Lymphocyte Subtypes in Local Inflammatory Response: A Comparative Analysis of Simple and Complicated Appendicitis

<i>Background and Objectives:</i> The immunological function of the appendix, as part of the gut-associated lymphoid tissue, and its immunological importance in developing and maintaining the intestinal immune system are not yet clearly understood. Therefore, we sought some answers by analyzing the lymphocyte population in appendiceal specimens and inflammatory markers from peripheral blood. <i>Materials and Methods:</i> After histopathological examination of appendiceal specimens, immunohistochemical analysis of lymphocyte subtypes CD8, CD19, and CD20 in appendiceal specimens was performed, and a panel of commercially available mouse monoclonal antibodies was used to detect immunopositivity. hematological and biochemical parameters were analyzed from peripheral blood samples, and results were correlated with immunohistochemical findings. <i>Results:</i> The study included 100 patients: n = 20 in the control group, where the appendix was removed during some other abdominal surgical procedure, n = 35 patients with simple appendicitis in Group A, and n = 45 with complicated appendicitis in Group B. There were 65.0% male patients, and the mean age at surgery was 10.8 ± 4.0 years. CD19 B-lymphocytes were significantly more present in the appendiceal specimens of patients with complicated appendicitis (<i>p</i> = 0.014 and <i>p</i> = 0.007), and CD8 T-lymphocytes in patients with simple appendicitis (<i>p</i> < 0.001). Also, there were significantly fewer CD8 T-lymphocytes in patients with complications (<i>p</i> = 0.024). <i>Conclusions:</i> The number of CD8 T-lymphocytes is increased in simple appendicitis and is considerably lower in patients who develop postoperative complications. CD19 lymphocytes were more present in complicated appendicitis.