RT Journal Article SR Electronic T1 Increased nitric oxide in expired air in patients with Sjogren's syndrome. BHR study group. Bronchial hyperresponsiveness JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 739 OP 743 DO 10.1034/j.1399-3003.1999.13d07.x VO 13 IS 4 A1 D Ludviksdottir A1 C Janson A1 M Hogman A1 B Gudbjornsson A1 E Bjornsson A1 S Valtysdottir A1 H Hedenstrom A1 P Venge A1 G Boman YR 1999 UL http://erj.ersjournals.com/content/13/4/739.abstract AB Nitric oxide has an important role in the regulation of airway function and can have pro-inflammatory effects. Bronchial hyperresponsiveness (BHR) and respiratory symptoms are common in patients with Sjogren's syndrome (SS). The aim of this study was to determine whether patients with SS have an increased amount of exhaled NO and whether this NO correlates with respiratory symptoms and BHR. Exhaled NO was measured in 18 patients with SS and 13 normal subjects on three different occasions with intervals of at least 3 days using a chemiluminescence method. Airway responsiveness was assessed with methacholine provocation. Serum levels of myeloperoxidase (MPO), human neutrophil lipocalin (HNL), eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) were measured. Exhaled NO was significantly higher in patients with SS than in controls (147+/-82 versus 88+/-52 nL x min(-1); mean+/-SD; p=0.041). Exhaled NO was correlated with age (partial r=0.52, p=0.006) and serum HNL (partial r=0.46, p=0.014). There were no significant correlations between exhaled NO and respiratory symptoms, BHR or serum MPO, ECP or EPO. Disease duration was negatively associated with serum MPO (r=-0.47, p=0.043). In patients with SS, a positive correlation was found between symptom score and serum ECP (partial r=0.65, p=0.003) and EPO (partial r=0.62, p=0.004) and a negative correlation with age (partial r=-0.60, p=0.005). In conclusion, elevated levels of exhaled nitric oxide in patients with Sjogren's syndrome were demonstrated. The mechanism underlying this increase in exhaled nitric oxide in Sjogren's syndrome is not known.