The immunomorphological study with determination of the relative volume of lymph plasmocytic macrophage infiltration in the stroma of organs of experimental animals with purulent-septic process, caused by S. aureus, has been carried out. The experimental studies were performed on 30 mice of inbred lines C57Bl/6JSto. The experiments were carried out in accordance with the national “Ethical Principles and Guidelines for Experi- ments on Animals” which correspond to guidelines of “European Convention for the Protection of Vertebrate Ani- mals Used for Experimental and Other Scientific Purposes”. The immunomorphological study was carried out on paraffin sections with thickness of 5. 6 microns by means of Koons indirect method. The relative volumes of general clones of the immune cells were determined by using the net of G. G. Avtandilov in the fluorescent microscope. The number of cytokine producer cells was counted within sight x400. The study of immunomorphological state of the heart of experimental animals showed that the epicardium, which was characterized by slightly fuchsinophil stroma, was thickened by edema and eosinophilic fibrin overlays with focal-diffuse inflammatory infiltrate with dominating segmental leukocytes (CD18). There were lymphocytes (CD3, CD4, CD8, CD45RA), plasmocytes of IgM, IgG, macrophages (ED1) including polykariotic and also single colonies of S. aureus and producer cells IL-1, IL-6, TNF. Valval and parietal endocardium with weak fuchsinophil edematous stroma, with signs of fibrinoid swelling and focal necrosis surrounded by inflammatory infiltrates of lymphocytes, histiocytes and polykariotic macrophages, in the cytoplasm of which colonies of bacteria were found. In the liver of animals of the experimental group, frank hyperemia of the central veins and adjacent capillaries was observed. The stroma was edematous; in the portal tracts the focal-diffuse infiltration by lymphocytes (CD3, CD4, CD8, CD45RA), histiocytes with numerous macrophages (ED1) and isolated neutrophils (CD18), which were characterized by marked Brashe reaction in the cytoplasm, was detected with spreading to the interlobular connec- tive tissue. The intravascular fixation of CD18 neutrophils to the surface was marked. In the spleen T-lymphocytes (CD3, CD4, CD8) were located mainly in the periarterial ares of follicles. B-lym- phocytes (CD45RA) were found in the light centers of the follicles and also in the red pulp. In all parts of the spleen macrophages, monocytes, producer cells of IgG and IgM, and interleukins IL-1, IL- 6, TNF, IL-2RL, IL- 4 were ob- served. The degree of macrophage reaction, plasmatization reaction and also relative volume of producer cells of cytokines was significantly higher of those ones in the comparison group. In the microscopic examination of lymph nodes, T-lymphocytes (CD3, CD4, CD8) were located mainly in the paracortical area of the cortex and in the medulla as well. B-lymphocytes (CD45RA) were found in the cortex and medulla regions. Macrophages, monocytes (ED1), producer cells of IgG and IgM were observed in all areas of the lymph node. In the case of purulent-septic process caused by S. aureus, the data of the immunomorphological studies in- dicate the development of severe septic state, which is proved by means of marked dystrophic and degenerative changes of the stroma and parenchyma, extensive interstitial inflammation with involvement of parenchymal struc- tures, alternative and productive processes in the vessels of the heart, liver and kidney. In addition, the intravascular fixation CD18 neutrophils to the surface was marked. Acute hyperplasia both of T- and B areas against the back- ground of marked macrophage reaction, enhanced by plasmatization and significant activation of proinflammatory interleukins, was detected in the peripheral immune organs (spleen and lymph nodes) Such a regularity of the local immune response is also found in the interstitium of the heart, kidneys and liver, where marked macrophage response, enhanced plasmatization and activated cytokine proinflammatory system are observed.
