Laboratory investigations
TNF-α
VITAMIN D DEFICIENCY
Routine investigations were done for all included children in the form of complete blood count (CBC) (Sysmex KX21N, Kobe, Japan). ESR (Westergren method) Coagulation profile (Stago, France), liver function, and kidney function (Cobas c 311, Roche, Germany).Measurement of serum 25(OH)D level using the enzyme-linked immunosorbent assay (ELISA) kit (Calbiotech, USA, California Cat# VD220B) according to the manufacturer's instructions. The detection range of the kit is 2.5–150 ng/ml. Each sample was run in duplicate and compared with a standard curve. The mean concentration was determined for each sample. Vitamin D deficiency was defined as 25(OH)D below 20 ng/ml, vitamin D insufficiency as 25(OH)D of 21–29 ng/ml, and normal 25(OH)D level as ≥ 30 ng/mlBlood samples were collected and centrifuged to separate serum from all groups. IL-2 (Elabscience, cat. No. E-El-H0099), TNF-α (Elabscience, cat. No. E-EL-H0109), IL-10 (Elabscience, Cat. No. E-El-H0103), and IL-4 (Elabscience, cat. No. E-El-H0101) were estimated using enzyme-linked immunosorbent assay (ELISA) technique and according to the manufacturer.Tonsillectomies were performed in the otolaryngology department of Al-Zahraa Hospital, Al-Azhar University, Cairo, Egypt, and outpatient clinics.