In humans the spleen functions in host defense as a filter and site for phagocytic clearance
of the bloodstream. The spleen serves an essential role in this phagocytic clearance if the
host has deficient concentrations of opsonizing antibodies. The spleen also produces
antibody, and splenic function is required for the host to mount an early IgM response. There
is evidence from experiments using animals that the spleen is important in regulating
secondary antibody response and in certain aspects of cell-mediated immunity. However …