Nationwide retrospective review of hematopoietic stem cell transplantation in children with refractory Langerhans cell histiocytosis
The efficacy of and indications for hematopoietic stem cell transplantation (HSCT) in pediatric Langerhans cell histiocytosis (LCH) remain undetermined. This retrospective study analyzed 30 children with refractory LCH who underwent HSCT in Japan between 1996 and 2014. Eleven patients received a myeloablative conditioning (MAC) regimen, while 19 patients received a reduced-intensity conditioning (RIC) regimen. Among the 26 patients with complete data, 23 patients had risk organ (RO) involvement during clinical course. Disease status at HSCT was no active disease (NAD) (4), active disease-regression (AD-r) (2), active disease-stable (AD-s) (4), and active disease-progressive (AD-p) (16). Seventeen of the 30 patients (57%) were alive with a median follow-up of 433 days (range 9–5307) after HSCT. Death occurred within 3 months after HSCT in eight of 13 patients. RIC and MAC patients were similar in both overall survival (OS) (56.8% vs. 63.6%, respectively, p = 0.789) and failure-free survival (56.8% vs. 54.6%, respectively, p = 0.938). Regarding disease status at HSCT, the six patients with NAD/AD-r experienced better outcomes than the 20 with AD-s/AD-p (5-year OS, 100% vs. 54.5%, respectively, p = 0.040). Disease state at the time of HSCT was the most important prognostic factor.
KeywordsRefractory Langerhans cell histiocytosis (LCH) Hematopoietic stem cell transplantation (HSCT) Reduced-intensity conditioning (RIC)
We thank all participating doctors and patients who were involved in the Japanese Hematopoietic Cell Transplantation Registry. This work was supported in part by the Practical Research Project for Allergic Diseases and Immunology (Research Technology of Medical Transplantation) of the Japan Agency for Medical Research and Development under grant number 18ek0510023h0002.
KK and AM designed the research, analyzed the data, and wrote the manuscript. MM, NS, HK, SO, EI, YS, TI, SI, YT, ME, AS, YK, YH, MN, MI, and KT collected and managed the clinical data and discussed the results.
Compliance with ethical standards
Conflict of interest
We have no conflicts of interest with regard to this manuscript.
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