Discrepancy of clinical, radiographic and histopathologic findings in two children with chronic pulmonary graft-versus-host disease after HLA-identical sibling stem cell transplantation

We report two children who presented with cough and shortness of breath 7-8 months after a matched sibling stem cell transplant (SCT) for chronic myelogenous leukemia and myelodysplastic syndrome, respectively. Pulmonary function tests (PFTs) revealed severe airways obstruction (AO). However, radiographic investigations showed no serious abnormalities in the early phase and open lung biopsy revealed only mild lymphocytic bronchiolitis and bronchiolitis obliterans consistent with pulmonary graft-versus-host disease (GVHD). Despite administration of bronchodilators and various immunosuppressive agents obstructive lung disease progressed to pulmonary failure in patient 1, whereas stabilization of the clinical course was observed in patient 2. Serial PFTs were the best predictor of the clinical course in contrast to radiographic and histologic findings. It is concluded that PFTs should be performed repeatedly in pediatric patients after allogeneic SCT with the aim of diagnosing GVHD-associated AO in the subclinical phase. Progressive post-transplant AO necessitates prompt initiation of intensive immunosuppressive therapy in order to stop the underlying immunopathologic process even in the absence of severe radiographic and histologic findings.