CHI3L1 and rheumatoid arthritis: At week 16 plasma IL-6 was significantly higher in RA patients who were in remission compared to healthy subjects (4.1 vs. 1.3 ng/l, p < 0.005) whereas plasma VEGF (81 vs. 45 ng/l, p = 0.318) and serum YKL40 were not (66 vs. 43 μg/l, p = 0.063).