Objective: To investigate the inhibitory effect of β-D-mannuronic acid (M2000)
on anti-cyclic citrullinated peptide antibodies (anti-CCP), rheumatoid factor (RF), antidouble
strand DNA (anti-dsDNA) and acute phase reactants in rheumatoid arthritis (RA)
Methods: The study included 40 patients with RA who had an inadequate response to
conventional therapy (identifier: IRCT2014011213739N2). The patients were permitted
to continue the conventional therapy excluding NSAIDs. 21 of them were treated orally
by M2000 at a dose of 500 mg twice daily for 12 weeks and the others did not. Serum
samples were collected at baseline, 4 weeks and 12 weeks after treatment and were tested
for the serum level of anti-CCP and anti-dsDNA antibodies using enzyme linked immunosorbent
assay. The serum level of RF and C-reactive proteins (CRP) was determined
by the immunoturbidimetric assay, respectively.
Results: At baseline, all patients in the M2000 treated group and the control group were
positive for anti-CCP, RF. moreover, 4 of 21 (19%) in the M2000 treated group and 2 of
the 19 (10.5%) patients in the control group were positive for anti-dsDNA antibodies, respectively.
The serum levels of anti-CCP, RF and anti-dsDNA were decreased significantly
after M2000 therapy (p<0.001, p<0.001 and p<0.001, respectively). The reduction in
the level of anti-CCP was positively correlated with disease activity, swollen joint count
and CRP. Furthermore, the level of inflammatory markers ESR and CRP decreased significantly
after M2000 therapy (p<0.001 and p<0.004, respectively).
Conclusion: M2000 shows inhibitory effect on anti-CCP, RF, anti-dsDNA antibodies and
acute phase reactants in RA patients.