Increased incidence of autoantibodies to interleukin-1a in rheumatoid arthritis with interstitial lung disease

• Published in: Respirology (Carlton, Vic.) Vic.), 2000-12, Vol.5 (4), p.315-320
• Main Authors: Maniwa, K, Ogushi, F, Tani, K, Ohmoto, Y, Muraguchi, M, Sone, S
• Format: Article
• Language: English
• Subjects: Adult; Aged; Anti-Inflammatory Agents - therapeutic use; Anti-Inflammatory Agents, Non-Steroidal - therapeutic use; Arthritis, Rheumatoid - complications; Arthritis, Rheumatoid - drug therapy; Autoantibodies - blood; Blood Sedimentation; Carrier Proteins; Case-Control Studies; Cyclic AMP Receptor Protein - blood; Female; Humans; Interleukin-1 - immunology; L-Lactate Dehydrogenase - blood; Lung Diseases, Interstitial - blood; Lung Diseases, Interstitial - etiology; Lung Diseases, Interstitial - immunology; Male; Middle Aged; Steroids
• ISSN: 1323-7799

To clarify the clinical significance of autoantibodies (auto-Ab) to interleukin-1alpha (IL-1alpha) in rheumatoid arthritis (RA) with interstitial lung disease (ILD), we examined the IL-1alpha auto-Ab level in serum of patients with RA with/without ILD. We investigated the level of IL-1alpha auto-Ab in serum of 70 patients with RA with/without ILD and 40 control patients (CP). Levels of IL-1alpha auto-Ab were measured by radioimmunoassay, and serum was regarded as IL-1alpha auto-Ab positive at an auto-Ab level of more than 5 ng/mL. Interleukin-1alpha auto-Ab was detected in the serum of 30 out of 70 RA patients (42.9%), and six out of 40 CP (15%) (P < 0.05). Interleukin-1alpha auto-Ab were detected in the serum of 18 out of 32 patients with RA with ILD (56.2%) and 12 out of 38 patients with RA without ILD (31.5%). The positive rate of these autoantibodies in RA with ILD was significantly higher than that in RA without ILD (P < 0.05). Although C-reactive protein, immunoglobulin G, rheumatoid factor and rheumatoid arthritis particle agglutination levels in serum from patients with RA with ILD were not significantly different between the IL-1alpha auto-Ab-positive and -negative groups, the lactate dehydrogenase level (LDH) and AaDO, in the IL-1alpha auto-Ab-positive group were significantly higher than those in the negative group (LDH: P < 0.001, AaDO2: P < 0.05). These results suggest that IL-1alpha auto-Ab are generated in response to the immunoinflammatory process of ILD in RA, and these autoantibodies may neutralize and regulate the IL-1alpha activity.