THE ROLE OF SCHWANN CELLS IN THE PATHOLOGY OF THE HUMAN APPENDIX IN CHILDREN

Abstract

Objective: To compare the immunohistochemical (IHC) characteristics of appendices removed from children with acute appendicitis and chronic pain syndrome (CP) in the right lower quadrant of the abdomen (RLQA), as well as to define clinical and morphological correlations. Methods: The structure of fifty-one appendices of children aged 5-14 years who underwent appendectomy for chronic appendicitis/CP in the RLQA (24 patients, Group 1) and acute appendicitis (27 patients, Group 2) was assessed. Image analysis of histological sections stained with hematoxylin-eosin and immunohistochemically for S100 protein and proliferating cell nuclear antigen (PCNA) was performed. Results: Image analysis showed the presence of a significantly higher volume density (VD) and numerical density (ND) (p0.05) of immunoreactive cells when stained for S100 protein, as well as the ND of intramural ganglia (p0.05) against the background of minimal histological changes in the wall of the appendix in patients of Group 1 compared to Group 2. On the contrary, the ND of PCNA-immunoreactive cells was significantly higher in patients of Group 2 against the background of pronounced inflammatory changes in the appendix (p0.01). In the biopsy samples of the Group 1 patients, a significantly higher ND of the lymphoid nodule germinal centers was also noted (p0.05), while the ND of tingible body macrophages was higher in Group 2 patients (p0.001). These results demonstrate differences in neuroimmune parameters in the appendices in the two described nosologic groups and indicate the possible role of the appendiceal neural component as a prerequisite for developing CP in the RLQA in children. Keywords: Appendix, Schwann cell, S100 protein, PCNA, appendicitis, chronic abdominal syndrome.