Background: Treatment of hemato-oncologic patients is often associated with severe pulmonary complications. Pulmonary function is routinely evaluated in older children, whereas in young patients, forced spirometry measurements are infrequently performed. Aim: To assess severity of airway disease using forced spirometry measured prior to and after treatment (over 3 years) in hemato-oncologic children aged 3-7 years in comparison to a healthy population.
Material and Method: 42-children (18-males; age 3-7 years old) with hemato-oncologic illnesses participated in the study. Spirometry was performed before the definitive treatment and up-to 3-years thereafter. Values were compared to those of healthy children of corresponding age.
Results: Most children (n=38) showed only minor long term airflow impairment (z-scores of FEV1 at last measurement was -0.00 to -0.45 SD). Prior to definitive treatment eight children presented severe airflow limitation (z-score =-1.35 + or - 0.72; -1.61 + or - 0.66 and -2.49 + or - 0.34 for FEV1, FEV0.5; and FEF25-75 respectively). Four of eight children resumed normal pulmonary function; the spirometry values of the other four children further deteriorated, in association with GVHD and development of bronchiolitis obliterans.
Conclusions: Our study suggests that it is important to follow spirometry in young children with hemato-oncologic diseases in order to detect these patients, whose condition may have prognostic implications for their treatment.

Keywords: Prevalence, Male, Israel - epidemiology, Humans, Hematologic Neoplasms - physiopathology, Female, Follow-Up Studies, Child, Case-Control Studies, Airway Obstruction - physiopathology, Spirometry - methods, Vital Capacity - physiology