| Abstract|| |
A prospective study of all native kidney biopsies performed over one year at the Riyadh Armed Forces Hospital, Riyadh, Saudi Arabia was conducted. During this period, 52 kidney biopsies were performed of which, 49 had adequate tissue. All biopsies were processed for light microscopy, immunofluorescence and electron microscopy. The indications for biopsy included the nephrotic syndrome (n=28; 53.8%), asymptomatic proteinuria (n=12; 21.2%), acute nephritic presentation (n=7; 13.5%) and asymptomatic hematuria (n=7; 13.5%). Primary glomerulonephritis (GN), excluding IgA nephropathy (IgAN) was seen in 34 of the 49 patients (77.6%). Focal and segmental glomerulosclerosis and mesangial proliferative GN were the most common histological diagnoses (31% and 20.4% respectively). Surprisingly, we found a high prevalence of IgA nephropathy (IgAN) of 14.5% in comparison with other studies. The prevalence of mesangiocapillary glomerulonephritis (MCGN) was low (2%) and can only be explained as incidental. The study patients were followed-up for an average of 26.3 weeks. At the end of the observation period, 50% has unchanged course, 37.5% had improved their renal function and protein excretion, and 12.5% had deteriorated. The prognosis of different GN groups and renal survival rate cannot be assessed or calculated in this study because of the relatively short duration of follow-up. Our study further emphasizes the need for a national GN registry and long-term follow-up, in order to recognize the common patterns of GN, their natural histories, the appropriate line of management, and to try and arrest their progression to endstage renal disease.
Keywords: Saudi Arabia, Glomerulonephritis, Nephrotic syndrome.
|How to cite this article:|
Mousa D H, Al-Hawas F A, Al-Sulaiman M H, Al-Khader AA. A Prospective Study of Renal Biopsies Performed Over One-year at the Riyadh Armed Forces Hospital. Saudi J Kidney Dis Transpl 2000;11:449-54
|How to cite this URL:|
Mousa D H, Al-Hawas F A, Al-Sulaiman M H, Al-Khader AA. A Prospective Study of Renal Biopsies Performed Over One-year at the Riyadh Armed Forces Hospital. Saudi J Kidney Dis Transpl [serial online] 2000 [cited 2020 Jun 5];11:449-54. Available from: http://www.sjkdt.org/text.asp?2000/11/3/449/36668
| Introduction|| |
End-stage renal disease (ESRD) and the increasing need for hemodialysis are growing problems in the Kingdom of Saudi Arabia (KSA). According to the annual report for the year 1999, published by the Saudi Center for Organ Transplantation, there are 5,706 patients receiving dialysis in 124 units all over KSA.  The reported incidence for ESRD in KSA is 120 per million per year, with about 629 deaths per year.  The average percentage of annual increase in dialysis population is 11.7%  and primary glomerulonephritis (GN) constitutes 28% of all newly registered dialysis patients.
Thus, renal disease in general and GN in particular, is an important cause of morbidity and mortality in the Saudi population. However, there are only few studies published so far, on GN, from KSA and all are based on retrospective data. The reports from the King Faisal Specialist Hospital show relatively high proportion of focal and segmental glomerulosclerosis (FSGS) and mesangiocapillary GN (MCGN) and a low prevalence of membranous GN (MGN)  while in another study, MCGN and MGN were the leading types in primary GN. 
In this prospective study, we collected all native kidney biopsies performed over a 1year period, excluding diabetic nephropathy (DNP). An attempt has been made to analyze the epidemiological characteristics, clinical presentation, histological diagnosis, and follow-up data up to one year from the patient's first registration.
| Patients and Methods|| |
A total of 52 native kidney biopsies, excluding DNP, performed between 1/1/1999 and 31/12/1999 were studied. Three patients had to be excluded as their biopsies were not adequate for diagnosis and they refused re-biopsy. A specimen was considered adequate when it contained at least six glomeruli. All biopsies were processed for light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM). All patients were Saudis except one.
The indications for renal biopsy were based on the clinical presentation at the time of onset [Table - 1]. All patients had full GN screening including anti-DNA antibodies, anti-neutrophil cytoplasmic antibodies (ANCA), and immunoglobulin electrophoresis performed once at the time of initial presentation and repeated again at follow- up.
The histological classification suggested by the World Health Organization was used in the labeling of LM findings, i.e., mild glomerular abnormalities (Mild), FSGS, focal mesangial proliferative glomerulonephritis (FMPGN), diffuse mesangial proliferative glomerulonephritis (DMPGN), mesangiocapillary glomerulonephritis (MCGN), membranous glomerulonephritis (MGN), and crescentic GN. 
The finding on IF of mesangial IgA deposits was labeled as IgA nephropathy (IgAN). All samples had EM examination except three due to inadequate tissue.
The age-range of the study patients was 1369 years with a mean of 30.8 years. Different GN types in relation to age-groups are shown in [Figure - 1]. No children were included in this study. The mean follow-up period was 26.2 weeks (6 to 52 weeks).
| Results|| |
The principal indication for renal biopsy was the nephrotic syndrome (NS) which was noted in 28 of the 52 study patients (53.8%).
The other indications were asymptomatic, non-nephrotic range proteinuria in 11 (21.2%), acute nephritic presentation in seven (13.5%) and asymptomatic hematuria in seven patients (13.5%). The mean serum creatinine of the study patients was 249 µmol/L (range 46 to 1506 µmol/L).
Primary or idiopathic GN, excluding IgAN was diagnosed in 34 of the 49 patients (69.4%) with adequate tissue for diagnosis. Eight patients (16.3%) had glomerular involvement secondary to systemic disease [Table - 2].
FSGS was the most common histological diagnosis on LM, (15/49; 30.6%) followed by mesangial proliferative GN (10/49; 20.4%) and MGN which was found in four out of 49 (8.2%) [Table - 2].
The IF findings were suggestive of IgAN in 14.3% (7/49) of the patients. High serum IgA levels were observed in all these patients and there was a female predominance of 1.2:1. On the contrary, male predominance was noted in patients with FSGS and MGN (1.5:1 and 4:1 respectively).
Of the patients with a nephrotic presentation, 53.5% (15/28) had FSGS and 14.3% (4/28) had MGN. On the other hand, 11 (61.1%) patients with asymptomatic proteinuria and seven (14.3%) with asymptomatic hematuria, were diagnosed as mesangial proliferative GN and IgAN respectively. Hepatitis markers could be studied in only 25 patients for logistic reasons. One study patient was positive for HbsAg and two (FSGS and IgAN) were anti-HCV positive. The results of ANCA and serum protein electrophoresis were noncontributory with the latter abnormal only in the patient with multiple myeloma.
Twenty-six out of the forty-nine patients received treatment at the time of presentation. Treatment was successful in 11 patients; the serum creatinine improved by 50% or more in six, full remission of proteinuria occurred in three, and partial remission (proteinuria less than nephrotic range) was seen in three patients [Table - 3].
When the group was taken as a whole (i.e. treated and untreated), the renal outcome at the end of the observation period was as follows: 12 patients were lost to follow-up, the serum creatinine and proteinuria were unchanged in 50% of the patients, and 37.5% showed improvement (50% of these had mesangial proliferative GN). A total of 12.5% of the patients showed deterioration in their renal function, 75% of whom had FSGS. Three patients died of non-renal causes, all due to sepsis and four patients were on hemodialysis at the end of the observation period.
| Discussion|| |
This is the first prospective study of patients with primary GN conducted in KSA, although the number of patients is small, and the observation period is short. The objective of this study was not only to assess the prevalence, but also to evaluate the natural history of primary GN, in an effort to improve patient management and reduce the risk of progression to chronic renal failure.
Our study further indicates that FSGS and mesangial proliferative GN remain the commonest causes of primary GN in Saudi Arabia. Similar results have been reported by Akhtar et al  and Qunibi et al  who found FSGS to be the commonest lesion (30.7% and 34.9% respectively) followed by MesPGN (25.3% and 29.1% respectively).
This is in contrast to our earlier report  and Huraib et al,  wherein minimal change disease (40.9%) and MCGN (25% and 26.4% respectively) were the commonest.
The two major findings in this study are, the relatively higher prevalence of IgAN (14.3%) in comparison to other studies 5.8%, 4%, and 2.8%, ,, which could be explained on the basis of more renal biopsies performed for asymptomatic hematuria, and doing more IF studies. However, it is worth noting that this figure is still lower than the reported prevalence of IgAN in Japan, and northern Europe which are 47.4% and 24%  respectively. It remains questionable whether differences in the prevalence of GN are due to differences in the indications of renal biopsy, differences in geography, or differences in race.
The second major difference is the surprisingly low prevalence of MCGN (2%) in comparison to other reports wherein the prevalence ranged between 10 to 18%.,,,, This observation cannot be explained on any scientific basis.
The prognosis of different primary GN groups, and renal survival rates cannot be assessed or calculated from this study, as the follow-up period was short.
All reports published so far are retrospective and as such, the study population and age-groups were different. Thus, our reports cannot be compared with what is published already.
In conclusion, FSGS and MesPGN were the commonest histological lesions in our study. There is an urgent need to establish a national GN registry in order to map out, not only the prevalence rates, but also measures to combat GN, both preventive and therapeutic.
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Abdullah A Al-Khader
Department of Nephrology, Riyadh Armed Forces Hospital, P.O. Box 7897, Riyadh 11159
[Figure - 1]
[Table - 1], [Table - 2], [Table - 3]