COMPUTER-ASSISTED IMAGE ANALYSIS OF INFLAMMATORY CELLS IN GINGIVAL TISSUE OF ORTHODONTIC PATIENTS

OBJECTIVE: The immunohistochemical characteristics of the inflammatory infiltrate in the gingiva of patients with titanium and/or nickel allergic sensitization have not been completely understood and investigated. The aim was to analyze the immunohistochemical profile of inflammatory infiltrate in the gingival tissue of patients undergoing orthodontic treatment and to compare it to patients’ titanium and/or nickel allergy status. MATERIALS AND METHODS: A total of 250 patients undergoing orthodontic treatment were invited to participate and 235 accepted (67% female). Patch test was performed on the allergens: nickel sulfate, titanium, titanium dioxide, titanium oxalate, titanium nitride, and petrolatum as control. Patients with gingival hyperplasia were subjected to initial periodontal therapy. In patients with persisting gingival enlargement after initial periodontal therapy, external gingivectomy was performed. Sample consisted of 44 subjects, 22 had allergic sensitization on titanium and/or nickel and 22 of them were used as control. Immunohistochemical analysis was performed on 44 formalin fixed and paraffin embedded gingival samples using antibodies against CD1a, CD3, CD4, CD8, CD20 and CD68 molecule. Computer assisted image analysis was used to evaluate the number of positive cells in gingival tissue for each immunohistochemical marker. RESULTS: Immunohistochemical analyzes showed that sensitized gingiva had slightly more Langerhans cells and helper T-lymphocytes and fewer T- lymphocytes, cytotoxic T-lymphocytes, macrophages and plasma cells than non-sensitized ones, but the differences were statistically significant only for macrophages with moderate effect size (82.8 vs. 133.9 ; p=0.041 ; r=0.308). No significant differences were noticed when analyzed separately by gender and separately by the type of metal to which the subject was sensitized. CONCLUSION: Immunohistochemical analyzes show that sensitized gingiva has slightly more Langerhans cells and helper T- lymphocytes and fewer T-lymphocytes, cytotoxic T- lymphocytes, macrophages, and plasma cells than non-sensitized ones.