Clinical characteristics of LCH patients
A total of 114 pediatric LCH patients with available plasma samples were enrolled in the present study. The patients’ clinical characteristics are shown in Table 1. There were 70 boys and 44 girls in this study cohort. The median age at diagnosis was 4.46 years (range, 0.08 to 15.08 years). These included patients were classified as follows: 68 (59.6%) patients with SS LCH, 27 (23.7%) with MS RO- and 19 (16.7%) with MS RO+ LCH. There was no significant difference in clinical features between the 114 included patients and 25 excluded patients. The 114 studied LCH patients included 55 cases (48.2%) with BRAF -V600E mutation, 31 cases (27.2%) with MAP2K1 mutation, 6 cases (5.3%) with BRAF indel mutation, 6 cases (5.3%) with BRAF -V600D mutation, 1 case (0.9%) with ARAF mutation, 1 case (0.9%) with c.1517+2_1517+3ins BRAF mutation and 14 cases (12.3%) without gene mutation.