations in the glucose diphosphate (GDP)-fucose transporter gene. Type 3 is caused by mutations in theFERMT3gene (11q13.1), which encodes kindlin-3 in hematopoietic cells. 