Biphasic decline/increase for anticitrulline and monophasic decline in anti-type II collagen antibody levels in recently diagnosed RA patients
© The Author(s) 2003
Received: 14 January 2003
Published: 24 February 2003
Antibodies against both type II collagen and citrulline residue containing peptides can be found in rheumatoid arthritis (RA) patients. We have noted that serum levels of both anticollagen and anticitrulline antibodies show significant decline after inclusion in an early arthritis clinic (EAC) cohort, and wanted to compare their kinetic patterns of disappearance.
Two hundred and fifty-five EAC patients and 80 RA patients were followed for 1 and 5 years, respectively, from the time of initial referral. Anticollagen and anticitrulline antibodies were determined with ELISA at inclusion and after 3 months and 1, 2, 3 and 5 years.
At the patients' inclusion, anticollagen and anticitrulline antibodies were found in 6.3% and 48.2%, respectively, of EAC patients and in 11.5% and 61.0% of the patients with definite RA. Serum levels of antibodies against type II collagen declined continously for the entire study period in both groups, being significant already at 3 months after inclusion. Serum levels of anticitrulline antibodies, on the other hand, showed a biphasic pattern. A significant decline from inclusion (for EAC patients at 1 year, and for RA patients at 3 months and at 1 and 2 years) was followed by increased serum levels (significant for RA patients between 2 and 5 years). No correlation was found between changes in serum levels of anticollagen and anticitrulline antibodies at any time.
These findings suggest that different immunological events predispose to immunity against collagen type II and against citrulline-containing peptides in RA.