Reactivations in multisystem Langerhans cell histiocytosis: data of the international LCH registry

J Pediatr. 2008 Nov;153(5):700-5, 705.e1-2. doi: 10.1016/j.jpeds.2008.05.002. Epub 2008 Jun 27.


Objective: To assess multisystem Langerhans cell histiocytosis reactivation and its impact on morbidity and mortality.

Study design: Retrospective analysis of 335 patients with MS-LCH and documented complete disease resolution (NAD1).

Results: The probability of a reactivation within 5 years of NAD1 was 46%. The first reactivation occurred within 2 years after NAD1 in most of the patients. Of 134 events, 35% were confined to skeleton, 24% were single-system nonbony lesions, 24% were multisystem reactivations without risk-organ involvement, and 10% with risk-organ involvement. In 7%, the location was unspecified. Only 3 deaths (2.2%) were documented within the context of a first reactivation. Second disease resolution (NAD2) was achieved in 85% of the cases. The probability of a second reactivation within 5 years of NAD2 was 44%. The risk for permanent consequences in patients with reactivations was higher, compared with patients without reactivation (RHR 2.2, P = .046).

Conclusions: Reactivation is a frequent and early event in MS-LCH, but involvement of risk organs at reactivation is rare and mortality is minimal. However, reactivations increase the risk for permanent consequences by about 2-fold. Prospective trials targeting reduction of acute morbidity and permanent disabilities through nontoxic treatment of the reactivations are warranted.

MeSH terms

  • Clinical Trials as Topic
  • Diabetes Insipidus, Neurogenic / diagnosis
  • Diabetes Insipidus, Neurogenic / pathology
  • Female
  • Histiocytosis, Langerhans-Cell / diagnosis*
  • Histiocytosis, Langerhans-Cell / mortality*
  • Histiocytosis, Langerhans-Cell / physiopathology
  • Humans
  • Infant
  • International Cooperation
  • Male
  • Probability
  • Prospective Studies
  • Recurrence
  • Registries
  • Retrospective Studies
  • Risk
  • Treatment Outcome