Table 1.
Characteristics of the patients at the time of diagnosis of PLCH
| Characteristic | N = 43 |
|---|---|
| Age, years, median, [IQR] | 26.5 [22.9–35.4] |
| Male sex, n (%) | 26 (60%) |
| Smoker, n (%) | 39 (91%) |
| Ex-smoker | 4 (9%) |
| Cannabisa, n (%) | 14 (33%) |
| Asymptomatic | 12 (28%) |
| Respiratory symptoms, n (%) | 25 (58%) |
| Cough | 17 (40%) |
| Dyspnoea | 14 (33%) |
| NYHA II/III | 13/1 |
| Constitutional symptoms | 11 (26%) |
| Histological diagnosis, n (%) | 33 (77%) |
| Genotyping, n | 22 |
| BRAFV600E, n (%) | 11 (50%) |
| Pneumothorax as initial manifestation | 28 (65%) |
| Isolated PLCH, n (%) | 30 (70%) |
| MS LCH, n (%) | 13 (30%) |
| Non-pulmonary LCH localizations, n | |
| Bone | 4 |
| Pituitary stalk | 9 |
| Diabetes insipidus | 9 |
| Anterior hypophysis dysfunction | 4 |
| Skin | 4 |
| Peripheral lymph nodes | 2 |
| CNS | 1 |
| Liver | 1 |
| Lung functionb, n | 36 |
| TLC, % of predicted, n = 33 | 94 [87–107] |
| VC, % of predicted, n = 35 | 80 [65–96] |
| RV/TLC, % of predicted, n = 29 | 141 [118–162] |
| FEV1, % of predicted, n = 36 | 75.5 [59–90.5] |
| FEV1/FVC %, n = 31 | 78 [70–84] |
| DLCO % of predicted, n = 21 | 58 [53–71] |
| Restrictionc, (%) | 3 (9%) |
| Obstruction, (%) | 7 (23%) |
| Air trapping, n (%) | 20 (69%) |
aall tobacco smokers
bevaluated before the first pneumothorax in 11 patients (median time interval of −7.0 months IQR [−21.8; − 2.8]) and after the pneumothorax within a median time of 4.5 months, IQR [2.0–10.5] in the 25 remaining patients
crestriction was defined as TLC < 80% of predicted; obstruction as FEV1/FVC < 70% and air trapping as RV/TLC > 120% of predicted
Abbreviation definitions: PLCH pulmonary Langerhans cell histiocytosis, NYHA New York heart association, MS multisystem, CNS central nervous system, TLC total lung capacity, VC vital capacity, RV residual volume, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, DLCO diffusion of carbon monoxide