Pulmonary Alveolar Proteinosis

Key Features

• Periodic acid-Schiff–positive phospholipids accumulate within alveolar spaces

• May be primary (idiopathic) or secondary to immunodeficiency, hematologic malignancies, or inhalation of mineral dusts, or may occur after lung infections

Clinical Findings

• Progressive dyspnea

• Chest radiograph shows bilateral alveolar infiltrates suggestive of pulmonary edema

• Spontaneous remission occurs in some; progressive respiratory insufficiency develops in others

• Pulmonary infection with Nocardia or fungi may occur

Diagnosis

• Based on characteristic findings on alveolar lavage, a milky appearance, and periodic acid-Schiff–positive lipoproteinaceous material, with typical clinical and radiographic features

• In secondary disease, an elevated anti-GM-CSF titer in serum or bronchoalveolar lavage (BAL) fluid is highly sensitive and specific

• Biopsy is necessary in some cases

Treatment

• Therapy consists of periodic whole-lung lavage

• Inhalational or subcutaneous GM-CSF may benefit patients who cannot tolerate or who do not respond to whole lung lavage