Recombinant Human IgG

Immunoglobulin G (IgG) is a monomeric immunoglobulin synthesized and secreted by plasma B cells. It is the most abundant immunoglobulin and is approximately equally distributed in blood and in tissue liquids (1). IgG antibodies are predominately involved in the secondary antibody response (the main antibody involved in primary response is IgM) (2). Pro-inflammatory cytokines particularly IL-4 and IL-2 have a crucial role in activation of the IgG antibody response. IgG is the only isotype that can pass through the human placenta, thereby providing protection to the fetus in utero (3). In addition, residual IgG absorbed through the placenta provides the neonate with humoral immunity before its own immune system develops.