[Primary pulmonary alveolar proteinosis--clinical observation of 68 patients in Japan]

The clinical features of 68 Japanese patients (53 men and 15 women; mean age 44 years) with primary pulmonary alveolar proteinosis were reviewed. Pulmonary alveolar proteinosis was diagnosed from histologic findings after open lung biopsy (n = 7) or transbronchial lung biopsy (n = 61). Major symptoms were a dry cough (24.2%) and dyspnea or shortness of breath on exertion (51.5%), but one third of the patients were asymptomatic. Crackles were audible in 30% of the patients, but clubbing (6%) and cyanosis (4%) were rare. Ten patients had been occupationally exposed to dust. Slightly less than half (46%) of the patients first presented with symptoms, and the remainder (54%) first presented with abnormal pulmonary infiltrates seen on chest roentgenograms taken during general health examinations. Many patients had abnormally high levels of LDH and CEA in serum (62% and 63%, respectively). Restrictive pulmonary dysfunction (%VC < 80%) was seen in 31% of the patients, an abnormally low DLco (%DLco < 70%) was seen in 62%,m and hypoxemia (PaO2 < 80 mmHg) was seen in 67%. Arterial blood gas tension was closely correlated with the severity of disease in these patients. Chest roentgenograms usually showed bilateral symmetric alveolar infiltrates, mainly distributed from hilar areas toward the pleura, but on CT scans many of the shadows were mixed with alveolar and interstitial infiltrates of various extent along the pulmonary arteries and bronchi. There was no apparent relation between chest roentgenographic findings and chest CT findings in these patients. Neither the extension nor other characteristics of shadows in the chest roentgenograms and chest CT scans were closely related to symptoms, laboratory data, or pulmonary function in these patients. Symptoms were alleviated and chest roentgenographic findings improved in 82% of the 51 patients who underwent therapeutic bronchoalveolar lavage, and in 94% of the 17 patients who did not undergo that procedure. In patients who underwent therapeutic bronchoalveolar lavage and also in those who recovered spontaneously, both diffusing capacity and blood gas values improved significantly. When compared to the patients who did not undergo therapeutic bronchoalveolar lavage, significantly more of those who did undergo that procedure has initial PaO2 values below 60 mmHg, and fewer of them had values greater than 80 mmHg. Thus, a PaO2 below 60 mmHg may be an indication for therapeutic bronchoalveolar lavage in patients with this disease. During the follow-up period (mean 5 years, range 2 months to 23 years), four patients had pneumothorax and none died of pulmonary alveolar proteinosis.