Association of large intergenic noncoding RNA expression with disease activity and organ damage in systemic lupus erythematosus

Despite growing evidence that large intergenic noncoding RNAs (lincRNAs) can regulate gene expression and widely take part in normal physiological and disease conditions, our knowledge of systemic lupus erythematosus (SLE)-related lincRNAs remains limited. The aim of this study was to detect the levels of four lincRNAs (ENST00000500949: linc0949, ENST00000500597: linc0597, ENST00000501992: linc1992, and ENST00000523995: linc3995) involved in innate immunity in the peripheral blood mononuclear cells (PBMCs) of patients with SLE and correlate these lincRNA levels with disease activity, organ damage, clinical features and medical therapies. PBMCs were obtained from 102 patients with SLE, 54 patients with rheumatoid arthritis (RA) and 76 healthy donors. lincRNA expression levels were measured by real-time quantitative polymerase chain reaction. Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) scores, and organ damage was evaluated with the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index. linc0949 and linc0597 were significantly decreased in patients with SLE compared with patients with RA and healthy control subjects. linc0949 was correlated with SLEDAI-2K score (r = −0.329, P = 0.0007), as well as with complement component C3 level (r = 0.348, P = 0.0003). The level of linc0949 was also reduced in patients with SLE who had the presence of cumulative organ damage. In addition, decreasing expression of linc0949 was associated with lupus nephritis. linc0949 expression significantly increased after treatment, whereas neither disease activity nor organ damage correlated with linc0597 expression. Our results provide novel empirical evidence that linc0949 could be a potential biomarker for diagnosis, disease activity and therapeutic response in SLE.