Spontaneous pulmonary alveolar proteinosis in captive "Moustached Tamarins" (Saguinus mystax)(primates: Callitrichidae)

Wednesday, October 26, 2011 — Poster Session IV
2:00 p.m. – 4:00 p.m.	Natcher Conference Center	NIAID	IMMUNO/INFLAM-21

Authors

• C Michaud
• D Ragland
• K Shea
• P Zerfas
• R Kastenmayer
• M St. Claire
• W Elkins
• A Gozalo

Abstract

Pulmonary alveolar proteinosis (PAP) is a rare human disease characterized by accumulation of surfactant in alveoli without generating an inflammatory response. Lung lesions resembling PAP were observed in seven adult tamarins. Gross lesions were characterized by areas of discoloration, slight bulging over the lung parenchyma, and occasional consolidation. Histological examination of tamarin lung samples revealed intra-alveolar accumulation of an amorphous, amphophilic, PAS-positive, finely granular to dense material. In some cases type II pneumocyte hypertrophy and hyperplasia with pleural and septal thickening and fibrosis were observed. 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 (SP-D) were present in lesser quantities. 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. This is, to our knowledge, the first report of spontaneous PAP in nonhuman primates.

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