Secretory Immunoglobulins

Abstract

A Number of reports in the older literature have suggested the existence of the local or regional immunity of a tissue that is not dependent on serum antibody.¹ However, the concept of a more or less distinct secretory immune system developed relatively recently,² primarily as a result of studies in man indicating that the immunoglobulin content of certain nonvascular fluids is quite different from that of serum. Most striking is the observation that immunoglobulin A (IgA), which represents a relatively small fraction (10 to 15 per cent) of the serum immunoglobulins, is the predominant species in most external secretions — . . .