Alveolar lipoproteinosis in lung allograft recipients

Three cases of pulmonary alveolar proteinosis developing in lung allograft recipients are reported. In each case, repeated bouts of alveolar damage from harvest/reperfusion injury, rejection, and infection were observed before the development of intraalveolar accumulation of granular, periodic acid-Schiff-positive material in the allograft lungs. It is speculated that iatrogenic immunosuppression combined with defective clearance of alveolar material by alveolar macrophages created a milieu conducive to the accumulation of surfactant, lipoprotein, and fibrinous debris that was morphologically identical to alveolar proteinosis.