J Pathol Transl Med.  2021 Nov;55(6):369-379. 10.4132/jptm.2021.08.03.

Post-mortem assessment of vimentin expression as a biomarker for renal tubular regeneration following acute kidney injury

• Moreno JCA
• Bahmad HF
• Febres-Aldana CA
• Pirela A
• Azuero A
• Salami A
• Poppiti R

• KMID: 2522438
• DOI: http://doi.org/10.4132/jptm.2021.08.03

Abstract

Background
Acute kidney injury (AKI) is a common cause of morbidity and mortality. It mainly targets the renal tubular epithelium with pathological changes, referred to as acute tubular injury. The latter is followed by a regenerative response that is difficult to visualize on routine hematoxylin and eosin (H&E) stains. In this study, we examined the regenerative capacity of renal tubules by correlating vimentin (VIM) immunohistochemical (IHC) expression and pathological findings of AKI and renal tubular regeneration (RTR) on H&E.
Methods
We reviewed 23 autopsies performed in the clinical setting of AKI and RTR. VIM expression was scored in the renal cortical tubular epithelium using a statistical cutoff ≥ 3% for high expression and < 3% for low expression.
Results
Of the 23 kidney tissues examined, seven (30.4%) had low VIM expression, and 16 (69.6%) had high VIM expression. Kidney tissues with evidence of AKI and RTR had significantly higher VIM expression. Renal peritubular microenvironment features showing regenerative changes on H&E were associated with high VIM expression. In the univariate model, kidney tissues with RTR were 18-fold more likely to have high VIM expression.
Conclusions
In conclusion, our findings suggest that VIM could serve as an IHC marker for RTR following AKI. However, correlation with H&E findings remains critical to excluding chronic tubular damage. Collectively, our preliminary results pave the way for future studies including a larger sample size to validate the use of VIM as a reliable biomarker for RTR.

Keyword

Acute kidney injury; Acute tubular injury; Renal tubular regeneration; Vimentin; Biomarker; Immunohistochemistry