The Lung in Sickle Cell Disease

Abstract

Patients with sickle cell disease (SCD) often present with acute pulmonary complications, which may have a protracted course. Morphologic observations of SCD patients at autopsy suggested a role of tissue necrosis in the failure of pulmonary infiltrates to resolve with therapy. Infarction of pulmonary parenchyma was seen in regions where alveolar gas exchange was compromised by edema or exudates. We reviewed the clinical and pathologic features of 72 patients with sickle cell disease (59 SS, 12 SC, and 1 S-Thal) autopsied at The Johns Hopkins Hospital and compared 72 age-sexrace matched controls. Alveolar wall necrosis attributed to vascular obstruction by sickling occurred in areas where the airspace was occupied by edema or inflammatory exudate. Twelve (17 percent) SCD patients had alveolar wall necrosis, three (27 percent) among the 11 patients with bronchopneumonia and nine (17 percent) among the 54 patients with edema. Only four (6 percent) control patients had alveolar wall necrosis, all (20 percent) among the 21 patients with bronchopneumonia. Thus, alveolar wall necrosis was significantly more frequent among SCD patients (P < 0.05). Focal parenchymal scars were more frequent with SCD (P < 0.005) and may have originated in part from previous episodes of alveolar wall necrosis. Pulmonary emboli of necrotic bone marrow were seen in nine (13 percent) SCD patients, but in no controls (P < 0.01). There was no significant difference in the frequency of ordinary thromboemboli and thromboembolic infarction between the SCD and control groups. The study suggests that alveolar wall necrosis and pulmonary embolization of necrotic marrow may often complicate SCD. Patients with sickle cell disease (SCD) often present with acute pulmonary complications, which may have a protracted course. Morphologic observations of SCD patients at autopsy suggested a role of tissue necrosis in the failure of pulmonary infiltrates to resolve with therapy. Infarction of pulmonary parenchyma was seen in regions where alveolar gas exchange was compromised by edema or exudates. We reviewed the clinical and pathologic features of 72 patients with sickle cell disease (59 SS, 12 SC, and 1 S-Thal) autopsied at The Johns Hopkins Hospital and compared 72 age-sexrace matched controls. Alveolar wall necrosis attributed to vascular obstruction by sickling occurred in areas where the airspace was occupied by edema or inflammatory exudate. Twelve (17 percent) SCD patients had alveolar wall necrosis, three (27 percent) among the 11 patients with bronchopneumonia and nine (17 percent) among the 54 patients with edema. Only four (6 percent) control patients had alveolar wall necrosis, all (20 percent) among the 21 patients with bronchopneumonia. Thus, alveolar wall necrosis was significantly more frequent among SCD patients (P < 0.05). Focal parenchymal scars were more frequent with SCD (P < 0.005) and may have originated in part from previous episodes of alveolar wall necrosis. Pulmonary emboli of necrotic bone marrow were seen in nine (13 percent) SCD patients, but in no controls (P < 0.01). There was no significant difference in the frequency of ordinary thromboemboli and thromboembolic infarction between the SCD and control groups. The study suggests that alveolar wall necrosis and pulmonary embolization of necrotic marrow may often complicate SCD.