IgG-mediated phagocytosis in regenerated splenic tissue

The risk of severe infections after splenectomy is well established. Operations such as auto-transplantation, splenic artery ligation or partial resection have been advocated for the retention or regeneration of splenic tissue following splenic trauma. The potential of such tissue to protect from infection is unclear. The ability of splenic tissue to phagocytose IgG opsonized syngeneic erythrocytes was measured in rats 6 months following splenectomy and splenic autotransplantation, splenic artery ligation, total or partial splenectomy, and compared with eusplenic controls. In eusplenic and partially splenectomized rats 71% of the label was cleared at 3 h, compared with approximately 50% in rats following total splenectomy, splenectomy and splenic autotransplantation or splenic artery ligation. The autotransplanted and the ligated splenic tissue cleared less than 10% compared with control spleen, but there was no difference between them when clearance was expressed as uptake per gram of tissue. Splenic autotransplants and ligated spleens were small and histologically abnormal, with an increase in the red pulp, significantly less white pulp and marginal zone, and the frequent absence of a central arteriole in the white pulp. The clearance of label was proportional to the amount of red pulp in the tissue, although the red pulp from the regenerated tissues was not as efficient at phagocytosis as control red pulp. The tissue which regenerated following autotransplantation or splenic artery ligation did not result in greater clearance of erythrocytes from the circulation than that which occurred in splenectomized rats.