Immune complex phagocytosis of human peripheral blood polymorphonuclear leukocytes.

An increased percentage of intracellular immunoglobulin containing-polymorphonuclear (PMN) leukocytes was found in patients with elevated level of circulating immune complexes. A more pronounced increase of positive cells was observed when PMN leukocytes of normal controls or patients were incubated in the presence of serum derived from patients with an elevated level of circulating immune complexes. Sera from patients with a normal immune complex level did not cause such an increase. Since both autologous and allogeneic serum (with higher immune complex levels) increased the percentage of positive cells of patients with elevated circulating immune complex levels, it is not likely that a "saturated" state would occur in these patients.