Infantile Langerhans Cell Histiocytosis - significant diagnostic and therapeutic challenges

Introduction: Langerhans Cell Histiocytosis (LCH) is an uncommon disorder with diverse clinical manifestations in the pediatric population.When diagnosed in infants under one year of age, the disease often exhibits a more aggressive course.Limited research on this pathology in Central Asia prompted a study in Uzbekistan to better understand its characteristics and outcomes. Methodology:We conducted a study involving 14 infants under one year of age with confirmed LCH diagnosis, established through immunohistochemical analysis.Patients were categorized based on organ involvement risk: no critical organ involvement and risk (involvement of liver, spleen, and/or cytopenia).Primary evaluation metrics included adverse events, assessed using the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, and therapeutic responses, evaluated according to disease activity assessments. Results:The median age at diagnosis was 8.15 months, with a boy/girl ratio of 9:5.Disease distribution revealed 11 patients with risk organ involvement and 3 without risk involvement.Molecular genetic testing identified the BRAF V600E mutation in 65% of patients.The median follow-up duration was 15 months (range: 5.3 to 32 months), and the median treatment duration was 12.6 months.All patients received 1-line therapy according to the LCH-III protocol.2-line treatment, when necessary, followed the Cladribine and Cytarabine regimen (4 curses).After 6 weeks of therapy, there were 5 complete responses and 5 partial responses; one patient died to septic shock.