Lymphocytic pneumonitis as the manifestation of acute graft-versus-host disease of the lung.

Acute graft-versus-host disease is a common complication after allogeneic stem cell transplantation. It normally affects the skin, liver, and gut. We report a 54-year-old male who developed shortness of breath, cough, and bilateral pulmonary infiltrates in which the work-up failed to demonstrate an infectious etiology 165 days post-HLA-matched allogeneic peripheral blood stem cell transplant. Eighteen days before, his tacrolimus had been tapered and it was subtherapeutic on admission. A transbronchial biopsy showed a perivascular and interstitial lymphocytic infiltrate without evident pathogens on histology or extensive work-up. The clinical picture was suggestive of pulmonary acute graft-versus-host disease. No disease was present elsewhere. Accordingly, the patient was treated with steroids and tacrolimus. After 12 hr on methylprednisolone, his symptoms disappeared with eventual resolution radiologically. Acute graft-versus-host disease of the lung is a very uncommon complication after stem cell transplant, but it should be considered in patients who are at high risk for graft-versus-host disease or developing symptoms soon after discontinuing immunosuppression. Its diagnosis requires work-up to rule out an infectious etiology and a biopsy to confirm histology.