Impairment of lung diffusion capacity-a new consequence in the long-term childhood leukaemia survivors

Childhood leukaemia survivors (CLS) are known to have developed long-term impairment of lung function. The reasons for that complication are only partially known. The aims of this study were to assess pulmonary function in CLS and identify (1) risk factors and (2) clinical manifestations for the impairment of airflow and lung diffusion. The study group included 74 CLS: 46 treated with chemotherapy alone (HSCT-), 28 with chemotherapy and haematopoietic stem cell transplantation (HSCT+), and 84 healthy subjects (control group (CG)). Spirometry and diffusion limit of carbon monoxide (DLCO) tests were performed in all subjects. Ten (14%) survivors had restrictive, five (7%) had obstructive pattern, and 47 (66%) had reduced DLCO. The age at diagnosis, type of transplant, and type of conditioning regimen did not significantly affect the pulmonary function tests. The DLCO%pv were lower in CLS than in CG (p < 0.03) and in the HSCT+ than in the HSCT- survivors (p < 0.05). The pulmonary infection increased the risk of diffusion impairment (OR 5.1, CI 1.16-22.9, p = 0.019). DLCO was reduced in survivors who experienced CMV lung infection (p < 0.001). The main symptom of impaired lung diffusion was poor tolerance of exercise (p < 0.005). The lower lung diffusion capacity is the most frequent abnormality in CLS. HSCT and pulmonary infection, in particular with CMV infection, are strong risk factors for impairment of lung diffusion capacity in CLS. Clinical manifestation of DLCO impairment is poor exercise tolerance. A screening for respiratory abnormalities in CLS seems to be of significant importance.