926TO STUDY ADENOID HYPERTROPHY AFFECTS SCREENING FOR PRIMARY CILIARY DYSKINESIA USING NASAL NITRIC OXIDEIn patients with primary ciliary dyskinesia (PCD), the release of nitric oxide (NO) is extremely low by epithelia of the nasopharynx and sinuses. Measurement of nasal NO (nNO) is recommended as a screening test for PCD. The study was approved by the Ethics Committee of SLIMS in Pondicherry. An informed consent was obtained from all parents and children older than 12?yr. Participants were recruited from children and adolescents indicated for adenoidectomy at Department of Otorhinolaryngology. The study aimed to evaluate if adenoids affects nNO and may deteriorate the performance of the test. In 48 nonallergic patients between 5 and 18 years of age with chronic symptoms of nasal obstruction and indications for adenoidectomy, the measurements of nNO by chemiluminescence analyser and nasal patency by active anterior rhinomanometry were performed both before and after adenoidectomy. Adenoidal tissue size was graded during surgery under general anaesthesia using transoral endoscopy. Patients were stratified into groups with adenoids grades 1, 2 and 3 (<1/3, 1/3–2/3 and?>?2/3 of the choana and post-nasal space covered by adenoids). Before adenoidectomy, the median of nNO decreased with the increasing grade of adenoids (920, 663, and 491?ppb, P?77?nL/min. nNO and FnNO are reduced in nonallergic children with obstructive adenoids. Adenoid hypertrophy can potentially cause a false positive result of the test for PCDdrvrvkk@gmail.comResearch942018Adenoidectomy; Adenoids; Nasal nitric oxide; Primary ciliary dyskinesia; Rhinomanometry, rhinosinusitis; allergic rhinitis; childrenPalli Vedita, Boyapalli Sudheer ChandraAssistant Professor of Paediatrics, Sri Lakshmi Narayana Institute of Medical Sciences, Pondichery, India,Assistant Professor of ENT, Sri Lakshmi Narayana Institute of Medical Sciences, Pondichery, India