AB0197 Metalloproteinase-7 as an early marker of lung damage among polymyositis and dermatomyositis patients
Authors: V. Kmyta, E. Prystupa, L. Prystupa, A. Kovchun
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Interstitial lung disease (ILD) can complicate the course of polymyositis/dermatomyositis (PM/DM) almost in the half of patients and represents as a high risk factor of mortality among such cohort of patients from chronic pulmonary insufficiency. Lung function monitoring and chest high resolution computer tomography (HRCT) are obligatory methods of investigation among PM/DM patients. However, these methods allow to determine already formed interstitial changes in the lungs. Therefore, there is a need for biomarkers to seek early changes of lung tissue, what allows to prescribe basic treatment in time, encountering its side effects. Metalloproteinase 7 (MMP-7) reflect lung damage and can also be an early biomarker of ILD which complicates PM/DM. It was early reported that −181A/G (rs11568818) polymorphism in MMP-7 promoter modulates gene expression and plays pivotal role in the MMP-7 upregulation in that way affects ILD progression. Here, we evaluated the impact of −181A/G polymorphism in MMP-7 promoter activity and its association with MMP-7 elevation. <h3>Objectives</h3> Our study was aimed to analyse the level of MMP-7 as an early marker of lung damage among PM/DM patients and also probable influence of rs11568818 on the MMP-7 elevation. <h3>Methods</h3> 17 patients with PM/DM have been observed in the rheumatology department with primary established diagnosis, 9 patients among them has proved diagnosis of ILD with HRCT. All patients have been examined according to the recommended EULAR standards and paraneoplastic reaction have been excluded. Patients have been divided into 2 groups, 1st group include 9 patients with PM/DM complicated with ILD, 2nd – 8 patients with isolated PM/DM. Control group included 17 healthy volunteers. MMP-7 level was assayed by the enzyme immunoassay system in the blood serum. −181A/G (rs11568818) polymorphism was genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR–RFLP) method. All statistical calculations were done using SPSS software 21.0. <h3>Results</h3> Results. Mean age of patients of the 1st group – 48,44±2,74, 2nd – 54,25±2,55, control group – 49,0±2,4 (p=0,33). DM have been established in 7 patients and PM – 10. Mean level of MMP−7 in the 1st group was 4,02±1,58 (CI 95% 2,81–5,24), 2nd – 1,43±0,2(CI 95% 0,93–1,92), control group – 1,3±0,75 (F=30,87, p &lt;0,001). It was determined that the level of MMP-7 was positively correlated with Anti-Jo1 antibodies (r=0,82, p=0,007) and it was higher among PM/DM patients complicated with ILD (p=0,001). Analysis of genotypes frequency AA/AG/GG with regard to rs11568818 polymorphism, shows no significant distribution(p=0,984) and is following in the 1st group – 66,7%/22,2%/11,1% and 62,5%/25%/12,5% – in the 2nd, in the control group – 70,6%/17,6%/11,8% respectively. The analysis of the connexion between studied genetic polymorphism with the level of MMP-7 didn't show any interdependence (p=0,771). <h3>Conclusions</h3> The level of MMP-7 is higher among the 1st group, in comparison with 2nd and control groups. Positive correlation connexion between the level of MMP-7 and Anti-Jo1 antibodies among PM/DM patients with ILD was found. The difference between genotypes distribution according to the rs11568818 gen polymorphism depending on existence of ILD and MMP-7 level is absent. Taking into account the results, we can admit that MMP-7 is a perspective marker of lung tissue damage among PM/DM patients. <h3>Disclosure of Interest</h3> None declared