Idiopathic interstitial pneumonitis possibly associated with chronic graft-versus-host disease

We described two cases of idiopathic interstitial pneumonitis (IP) after allogeneic bone marrow transplantation (BMT), who were successfully treated with prednisolone (PSL). A 40-year-old male with AML (M3) in the first remission (case 1) and a 36-year-old male with CML in chronic phase (case 2) were treated with BMT from HLA genotypically identical female siblings. Both patients were conditioned with busulfan (16mg/kg) and cyclophosphamide (120mg/kg), and given a combination of cyclosporin A and methotrexate to prevent acute GVHD (aGVHD). Engraftment of donor marrow was documented in both cases. Grade I of aGVHE developed in case 1 and no aGVHD in case 2. Both patients had clinical manifestations of chronic GVHD (cGVHD), which were followed by dyspnea and cough without fever 120 days (case 1) or 100 days (case 2) after BMT. Abnormal lung function tests and radiographic infiltrates indicated that patients developed IP, but causative microorganisms could not be detected in the bronchoalveolar lavage (BAL) specimens. Subjective symptoms disappeared in a few days after administering PSL (1mg/kg/day). Laboratory data also improved thereafter. These observations, including the development of radiographic infiltrates along with clinical manifestations of cGVHD, absence of febrile episodes, absence of causative microorganisms in the BAL specimens, and effectiveness of immunosuppressive drugs, suggested that idiopathic IP observed in our cases might be a manifestation of cGVHD.