Localization of parvovirus B19 in the renal allografts of healthy donors.

Parvovirus B19 (PVB19) is usually not a subject of pre-transplant evaluation. Little is known regarding the localization of PVB19 in normal kidneys, particularly in relation to its cellular receptor, the P antigen. Tissue specimens obtained from 0-h renal allograft biopsies were investigated for the presence of PVB19 DNA by polymerase chain reaction (PCR) and the relative localization of P antigen and PVB19-related protein by double immunofluorescence staining. Double staining of in situ hybridization for PVB19 DNA and immunofluorescence staining for PVB19-related proteins was also performed. The presence of the virus was further evaluated by electron microscopy in selected biopsy specimens. PCR analysis detected PVB19 DNA in 39 out of 112 (35%) tissue samples. Immunohistochemical analysis of these 39 PVB19 DNA-positive samples revealed that 28 (72%) exhibited positive staining for PVB19-related proteins within some tubular epithelial cells. Electron microscopy demonstrated regular polygonal virus-like particles within tubular epithelial cells. Furthermore, most PVB19-positive tubular epithelial cells expressed the P antigen on their apical surfaces. PVB19 DNA and PVB19-related proteins co-localized in some tubular epithelial cells. Thus, approximately 1/3 of healthy adult kidneys contain PVB19, which is localized mainly in distal tubules expressing P antigens on their apical surface. The concurrent detection of PVB19 DNA and proteins, along with the visualization of virus-like particles by electron microscopy, suggests that PVB19 could live with protein-producing capacity. Given the relatively high frequency of detection, the possibility of PVB19 infection should be carefully considered in the context of kidney transplantation.