Kidney biopsy in AA amyloidosis: impact of histopathology on prognosis

Abstract

In AA amyloidosis, while kidney biopsy is widely considered for diagnosis by clinicians, there is no evidence that the detailed investigation of renal histopathology can be utilized for the prognosis and clinical outcomes. In this study, we aimed to obtain whether histopathologic findings in kidney biopsy of AA amyloidosis might have prognostic and clinical value. This is a retrospective cohort study that included 38 patients who were diagnosed with AA amyloidosis by kidney biopsy between 2005 and 2013.The kidney biopsy specimens of patients were evaluated and graded for several characteristics of histopathological lesions and their relationship with renal outcomes. Segmental amyloid deposition in the kidney biopsy was seen in 29%, global amyloid deposition in 71, diffuse involvement of glomeruli in 84.2%, focal involvement in 7%, glomerular enlargement in 53%, tubular atrophy in 75% and interstitial fibrosis in 78% of patients. Histopathologically, glomerular enlargement, interstitial fibrosis, tubular atrophy, interstitial inflammation and global amyloid deposition were significantly associated with lower estimated glomerular filtration rate (eGFR) (p = .02, p < .001, p = .001, p = .009, p = .002, respectively) in univariate analysis. In multivariate analysis, tubular atrophy was the only predictor of eGFR (p = .019 B = -20.573). In the follow-up at an average of 27 months, 18 patients developed end-stage renal disease (ESRD). Among them, global amyloid deposition was the only risk factor for the development of ESRD (p = .01, OR = 18.750, %95 CI= 2.021-173.942). This is the first study showing that the histopathological findings in kidney biopsy of AA amyloidosis might have a prognostic and clinical value for renal outcomes.

A multicenter study of the clinical, laboratory characteristics, and potential prognostic factors in patients with amyloid A amyloidosis on hemodialysis

“…Another retrospective study, conducted by Erdogmus et al reported that FMF is the leading cause of AA amyloidosis (62%) 15 . In addition to diagnostic aid, a paper by Kendirli et al claimed that renal pathology in AA amyloidosis may help guide prognosis as well as establishing renal involvement of AA amyloidosis 14 …”

“…15 In addition to diagnostic aid, a paper by Kendirli et al claimed that renal pathology in AA amyloidosis may help guide prognosis as well as establishing renal involvement of AA amyloidosis. 14…”

“…13 On the contrary, there are scant data evaluating the renal involvement in AA amyloidosis which typically manifests with proteinuria, nephrotic syndrome, and, often progression to end-stage renal disease (ESRD) if insufficiently treated chronic inflammatory state. 14,15 At the time of diagnosis, 11% of the patients with AA amyloidosis had an end-stage renal failure 16 and approximately half (56.2%) of these patients ultimately receive renal replacement therapy during long-term follow-up. 17 After the development of ESRD, AA amyloid patients can be treated with renal replacement therapies including hemodialysis, peritoneal dialysis, and kidney transplantation successfully [18][19][20] However, there have been increased mortality rates noticed in this patient group during renal replacement therapies.…”

“…About 19% of cases of AL amyloidosis will require renal replacement therapy (RRT) during the course of their disease 13 . On the contrary, there are scant data evaluating the renal involvement in AA amyloidosis which typically manifests with proteinuria, nephrotic syndrome, and, often progression to end‐stage renal disease (ESRD) if insufficiently treated chronic inflammatory state 14,15 . At the time of diagnosis, 11% of the patients with AA amyloidosis had an end‐stage renal failure 16 and approximately half (56.2%) of these patients ultimately receive renal replacement therapy during long‐term follow‐up 17 .…”

Noninvasive assessment of kidney dysfunction in children by using blood oxygenation level-dependent MRI and intravoxel incoherent motion diffusion-weighted imaging

“…Three parameters, D t , D p , and f p were calculated based on a biexponential model: All patients underwent ultrasound-guided kidney biopsies and performed by two renal pathologists within 1-2 days after completing the MR examination in our research. We selected the lower pole of the right kidney as the biopsy position and fewer than 8 glomeruli were not included to the study which was similar to the method used by previous study [20]. All renal biopsy specimens were sent to outside pathology laboratories and read by two pathologists with more than 8 and 10 years of clinical experience in kidney disease.…”