High serum values of soluble CD154, IL-2 receptor, RANKL and osteoprotegerin in langerhans cell histiocytosis

Background. To determine useful biochemical markers ill Langerhans cell histiocytosis (LCH), we analyzed the serum levels of soluble CD154 (sCD154), IL2 receptor (sIL2-R), receptor activator of NF-kappa B ligand (sRANKL), and osteoprotegerin (OPG). Procedure. Our study included 46 newly diagnosed LCH patients (single-system multi-site ISM type): n = 20, and multi-system multi-site (MM type): n = 26) who were treated with the JLSG-02 protocol between 2002 and 2004. The median age of the patients was 3.8 years old (range 018). sCD154, sIL2-R sRANKL, and OPG were measured by ELISA at diagnosis (n = 46) and after 6-weeks of induction therapy (n = 14). Results. The values of sCD154, sIL-2R, sRANKL,,and OPG, and the sRANKL/OPG ratio in sera were significantly higher in patients with LCH compared with controls (1.83 +/- 1.38 vs. 0.22 +/- 0.16 ng/ml, P < 0.001; 1,600 +/- 1,060 vs. 420 +/- 160 pg/ml, P < 0.001; 1.72 +/- 1.20 vs. 1.04 +/- 1.09 pmol/L, P=0.019; 6.34 +/- 2.94 vs. 3.71 +/- 2.03 pmol/L, P < 0.001; and 0.40 +/- 0.45 vs. 0.16 +/- 0.17, P=0.023, respectively). Serum levels of sIL-2R were significantly elevated in the MM type compared with the SM type (2,050 1,060 vs. 870 340 pg/ml, P < 0.001). Serum OPG levels were also significantly elevated in the MM type compared with the SM type (7.58 +/- 2.72 vs. 5.13 +/- 2.69 pmol/L, P=0.008) and negatively correlated with the number of bone lesions (r = -0.56, P = 0.007). In contrast, the sRANKL/OPG ratios were significantly higher in the SM type than the MM type (0.57 +/- 0.54 vs. 0.19 +/- 0.14, P = 0.002) and positively correlated with the number of bone lesions (r = 0.34, P = 0.040). In patients who responded to the induction therapy, serum levels of sIL-2R, sRANKL, and OPG, and the sRANKL/OPG ratio decreased significantly after the therapy (1,170 600 vs. 730 290 pg/ml, P=0.029; 2.19 +/- 1.06 vs. 1.24 +/- 0.66 pmol/L, P < 0.001; 6.13 +/- 2.40 vs. 4.72 +/- 2.03 pmol/L, P = 0.040; and 0.57 +/- 0.52 vs. 0.41 +/- 0.37, P=0.02, respectively). In the three patients who did not respond to the induction therapy, the serum levels of sCD154 increased significantly after the therapy (1.3 +/- 1.1 vs. 2.7 +/- 1.2, P=0.004). Conclusions. Serum levels of sIL-2R and sCD154 could be useful as indicators of inflammation and sRANKL/ OPG ratios as markers of osteolytic activity in LCH patients.