Journal Article

POS1209 TELOMERES IN RHEUMATOID ARTHRITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE

D’antonio, A., Chimenti, M. S., Latini, A., Kroegler, B., Conigliaro, P., De Benedittis, G., Borgiani, P., Ciccacci, C., Bonini, C., Bergamini, A.

2024

Overview

Background:Telomeres are specific regions of repetitive nucleotide sequences that protect chromosome ends and preserve genetic information. In each cell division, telomeres shorten, leading finally to apoptosis and cell cycle arrest when reaching a critical point. The telomere-associated protein (telomeric repeat-binding factor 1 [TERF1]) is essential for the maintenance of telomeres, acting as an inhibitor of telomerase, and its levels correlate with telomere length (TL).Shortened telomeres have been demonstrated in Rheumatoid Arthritis (RA). Furthermore, they are a recognized risk factor for idiopathic pulmonary fibrosis. Few data are present in the literature regarding TL in RA-associated interstitial lung disease (RA-ILD), while no data are present regarding TERF1 in RA and RA-ILD.Objectives:We aimed to evaluate the TL and TERF1 expression levels in RA-ILD.Methods:TL and TERF1 expression levels were evaluated in patients with RA-ILD compared to age-matched RA patients without lung involvement (RA-non-ILD) and healthy controls. Genomic DNA and total RNA were isolated from peripheral blood mononuclear cells. Relative TL was measured using real-time quantitative polymerase chain reaction (qPCR) assay, which quantifies a ratio of telomeric repeat copy signal and a reference single-copy gene (human beta globin) signal. Expression analysis of TERF1 was performed by qPCR assay. T-test was used to compare mean TL and TERF1 expression data among the different phenotypic groups. RA patients were divided according to whether their TL fell within or above the first quartile of the cohort. A multivariate logistic regression analysis was used to correct the p-value for sex, age and disease duration.Results:Eighty-nine RA patients were included (mean age 63.6 ± 13.8 years, median disease duration 9 [IQR 8.4-11.6] years): 42 RA-ILD and 47 RA-non-ILD. 21 age- and sex-matched controls were collected. RA-ILD patients were older and with minor disease duration than RA-non-ILD patients. They exhibited higher disease activity, CRP levels, positivity for RF and ACPA, and were more treated with bDMARDs than RA-non-ILD patients (Table 1). TL in all patients was significantly shorter compared to controls (p = 0.0016). RA-ILD patients presented significantly shorter TL compared to controls (p = 0.00001) and compared to RA-non-ILD (p = 0.0006) (Figure 1A). In the multivariate regression analysis, TL was reduced in RA-ILD compared with RA-non-ILD when adjusted for sex, age and disease duration (p<0.001). After patients stratification according to their TL, it is observed that the prevalence of ILD was significantly higher in patients with short vs normal-length telomeres (82.6% vs 34.8% p=0.00008). In RA-ILD, TL correlated negatively with disease duration (p= 0.007 r= -0.408). TERF1 expression levels were reduced in RA compared with controls (p= 2.17E-17). Both RA-ILD patients and RA-non-ILD patients exhibited reduced TERF1 expression levels than controls (p= 3.37E-10 and p= 2.78E-10, respectively. Figure 1B). TERF1 levels correlated positively with TL (p= 0.004 r= 0.328).Conclusion:Telomere shortening is a feature of immunosenescence and it has been linked to more severe articular disease. Shorter TL and reduced TERF1 expression levels characterize RA. In particular, RA-ILD patients displayed higher disease activity, negative prognostic factors, received more biologic treatments, and exhibited shorten TL than RA-non-ILD patients suggesting that TL might represent a hallmark of a more aggressive disease with lung involvement.Table 1.Figure 1.Acknowledgements:NIL.Disclosure of Interests:None declared.

• Publisher: BMJ Publishing Group Ltd and European League Against Rheumatism,Elsevier B.V,Elsevier Limited
• Subject: Apoptosis / Biomarkers / Cell cycle / Cell division / DNA-directed RNA polymerase / Fibrosis / Genetics / Immunosenescence / Leukocytes (mononuclear) / Lung diseases / Lungs / Peripheral blood mononuclear cells / Regression analysis / Rheumatoid arthritis / Risk factors / Scientific Abstracts / Telomerase / Telomeres / Yeast