|Year : 2017 | Volume
| Issue : 2 | Page : 80-82
Spectrum of renal biopsy finding in idiopathic nephrotic syndrome in children: An 18-month retrospective analysis at a tertiary care pediatric nephrology center in North Karnataka, India
Prithi Rajendra Inamdar, Mahantesh Vishwanath Patil, Andleeb Majeeb
Department of Pediatrics, Jawaharlal Nehru Medical College, KLE University, Belagavi, Karnataka, India
|Date of Web Publication||11-Oct-2017|
Prithi Rajendra Inamdar
A14/2, JNMC Quaters, Nehru Nagar, Belagavi - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
Context: Idiopathic nephrotic syndrome (NS) is the most common glomerular nephropathy in pediatrics, with great variation in patient characteristics in different regions of the world. Difficult childhood NS poses a great diagnostic and management challenge for the treating nephrologists. The histopathological features of NS have been extensively studied by various authors from different regions of the world with a wide variation in the histopathological distribution. We aimed to describe the spectrum of histopathological diagnosis in childhood NS from North Karnataka, India, where there is a high incidence of consanguinity. Aims: The aim of this study is to study the spectrum of histopathology in children who underwent a renal biopsy in our tertiary care pediatric nephrology center. Settings and Design: Retrospective observational study at a tertiary care pediatric nephrology center over 1 year from January 2013 to June 2015. Subjects and Methods: The medical records of all children diagnosed as NS were retrospectively reviewed for demographic data, clinical course, and histopathological diagnosis. Statistical Analysis Used: Descriptive statistics. Results: Twenty-five children underwent biopsy in the study period. Seventeen (68%) were male as compared to 8 (32%) females. Thirteen (52%) of biopsied patients showed minimal change NS, 6 (24%) had focal segmental glomerulosclerosis, and 3 (14%) patients showed IgA nephropathy while 1 patient had mesangioproliferative glomerulonephritis, IgM nephropathy, and Finnish type NS each. Conclusions: Minimal change nephritic syndrome is the major biopsy finding in our part of the country even in steroid-resistant NS. This finding needs to be confirmed with studies with bigger sample size.
Keywords: Minimal change, nephrotic syndrome, steroid dependence, steroid resistance
|How to cite this article:|
Inamdar PR, Patil MV, Majeeb A. Spectrum of renal biopsy finding in idiopathic nephrotic syndrome in children: An 18-month retrospective analysis at a tertiary care pediatric nephrology center in North Karnataka, India. J Sci Soc 2017;44:80-2
|How to cite this URL:|
Inamdar PR, Patil MV, Majeeb A. Spectrum of renal biopsy finding in idiopathic nephrotic syndrome in children: An 18-month retrospective analysis at a tertiary care pediatric nephrology center in North Karnataka, India. J Sci Soc [serial online] 2017 [cited 2018 Sep 19];44:80-2. Available from: http://www.jscisociety.com/text.asp?2017/44/2/80/216497
| Introduction|| |
Idiopathic nephrotic syndrome (NS) is the most common glomerular nephropathy in pediatrics, with great variation in patient characteristics in different regions of the world. Its incidence is 2–7 cases per 100,000 children and prevalence of 16 cases per 100,000. The overall prevalence of NS varies across various geographical regions with a 6-fold increase in incidence in Indian population as compared to European children.,
Difficult childhood NS poses a great diagnostic and management challenge for the treating nephrologists. Common clinical challenges are steroid resistance, steroid dependence, frequent relapses with steroid toxicity, and decision regarding starting cytotoxic drugs, especially the nephrotoxic ones. Renal histopathology aids in deciding the treatment options in such situations. Histology, particularly, aids in cases of steroid-resistant NS (SRNS). It is also commonly done in steroid-dependent and frequently relapsing NS before initiating nephrotoxic agents although there are no evidence-based recommendations regarding the role of renal biopsy on the outcome. Although the overall incidence of childhood NS has been generally stable over the past three decades, the histological pattern has changed; the incidence of focal segmental glomerulosclerosis seems to be increasing. Ethnic origin may affect the histological variant and the response to immunosuppressive treatment.
A large cohort of children presenting with both steroid-resistant and steroid-sensitive NS are known to have underlying genetic mutations and have a different spectrum of biopsy finding. Availability of mutation analysis is sparse and cost prohibitive.
The histopathological features of NS have been extensively studied by various authors from different regions of the world with a wide variation in the histopathological distribution. We aimed to describe the spectrum of histopathological diagnosis in childhood NS from North Karnataka, India, where there is a high incidence of consanguinity.
Aims and objective
The aim of this study is to study the spectrum of histopathology in children who underwent a renal biopsy in our tertiary care pediatric nephrology center. We also aimed to correlate their prebiopsy clinical course with the histology finding.
| Subjects and Methods|| |
All children from 1 to 18 years of age with a diagnosis of NS, who underwent renal biopsy from January 2013 to June 2015, were included in this study. NS, frequently relapsing NS (FRNS), steroid-dependent NS (SDNS), and SRNS were defined as per the standard International Study of Kidney Disease in Children definitions. Children with preexisting chronic kidney disease and nephritic onset of NS were excluded from the study as etiology of nephritic onset differs from nephritic syndrome. Nephritic onset NS was excluded as they did not receive conventional doses of prednisolone.
The medical records of all included children were retrospectively reviewed using a data sheet for their demographic characteristic, indication of biopsy, and prebiopsy immunosuppressant regimen. The indication of biopsy was at the clinical discretion of the treating pediatric nephrologist. The indications of biopsy were (1) SRNS, (2) atypical presentation: Age: <12 months or >10 years, gross hematuria, low C3, sustained hypertension or renal impairment, and (3) SDNS and FRNS, before starting the immunosuppressive therapy.
The patients were admitted to the pediatric ward 1 day before the procedure. All biopsies were performed on native kidneys and as elective procedures after obtaining consent from the guardians before the procedure. Complete blood count, bleeding time, prothrombin, and partial thromboplastin time were performed for all the patients. Sedation and analgesia were used in our patients with midazolam (0.1 mg/kg body weight) and intravenous ketamine (1 mg/kg body weight) by the anesthetist in addition to local infiltration with lidocaine 1% before the procedure. The procedure was carried out under complete aseptic techniques by pediatric nephrologist with the patients placed in the prone position and after the radiologist confirmed the presence of both kidneys. Spring-loaded biopsy needles (gauge 16–18) were used for all the patients. After the procedure, the children were observed for vital signs and any change in urine color for at least 24 h.
All histopathology slides were reviewed by a single pathologist. Biopsy sample was processed for light microscopy and immunofluorescence. Data on postbiopsy treatment regimen were collected.
Descriptive statistical was used using mean, median, and percentage.
| Results|| |
Twenty-five children underwent a biopsy in the study period. Seventeen (68%) were male as compared to 8 (32%) females. The median age of onset of NS in children undergoing biopsy was 31/2 years with age ranging from 1 month to 8 years. The average age of biopsy is 6 years. In patients with SDNS, the time lag between diagnosis and biopsy was at an average of 3 years. The average age of presentation of children with SRNS is 3 years 9 months.
Twelve (48%) children underwent biopsy for SDNS before starting alternative immunosuppressants. All of these children had received 12-week course of cyclophosphamide before biopsy. Twelve (48%) children had SRNS while one child was biopsied as the age of onset was at 1 month 5 days.
[Figure 1] shows spectrum of the biopsy reports. Thirteen (52%) of biopsied patients showed minimal change NS (MCNS), 6 (24%) had focal segmental glomerulosclerosis, and 3 (14%) patients showed IgA nephropathy while one patient had mesangioproliferative glomerulonephritis, IgM nephropathy, and Finnish type NS each.
As shown in [Table 1], for focal segmental glomerulosclerosis (FSGS), 3 (50%) had SRNS while 3 (50%) had SDNS. The average age of presentation was 3 years. Of 13 children with MCNS, majority was male children (84%) with average age of presentation being 3.36 years. Seven (53.54%) had SDNS with 6 (46.1%) patients having SRNS.
|Table 1: Details of distribution of biopsy findings between steroid-resistant nephrotic syndrome/steroid-dependent nephrotic syndrome|
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None of the biopsied patients had any major complications. Hematuria was reported in 16 patients.
One patient who underwent biopsy had absent right kidney; biopsy was done on the left kidney percutaneously under ultrasound guidance. No complications were noted.
| Discussion|| |
In our study, MCNS was the most common histological finding in biopsied NS patients. This is consistent with other reports worldwide.,,
In patients with SRNS, FSGS accounted only for 12% of cases. This is contradictory to other reports both in India and worldwide. In an Indian study by Gulati et al., FSGS accounted for 59% of children, followed by mesangioproliferative glomerulonephritis which accounted for 18%. MCNS accounted for 17.4% of their patients. They have also reported an increasing incidence of FSGS in North Indian population. Data from other parts of country are not available. Worldwide FSGS remains the major cause of SRNS. The probable reason for this discrepancy in our finding is probably due to the small sample size and also due to focal nature of the disease, glomeruli sampled in the biopsy might not show the disease sclerosis. We did not find any case of membranoproliferative glomerulonephritis or membranous glomerulonephritis. This was probably because we had excluded patients with nephritic onset of nephrotic syndrome from the study.
In our study, 50% of children with FSGS were steroid responsive with a dependent course. A similar study of 94 children with FSGS by Lanewala et al. from Pakistan shows 33% of steroid resistance in children with FSGS.
One patient who had single kidney was biopsied. His diagnosis was MCNS. Although single kidney was conventionally an indication of open biopsy, the literature review shows that the solitary kidney is no longer considered to be an absolute contraindication for percutaneous biopsy.
| Conclusions|| |
Minimal change nephritic syndrome is the major biopsy finding in our part of the country even in SRNS. This finding needs to be confirmed with studies with bigger sample size.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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