Interstitial fibroblasts in donor kidneys predict late posttransplant anemia

Morphometric analysis of chronicity on kidney biopsy: a useful prognostic exercise

Chronic changes on kidney biopsy specimens include increasing amounts of arteriosclerosis, glomerulosclerosis, interstitial fibrosis and tubular atrophy, enlarged nephron size, and reduced nephron number. These chronic changes are difficult to accurately assess by visual inspection but are reasonably quantified using morphometry. This review describes the various patient populations that have undergone morphometric analysis of kidney biopsies. The common approaches to morphometric analysis are described. The chronic kidney disease outcomes associated with various chronic changes by morphometry are also summarized. Morphometry enriches the characterization of chronicity on a kidney biopsy and this can supplement the pathologist's diagnosis. Artificial intelligence image processing tools are needed to automate the annotations needed for practical morphometric analysis of kidney biopsy specimens in routine clinical care.

Histopathological Features of Time-Zero Kidney Biopsy Are Predictive Factors for Posttransplant Anemia

INTRODUCTION

Posttransplant anemia (PTA) is a common complication of kidney transplantation, associated with reduced graft survival and higher mortality. We aimed to determine the association of PTA with histopathological characteristics of time-zero allograft biopsy and donor clinical characteristics.

METHODS

We conducted a retrospective, observational cohort study that included 587 patients who underwent kidney transplantation in our center. Hemoglobin levels were assessed at 6 and 12 months after transplantation, and anemia was defined according to World Health Organization criteria. The kidney allograft time-zero biopsy has been done in all investigated cases. The evaluated histopathological parameters of the kidney allografts included glomerulosclerosis, arteriolar hyalinosis (AH), vascular fibrous intimal thickening (CV), interstitial fibrosis, tubular atrophy, and interstitial fibrosis and tubular atrophy. The Banff Classification of Allograft Pathology criteria were followed to assess the allograft histopathological changes.

RESULTS

The prevalence of anemia was 31.3% at 6 months after transplantation and 23.5% at 12 months. There was an association between 20-50% glomerulosclerosis and PTA in both time points, independently from estimated glomerular filtration rate. AH and interstitial fibrosis were identified as independent risk factors for anemia 6 months after transplantation.

CONCLUSION

Histopathological features of time-zero kidney biopsy may be predictors of PTA. Among them, our study recognized 20-50% degree of glomerulosclerosis, AH, and CV as the most significant risk factors for PTA.