Analysis of recombinant adeno-associated viral vector shedding in sheep following intracoronary delivery.

Differences between mouse and human hearts pose a significant limitation to the value of small animal models when predicting vector behavior following recombinant adeno-associated viral (rAAV) vector-mediated cardiac gene therapy. Hence, sheep have been adopted as a preclinical animal, as they better model the anatomy and cardiac physiological processes of humans. There is, however, no comprehensive data on the shedding profile of rAAV in sheep following intracoronary delivery, so as to understand biosafety risks in future preclinical and clinical applications. In this study, sheep received intracoronary delivery of rAAV serotypes 2/6 (2 × 1012 vg), 2/8, and 2/9 (1 × 1013 vg) at doses previously administered in preclinical and clinical trials. This was followed by assessment over 96 h to examine vector shedding in urine, feces, nasal mucus, and saliva samples. Vector genomes were detected via real-time quantitative PCR in urine and feces up to 48 and 72 h post vector delivery, respectively. Of these results, functional vector particles were only detected via a highly sensitive infectious replication assay in feces samples up to 48 h following vector delivery. We conclude that rAAV-mediated gene transfer into sheep hearts results in low-grade shedding of non-functional vector particles for all excreta samples, except in the case of feces, where functional vector particles are present up to 48 h following vector delivery. These results may be used to inform containment and decontamination guidelines for large animal dealings, and to understand the biosafety risks associated with future preclinical and clinical uses of rAAV.

Persistent erythrovirus B19 urinary tract infection in an HIV-positive patient.

We report a urinary tract infection (UTI) with erythrovirus B19 in an HIV-1-positive homosexual man persisting for more than 7 months after the decline of viremia after a primary infection. During the course of the UTI, the patient complained of soreness in the kidney region and suffered from transient episodes of edema and hematuria. Proteinuria and elevated serum concentrations of creatinine further substantiated the hypothesis of a renal focus of a persistent erythrovirus B19 infection.

Renal involvement induced by human parvovirus B19 infection.

In an attempt to clarify the renal involvement induced by human parvovirus B19 (HPB19) infection, we investigated 6 adult patients with transient urinary abnormalities followed by erythema infectiosum. All patients had HPB19-specific IgM antibody and showed mild proteinuria of 0.2-1.2 g/day with or without microscopic hematuria. In 5 patients a decrease of complement was present, and in 2 the circulating immune complex levels were elevated. All patients showed mild or moderate endocapillary proliferation with leukocytic infiltrates in glomeruli and leukocytic infiltrates with edema around interlobular arteries and arterioles. Immunofluorescence microscopy revealed C3c deposits with immunoglobulins along the glomerular capillary walls and in the walls of small arteries and arterioles. Electron microscopic studies showed swelling of the endothelial cells and small electron-dense deposits in mesangium (in all 6 patients) and subendothelium (in 5 of 6 patients). However, HPB19 VP1 and VP2 capsid antigens were not demonstrated in the glomerulus or the vascular wall in any patient. These findings suggest that the renal lesions caused by an immune complex mediated phenomenon would be closely correlated with the HPB19 infection, although the precise mechanism is not entirely clear, and that in adults HPB19 should be thought of as a possible cause of acute postinfectious glomerulonephritis.