Ultrastructural 3d visualization of the nephron in the process of realization of chronic kidney disease using infectious tubulointerstitial nephritis (pilot study)

INTRODUCTION. Chronic kidney disease (CKD), particularly infectious tubulointerstitial nephritis, is a significant medical and social problem, characterized by morphological changes in the nephron that are difficult to study in detail using traditional methods. Modern technologies, such as 18F-FDG PET/CT and transmission electron microscopy (TEM) with subsequent 3D reconstruction, offer new opportunities for assessing the structural and functional state of the nephron and renal parenchyma. 

THE AIM. To evaluate ultrastructural 3D visualization of the nephron during the progression of chronic kidney disease using infectious tubulointerstitial nephritis as an example.

 MATERIALS AND METHODS. A pilot study was conducted involving three patients who underwent PET/CT with calculation of the standardized uptake level (SUVmax) of 18F-FDG by the kidneys and TEM of renal parenchymal biopsies at 10,000x magnification to study the ultrastructure of nephrons. Based on electron microscopy data, 3D block reconstruction of the nephron was performed, as well as 3D sectional reconstruction of the kidney after nephrectomy using a macrospecimen. 

RESULTS. In patients with infectious tubulointerstitial nephritis, 3D ultrastructural findings revealed thickening and disorganization of the basement membranes, focal necrosis, glomerular sclerosis, and epithelial desquamation. SUVmax values on PET/CT decreased proportionally to the severity of ultrastructural changes. 

CONCLUSION. An original method for ultrastructural 3D visualization of the nephron at 10,000x magnification using transmission electron microscopy data during chronic kidney disease (CKD) is evaluated using infectious tubulointerstitial nephritis as an example. This method is complemented by PET/CT imaging of renal parenchyma metabolism to 18F-FDG and 3D anatomical visual reconstruction of the renal parenchyma using a post-nephrectomy specimen.

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