1
|
Klinkhammer BM, Lammers T, Mottaghy FM, Kiessling F, Floege J, Boor P. Non-invasive molecular imaging of kidney diseases. Nat Rev Nephrol 2021; 17:688-703. [PMID: 34188207 PMCID: PMC7612034 DOI: 10.1038/s41581-021-00440-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2021] [Indexed: 02/05/2023]
Abstract
In nephrology, differential diagnosis or assessment of disease activity largely relies on the analysis of glomerular filtration rate, urinary sediment, proteinuria and tissue obtained through invasive kidney biopsies. However, currently available non-invasive functional parameters, and most serum and urine biomarkers, cannot capture intrarenal molecular disease processes specifically. Moreover, although histopathological analyses of kidney biopsy samples enable the visualization of pathological morphological and molecular alterations, they only provide information about a small part of the kidney and do not allow longitudinal monitoring. These limitations not only hinder understanding of the dynamics of specific disease processes in the kidney, but also limit the targeting of treatments to active phases of disease and the development of novel targeted therapies. Molecular imaging enables non-invasive and quantitative assessment of physiological or pathological processes by combining imaging technologies with specific molecular probes. Here, we discuss current preclinical and clinical molecular imaging approaches in nephrology. Non-invasive visualization of the kidneys through molecular imaging can be used to detect and longitudinally monitor disease activity and can therefore provide companion diagnostics to guide clinical trials, as well as the safe and effective use of drugs.
Collapse
Affiliation(s)
| | - Twan Lammers
- Institute for Experimental Molecular Imaging, RWTH Aachen University Hospital, Aachen, Germany,Department of Pharmaceutics, Utrecht University, The Netherlands,Department of Targeted Therapeutics, University of Twente, Enschede, The Netherlands
| | - Felix M. Mottaghy
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Germany,Department of Radiology and Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, RWTH Aachen University Hospital, Aachen, Germany,Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany
| | - Jürgen Floege
- Department of Nephrology and Immunology, RWTH Aachen University Hospital, Aachen, Germany
| | - Peter Boor
- Institute of Pathology, RWTH Aachen University Hospital, Aachen, Germany,Department of Nephrology and Immunology, RWTH Aachen University Hospital, Aachen, Germany,Electron Microscopy Facility, RWTH Aachen University Hospital, Aachen, Germany,
| |
Collapse
|
2
|
Liu P, Johnson SE, Xie X, Gao L, Haney CR, Zhao M, Jin J. Targeted design of a recombinant tracer for SPECT renal imaging. Am J Cancer Res 2021; 11:9118-9132. [PMID: 34522230 PMCID: PMC8419037 DOI: 10.7150/thno.60132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 08/18/2021] [Indexed: 12/23/2022] Open
Abstract
Rationale: A robust radiopharmaceutical has high uptake in the target and low retention in non-target tissues. However, traditional tracers for renal imaging that chemically chelate 99mTc are excreted through the renal route with transient resident time in the kidney. Following a rational design approach, we constructed a protein-based radiotracer, designated PBT-Fc, to sequentially bind tubular neonatal Fc-receptor and subsequently proximal tubular basement membrane for its targeted sequestration in kidney parenchyma. In this process, the tracer participates in physiologic glomerular filtration and tubular reabsorption while escaping lysosomal catabolism and urinary clearance. Methods: To specifically target renal receptors in navigating the urinary passage in the kidney, we produced a recombinant fusion protein with two separate functional parts: a polybasic PBT segment derived from human Vascular Endothelial Growth Factor and Fc segment of IgG1. The chimeric fusion of PBT-Fc was labeled with radionuclide 99mTc and tested in rodent models of kidney diseases. Planar scintigraphy and single-photon emission computerized tomography (SPECT) were performed to evaluate renal-specificity of the tracer. Results: When injected in mouse and rat, following a brief 10 - 15 min dynamic redistribution phase in circulation, ~ 95% of the [99mTc]-PBT-Fc signal was concentrated in the kidney and lasted for hours without urinary loss or surrounding tissue activities. Long-lasting tracer signals in the kidney cortex in conjunction with SPECT greatly augmented the image quality in detecting pathological lesions in a variety of disease models, including ischemic acute kidney injury, drug-induced renal toxicity, and chronic kidney disease from renin-angiotensin system (RAS) overactivation. Conclusion: Exclusive renal retention of the recombinant radiotracer greatly facilitated static-phase signal acquisition by SPECT and achieved submillimeter spatial resolution of kidney alternations in glomerular and tubular disease models.
Collapse
|