Lung Function in Pregnancy in Langerhans Cell Histiocytosis.

Pulmonary Langerhans cell histiocytosis (LCH) is a rare disease, affecting usually young people. The course of the disease is variable. In some pulmonary LCH patients a severe lung destruction and progression in spite of chemotherapy is observed, but in others just a cessation of smoking induces a regression of the disease. In the present study we seek to determine the influence of pregnancy on pulmonary function in LCH patients, an unchartered area of research. We addressed the issue by investigating eight pregnant women out of the 45 women hospitalized with the diagnosis of pulmonary LCH in the period from 2000 to 2015. For five of the eight pregnant women it was the second gestation. The median follow-up period was 120 months (range 72-175 months). Ten healthy children were born by a C-section. Two spontaneous miscarriages in the seventh week of gestation, and one tubal ectopic pregnancy were recorded. We found that pregnancy did not significantly influence pulmonary function assessed by the following indices: forced expiratory volume in 1 s (FEV1), lung vital capacity (VC), total lung capacity (TLC), residual volume (RV), diffusing capacity of the lungs for carbon monoxide (DLCO), and the distance and arterial oxygen saturation in 6-min walk test. Only one patient in the third trimester of pregnancy experienced bilateral pneumothorax, with persistent air leak. In all patients, delivery and postpartum period were uneventful. We conclude that pregnancy in pulmonary LCH patients is safe and not associated with deterioration of pulmonary function or blood oxygenation.