Serum levels of soluble interleukin 2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-α), and immunoglobulin M are correlated with the disease extent in childhood Langerhans cell histiocytosis

Purpose: This study aimed to identify peripheral parameters associated with the severity of Langerhans cell histiocytosis (LCH) and to look for indicators associated with improvement in LCH patients with risk-organ involvement.

Methods: This study enrolled LCH patients who were assessed as active disease-better (AD-B) after treatment. Patients were divided into the single system (SS) group, multisystem disease without risk-organ involvement (RO- MS) group, and multisystem disease with risk-organ involvement (RO + MS) group. Serum cytokines, immunoglobulins, and lymphocyte subsets were measured at admission for all three groups. Changes in these indicators after treatment were also analyzed.

Results: From January 2015 to January 2022, a total of 46 patients were recruited in the present study, including 19 patients (41.3%) in the SS group, 16 patients (34.8%) in the RO- MS group, and 11 patients (23.9%) in the RO + MS group. Serum levels of soluble interleukin 2 receptor (sIL-2R) (> 912.5 U/mL), tumor necrosis factor-alpha (TNF-α) (> 20.3 pg/mL), and immunoglobulin M (< 1.12 g/L) were found to be effective in identifying patients in the RO + MS group. Furthermore, the levels of sIL-2R (SS vs RO + MS: P = 0.002, RO- MS vs RO + MS: P = 0.018) and CD8 + T-cell count (SS vs RO + MS: P = 0.028) significantly declined in the RO + MS group after treatment, indicating disease improvement.

Conclusions: The levels of sIL-2R and TNF-α were positively correlated with the extent of disease, while the levels of IgM were negatively correlated with the extent of disease. Additionally, the levels of sIL-2R and CD8 + T-cell count could serve as useful indicators to evaluate the treatment response in RO + MS-LCH patients.