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A 25-year-old woman, a never smoker with a history of heart-lung transplantation for World Health Organization group 1 pulmonary arterial hypertension performed 20 months prior to presentation, was evaluated for shortness of breath. Following transplantation, she was initiated on standard therapy of prednisone, tacrolimus, and azathioprine, along with routine antimicrobial prophylaxis. Her posttransplant course was complicated by persistent acute cellular rejection, as determined from a transbronchial biopsy specimen, without evidence of rejection in an endomyocardial biopsy specimen. The immunosuppressive medications were supplemented with pulse-dosed steroids, and the patient was transitioned from azathioprine to mycophenolate mofetil. Sirolimus was added 9 months prior to presentation. Three months prior to presentation, she was admitted for increasing oxygen requirements, shortness of breath, and bilateral infiltrates on the CT scans of the chest.

Pulmonary alveolar proteinosis is characterized by the accumulation of proteinaceous material in the alveoli leading to varying degrees of impairment in gas exchange. Generally, the degree of hypoxemia is mild, and it is rare to have respiratory failure requiring mechanical ventilation. We present a 53-year-old woman with the most severe degree of hypoxemia associated with alveolar proteinosis reported in the English-language adult literature. Her therapy of sequential whole-lung lavage performed while receiving venovenous extracorporeal membrane oxygenation in one operative session is the first reported successful use of this approach.

Pneumocystis carinii (PC) has been recognized as frequently responsible for most opportunistic pulmonary infections occurring in immunocompromised AIDS and non-AIDS patients. Moreover, these patients can be considered at risk for secondary pulmonary alveolar proteinosis. Therefore, we have investigated the occurrence of associated secondary alveolar proteinosis and PC pneumonitis in AIDS and non-AIDS immunocompromised patients. In a series of 26 bronchoalveolar lavages (BAL) in patients with PC pneumonitis (19 AIDS and seven non-AIDS patients), we observed on light microscopy, in addition to the honeycombed material, areas of an extracellular material that had a different pattern which was suggestive of that described in alveolar proteinosis. A systematic ultrastructural study of these 26 BAL fluid samples demonstrated in each of them an accumulation of phospholipid surfactantlike extracellular material mixed or not with the PC cysts. In nine cases, the observation of lipoproteinaceous material on light microscopy and abundant phospholipid material with myelinlike and myelin tubular laminated structures on electron microscopy was highly suggestive of an associated pulmonary alveolar proteinosis (PAP). Such an accumulation of extracellular material was not observed in the 11 BAL fluid samples collected in immunocompromised patients (seven AIDS and four non-AIDS patients) without PC pneumonitis. These findings demonstrated a particular frequency of associated PAP with PC pneumonitis. These results raise important questions concerning (1) the consequence of such an alveolar accumulation of lipoproteinaceous material on the clinical status and prognosis of the pneumonitis, and (2) the mechanisms responsible for this accumulation.

A patient with acute myelogenous leukemia developed pulmonary alveolar proteinosis in the terminal phase of the leukemia. The diagnosis of pulmonary alveolar proteinosis was unsuspected during life and was established only at autopsy. Other reported cases of the same association are reviewed. This report serves to stress the importance of considering the diagnosis of pulmonary alveolar proteinosis in malignant hematologic diseases and the need for hematologic evaluations in pulmonary alveolar proteinosis.

Whole-lung lavage under hyperbaric oxygen conditions was performed in two patients suffering from severe respiratory insufficiency in pulmonary alveolar proteinosis. Under these conditions, gas exchange was maintained and the mixed venous partial pressure of oxygen and oxygen saturation showed increases to acceptable levels. This enabled us to limit the FIO2 in order to extend the oxygen tolerance and to perform lavage procedures more effectively. Both patients showed a very significant improvement of their clinical course, and we conclude that elective use of hyperbaric oxygen in unilateral lung lavages should be considered in these severe cases.

A 23-year-old woman became pregnant in the setting of long-standing severe pulmonary alveolar proteinosis. A previous twin gestation had resulted in low birth-weight infants. Progressive clinical and respiratory deterioration occurred, associated with exertional arterial oxygen desaturation. Because of the severity of her physiologic derangements and concern for the fetus, whole-lung bronchopulmonary lavage was performed twice under controlled conditions. This resulted in subjective and objective improvement, followed by successful term delivery.

Pulmonary alveolar proteinosis is characterized by excessive accumulation of surfactant-like material in the alveoli, resulting in part from defective alveolar clearance by macrophages. We present a case of alveolar proteinosis in a patient with malignant melanoma metastatic to lung and discuss possible alteration in macrophage function in the pathogenesis of these two concomitant processes.