Multiorgan WU Polyomavirus Infection in Bone Marrow Transplant Recipient

Abstract

WU polyomavirus (WUPyV) was detected in a bone marrow transplant recipient with severe acute respiratory distress syndrome who died in 2001. Crystalline lattices of polyomavirus-like particles were observed in the patient's lung by electron microscopy. WUPyV was detected in the lung and other tissues by real-time quantitative PCR and identified in the lung and trachea by immunohistochemistry. A subset of WUPyV-positive cells in the lung had morphologic features of macrophages. Although the role of WUPyV as a human pathogen remains unclear, these results clearly demonstrate evidence for infection of respiratory tract tissues in this patient.

Keywords: WU polyomavirus; epithelial cells; immunosuppression; transplant; tropism; viruses.

Figure 1

Electron micrographs of polyomavirus-like particles in lung from a child with fatal acute respiratory illness. A) Low-power view of a nucleus displaying multiple electron dense crystalline arrays. Scale bar indicates 0.5 μm; original magnification ×10,000. B) Higher-power magnification of nucleus in panel A. Scale bar indicates 100 nm; original magnification ×30,000. C) Large cluster of putative polyomavirus virions. Scale bar indicates 250 nm; original magnification ×20,000.

Figure 2

Immunohistochemical detection of WU polyomavirus viral protein 1 in respiratory tract of a child with fatal acute respiratory illness. Human lung tissue at original magnification of ×200, stained with a monoclonal antibody against WU polyomavirus viral protein 1 (designated NN-Ab06) (A, C) or an isotype control antibody (B, D). Human tracheal tissue at original magnification of ×200, stained with NN-Ab06 (E) or an isotype control antibody (F). The middle panels show insets from panels A, C, and E (dotted boxes) at higher original magnifications (×600).

Figure 3

Detection of WU polyomavirus viral protein 1 in CD68-positive cells from a child with fatal acute respiratory illness. Lung tissue stained with NN-Ab06 (blue) and a monoclonal antibody against CD68 (brown). A) Tissue at original magnification of ×400. B) Closer view of cell from panel A consistent with a foamy macrophage (arrow). Original magnification ×1,000. C) Closer view of cells from panel A. Original magnification ×1,000. D) Different field of the tissue section with another double-positive cell. Original magnification ×1,000.

Figure 4

Detection of WU polyomavirus viral protein 1 in close proximity to MUC5AC-positive cells in the trachea of a child with fatal acute respiratory illness. Tracheal tissue stained with NN-Ab06 (blue) and a monoclonal antibody against MUC5AC (brown). A) Tissue at original magnification of ×200. B) Tissue at original magnification of ×600.