Serum Levels of Ficolin-3 (Hakata Antigen) in Patients with Systemic Lupus Erythematosus

Objective. Ficolin-3 is a serum protein of putative importance in autoimmunity. Our objective was to investigate,my differential expression of ficolin-3 in patients with systemic lupus erythematosus (SLE) or its clinical subsets. Methods. Serum levels of ficolin-3 (S-ficolin-3) were determined in 95 patients with SLE and 103 healthy controls using an ELISA. Results. Median S-ficolin-3 was 56.1 mu g/ml (range 0 to >= 87.3) and 32.4 mu g/ml (10 to >= 87.3) in patients and controls, respectively (p < 0.001). Increased S-ficolin-3 was associated with hemolysis, Positive Coombs test, and lymphopenia, but not with SLE Disease Activity Index scores or C-reactive protein. In one patient without detectable S-ficolin-3, the FCN3 gene appeared normal. Conclusion. The elevation of S-ficolin-3 and its association with specific manifestations in SLE may indicate a pathogenetic role of ficolin-3 in SLE. (First Release Feb 1 2009; J Rheumatol 2009; 36:757-9; doi: 10.3899/jrheum.080361)