Drug-induced lupus following treatment with infliximab in rheumatoid arthritis

After introduction of infliximab for the treatment of rheumatoid arthritis (RA), there have been many reports of patients developing asymptomatic higher rate of antinuclear antibodies and anti-dsDNA antibodies than in non-infliximab-treated patients. However, only five clinical drug-induced lupus (DIL) cases have been documented following treatment with infliximab, in RA and in Crohn's diseases. We report a case of a 69-year-old female with a 5 year history of RA, who was successfully treated with low-dose methotrexate (MTX) and infliximab (initially 3 mg/kg and from the fourth infusion 5 mg/kg) for 23 weeks. Before the sixth infusion, she was diagnosed with DIL by both clinical features (fever > 38°C, recurrence of active synovitis, myalgia, erythematous rash and general malaise) and laboratory findings (antinuclear antibodies 1:160, anti-double-stranded DNA positive by ELISA assay, decreased serum complement C3 and C4, hypergammaglobulinaemia, increased erythrocyte sedimentation rate). After discontinuation of treatment and therapy with oral prednisone, lupus resolved within 8 weeks.