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RENAL DATA FROM ASIA-AFRICA |
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| Year : 2012 | Volume
: 23
| Issue : 3 | Page : 614-618 |
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| Percutaneous renal biopsy results: A retrospective analysis of 511 consecutive cases |
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Malik Anas Rabbani1, Ghulam Murtaza Memon2, Bushra Ahmad2, Shehla Memon2, Syeda Anjala Tahir3, Shumaila Tahir1
1 Department of Nephrology, The Kidney Center, Post Graduate Training Institute, Karachi, Pakistan
2 Section Nephrology, Department of Medicine, Aga Khan University Hospital, Karachi, Pakistan
3 Department of Medicine, Civil Hospital, Karachi, Pakistan
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| Date of Web Publication | 7-May-2012 |
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 Abstract | | |
To determine the patterns of the prevalent glomerulonephritis (GN) in our region, we studied the results of 511 consecutive renal biopsies performed on patients with proteinuria, hematuria and mild to moderate renal impairment at the Aga Khan University Hospital during a period of 18 years from January 1990 to December 2008. Primary glomerular disease accounted for two-thirds of the glomerular diseases, which in turn constituted 49% of all renal biopsies. The most common histological lesion was membranoproliferative disease (28%). Membranous GN was the second most common lesion (19%), followed by minimal change disease (16%) and focal segmental GN (11%). Secondary glomerular disease comprised 30% of glomerular diseases (21% of all the renal biopsies), with lupus nephritis forming the most common lesion (34%) followed by amyloidosis (22%), diabetic nephropathy (10%), Wagener's granulomatosus and post-infectious GN (9% each). Tubulointerstitial diseases accounted for 16% of all the renal biopsies. We conclude that there exists a wide variability in the different categories of primary and secondary glomerular diseases in our region as compared with different parts of the world. Future studies should be directed to analyze the causes for these variations.
How to cite this article:
Rabbani MA, Memon GM, Ahmad B, Memon S, Tahir SA, Tahir S. Percutaneous renal biopsy results: A retrospective analysis of 511 consecutive cases. Saudi J Kidney Dis Transpl 2012;23:614-8 |
How to cite this URL:
Rabbani MA, Memon GM, Ahmad B, Memon S, Tahir SA, Tahir S. Percutaneous renal biopsy results: A retrospective analysis of 511 consecutive cases. Saudi J Kidney Dis Transpl [serial online] 2012 [cited 2013 May 22];23:614-8. Available from: http://www.sjkdt.org/text.asp?2012/23/3/614/95858 |
| Introduction | |  |
Glomerular disease represents the most common cause of end-stage renal disease (ESRD) in many countries. Its patterns, however, are variable among the different countries. Besides the primary glomerulopathies, the glomeruli are affected by a variety of environmental insults and systemic disorders. Glomerular diseases generally present with variable degrees of proteinuria, hematuria, hypertension and/or impaired renal function. Some glomerular diseases may be indolent or progress into ESRD. Renal biopsies play a fundamental role in the evaluation of proteinuric patients not only to establish an accurate diagnosis but also help to decide about appropriate treatment and assess prognosis.
There is limited data on the patterns of glomerular diseases in Pakistan. Therefore, we retrospectively studied the results of renal biopsies performed during an 18-year period at our center.
| Patients and Methods | | |
A total of 511 patients who underwent kidney biopsies at the Aga Khan University Hospital, Karachi, from January 1990 to December 2008 were included in the study. Record files of these patients were reviewed retrospectively to analyze the patterns of glomerular diseases.
There were 320 males and 191 females, with a mean age of 36.0 ± 17.9 years. The indications for renal biopsy included proteinuria, unexplained microscopic or macroscopic hematuria and systemic disease with evidence of renal involvement, unexplained renal impairment and renal impairment in post-transplant patients. All samples were obtained by a percutaneous method using a trucut needle under ultrasound guidance. Two renal biopsy samples were taken from each patient, which were processed for light microscopy and immunofluorescence studies. Sections were made from formalin-fixed paraffin-embedded tissue and stained by hematoxylin-eosin, Periodic-Acid Schiff (PAS) and Jones stains for light microscopy; special stains such as congo-red stain were also used where indicated. All samples were examined by a certified histopathologist. Re-biopsies were performed in case of inadequate tissue for light microscopy and immunofluorescence examination with the help of a radiologist either under real-time ultrasound examination or computed tomography (CT)-Scan guidance. The immunofluorescence microscopy panel included staining for IgA, IgM, IgG, C3, C 1q and fibrinogen. Patients' data were obtained from the medical records. Relevant investigations including complement levels, auto-immune profile, ANCA antibodies extractable nuclear antigens, ASO titers and virology results were also recorded.
| Results | | |
Glomerular disease constituted 70% of the total renal biopsies. Of the patients with glomerular diseases, 210 patients were male and 147 were female. The histopathological profile of the renal biopsies is shown in [Table 1]. Primary glomerular disease constituted 69% of the glomerular diseases, while secondary glomerular disease accounted for 31% [Table 2]. Among primary glomerular diseases, the most common histological lesion was membrano-proliferative glomerulonephritis (MPGN) (28%). Because the hospital lacked the facility of electron microscopy, it was therefore not possible to comment with certainty about the different histological variants of MPGN.[Figure 1] | Table 1: Histopathological profile of the 511 renal biopsies according to gender of the patients.
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 | Table 2: Categorization of glomerular diseases in the renal biopsies according to sex of the patients.
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Membranous GN was the second most common lesion (19 %), followed by minimal change disease (16%) and focal segmental GN (11%).
Of the total 27 cases of primary focal segmental glomerulosclerosis (FSGS), IgM type was observed in six, collapsing in eight, mesangial proliferative in nine patients and C1q nephropathy in four. The other types of primary glomerular disease, their frequency and gender of the patients are shown in [Table 3]. | Table 3: Categorization of primary glomerular diseases according to sex of the patients.
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Lupus nephritis (34%) was the most common cause of secondary glomerular disease followed by diabetic nephropathy (10%), acute post infectious and Wagener's granulomatosis (9% each). In the lupus nephritis group, World Health Organization (WHO) class 4 was the most common variant (64%), followed by Class 3 (16%) and Class 5 (14%). In the diabetes group, the dominant lesion was diffuse glomerulosclerosis (n = 6), followed by nodular (n = 3) and focal segmental glomerulosclerosis (n = 1). In patients with Wagner's granulomatosis, segmental necrotizing glomerulonephritis (SNGN) was the most common lesion observed. The SNGN was generally focal in most of these biopsies (n = 7). In addition, on light microscopic examination, evidence of glomerular thrombosis, with or without necrosis, was also found in some cases (n = 3).
[Table 4] shows the histopathological profile along with the sex of the secondary glomerular diseases. There were more males than females affected with primary glomerular diseases in general (59.3% vs. 40.7%). When assessed individually, the male preponderance was evident in IgA nephropathy (75% vs. 25%), MCD (65% vs. 35%), nd MPGN (60% vs. 40%). Male dominance was also evident in secondary glomerular diseases (58% vs. 42%), except in systemic lupus erythematosusu (SLE), diabetic nephropathy and amyloidosis, which showed a female preponderance [Table 4]. Eleven patients with transplanted kidneys underwent renal biopsies because of unexplained deterioration of graft function; five patients had features consistent with diagnosis of acute tubular necrosis, three had acute cellular rejection, while the other three had features of chronic allograft dysfunction. All of these patients received transplant kidneys at different hospitals and were only followed-up at our center. The details regarding primary renal pathology, tissue matching and induction immunosuppression were not available. | Table 4: Categorization of the secondary glomerular diseases according to sex of the patients.
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| Discussion | | |
In the literature, there is limited population-based epidemiological data on the spectrum of biopsy-proven glomerular diseases from Pakistan. Our institution receives renal biopsies from all the four provinces of the country. Hence, this report is a national epidemiological study of the biopsy-proven renal diseases. However, because of the non-availability of electron microscope diagnosis in certain cases such as minimal change disease and FSGS could not be diagnosed with certainty.
The rate of biopsy-proven renal diseases underestimates the true prevalence of diseases, as not all patients with renal disease are biopsied. The incidence rates of renal biopsies performed vary in different countries. We have an incidence of 5.8/100,000/year, which was similar to the studies in Spain [1] and Macedonia, [2] while a report from Australia [3] showed a much higher incidence of 21/100,000/year. An epidemiological study from the United Arab Emirates [4] (UAE) reported 490 biopsies over an 18-year period, which is less than that in our series. These variations could be because of the time span of the reviews and/or because of the different biopsy polices adopted by different centers. Glomerular diseases in our study constituted 3.9/100,000/year, which is 67% of the total renal biopsies. This is similar to reports from Australia, Denmark, Iran and Senegal, [3],[5],[6],[7] while data from the UAE and Saudi Arabia [4],[8] revealed a higher rate of glomerular diseases. This discrepancy may be due to the fact that Saudi Arabia and UAE reported on only native kidney biopsies, while our study also included transplant biopsies. The 44.8% prevalence of primary glomerular diseases among the total renal biopsies in our series was low compared with studies from UAE, Iran, Senegal and Saudi Arabia. [4],[6],[7],[8] This could be explained by the high rate of inadequate biopsy samples (approximately 10%) as well as the inclusion of transplant biopsies in our study.
Among the primary glomerular diseases, the various conditions differ in their incidences in different studies. Our study showed a high incidence of MPGN, which is in contrast to a study from Saudi Arabia [8] that reported a high incidence of FSGS. However, it is comparable to a study in the UAE, [4] which revealed MPGN as the most common primary glomerular disease. This difference could be due to a selection bias in the study from Saudi Arabia, which is a single hospital study. Moreover, despite the incidence of MPGN declining all over the world, significant numbers of cases were labeled as primary MPGN in our cohort of renal biopsies. One possible explanation is the high incidence of infections such as hepatitis C in our region. However, diagnosis of primary MPGN was made after excluding possible secondary etiologies such as monoclonal immunoglobulin deposition diseases, autoimmune diseases, chronic thrombotic microangiopathies, disorders of complement metabolism, hereditary disorders and chronic infections (mainly hepatitis C). Changing incidence of glomerular diseases over a time frame has been found in different communities due to genetic and environmental factors. [9]
Vasculitis was not a major cause in any of the studies from the Arab countries. However, similar to the European studies, [1],[3] it formed one of major diagnosis in our study. Among the secondary glomerular diseases, lupus nephritis constituted the most common condition with female preponderance, which is consistent with the reports from Spain, Australia and some Arab countries. [1],[3],[4],[6],[7],[8]
There exists a wide variability in the different categories of primary and secondary glomerular diseases in different parts of the world and even within the Asian countries. Future studies should be directed to analyze the causes for these variations. Moreover, being a private sector hospital, the present histopathological data my not be a true reflection of the pattern of renal diseases in our region.
| References | | |
| 1. | Rivera F, Lopez-Gomez JM, Perez-Garcia R. Frequency of renal pathology in Spain 1994-1999. Nephrol Dial Transplant 2002;17:1594-602. 
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| 2. | Polenakovic MH, Grcevska L, Dzikova S. The incidence of biopsy-proven primary glomerulonephritis in the Republic of Macedonia -long term follow-up. Nephrol Dial Transplant 2003;18(Suppl 5):v26-7.
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| 3. | Briganti EM, Dowling J, Finlay M, et al. The incidence of biopsy-proven glomerulonephritis in Australia. Nephrol Dial Transplant 2001;16: 1364-7.
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| 4. | Yahya TM, Pingle A, Boobes Y, Pingle S. Analysis of 490 Kidney biopsies: data from the United Arab Emirates Renal Diseases Registry. J Nephrol 1998;11:148-50.
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| 5. | Heaf J, Lokkegaard H, Larsen S. The epidemiology and prognosis of glomerulonephritis in Denmark 1985-1997. Nephrol Dial Transplant 1999;14:1889-97.
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| 6. | Antonoovych TT, Sabnis SG, Broumand BB. A study of membranoproliferateive glomerulonephritis in Iran. Ann Saudi Med 1999;19:505-10.
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| 7. | Abdou N, Boucar D, Fary KA, et al. Histopathological Profiles of Nephropathies in Senegal. Saudi J Kidney Dis Transpl 2003;14: 212-4.
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| 8. | Mitwalli AH, Wakeel JS, Al Mohaya SS, et al. Pattern of Glomerular Disease in Saudi Arabia. Am J Kidney Dis 1996;27:797-802.
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| 9. | Braden GL, Mulhem JG, O'Shea MH, Nash SR, Ucci AA Jr, Germain MJ. Changing incidence of glomerular diseases in adults. Am J Kidney Dis 2000;35;878-83.
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Correspondence Address:
Malik Anas Rabbani
Associate Professor and Consultant Nephrologist, Program Director Post Graduate Training in Nephrology, The Kidney Center, Post Graduate Training Institute, Karachi 75530
Pakistan
[Figure 1]
[Table 1], [Table 2], [Table 3], [Table 4] |
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