Journal Article

AB0327 INTERSTITIAL LUNG DISEASE IN MIXED CONNECTIVE TISSUE DISEASE: EXPLORING THE POTENTIAL ASSOCIATION WITH MICROVASCULAR DAMAGE

Chimenti, M. S., Chiocchi, M., Idone, G., Rogliani, P., Capparelli, E., Greco, E., Kroegler, B., Cavalli, F., Cristiano, I., Puxeddu, E., Triggianese, P.

2024

Overview

Background:Mixed connective tissue disease (MCTD) is a rare complex syndrome with features of different autoimmune connective tissue diseases (CTDs) in patients with antibodies targeting the U1 small nuclear ribonucleoprotein particle. In MCTD, immune-system abnormalities and, thus, fibrosis may involve skin and other internal organs, including lungs, also leading to diffuse microangiopathy. Lung involvement in terms of interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are key manifestations strongly affecting morbidity and mortality in MCTD.Objectives:MCTD patients’ phenotypic pattern were analyzed according to the presence of concomitant lung involvement to explore potential association with microvascular damage.Methods:We performed a cross sectional observational study including patients with a defined diagnosis of MCTD, referring to the Reference Centre of “Tor Vergata” University Hospital in Rome (Italy). Recorded data included clinical and laboratory findings. Nail fold videocapillaroscopy (NVC) patterns and trans-thoracic echocardiographic PAPs value (PAPs>25 mmHg defined PAH) were analyzed. Concomitant ILD was defined based on chest computed tomography (chest CT) features: patients were thus divided in accordance with the presence of ILD. Continuous variables were compared with T test, categorical variables by using Chi-square or Fisher’s exact test. P<0.05 values were considered statistically significant.Results:The study cohort included 24 patients (95.8% women). Patients’ characteristics were shown in [Table 1]. Patients with ILD were 37.5% (n=9; Group 1) while patients without were 63.5% (n=15 Group 2). Disease duration was greater in Group 1 than in Group 2 (p=0.02). PAH has been revealed in a significantly higher percentage in Group 1 than Group 2 (P<0.01). Patients from Group 1 also exhibited a higher prevalence of telangiectasias, digital ulcers, pitting scars, and serositis than patients from Group 2 (p<0.02 for all the comparisons) along with a NVC late pattern (p<0.01) [Graphic 1]. A higher prevalence of cardiovascular and other respiratory comorbidities was observed in Group 1 than Group 2 (p<0.001 and p<0.05, respectively). A joint involvement showed a trend to be more frequent in Group 2. Patients from Group 1 showed a higher prevalence of both RoSSA-60 and -52 autoantibodies than those from Group 1 (p<0.01). Azathioprine resulted administered more frequently in Group 1 than in Group 2 (p<0.01).Conclusion:Our study documented in MCTD patients complicated with ILD a disease phenotype characterized by a more severe microvascular damage while confirming the role of specific autoantibodies profile in lung disease.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of Interests:None declared.

• Publisher: BMJ Publishing Group Ltd and European League Against Rheumatism,Elsevier B.V,Elsevier Limited
• Subject: Autoantibodies / Azathioprine / Chest / Comorbidity / Computed tomography / Connective tissue diseases / Fibrosis / Interdisciplinary research / Lung diseases / Lungs / Microvasculature / Mixed connective tissue disease / Morbidity / Patients / Phenotypes / Rare/orphan diseases / Real-world evidence / Scientific Abstracts / Serositis / Skin diseases / Statistical analysis / Thorax / Ulcers