Abstract
Pulmonary Langerhans cell histiocytosis (PLCH) is a rare sporadic cystic lung disease of unknown aetiology that is characterised by the infiltration and destruction of the wall of distal bronchioles by CD1a+ Langerhans-like cells. In adults, PLCH is frequently isolated and affects young smokers of both sexes. Recent multicentre studies have led to the more standardised management of patients in clinical practice. Smoking cessation is essential and is occasionally the only suitable intervention. Serial lung function testing is important because a significant proportion of patients may experience an early decline in forced expiratory volume in 1 s and develop airflow obstruction. Cladribine was reported to dramatically improve progressive PLCH in some patients. Its efficacy and tolerance are currently being evaluated. Patients who complain of unexplained dyspnoea with decreased diffusing capacity of the lung for carbon monoxide should be screened for pulmonary hypertension by Doppler echocardiography, which must be confirmed by right heart catheterisation. Lung transplantation is a therapeutic option for patients with advanced PLCH.
The identification of the BRAFV600E mutation in approximately half of Langerhans cell histiocytosis lesions, including PLCH, and other mutations of the mitogen-activated protein kinase (MAPK) pathway in a subset of lesions has led to targeted treatments (BRAF and MEK (MAPK kinase) inhibitors). These treatments need to be rigorously evaluated because of their potentially severe side-effects.
Abstract
Recent advances have led to the more standardised management of patients with PLCH in clinical practice http://ow.ly/pyk930dWVxN
Footnotes
Conflict of interest: Disclosures can be found alongside this article at err.ersjournals.com
Provenance: Commissioned article, peer reviewed.
- Received June 15, 2017.
- Accepted July 12, 2017.
- Copyright ©ERS 2017.
ERR articles are open access and distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0.