Circulating interleukin-16 in systemic lupus erythematosus

OBJECTIVE: To investigate the relationship between interleukin (IL)-16 and systemic lupus erythematosus (SLE). METHODS: Serum levels of IL-16 were examined in SLE patients using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The serum level of IL-16 in the patients was much higher than that in healthy volunteers (P < 0.001). An increase in IL-16 was observed in proportion to the activity of SLE assessed by the SLE Disease Activity Index (SLEDAI) score (P < 0.0001). CONCLUSIONS: Our observations suggest an interaction between disease activity and the production of IL-16 in SLE, and reveal that IL-16 is a useful indicator of disease activity. This is the first report describing the relationship between IL-16 and SLE.