HRCT findings in idiopathic pneumonia syndrome with documentation of the disease course

ObjectiveTo analyze extent and patterns of lung involvement in patients with idiopathic pneumonia syndrome (IPS) following allogeneic stem cell transplantation (SCT), and demonstrate their course during therapy.Methods14 consecutive patients (age 29–64 years, mean 46.2 years) who experienced IPS after allogeneic SCT (as defined by current guidelines of NIH) were treated with either steroids (n = 5), or steroids and the TNF-α blocker etanercept in more severe cases (n = 9). CT-scans obtained before, during and after IPS were evaluated retrospectively. Quantification of pulmonary involvement was performed by visual estimation. Surveillance time ranged from 21 to 914 days with a total of 99 CT-scans (2–12 CT-scans per patient) obtained.ResultsIPS was mainly confined to the central lung regions (71%) with a bilateral and symmetric distribution (71%). Ground-glass opacity (93%) was the prominent CT-morphologic correlate, whereas concomitant consolidation of lung areas (noted in 43% of patients at the time of maximum infiltrates) only occurred in severe courses of IPS (p < 0.01). Favourable courses (50%) showed an earlier peak with respect to extent and CT-attenuation of IPS infiltrates (p < 0.01) followed by a rapid decline (median IPS duration 8 days) whereas a significantly more protracted course was observed in severe (unfavorable) cases (median IPS duration 52 days, p = 0.01). The death rate in the first and the latter groups (all of the severe cases receiving TNF blockage) was 0% and 43%, respectively. Pulmonary sequelae were recorded in almost all patients during follow-up with fibrotic residues.ConclusionHRCT-features of IPS are non-specific, but predictable. Response monitoring in IPS can be well accomplished via HRCT and the course of pulmonary infiltrates heralds patient's outcome.