The impact of splenectomy on antibody response in the porcine model

Some controversy exists regarding the antibody response after splenectomy and spleen preserving operations. In a porcine model the specific IgG antibody response to tetanus toxoid and type 6B pneumococcal polysaccharide was studied in 10 animals with splenectomy, 11 animals with splenic resection, 10 animals with splenic autotransplantation and 10 sham operated control animals. The operative groups were divided in two subgroups, receiving either the immuno adjuvant MTP-PE or the vehicle alone. Specific antibodies were determined by ELISA. Immunization with tetanus toxoid led to slightly lower peak IgG levels in splenectomized animals, but this was statistically not significant as compared to controls. In addition, the distribution of responders (78%) was not influenced by type of operation. Type 6B-pneumococcal polysaccharide proved to be a weak immunogen (19% responders). Splenectomy or spleen preserving surgery had no impact on the proportion of responders and peak IgG antibody titers of responders to this antigen. Additional administration of MTP-PE did not significantly increase the proportion of responders and had no impact on peak IgG antibody levels to tetanus toxoid and type 6B pneumococcal polysaccharide. These results show in contrast to previous studies in man, that under controlled conditions in the porcine model serum antibody responses to T-cell dependent and T-cell independent antigens are only slightly decreased by splenectomy. In addition, no effects of spleen preserving operations on antibody response are observed, and there is no change after concomitant administration of a muramyl peptide.