Human Fc receptor polymorphisms in relation to bacterial infection

Human IgG receptors are very heterogeneous. Currently there are three Fc gamma receptor classes specifying at least 12 receptor isoforms to be distinguished. On top of this complexity, Fc gamma receptors (FcgammaRs) differ between different individuals. Polymorphisms have been identified for two FcgammaR classes, representing allelic variation of the FcgammaRIIa (CD32), FcgammaRIIIa and FcgammaRIIIb (CD16). The FcgammaRIIa polymorphisms are now considered to be a heritable risk factor for infectious diseases and some manifestations of autoimmune disorders. A relevant role of the IIIb polymorphism in infectious disease has been suggested, though less convincingly. Detailed analysis of the exact contribution of each of these polymorphisms in relation to previously implicated risk factors for infectious or immunological disease should unravel the pathophysiological contribution of FcgammaR polymorphisms in the wide variety of factors now being investigated. The information obtained about the multiple genes that impact inflammatory responses of the host - and most likely in reaction to exogenous triggers and pathogens - is becoming overwhelming. The rapid development of molecular techniques makes it possible to determine the incidence of all these individual genetic polymorphisms. Although its relevance will be more difficult to ascertain, the information on all the different genes and their allelic variations involved in the host immune response will be very important for our understanding of infectious disease in modern times