Mannan binding lectin in rheumatoid arthritis. A longitudinal study.

OBJECTIVE

Low serum levels of mannan binding lectin (MBL) are associated with increased risk of recurrent infections. We determined whether there was an association between serum MBL levels and the course and prognosis of rheumatoid arthritis (RA).

METHODS

MBL was analyzed in sera from 99 patients with RA who were included in a longterm prospective study.

RESULTS

Compared with controls, a high fraction of patients lacked detectable MBL in serum (11 vs 3%; p = 0.025). Comparing patients with MBL serum levels above and below the median revealed that those with levels below the median were younger at onset of RA (p = 0.043) and had higher erythrocyte sedimentation rate (p = 0.006), joint swelling score (p = 0.019), limitation of joint motion score (p = 0.027), and annual increase in radiographic destruction score (p = 0.053).

CONCLUSION

MBL insufficiency may be a contributing pathogenetic factor in RA.