Mannose binding lectin in sera and synovial fluids of patients with rheumatoid arthritis

Summary: It has been supposed that low levels of mannose binding lectin (MBL) may be involved in protection of rheumatoid arthritis associated with agalactosil forms of GOIgG immunoglobilins found in rheumatoid synovial fluid and lead to enhanced complement activation and joint cartilage damages. In order to examine the possible link between MBL and mediated complement activation, its concentration was measured in sera and synovial fluids of 59 patients classified in moderate and severe activity RA groups and compared with the levels in the same biological fluids of the control group with menisci lesions. No patients had undetectable or lowered MBL in both RA groups. Mean values were either normal or elevated depending on the severity of the disease as a response to inflammation. This finding does not exclude a possible role of MBL-GOIgG mediated complement activation, but provides no support to mitigating RA severity.