Nasal nitric oxide in atypical primary ciliary dyskinesia

Background:Atypical cases of primary ciliary dyskinesia (PCD) may present with minimal transmission electron microscopy (TEM) defects. The diagnostic role of nasal nitric oxide (nNO) levels was evaluated in those patients. Methods:Sixty-four children with recurrent pneumonia were studied with ciliary motion analysis, TEM, and nNO. Results:Investigations indicated PCD in 12 patients, secondary ciliary dyskinesia (SCD) in 50 patients, and normal results in 2 patients. In 4 of 50 children with SCD, atypical PCD was considered possible. The mean (± SD) nNO was 130 ± 46.95 parts per billion in children affected by PCD, 127.79 ± 68.58 parts per billion in atypical patients, and 760 ± 221 parts per billion in children with SCD. Three to 5 months later, the nNO level was 132.75 ± 55.76 parts per billion in children with atypical disease and 778.00 ± 197 parts per billion in children with SCD. Conclusion:Low levels of nNO may help to identify patients with atypical PCD.