MONITORING CIRCULATING CD207+CD1A+ CELLS IN LANGERHANS CELL HISTIOCYTOSIS AND CLINICAL IMPLICATION

OLEXEN CINTHIA M; ROSSO, DIEGO A.; NOWAK W; FORTUNATI DANIELA; ERRASTI ANDREA E; CARRERA SILVA EA

JOURNAL OF IMMUNOLOGY

AMER ASSOC IMMUNOLOGISTS

Lugar: Bethesda; Año: 2022 p. 270 - 279

0022-1767

Langerhans cell histiocytosis (LCH) is a disorder characterized by an abnormal accumulation of CD207+ and CD1a+ cells in almost any tissue. Currently, there is a lack of prognostic markers to follow up patients, and track disease reactivation or treatment response. Putative myeloid precursors CD207+ and CD1a+ cells were previously identified circulating in the blood. Therefore, we aim to develop a sensitive tracing method to monitor circulating CD207+ and CD1a+ cells in a drop of blood sample of patients with LCH. A total of 202 blood samples from patients with LCH and 23 controls were tested using flow cytometry. A standardized cellular score was defined by quantifying CD207+ and CD1a+ expression in monocytes and dendritic cells, based on CD11b, CD14, CD11c, and CD1c subpopulations, resulting in a unique value for each sample. The scoring system was validated by a ROC curve showing a reliable discriminatory capacity (AUC: 0.849) with a threshold value of 14, defining the presence of circulating CD207+ and CD1a+ cells. Interestingly, a fraction of patients with no evident clinical manifestation at the time of sampling also showed presence of these cells (29.6%). We also found a differential expression of CD207 and CD1a depending on the organ involvement, and a positive correlation between the cellular score and plasma inflammatory markers such as sCD40L, sIL-2Ra, and CXCL12. In conclusion, the analysis of circulating CD207 and CD1a cells in a small blood sample will allow setting a cellular score with minimal invasiveness helping with prognostic accuracy, detecting early reactivation, and follow-up.