Association of peripheral leukocyte telomere length with patients with rheumatoid arthritis with a focus on interstitial lung disease

Abstract

Background/Aims: This study investigated whether telomere length (TL) in rheumatoid arthritis (RA) patients is shorter than in controls, whether TL in RA patients with interstitial lung disease (RA-ILD) differs from that in those without ILD (RA-nonILD), and whether TL varies according to RA-ILD patterns. Methods: TL was measured in peripheral leukocytes using quantitative polymerase chain reaction. Results were compared between controls (n = 14), RA (n = 70), RA-ILD (n = 53), and RA-nonILD (n = 53), and between the subgroups with usual interstitial pneumonia (UIP; n = 32) and nonspecific interstitial pneumonia (NSIP; n = 8), with age-and sex-matching in each comparison. The correlation between TL and honeycombing extent was determined. Results: RA patients had significantly shorter TL (8.3 +/- 2.5 kb) than controls (9.5 +/- 0.8 kb; p = 0.002). No significant TL difference was found between RA-ILD and RA-nonILD (8.2 +/- 2.8 vs 7.7 +/- 2.4 kb, p = 0.271). Among RA-ILD, age (p = 0.011), disease activity (p = 0.018), and UIP (p = 0.038) were significantly associated with shortened TL. TL in UIP was shorter than in NSIP (7.4 +/- 1.9 vs. 10.0 +/- 3.1 kb, p = 0.026). Honeycombing extent in UIP showed a negative correlation with TL but it was nonsignificant (Rho =-0.131, p = 0.387). Conclusions: This study confirms that RA is associated with shorter TL than in healthy individuals and suggests variations in TL among RA-ILD subtypes, indicating that telomere involvement in pathogenesis may differ by subtype.