Splenic autotransplantation and the immune system. Adequate testing required for evaluation of effect

The risk of severe infections after splenectomy, even after many years, is now well established. In attempts to prevent these infections, spleen-saving techniques, including autotransplantation of spleen fragments, have been performed, when possible in combination with vaccination. The problem in autotransplantation is the evaluation of functional activity. The results of the tests used until now often do not seem to correlate very well with the risk of developing an overwhelming postsplenectomy infection (OPSI). This may be related to the fact that the tests used evaluate general functions, and not specific spleen-related functions, such as the capacity to mount a primary response to certain polysaccharide antigens present in the capsule of bacteria known to cause OPSI. In this review, the significance of the spleen in the human immune system is discussed and the effects of splenectomy are described, including the precautions that can be taken to diminish the risk of postsplenectomy infections and sepsis. It appears that postsplenectomy vaccination is more successful when recently developed protein-conjugated polysaccharide vaccines are used. Because the present testing of the function of spleen autotransplants is not adequate, we suggest that new tests should be developed, employing appropriate polysaccharide antigens.