Kidney biopsy in elderly patients

Girish P. Vakrani; Nambakam Tanuja

doi:10.4103/jesnt.jesnt_28_21

ORIGINAL ARTICLE

Year : 2022 | Volume : 22 | Issue : 2 | Page : 111-116

Kidney biopsy in elderly patients

Girish P. Vakrani¹, Nambakam Tanuja²
¹ Department of Nephrology, Vydehi Institute of Medical Sciences and Research Centre, Whitefield, Bengaluru, Karnataka, India
² Department of General Medicine, Vydehi Institute of Medical Sciences and Research Centre, Whitefield, Bengaluru, Karnataka, India

Date of Submission	03-Nov-2021
Date of Acceptance	21-Dec-2021
Date of Web Publication	19-May-2022

Correspondence Address:
Dr. Girish P. Vakrani
Department of Nephrology, #82, Vydehi Institute of Medical Sciences and Research Centre, Whitefield, Bengaluru 560066, Karnataka
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jesnt.jesnt_28_21

Abstract

Background Although there is progressive loss of renal mass and function as age progresses, still newer kidney diseases occur. Kidney diseases in the elderly are different compared with younger population. This is because of more commoner occurrence of secondary kidney diseases than primary kidney diseases compared with younger. There is a paucity of Indian literature regarding kidney biopsy in the elderly. The reasons could be fear of increased risk of complications in the elderly, or attributing all kidney diseases to common comorbidities like diabetes mellitus, hypertension, malignancy, intake of potential nephrotoxic medications, and not subjecting them to kidney biopsy. Thus, performing kidney biopsies and analyzing the biopsy findings is not only important for diagnosis of potentially curable kidney diseases, but also guides the therapy.
Patients and methods It was a retrospective observational study conducted to assess the clinical profile and histopathological spectrum in elderly patients who underwent kidney biopsies.
Results The most common indication of kidney biopsy was nephrotic syndrome. The commonest histological finding was membranous nephropathy. Compared with the elderly group, the frequency of lupus nephritis, focal segmental glomerulosclerosis, minimal change disease, IgA nephropathy, and acute tubular necrosis was significantly more in younger age.
Conclusions The most common indication for kidney biopsy in the elderly was nephrotic syndrome. Membranous nephropathy was the commonest histologic finding. The results obtained in this study could add to previous studies to give valuable information of kidney diseases in the elderly. Kidney biopsy is useful in diagnosing many treatable kidney diseases in the elderly and prevents unwanted exposure to empirical immunosuppression.

Keywords: elderly, kidney biopsy, nephrotic syndrome

How to cite this article:
Vakrani GP, Tanuja N. Kidney biopsy in elderly patients. J Egypt Soc Nephrol Transplant 2022;22:111-6

How to cite this URL:
Vakrani GP, Tanuja N. Kidney biopsy in elderly patients. J Egypt Soc Nephrol Transplant [serial online] 2022 [cited 2023 Jun 8];22:111-6. Available from: http://www.jesnt.eg.net/text.asp?2022/22/2/111/345436

Introduction

The elderly population has been increasing tremendously all over the world due to better healthcare facility, leading to longer life expectancy. Even though there is a progressive loss of renal mass and function as age progresses, still newer kidney diseases do occur. Kidney diseases in the elderly are quite different compared with younger population [1],[2],[3],[4],[5]. This is because of more commoner occurrence of secondary kidney diseases than primary kidney diseases in the elderly [3]. There is inconsistency and frequent poor correlation between clinical and histopathological entities in the elderly [3],[6]. Kidney biopsy has led to diagnosis of various histopathological disease entities in order to understand the etiology and also guide the treatment [1],[7],[8]. There is a paucity of Indian literature regarding kidney biopsy in the elderly [1],[3]. The reasons could be fear of increased risk of complications in the elderly, or thinking that the kidney diseases are due to common comorbities like diabetes mellitus, hypertension, malignancy, intake of potential nephrotoxic medications like NSAIDS, and not subjecting them to kidney biopsy [1],[2],[6]. Thus, performing kidney biopsies and analyzing the biopsy findings is not only important for diagnosis of potentially curable kidney diseases but also to guide the therapy [1],[3],[4],[5],[6].

Hence, as the spectrum of kidney diseases in the elderly, defined as more than or equal to 60 years, is different from the younger patients and as there is paucity of literature regarding histopathological entities on kidney biopsy in the elderly, hence this study was conducted. It will also help to correlate between clinicolaboratory findings with kidney biopsy histopathological findings in the elderly.

Aims and objectives

To assess demography, comorbidities, clinical profile of kidney disease, and histopathological entities of kidney biopsy in the elderly.
To assess the correlation between clinical profile [nephrotic syndrome, nephritic syndrome, acute kidney injury (AKI), rapidly progressive renal failure (RPRF), and chronic kidney disease (CKD)] and histopathological entities in elderly patients who underwent kidney biopsies.
To compare the following:
- Demography, comorbidities, clinical profile, and histopathological entities between two age groups:
  - Elderly (aged ≥60 years).
  - Younger (aged 18–59 years).

Patients and methods

Participant recruitment procedures

Study area: this study was conducted using medical records of elderly patients with kidney disease who underwent kidney biopsy in Nephrology Department at Vydehi Institute of Medical Sciences and Research Centre, which is a tertiary care hospital in Bangalore.

Data collection: data were collected regarding:

Patient’s demography (age and sex).

Comorbidities (hypertension and diabetes mellitus).

Clinical features − biochemical parameters: edema, 24-h urine protein, urine microscopy, and serum creatinine.

Nephrotic syndrome − was defined as proteinuria more than 3.5 g/day, hypoalbuminemia less than 3 g/dl with clinical evidence of edema, nephritic syndrome was defined as patients having hypertension and edema along with hematuria, proteinuria, and dysmorphic red-blood cells/red-blood cell casts, AKI was defined as rapid increase in serum creatinine by 0.3 mg/dl or 50% increase or 1.5-fold increase of serum creatinine from baseline, leading to deterioration of glomerular-filtration rate (GFR) according to KDIGO 2012 guidelines [9], RPRF was defined as doubling of serum creatinine or a 50% decrease in GFR over few weeks, and CKD was defined as an estimated GFR that was persistently less than 60 ml/min/1.73 m² for more than 3months.

Kidney-biopsy histopathological findings of light microscopy and immunofluorescence study.

Inclusion criteria: all patients who underwent kidney biopsies in Vydehi Hospital between January 2012 and August 2020. The indications for kidney biopsies would be unexplained proteinuria (>200 mg/day), hematuria (urine red blood cell >5/HPF), or renal failure (serum creatinine >1.2 mg/dl). Aged 60 years and above were called elderly and aged more than 18 years to less than or equal to 59 years were called young aged.

Exclusion criteria

Patients aged below 18 years.

Precise description of the methodology of the proposed research

Study design: a retrospective observational study was conducted to assess the clinical profile and histopathological spectrum in elderly patients who underwent kidney biopsies. Patients with diabetes mellitus and hypertension were subjected for kidney biopsy on suspicion of the presence of nondiabetic renal disease, secondary hypertension, or any other primary glomerular disease [4],[10].

Outcomes/endpoints observed: to assess the clinical profile and histopathological spectrum in elderly patients who underwent kidney biopsies.

Statistical analysis of the study: the data will be collected, entered, and analyzed with SPSS, version 19 (IBM SPSS Statistics 19.0). Continuous variables will be presented as mean±SD. Categorical variables will be presented as frequency and percentage. χ² test or Fisher exact test will be performed to see the association between any two categorical variables.

Results

The study had in total 29 elderly patients from a total of 476 biopsies performed during this period, leading to 6% proportion of biopsy in the elderly. In this elderly group, male population was 26 (89.7%) with male : female ratio 8.6 : 1. The prevalence of comorbidities like diabetes mellitus, hypertension, and clinical nephrological presentation like nephritic syndrome, nephrotic syndrome, AKI, RPRF, and CKD was six (20.7%), seven (24.1%), two (6.9%), 20 (69%), three (10.3%), two (6.9%), and two (6.9%), respectively, as depicted in [Table 1].

Table 1 Comparison of baseline characters between two groups

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In these elderly patients, the prevalence of various histopathological entities like C1q nephropathy was 0, C3 glomerulopathy was one (3.4%), acute tubular necrosis (ATN) was 0, acute interstitial nephritis (AIN) was one (3.4%), chronic interstitial nephritis (CIN) was three (10.3%), ATN–AIN was one (3.4%), lupus nephritis was two (6.8%), minimal change disease (MCD) was three (10.3%), focal segmental glomerulosclerosis (FSGS) was three (10.3%), membranous nephropathy (MGN) was 10 (34.5%), membranoproliferative glomerulonephritis was one (3.4%), mesangioproliferative glomerulonephritis was 0, postinfective glomerulonephritis (PIGN) was one (3.4%), IgA nephropathy was 0, renal amyloidosis was two (6.9%), cast nephropathy was 0, crescentric glomerulonephritis was two (6.9%), chronic glomerulosclerosis was one (3.4%), and diabetic nephropathy was one (3.4%), as depicted in [Table 2].

Table 2 Comparison of histopathological entities between two groups

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In the younger patients, the prevalence of various histopathological entities like lupus nephritis was 23.3%, FSGS was 16.6%, and MCD was 12.5%. Compared with the elderly group, the frequency of lupus nephritis, FSGS, MCD, IgA nephropathy, and ATN was significantly more in younger age, whereas the frequency of CIN, MGN, renal amyloidosis, and crescentric GN was lower in younger age as depicted in [Table 2].

When histopathology was compared with clinical presentation in elderly patients, it was found that the most common histological finding in nephrotic syndrome (n=20) was MGN (n=10, 34.5%), followed by FSGS (n=3, 10.3%). The most common histological finding in nephritic syndrome (n=2) was lupus nephritis (n=1, 50%), and PIGN (n=1, 50%) due to skin infection − cellulitis. The most common histological finding in the patients who underwent kidney biopsy for AKI (n=12) was FSGS (n=3, 25%). The most common histological finding in the patients who underwent kidney biopsy for RPRF (n=2) was crescentric glomerulonephritis (n=2, 50%). Both were ANCA negative. The most common histological finding in the patients who underwent kidney biopsy for CKD (n=4) was CIN (n=2, 28%) as depicted in [Table 3].

Table 3 Clinical presentation of various histopathological entities in the elderly group

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The cause of ATN–AIN was sepsis and NSAID. Only one patient had macroscopic hematuria following kidney biopsy, which resolved with conservative treatment. No major complication was seen.

Discussion

Gold-standard method to diagnose kidney parenchymal disease is kidney biopsy. There is paucity of data on kidney biopsy in the elderly in India. The main reasons could be fear of increased procedure risk and avoidance of biopsy attributing kidney disease to comorbidities like diabetes mellitus and essential hypertension that are more common in elderly age group [1]. But with passing of time, this perception has changed. Many diseases like amyloidosis are first diagnosed on kidney biopsy [3]. Thus, kidney biopsy in the elderly is not only necessary for diagnosis but also to guide therapy appropriately. This study hopes to provide insight into kidney diseases in the elderly.

About 6% of total patients who underwent kidney biopsy during this period were elderly. This proportion is much lower than the studies reported in India. This proportion is lower than those quoted in western literature where it is between 20 and 25% [1]. The reason could be increased elderly population in this world due to better healthcare facility in developed countries.

Males dominated in this study to 89%, like in other Indian studies [1].

When the present study was compared with other Indian studies as depicted in [Table 4], it was found that the most common histological finding in nephrotic syndrome was MGN consistent with other Indian and western studies [1],[2],[3]. In few Indian studies, both MGN and renal amyloidosis are reported as the most common etiology to accuse nephrotic syndrome [3]. The most common histological finding in nephritic syndrome was lupus nephritis and PIGN. Histological findings in nephritic syndrome have been varying in different studies [1],[3]. The most common histological finding in the patients who underwent kidney biopsy for AKI was FSGS consistent to Jin et al. [2] study. This could be related to early presentation by these sets of patients to hospital due to troublesome anasarca. The most common histological finding in the patients who underwent kidney biopsy for RPRF was crescentric glomerulonephritis. Both were ANCA negative. This is consistent to other Indian studies [1],[3]. The most common histological finding in the patients who underwent kidney biopsy for CKD was CIN. This finding is different compared with other Indian studies. This could be related to chronic urinary-tract infection, NSAID intake in this elderly group, and also related to possible avoidance of biopsy in the elderly attributing kidney disease to the associated comorbidities like hypertension and diabetes mellitus.

Table 4 Comparison between studies

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Kidney biopsy was safe in this study with no major complication noted, stating that biopsy is safer in the elderly. This could be related to usage of real-time ultrasound-guided biopsy and guidance of an experienced sonologist in difficult cases.

Limitations

First, as it is a retrospective study, there is limitation of data collected. Second, as the hospital is a tertiary referral center, hence, it may not depict the real spectrum of kidney disease in aged. Third, the study group is less and hence the results cannot be generalized. Hence, it needs a larger study group. Fourth, some elderly patients would have refused biopsy and preferred empirical treatment, hence, the results cannot be generalized.

Conclusions

The most common indication for kidney biopsy in the elderly was nephrotic syndrome. MN was the commonest histologic finding. The results obtained in this study could add to previous studies to give valuable information of kidney diseases in the elderly. Kidney biopsy is useful in diagnosing many treatable kidney diseases and prevents unwanted exposure to empirical immunosuppression.

Acknowledgements

The authors acknowledged Mrs Supriya and Dr Hemavarneshwari, Department of Community Medicine, in helping in statistics for this study.

Each author’s contribution statement: contributed toward management of patients, data collection, data analysis, and paper preparation (Girish P. Vakrani). Contributed toward management of patients, statistics, and paper preparation (Nambakam Tanuja).

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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