THU0366 Blood Gases in Familial Mediterranean Fever: Correlations with Markers of Endothelial Dysfunction and Inflammation
Authors: A. Sargsyan
Journal: Annals of the Rheumatic Diseases (2014)

<h3>Background</h3> Familial Mediterranean Fever (FMF) is an autosomal recessive disease characterized by recurrent inflammatory febrile attacks of peritonitis, pleuritis and arthritis. Vasculitis, pulmonary hemorrhage, infarction, or infiltrates<sup>1</sup>, diffuse opacities and hilar adenopathy<sup>2</sup>, pulmonary hypertension due to amyloidosis<sup>3</sup> may be associated or developed in a course of the disease. However these complications have been reported only rarely. <h3>Objectives</h3> To evaluate the respiratory involvement and pulmonary consequences in FMF we measured blood gases, nitric oxide (NO), endothelin (ET-1), C-reactive protein (CRP) and serum amyloid-A (SAA) in 102 FMF patients with respiratory complaints during attack-free period. <h3>Methods</h3> FMF patients were divided into two groups, with and without amyloidosis. Oxygen tension (PO2), carbon dioxide tension (PCO2) and oxygen saturation (O<sub>2</sub>Sat) were measured in capillary and venous blood. Simultaneously serum NO, plasma ET-1, CRP and SAA were determined. Student9s t-test and Pearson correlation analysis were used. <h3>Results</h3> Blood gases values (mean ± SD) were within normal ranges in patient group without amyloidosis (n=53), and were slightly decreased in amyloidosis patients group (n=49) (PO<sub>2</sub> 82.2±9.73 mm Hg, PCO<sub>2</sub> 39.4±3.83 mm Hg, O<sub>2</sub>Sat 94.6±3.8% vs. PO<sub>2</sub> 74.5±12.13 mm Hg, t=3,529, PCO<sub>2</sub> 35.1±5.2 mm Hg, t=4.69, O<sub>2</sub>Sat 88.8±12.4%, t=3.14 P&lt;0.00001). In the group of patients without amyloidosis O<sub>2</sub>Sat was positively correlated with NO and negatively with ET-1 levels (r=0.271, p=0.05 and r=-0.570, p=0.000), PO<sub>2</sub> showed negative correlation with ET-1 level (r=-0.479, p=0.479), and both PO<sub>2</sub> and O<sub>2</sub>Sat were negatively correlated with CRP (r=-0.492, p=0.000; r=-0.534, p=0.000, respectively). In the group of patients with amyloidosis there was no correlation between blood gases values and NO, whereas PCO<sub>2</sub> was negatively correlated with ET-1 levels (r=-0.371, p=0,009) and CRP (r=-0.302, p=0.035). There was no correlation between blood gases and SAA in both groups. <h3>Conclusions</h3> Blood gas abnormalities in patients with FMF are related to disease severity, inflammation and vascular (endothelial) alteration. Correlations between PO<sub>2</sub>, O<sub>2</sub>Sat and ET-1 and CRP in FMF patients without amyloidosis suppose possible high risk of pulmonary vascular manifestations. Mild hypocapnia in FMF patients with amyloidosis associated with an increase in plasma ET-1 and CRP, whereas hypoxia is not correlated with both ET-1 and CRP. Concerning the latter finding it could be due to the limitation of our study and necessity of arterial blood examination to assess the oxygenation status. Taking into account that capillary blood accurately reflects arterial PCO<sub>2</sub><sup>4</sup> we may conclude that patients with FMF-amyloidosis have an increased risk of pulmonary complications. <h3>References</h3> Livneh A, Langevitz P, Pras M. Pulmonary associations in familial Mediterranean fever. Curr Opin Pulm Med. 1999; 5:326–331. Berk JL., O9Regan A., Skinner M. Pulmonary and Tracheobronchial Amyloidosis. Seminars in Respiratory and Critical Care Medicine/Vol 23, No 2, 2002 Johnson WJ, Lie JT. Pulmonary hypertension and familial Mediterranean fever: a previously unrecognized association. Mayo Clin Proc. 1991;66:919–925. Zavorsky G, Cao J, Mayo N. Arterial versus capillary blood gases: a meta-analysis. Respir Physiol&amp; Neurobiology. 2007;155:268-279 <h3>Acknowledgements</h3> The author thanks Anahit Davtyan and laboratory staff for their collaboration. <h3>Disclosure of Interest</h3> : None declared <h3>DOI</h3> 10.1136/annrheumdis-2014-eular.1089