Expression of CD3 and CD20 in Antistreptolysin-O Titer Seropositive and Seronegative Children with Chronic Tonsillitis.

Background: Chronic tonsillitis (CT) is a common inflammatory illness in children, and serum antistreptolysin O titer (ASOT) is a common investigation performed for these cases and considered a perfect sign for tonsillectomy.

Objective: To evaluate the expression of tonsillar T-and B-lymphocytes markers in relation to seropositive or seronegative ASOT in cases of CT.

Materials And Methods: Thirty children (15 males and 15 females) aged 6-10 years were divided equally into two groups: Group A seropositive ASOT (≥400 IU) and Group B seronegative ASOT (<400 IU). Both performed bilateral tonsillectomy. Specimens from the removed tonsils were taken and prepared for light microscopic examination and immunohistochemical evaluation of CD20 and CD3 expression.

Results: Seropositive ASOT group showed significant histopathologic changes in the form of hyperplasia of the stratified squamous nonkeratinized epithelium, Urgas's abscess, and severe lymphocytic infiltration. Immunohistochemical results of seropositive ASOT group showed marked expression of CD3 and CD20, while seronegative ASOT group showed mild expression of CD3 and CD20.

Conclusion: Seropositive ASOT CT, in addition to histopathological changes, is associated with significant increase in both B-lymphocytes (CD20 expression) and T-lymphocytes (CD3 expression) markers.