Langerhans Cell Histiocytosis (LCH) is a rare, dendritic cell disorder commonly involving the lungs either alone, (PLCH) or as part of multi-system disease (MSLCH). The natural history is variable, ranging from spontaneous resolution to progressive respiratory failure and death. Until recently there were no large follow up series containing lung function data (Tazi A et al, ERJ 2012; 02107–2011).
We retrospectively compared pulmonary function over time in patients with PLCH and in MSLCH with lung involvement from our database of 83 adult LCH patients. 46 patients were male; mean age at diagnosis was 34 (range 16–76) years (y). 9/83 patients, 4 male, mean age 32 y, had PLCH. 21/83 13 male, mean age 28y, had MSLCH with lung involvement.
All PLCH had smoked with mean 14 pack-y. 7 continued smoking after diagnosis. Initial lung function (n=8) at a mean of 1 (–1 to +3) y post-diagnosis, showed wide variation in spirometric volumes, flows and gas transfer measurements (See table). 1 patient had obstructive, 2 restrictive, 3 mixed patterns, 1 isolated reduction in gas transfer and 2 were normal.
18/21 MSLCH had smoked; mean 12 pack-y. 10 continued smoking after diagnosis. Initial lung function (n=14) at mean 2 (0–12) y post-diagnosis showed slightly less impairment than PLCH but again wide variation.
In PLCH (n=7) at mean follow up of 7 (2–10) y, mean changes in lung function were minor but there was variation; 2 patients deteriorated significantly. 4/9 patients received treatment. To date, 1 has died, 5 are in remission and 3 have active disease.
In MSLCH (n=12) at mean follow up of 7 (1–16) y, mean changes in lung function were minor apart from 2 patients who showed major reductions. 17/21 patients received treatment. To date 3 have died, 12 are in remission and 6 have active disease.
Pulmonary involvement in LCH and impairment of lung function are common in both single and multisystem disease. Changes in lung function over time are very variable with some patients showing marked deterioration and others minor improvement. Lung function determination is important in monitoring all LCH patients with lung involvement.