Delayed hypersensitivity reactions in guinea-pigs using cotton pellets; demonstration of macrophage migration inhibition activity in the cell free exudate

Assessment of immune cells and function of the residual spleen after subtotal splenectomy due to splenomegaly in cirrhotic patients

Background

The spleen is thought to be central in regulating the immune system, a metabolic asset involved in endocrine function. Overwhelming postsplenectomy infection leads to a mortality rate of up to 50%. However, there is still controversy on performing subtotal splenectomy as treatment of splenomegaly due to portal hypertension in cirrhotic patients. In the present study, immunocytes and the indexes of splenic size, hemodynamics, hematology and immunology in the residual spleen were analyzed to support subtotal splenectomy due to splenomegaly.

Results

In residual spleen, T lymphocytes mainly were focal aggregation in the periarterial lymphatic sheath. While B lymphocytes densely distributed in splenic corpuscle. In red pulp, macrophages were equally distributed in the xsplenic cord and adhered to the wall of splenic sinus with high density. The number of unit area T and B lymphocytes of splenic corpuscle and marginal zone as well as macrophages of red pulp were obviously increased in the residual spleen, while the number of macrophages didn’t be changed among the three groups in white pulp. While there were some beneficial changes (i.e., Counts of platelet and leucocyte as well as serum proportion of CD3+ T cells, CD4+ T cells, CD8+ T cells were increased markedly; serum levels of M-CSF and GM-CSF were decreased significantly; The proportion of granulocyte, erythrocyte, megakaryocyte in bone marrow were changed obviously; But serum IgA, IgM, IgG, Tuftsin level, there was no significant difference; splenic artery flow volume, portal venous diameter and portal venous flow volume, a significant difference was observed in residual spleen) in the clinical indices.

Conclusion

After subtotal splenectomy with splenomegaly due to portal hypertension in cirrhotic patients, the number of unit area T and B lymphocytes, and MØ in red pulp of residual spleen increased significantly. However, whether increase of T, B lymphocytes and MØs in residual splenic tissue can enhance the immune function of the spleen, still need further research to confirm.

Postnatal development of the splenic white pulp in the golden hamster Mesocricetus auratus. I. The periarterial lymphoid sheath (PALS)

The histological organization of the periarterial lymphoid sheath (PALS) was studied during the postnatal life of the golden hamster Mesocricetus auratus with special interest in the cell components occurring in each of their regions. Our results suggest a role of the cell components defining the splenic microenvironment at each developmental stage in governing the developmental process. This process can be temporarily and histologically divide into three stages: 1. At birth, a few lymphocytes and lymphoblasts surrounding the central artery define primitive PALS. 2. A second period is determined on the 2nd day by the appearance of a marginal sinus which bounds the two splenic compartments, white and red pulp. The PALS increases circumferentially around the central artery defined by the pattern of reticular cells and fibres. 3. Between the 4th and 10th days, the PALS reaches its definitive organization, except for the absence of primary and secondary lymphoid follicles, defining an inner and outer region. The marginal zone appears on the 6th day.

Accumulation of T cells and local anti-PPD antibody production in lymphokine-mediated chronic peritoneal inflammation in the guinea pig

The role of lymphokines in chornic peritoneal inflammation in the guinea pig has been investigated. A model of chronic inflammation was used in which a large intraperitoneal accumulation of macrophages and lymphocytes occurred, following repeated local injection of PPD into FCA-immunised animals. Activity attributable to the lymphokine, MIF could be demonstrated in chronic peritoneal exudate fractions even after several weeks of continuous stimulation. Characterisation of the lymphoid infiltrates revealed a large predominance of T cells. Very high percentages but low absolute numbers of T lymphocytes were also found in chronic peritoneal exudates of non-preimmunised, continuously stimulated guinea pigs. Ectopic lymphoid foci were found only in the peritoneal lining tissue of the preimmunised animals and were shown to contain many anti-PPD antibody producing cells. These lymphoid foci may have been induced by the continuous local generation of lymphokines. Their presence suggests that significant local, specific antibody production is particularly likely to occur in chornic inflammation with a delayed hypersensitivity component.