title: Pulmonary Langerhans cell histiocytosis-associated pulmonary hypertension: clinical characteristics and impact of pulmonary arterial hypertension therapies.
abstract: BACKGROUND
  Precapillary pulmonary hypertension (PH) is a complication of pulmonary Langerhans cell histiocytosis (PLCH) associated with increased mortality. However, outcomes and efficacy of pulmonary arterial hypertension (PAH) therapies in patients with PH complicating PLCH(PLCH-PH) remain unknown.
  
  
  METHODS
  Consecutive patients with PLCH with PH confirmed by right-sided heart catheterization were included in the study. Characteristics at baseline and during follow-up as well as survival were analyzed.
  
  
  RESULTS
  Twenty-nine patients were studied. Baseline characteristics of patients with PLCH-PH wereas follows: 83% of patients in World Health Organization (WHO) functional class III to IV, mean 6-min walk distance of 355 ±95 m, mean pulmonary arterial pressure (mPAP) of 45 ±14 mm Hg,cardiac index of 3.2± 0.9 L/min/m 2 , and pulmonary vascular resistance (PVR) of 555 ±253 dyne/s/cm 5. Use of PAH therapy in 12 patients was followed by an improvement in mPAP (56±14 mm Hg and 45±12 mm Hg, P 5 .03) and PVR (701±239 dyne/s/cm 5 and 469±210 dyne/s/cm 5 , P = .01) between baseline and follow-up evaluations. No significant oxygen worsening was observed in the treated group. The 1-, 3-, and 5-year survival estimates of the 29 patients were 96%, 92%, and 73%,respectively. Except a trend toward a better survival rate associated with the use of PAH therapy,WHO functional class was the only variable significantly associated with death.
  
  
  CONCLUSIONS
  In this group of patients, PAH therapies improved hemodynamics without oxygen worsening or pulmonary edema. WHO functional class was the only prognostic factor identified.Prospective clinical trials focusing on this population of patients are warranted
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Univ Paris Diderot, Sorbonne Cité, Assistance Publique Hôpitaux de Paris, Service de Pneumologie, Hôpital Saint Louis, Paris.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Le Pavec
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Univ Paris Diderot, Sorbonne Cité, Assistance Publique Hôpitaux de Paris, Service de Pneumologie, Hôpital Saint Louis, Paris.
authors.forename: Gwenaël
authors.initials: G
authors.lastname: Lorillon
authors.affiliation: Université Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre; Assistance Publique Hôpitaux de Paris, Centre National de Référence de l'Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine, Béclère, Clamart; INSERM U999, Clamart.
authors.forename: Xavier
authors.initials: X
authors.lastname: Jaïs
authors.affiliation: Service de Pneumologie, Hôpital Foch, Suresnes.
authors.forename: Colas
authors.initials: C
authors.lastname: Tcherakian
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Univ Paris Diderot, Sorbonne Cité, Assistance Publique Hôpitaux de Paris, Service de Pneumologie, Hôpital Saint Louis, Paris.
authors.forename: Séverine
authors.initials: S
authors.lastname: Feuillet
authors.affiliation: Université Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre; INSERM U999, Clamart; Service d'Anatomie et Cytologie Pathologiques, Centre Chirurgical Marie Lannelongue, Le Plessis Robinson, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Dorfmüller
authors.affiliation: Université Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre; Assistance Publique Hôpitaux de Paris, Centre National de Référence de l'Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine, Béclère, Clamart; INSERM U999, Clamart.
authors.forename: Gérald
authors.initials: G
authors.lastname: Simonneau
authors.affiliation: Université Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre; Assistance Publique Hôpitaux de Paris, Centre National de Référence de l'Hypertension Pulmonaire Sévère, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine, Béclère, Clamart; INSERM U999, Clamart.
authors.forename: Marc
authors.initials: M
authors.lastname: Humbert
authors.affiliation: Centre National de Référence de l'Histiocytose Langerhansienne, Univ Paris Diderot, Sorbonne Cité, Assistance Publique Hôpitaux de Paris, Service de Pneumologie, Hôpital Saint Louis, Paris. Electronic address: abdellatif.tazi@sls.aphp.fr.
authors.forename: Abdellatif
authors.initials: A
authors.lastname: Tazi
mesh_terms: D000328:Adult; D006328:Cardiac Catheterization; D016009:Chi-Square Distribution; D005260:Female; D006439:Hemodynamics; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012042:Registries; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016896:Treatment Outcome