[Langerhans cell histiocytosis in adults]. / Histiocytose langerhansienne de l'adulte.

Langerhans cell histiocytosis (LCH) is a rare disease characterized by the infiltration of one or more organs by Langerhans cell-like dendritic cells, most often organized in granulomas. The disease has been initially described in children. The clinical picture of LCH is highly variable. Bone, skin, pituitary gland, lung, central nervous system, lymphoid organs are the main organs involved whereas liver and intestinal tract localizations are less frequently encountered. LCH course ranges from a fulminant multisystem disease to spontaneous resolution. Several randomized controlled trials have enable pediatricians to refine the management of children with LCH. Adult LCH has some specific features and poses distinct therapeutic challenges, knowing that data on these patients are limited. Herein, we will provide an overview of current knowledge regarding adult LCH and its management. We will also discuss recent advances in the understanding of the disease, (i.e. the role of BRAF oncogene) that opens the way toward targeted therapies.

Bronchiolitis obliterans syndrome after allogeneic hematopoietic SCT: phenotypes and prognosis.

Bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic SCT (HSCT) is recognized as a new-onset obstructive lung defect (OLD) in pulmonary function testing and is related to pulmonary chronic GVHD. Little is known about the different phenotypes of patients with BOS and their outcomes. We reviewed the data of all allogeneic HSCT recipients referred to our pulmonary department for a non-infectious bronchial disease between 1999 and 2010. We identified 103 patients (BOS (n=77), asthma (n=11) and chronic bronchitis (n=15)). In patients with BOS, we identified two functional phenotypes: a typical OLD, that is, forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) ratio <0.7 (n=53), and an atypical OLD with a concomitant decrease in the FEV1 <80% and FVC <80% predicted with a normal total lung capacity (n=24). The typical OLD was characterized by more severe FEV1 and fewer centrilobular nodules on the computed tomography scan. The FEV1 was not significantly affected during the follow-up, regardless of the phenotype. In addition to acute and extensive chronic GVHD, only the occurrence of BOS soon after transplantation and the intentional treatment of BOS with steroids were associated with a poor survival. The determination of patient subgroups should be explored to improve the management of this condition.