Pulmonary function in familial amyloidosis with polyneuropathy.

Pulmonary function tests were performed in 14 patients with familial amyloidosis with polyneuropathy. Low maximum expiratory and inspiratory pressures were found in all patients with advanced polyneuropathy, indicating that the neuropathy in this disease involves not only the extremities but also the respiratory muscles. The spirometric findings were consistent with a slight restrictive pattern in several patients, but in two of them the expiratory and inspiratory flows were also low. The intrapulmonary gas distribution was uniform in all. The diffusing capacity was reduced in patients who had had the disease for a long time, which suggests alveolo-capillary block caused by amyloid deposits. The arterial oxygen tension at rest was essentially normal in these patients.