[Respiratory complications in hematopoietic stem cell transplantation. What does radiology contribute?]

To determine the incidence of respiratory complications and their manifestations in both conventional radiology and high-resolution computerized tomography (HRCT) in a series of patients who had undergone blood progenitor cell transplantation (BPCT). The objective was to evaluate whether the radiological findings associated with post-transplantation time can be useful for establishing the differential diagnosis.

A study was undertaken of a total of 108 consecutive patients who had undergone BPCT and were alive one year after; from these patients a selection was made of those who had some respiratory complications during the first year after transplantation. Complications were classified in three different groups on the basis of time elapsed since transplantation (early, intermediate, and late stages). Chest X-ray films of each patient were examined and in 17 cases the study was completed with HRCT. These findings were correlated with both definitive diagnosis and time elapsed since BPCT. The following procedures were useful for diagnostic confirmation: blood culture, sputum culture, fibrobronchoscopy with bronchoalveolar lavage or lung biopsy, biopsy by other methods, necropsy, or clinical course after empirical therapy.

Thirty-three out of the 108 patients undergoing BPCT had some form of respiratory complication during the first year after transplantation. The most common radiological pattern both in the chest X-ray and in HRCT was alveolar consolidation. Other findings included ground-glass appearance, interstitial pattern, pulmonary nodules, and pleural effusion. The diagnoses in relation to the different stages of transplantation were: a) early stage: three cases of heart failure, two cases of alveolar hemorrhage, two cases of pulmonary aspergillosis and three cases of undocumented complications; b) intermediate stage: four cases of cytomegalovirus pneumonia, one case of pulmonary aspergillosis, two cases of bacterial pneumonia, and two cases of undocumented pneumonitis; c) late stage: four cases of bacteriologically documented pneumonia, two cases of pneumonitis with an unidentified agent, two cases of graft-versus-host disease, one case of pulmonary aspergillosis and two complications without established diagnosis.

The relationship between radiological findings and time elapsed since transplantation of blood precursor cells is very useful for establishing the diagnosis of pulmonary complications. High resolution computerized tomography is useful for detecting unnoticed lesions in conventional X-ray, and for diagnosing bronchiolitis obliterans and some fungal lesions.