Induction of ANA, anti-dsDNA and anti-nucleosome antibodies following infliximab treatment in rheumatoid arthritis and spondyloarthropathy patients

Background

Rheumatoid arthritis (RA) and spondyloarthropathy (SpA) patients are successfully treated with infliximab. There is indication that this therapy induces ANA and anti-dsDNA antibodies in RA.

Objectives

To investigate the induction of ANA, anti-dsDNA and anti-nucleosome antibodies in both RA and SpA after infliximab treatment.

Patients and methods

Sera from 62 patients with refractory RA treated with infliximab (3 mg/kg infliximab IV at week 0, 2, 6 and every 8 weeks thereafter) were obtained at baseline and week 30. Sera from 35 patients with active SpA treated with infliximab (5 mg/kg infliximab IV at week 0, 2 and 6 and 10 mg/kg every 14 weeks thereafter) were obtained at baseline and week 34. Samples were tested for ANA (indirect immunofluorecence [IIF] on HEp-2 cells), anti-dsDNA antibodies (IIF on Crithidia luciliae and Varelisa, PharmaciaDiagnostics), anti-nucleosome antibodies (Medizym anti-Nucleo, Medipan Diagnostica).

Results

At baseline, 32/62 RA and 6/35 SpA patients were positive for ANA. After infliximab treatment, an increase in ANA intensity of 2 or more steps (on a 0 to 5+ scale) was observed in 28/62 RA and in 26/35 SpA patients. A patient was defined as having developed anti-dsDNA antibodies when a positive result in both the IIF on Crithidia luciliae and anti-dsDNA ELISA was observed. At baseline, none of the RA and SpA patients had anti-dsDNA antibodies. After treatment, 7/62 RA and 6/35 SpA patients developed anti-dsDNA antibodies. At baseline, anti-nucleosome antibodies were observed in 1/62 RA and 3/35 SpA patients. After treatment, 5/62 RA and 4/35 SpA patients were positive for anti-nucleosome antibodies.

Conclusion

Infliximab treatment induced ANA and anti-dsDNA antibodies in both RA and SpA patients. After treatment, anti-dsDNA antibodies were significantly associated with anti-nucleosome antibodies.