Fig. 4.

Interaction of anti-mannose-binding lectin (anti-MBL) with MBL in vivo. The mean MBL concentration per patient is shown in serum samples of 20 patients with systemic lupus erythematosus (SLE) and in 70 samples of healthy controls (a). Statistical analysis was performed on the mean MBL level of the different serum samples from one patient. The correlation between anti-MBL levels and the ratio between the MBL complex activity and the MBL concentration is shown (b). For detection of complexes between immunoglobulin G (IgG) and MBL in serum, plates were coated with monoclonal antibody (MoAb) anti-MBL or control MoAb, as indicated, and incubated with serial dilutions of a systemic lupus erythematosus (SLE) serum containing anti-MBL, followed by detection of IgG binding (c). The number of circulating complexes between IgG and MBL in serum samples from SLE patients and controls (d). aU, arbitrary units.