Serum Fractalkine, Interleukin 6 and C-reactive protein levels in children with pulmonary arterial hypertension

Introduction and Aim: Endothelial dysfunction has an important role in the pathogenesis of vascular inflammation and pulmonary arterial hypertension. Increased levels of serum Fractalkine (FKN), Interleukin 6 (IL-6) and C-reactive protein(CRP) are found in various conditions associated with endothelial dysfunction. In this study, it is aimed to investigate the reproducibility of serum FKN, IL-6 and CRP levels as biomarkers and the correlation of this biomarkers with echocardiographic findings, catheter angiographic findings, pulmonary function tests, treatment regimes, functional classes and 6-minute walk test (6-MWT) results in patients with PAH. Materials and Methods: A total of 80 individuals composed of 37 patients with PAH, 21 patients having congenital heart disease with left-to-right cardiac shunt without PAH and 22 healthy controls who were followed at the department of pediatric cardiology, Gazi University Faculty of Medicine have been included in the study. Detailed history, physical examination findings, anthropometric values, treatment regimes, chest X-ray, ECG, ECHO, catheter angiography, lung function testings, 6-MWTs, biochemical measurements and CBC values were recorded. Serum FKN, IL-6 and CRP levels from all patients were determined. Results: Three groups were included in this study. First group consist of 37 PAH patients of with twenty male (54.1%) with an age range of 6 months 25 years. Second group consist of 21 patients having congenital heart diseases (CHD) of with 18 female (85.7%) with an age range of 3 mounts 15 years. IL-6 and CRP levels were higher in patients with pulmonary arterial hypertension than in healthy control subjects (p <0.05). However FKN levels were also higher in PAH patients but it is not statistically significant. In the comparison of the FKN levels (p<0.05) between cyanotic and acyanotic patients in PAH group a significant difference has been found. IL-6 level was also higher in cyanotic group than acyanotic group. It was shown that there were no correlation between ECO parameters (TRV, TRVPAP, TAPSE) hemodynamic parameters and measured biomarker levels in patients with PAH. Additionally there were no correlation between FKN, IL-6, CRP levels and functional class, 6-MWT results, clinical follow-up period, treatment regimes, pulmonary function test results in the group with PAH. Discussion: It is concluded that elevated FKN, IL-6 and CRP levels in patients with PAH contributes to development of PAH together with other predisposing factors and therefore these biological markers could add some more data in diagnosing and monitoring of the treatment in PAH patients together with other routine tests. However, usability of these biomarkers are needed to be evaluated by means of large, multicentric and prospective studies. Key words: Pulmonary arterial hypertension, congenital heart disease, Fractalkine, Interleukin 6 and C-reactive protein