Antinuclear Antibodies and Lupus-like Manifestations in Rheumatoid Arthritis and Ankylosing Spondylitis Patients at 4 Months' Follow-up After Treatment with Infliximab and Etanercept

Background: Up to 44% of patients treated with infliximab and 7% of patients treated with etanercept reported to have anti-drug antibodies within the first 6 months of treatment. Recently, anti-TNF-α therapies have been reported to be employed in the induction of the druginduced lupus erythematous. Objective: The aim of the present study was to investigate the relationship between anti-TNFα antibodies and various manifestations of lupus erythematous. Methods: We enrolled a total of 56 cases divided into 28 known cases of rheumatoid arthritis and 28 cases of ankylosing spondylitis patients and 56 controls. The case group was divided into 4 groups according to the underlying disease (RA or AS) and treatment regimen (infliximab or etanercept). ANA and anti-dsDNA levels and lupus criteria were assessed at the beginning of the study and 4 months after the initiation of anti-TNFα. Results: 36% and 21% of RA patients treated with infliximab, were ANA and anti-dsDNA positive after 4 months (P=0.003, P=0.025). 28% and 7% of RA patients treated with etanercept, were ANA and anti-dsDNA positive after 4 months (P=0.009, P=0.15). 21% and 7% of AS patients treated with infliximab, were ANA and anti-dsDNA positive, respectively (P=0.025, P=0.15). 14% and 7% of AS patients treated with etanercept, were ANA and anti-dsDNA positive, respectively (P=0.63, P=0.15). Three patients who were positive for auto-antibodies developed three criteria for SLE. Conclusion: Infliximab potentially may increase both ANA and anti-dsDNA levels in rheumatoid arthritis, but only ANA in ankylosing spondylitis patients. In general, clinicians should consider different clinical symptoms of ATIL, which may be present as a lupus-like syndrome similar to idiopathic SLE or classical DIL.