Pulmonary alveolar proteinosis in a cat.

BACKGROUND: Pulmonary alveolar proteinosis is an extremely rare lung disease in animals and humans. It is characterized by the deposition of a large amount of phospholipoproteinaceous material in the alveoli. There are several possible etiologies, both congenital and acquired. Alveolar macrophages play an important role in the clearance of surfactant. This is the first report of pulmonary alveolar proteinosis in the feline species. CASE PRESENTATION: Pulmonary alveolar proteinosis was diagnosed in an 8-month-old cat with chronic tachypnea, failure to thrive and finally respiratory distress. The diagnosis was based on the milky appearance of the bronchoalveolar lavage fluid taken under general anesthesia after bronchoscopy. Because of the worsening respiratory distress and development of anorexia the kitten was euthanized. Histopathology of the lungs showed alveoli and bronchi filled with eosinophilic material. Electron microscopy revealed lamellated intra-alveolar bodies. As the granulocyte-macrophage colony-stimulating factor was elevated in the serum and no autoantibodies against granulocyte-macrophage colony-stimulating factor were detected, a primary hereditary pulmonary alveolar proteinosis was suspected. The underlying cause was thought to be a dysfunction of the receptor of the granulocyte-macrophage colony-stimulating factor, however, a mutation in the genes encoding the alpha and beta chains of this receptor has not been found. CONCLUSION: This is the first description of pulmonary alveolar proteinosis in a cat. This kitten is thought to have a primary hereditary pulmonary alveolar proteinosis with a possible defect in the signalling pathway of the receptor of the granulocyte-macrophage colony-stimulating factor. The imaging and pathologic findings are similar to those of humans.

Imaging diagnosis--pulmonary alveolar proteinosis in a dog.

A young dog was presented for cyanosis and right heart failure. Radiographic and CT characteristics included right heart/pulmonary artery enlargement, hepatomegaly, abdominal effusion, and severe, generalized air-space filling. Focal increased opacities were present in the peripheral lung, as were multiple pulmonary blebs and bullae. Echocardiographic findings were consistent with cor pulmonale and pulmonary hypertension. Bronchoscopic findings were consistent with chronic inflammation. Pulmonary alveolar proteinosis (PAP) was confirmed at necropsy. Pulmonary alveolar proteinosis is an interstitial lung disease that results in accumulation of phospholipoproteinaceous material and should be included as a differential diagnosis for dogs with these clinical and imaging characteristics.

Spontaneous pulmonary alveolar proteinosis in captive "moustached tamarins" (Saguinus mystax).

Pulmonary alveolar proteinosis is a rare human disease characterized by accumulation of surfactant in alveoli without generating an inflammatory response. Lung lesions resembling pulmonary alveolar proteinosis were observed in 7 adult tamarins (5 males and 2 females). Gross lesions were characterized by areas of discoloration, slight bulging over the lung parenchyma, and occasional consolidation. Histologic examination of tamarin lung samples revealed intra-alveolar accumulation of amorphous, amphophilic, periodic acid-Schiff-positive, finely granular to dense material. In some cases, type II pneumocyte hypertrophy and hyperplasia were observed with pleural and septal thickening and fibrosis. Large numbers of intra-alveolar foamy macrophages were noted surrounding and/or in the vicinity of the lesions. Immunohistochemical analysis of the lung lesions using polyclonal (surfactant proteins A, B, and C) and monoclonal (surfactant protein D) antibodies revealed the granular material to be composed largely of surfactant protein B, followed by surfactant protein A. Surfactant proteins C and D were present in lesser quantities, with the latter observed surrounding the lipoproteinaceous deposits. Transmission electron microscopy of the affected lungs showed numerous, irregularly shaped osmiophilic lamellar bodies in type II pneumocytes. The cytoplasm in alveolar macrophages was expanded, containing ingested surfactant with swollen mitochondria and rough endoplasmic reticulum. Thoracic radiographs, available in 1 animal, depicted the lesions as small multifocal opacities randomly distributed in cranial and diaphragmatic lung lobes. This is, to the authors' knowledge, the first report of spontaneous pulmonary alveolar proteinosis in nonhuman primates.

Avian pulmonary proteinosis: six cases and a review of the literature.

Pulmonary alveolar proteinosis (PAP) is a disease of surfactant clearance in which functional abnormalities in alveolar macrophages lead to accumulation of surfactant within alveoli in mammals. Histologic examination of 6 avian autopsies, including 4 chickens, a turkey, and a cockatiel, revealed accumulation of hypereosinophilic densely arrayed lamellar material in the lungs that was magenta by periodic acid-Schiff stain and diastase resistant. Transmission electron microscopy of the proteinaceous material in 2 cases demonstrated alternating electron-dense and electron-lucent lamellae that formed whorls and had a regular periodicity of 6-14 nm, consistent with pulmonary surfactant. Given the anatomic differences between avian and mammalian lungs, we designated the presented condition "pulmonary proteinosis," which can be observed as both an incidental finding or, when severe, may be a contributing factor to death through respiratory failure.

Histopathology of pulmonary alveolar proteinosis spontaneously occurring in aged KK mice.

Histopathological findings of pulmonary alveolar proteinosis occurring spontaneously in aged KK mice (72 weeks of age) were described. The lung tissues examined were obtained from the mice used for a one-year toxicity study of some oral hypoglycemic drugs, but there was no relationship between the incidence of the disease and the drug treatment. The disease occurred in 67 of 319 males (21.0%) and 124 of 284 females (43.7%). The gross lesions of the lungs were solitary or multiple nodules. Microscopically, the lesions developed in the peribronchial areas and were well-circumscribed. The initial lesions consisted of the aggregation of foamy cells in the alveoli. In the advanced lesions, amorphous substance resulting from destructed foamy cells and proteinous material accumulated in the alveoli. In the more advanced lesions, neutrophils and nuclear fragments were contained in the proteinous material and some of the alveolar walls were thickened with cell infiltration, fibrosis and so-called epithelialization. The etiology of the present condition was unknown.