Table 4– Characteristics of the patients whose forced expiratory volume in 1s (FEV1) decreased within the first 2 yrs after their pulmonary Langerhans’ cell histiocytosis diagnosis compared with the remaining study population
CharacteristicDecline of FEV1 within 2 yrsNo decline of FEV1 within 2 yrsp-value
Subjects n1039
At diagnosis
 Age yrs28.1±8.631.5±7.50.24
 Male sex4 (40.0)20 (51.3)0.73
 Smoking status
  Current smokers8 (80.0)38 (97.4)0.10
  Ex-smokers2 (20.0)1 (2.6)
  Exposure pack-years11.0±9.424.4±20.00.02
 TLC % pred#99.4±15.9+100.6±16.90.90
 FVC % pred86.3±18.989.8±18.70.79
 FEV1% pred74.7±21.678.3±22.20.65
 FEV1/FVC %71.1±11.373.2±13.00.48
 RV % pred#137.1±52.4+127.3±47.1##0.69
 RV/TLC % pred#137.0±48.1+123.6±35.0##0.64
DL,CO% pred#70.9±27.9§60.6±20.9¶¶0.39
 HRCT nodular score6.4±4.86.7±3.00.65
 HRCT cystic score13.1±7.411.6±5.70.61
During follow-up
DL,CO deterioration5/8 (62.5)ƒ13/32 (40.6)++0.43
 Smoking cessation1/8 (12.5)15/38 (39.5)0.23
  • Data are presented as mean±sd or n (%), unless otherwise stated. The lung function parameters represent all patients, unless otherwise specified. TLC: total lung capacity; % pred: % predicted; FVC: forced vital capacity; RV: residual volume; DL,CO: diffusing capacity of the lung for carbon monoxide; HRCT: high-resolution computed tomography. #: at diagnosis, TLC and RV results were available for 47 patients and DL,CO for 42 patients; : serial DL,CO results were available for 40 patients; +: n=10; §: n=9; ƒ: n=8; ##: n=37; ¶¶: n=33; ++: n=32.