The non-specific stimulation of immunoglobulin secretion following specific stimulation of the immune system.

Immunization leads to an increase in serum immunoglobulin levels, but only a fraction of this increase is attributable to specific antibody. This report presents data showing that this increase in serum immunoglobulin levels can be correlated with an increase in the number of immunoglobulin-secreting cells. An absolute increase in the number of immunoglobulin-secreting cells occurred in every organ tested but was greatest in spleen and peripheral blood. Peyer's patches contained very few such cells. A comparison of cells secreting immunoglobulin with those containing surface immunoglobulin receptors indicated that there is a differential anatomical distribution of the two cells following antigenic challenge.