Source: Diabetes  |  Posted 8 years ago

The monoclonal antibody infliximab may induce antinuclear antibodies -- especially IgM and IgA anti-double stranded DNA antibodies -- in patients with rheumatoid arthritis and spondyloarthropathy, according to research conducted at Ghent University Hospital, Belgium.

The study showed no anti-double stranded DNA IgG antibodies and signs or symptoms of lupus over the 30-34 weeks of infliximab treatment.

However, the researchers emphasise, further follow-up is essential because their findings did not exclude potential long-term induction of clinically significant lupus.

They investigated the effect of infliximab on antinuclear antibodies, anti-double-stranded DNA, antinucleosome, antihistone and anti-extractable nuclear antigen antibodies in 62 patients with rheumatoid arthritis and 35 with spondyloarthropathy. All were tested at baseline and at week 30 (rheumatoid arthritis) or week 34 (spondyloarthropathy).

Initially, 32 of the rheumatoid arthritis patients tested positive for antinuclear antibodies but after infliximab treatment 51 patients tested positive (P<0.001). Likewise, the number of spondyloarthropathy patients testing positive increased from six at baseline to 31 at 34-week follow-up (P<0.001).

At baseline, no patient in either group had anti-double stranded DNA antibodies, but after infliximab treatment, seven rheumatoid arthritis patients and six spondyloarthropathy patients tested positive(P=0.016 and P=0.031 respectively).

All seven rheumatoid arthritis patients who were positive for anti-double stranded DNA had IgM and IgA anti-double stranded DNA antibodies. In the spondyloarthropathy group, that number, three of six had IgM and IgA anti-double stranded DNA antibodies, and two had IgM anti-double stranded DNA antibodies alone.

In both groups, the IgM anti-double stranded DNA antibodies appeared before the IgA anti-double stranded DNA antibodies.

Although some patients who were treated with infliximab developed antibodies to antinucleosome, antihistone and anti-ENA, the numbers were not statistically significant, the researchers note.