Indomethacin was effective in the osseous compromise of LCH patients.

MARÍA CATALINA LAVA; DANIELA FORTUNATI; CINTHIA MARIEL OLEXEN; GUIDO LUIS DALLA VECHIA; EUGENIO ANTONIO CARRERA SILVA; ANDREA EMILSE ERRASTI ; DIEGO ALFREDO ROSSO

Estocolmo

Congreso; 38th Annual Meeting of the Histiocyte Society; 2022

Histiocyte Society

Purpose: We aim to evaluate the response and outcome of bone LCH patients treated with indomethacin at diagnosis or after reactivation. Its use has not only shown improvement in regards to clinical manifestations but also in accessibility and adherence to the treatment. Methods: We retrospectively (2018-2022), evaluate the outcome of patients with bone LCH and under indomethacin treatment analyzing bone healing, clinical improvement, toxicity, biochemical parameters and the presence of circulating CD1a+/CD207+cells in the bloodstream by flow cytometry. Results: 31 patients with bone compromise received indomethacin at a dose of 2 mg/kg/day. Since diagnosis, 21 patients received only indomethacin, and 6 combined with another treatment. Additionally, 4 patients with bone reactivation were included, receiving indomethacin alone (n=2) or combined with another drug (n=2). Clinical and imaging improvements were observed in all groups. Patients receiving indomethacin alone did not show toxicity. The biochemical parameters, including platelets number, eritrosedimentation rate, were restored to normal values after treatment. Curiously, the clinical improvement of bone LCH under indomethacin treatment still showed presence of circulating CD1a+/ CD207+cells, which suggests that the treatment could be restraining the bone arriving of these cells. Conclusion: Indomethacin has proven to be a useful drug in the treatment of LCH patients who had bone affection, including patients with reactivation in bone from another primary compromise, reaching a significant clinical improvement.