IGG RECEPTOR POLYMORPHISMS - RISK-FACTORS FOR DISEASE

Two groups of receptors for immunoglobulin G (Fc gamma R) can be disti nguished. Endothelial cells and placental syncytiotrophoblasts express an MHC class I-like Fc gamma R important for regulation of IgG half-l ife and IgG transport, respectively. Fc gamma R expressed on leukocyte s constitute a heterogeneous family of membrane bound and soluble prot eins. The various Fc gamma R (sub) classes of this family differ in li gand affinity and specificity, which is determined by primary structur e, glycosylation, association with signaling subunits, and environment al factors (such as serine proteases). The finding that polymorphisms of Fc gamma RIIa. Fc gamma RIIIa, and Fc gamma RIIIb critically affect interaction with antibodies has prompted analysis in patients which p rovided tantalizing evidence for the relevance of Fc gamma R polymorph isms as risk factors for a number of infectious and autoimmune disease s.