Combining field effect scanning electron microscopy, deep UV fluorescence, Raman, classical and synchrotron radiation Fourier transform Infra-Red Spectroscopy in the study of crystal-containing kidney biopsies

Abstract

International audienceCrystal formation in kidney tissue is increasingly recognized as a major cause of severe or acute renal failure. Kidney biopsies are currently performed and analyzed using different staining procedures. Unfortunately, none of these techniques are able to distinguish the different Ca phosphates (e.g., amorphous or nanostructured Ca phosphate apatite, octacalcium phosphate, brushite…) or Ca oxalates (whewellite and weddellite). Moreover, the crystal’s morphology, a structural parameter proven as a major information to the clinician regarding kidney stones, is not taken into account. Such major limitations call for a different research approach, based on physicochemical techniques. Here we propose classical observations through field-emission scanning electron microscopy experiments combined with energy dispersive spectroscopy as well as measurements through Raman and μFourier transform Infra-Red Spectroscopy. If necessary, in the case of microcrystals, observations using cutting edge technology such as Synchrotron Radiation (SR) – FTIR or SR-UV visible spectroscopy can be subsequently performed on the same sample. Taken together this set of diagnostic tools will help clinicians gather information regarding the nature and the spatial distribution at the subcellular scale of different chemical phases present in kidney biopsies as well as on the crystal morphology and therefore obtain more precise diagnosis

Raman Spectroscopy for the Diagnosis of Intratubular Triamterene Crystallization

“…20 , 21 Several groups have used Fourier-transformed infrared spectroscopy to confirm 2,8-DHA, as well as other crystals in kidney biopsies. 15 , 22 , 23 Our case extends the application of Raman spectroscopy to making a de novo clinical diagnosis from the analysis of unidentified crystalline material. These results underscore the molecular specificity of Raman spectroscopy and its ability to identify crystals in a biopsy specimen.…”

Pathological Mineralization: The Potential of Mineralomics

“…Red and pink indicate inorganic and turquoise (blue/green) indicates organic material. Electron micrograph of mineral found in the kidney (arrows) [145]. Scale bar = 2 µm.…”

Physicochemistry in medicine: some selected examples

“…115,116 Finally, as mentioned previously, several papers show the large chemical diversity of the abnormal deposits in kidney biopsies. [117][118][119] In Figure 6, we use the fact that high spatial resolution infrared mapping constitutes a very powerful tool to study the kidney distribution of foscarnet and metabolites. It is well known that foscarnet crystallises in glomeruli.…”

“…Then, we started an investigation on the DISCO beamline. 118,121 We started by considering macroscopic kidney stones made of calcium oxalate monohydrate (COM). The spectrum of these kidney stones has a specific signal around 410 nm.…”