CHI3L1 and lymphopenia: Additionally, the YKL-40 level was significantly higher in patients with photosensitivity, fever, vasculitis, blood disorders (anemia, lymphopenia, and thrombocytopenia), positive anti dsDNA, and APL ab (p = 0.009, < 0.001, 0.006, 0.002, 0.012, < 0.001, 0.003, and 0.03, respectively).