A HISTOLOGICAL PICTURE OF BONE TISSUE IN CHILDREN WITH HEMATOGENOUS OSTEOMYELITIS

. Currently, there is a limited number of works devoted to the comprehensive study of specific features of surgical treatment of patients with acute hematogenous osteomyelitis (AHO) which includes histological and immune histochemical (IHC) tests of the bone marrow at different periods of the disease. In this regard, the purpose of our work was to make the morphological analyses of bone tissue and bone marrow fragments in children with hematogenous osteomyelitis. Material and methods. In 2013- 2016, in the department of purulent surgery of the city hospital in Stavropol, there were 64 children with AHO of long tubular bones aged from 3 to 17. 47 boys (73.4%), 17 girls (26.6%). The lesion was located in : femur - 25 (39.1%) children; tibia - 24 (37.5%); fibula - 6 (9.4%); humerus - 5 (7.8%); ulna - 3 (4.7%); radius - 1 (1.5%). All children had urgent osteoperforation of the affected bone. Bone slices were taken for histological examination and bone marrow fragments for IHC examination. Tissue sections were stained with hematoxylin and eosin, pikrofuksin by Van Gieson, aniline blue by Mallory, trichrome by Masson. IHC examination was done using a standard protocol with anti-CD3, CD4, CD8 monoclonal antibodies. Results. In AHO, the histological examination has revealed fragments of spongy bone tissue, elements of yellow and red bone marrow with diffuse abundant leukocyte infiltration, hemorrhages in bone marrow spaces, microcore fractures and necrotic foci in the trabeculae, vast areas of pronounced autolytic resorption of the bone tissue. Accumulation of CD3+cells (2-4) is seen in the inflammation infiltrate areas located along the fistula passage. The expression of T-lymphocyte-helper markers, or CD4 +, is moderate in chronic osteomyelitis (2 points). The expression of T-lymphocyte suppressor marker, or CD8 +, is moderate in chronic osteomyelitis (2 points). Immunoreactive material - coarse granular, cytoplasmic, disseminated (3 points). CD8 + lymphocytes are seen in clusters of cells in the amount from 4-6 to 20-30. In addition, to our mind, the picture of structural location of lymphocytes, is not completed, since cells are moving to the zone of interaction of CD8 + lymphocytes. Conclusions. Thus, minor subpopulations of lymphocytes, in particular double-positive T cells, or CD3 + / CD4 + / CD8 + lymphocytes, or highly differentiated memory cells are registered in the red bone marrow of patients with AHO. It characterizes the immunoregulatory index of the organism and may indicate the presence of autoimmune component in the immune response. If even separate CD8 + lymphocytes are revealed in the bone marrow of children with hematogenous osteomyelitis at IHC, it may indicate a risk of complications.