Ismail MB, Åkefeldt SO, Lourda M, et al. - In order to verify if increased plasma interleukin-17A (IL-17A) levels are detected in patients with Langerhans cell histiocytosis (LCH), as already reported, researchers used an extensive study sample of patients. They also examined the link between IL-17A and LCH sequelae, especially ND-LCH (neurodegeneration as a complication of LCH). This study included 68 LCH patients and 127 controls, from whom, plasma samples were obtained and were examined for IL-17A levels by two ELISAs with different anti-IL-17A capture antibodies. Findings corroborated the link between high levels of IL-17A and LCH. The link of IL-17A with LCH was found to be independent of the ELISA employed, and of gender, age, disease class activity, and pattern of tissue-organ involvement (single-system vs multi-system). A significant link of high IL-17A levels with LCH patients experiencing sequelae was identified, with the highest plasma levels seen in patients with ND-LCH. A possible link was suggested between IL-17A and ND-LCH development. For the precision treatment of ND-LCH, this might afford a new target having therapeutic implications.