Steroid response varies greatly with the original ethnicity, for example, SRNS is three times more common among African Americans than European Americans residing in the USA. The incidence of SRNS is also lower among European studies than among African studies [20].

In this study, the prevalence of idiopathic SRNS was 6.9%. This was similar to rates reported in another study from upper Egypt, which stated that the prevalence of SRNS is 6% in a retrospective study [21]. Regional discrepancies may be ascribed to selection bias because regional tertiary care centers are used as samples rather than all children with NS. Differences in rates reported could also be attributed to the sampling technique used some studies included also patients with late steroid resistance, secondary NS, patients with low C3, or patients with a family history of NS [22,23,24,25,26].

Unlike several other studies, in this study we decided against including patients with a family history of nephrotic syndrome, this was because we believed that even if these patients had an inconclusive genetic analysis, it was still likely that they had a genetic form of NS. In Kaddah et al.’s study in Cairo, a family history of NS was present among 11.7% of SRNS patients, and when comparing their SRNS and SSNS patients, there was a significant correlation between family history and SRNS (p = 0.013) [26]. Moreover, AlHarthi reported a positive family history in 71.4% of their SRNS patients [22]. As for consanguinity among parents, it was found in 21.6% of our patients, and expectedly was found in an even higher percentage in Saudi Arabia (76%). AlHarthi actually justified that the higher percentage of SRNS patients in his study (24%) was due to this extreme rate of consanguinity among parents and positive family history [22].

Hypertension at presentation was found among 54.9% of our cases. All of them continued to be hypertensive and controlled on antihypertensive medication throughout the duration of this study. The reported rates of HTN in Cairo, Saudi Arabia, Bangladesh, and Nigeria varied between 7.5% and 81% [11, 12, 22, 27]. In Sudan their definition of HTN was clearly stated to be blood pressure above 95th percentile for age, therefore their methods were similar to ours, and not surprisingly the rate of HTN recorded was 48% which is very close to our reported rate of 54.9% [23].

As for hematuria, 25.5% of our cases had persistent hematuria either microscopic or gross. Great variation in reported incidences of persistent hematuria was noted in several other studies, with incidence ranging from 15.1 to 81% [12, 22, 23, 25, 27]. In Sudan, they used a lower cutoff value of 3 RBCs/ HPF, which might explain why they reported a higher number of cases [23]. Other studies did not clarify their cut-off values for diagnosing hematuria, so this huge discrepancy between our results and their results could be due to different definitions used. Again, we have to note that in Bangladesh they also included patients with low C3 in their study which are more likely to present with nephritic manifestations [12, 22, 23, 25].

Most of our patient’s biopsies showed MesPGN, followed by FSGS and MCNS. MesPGN was also the most common biopsy finding in several other studies [12, 26, 28, 29], while other studies reported that MCNS was the most prevalent among SRNS patients [13, 30]. Focal segmental glomerulosclerosis was the most common biopsy finding in many studies [10, 22, 24, 31]. These differences between different countries could be aroused because of ethnic differences and genetic factors. The limitation in resources might have affected these results as well. It is not clear whether all centers examined their biopsy specimens by all 3 methods, light microscope, electron microscope, and immunofluorescence. It is also uncertain whether all immune stains were readily available, especially in developing countries. Differences perhaps also occur because biopsy readings are subjective and not all centers might have an experienced pathologist in nephrology, this might have also contributed to these discrepancies between the results, as early features of FSGS might be missed.

Recurrent infections were a common complication in this study, occurring in 8/51 patients (15.7%). Details of the organisms isolated by blood or urine culture in those patients suffering from recurrent infections were lacking, however, it is well known that the most common cause of infection in cases of NS are pneumococci and E. coli. [2]. In a study from Sudan, among the most encountered complications were recurrent infections (13%) as well. Patients in their study suffered from recurrent infections in the form of respiratory tract infections, urinary tract infections, and peritonitis [23]. Pneumococcal vaccination is not present in the routine vaccination schedule in our country, so most of our patients have not received vaccinations against pneumococci, which explains their susceptibility and the high rate of recurrent infections recorded.

The reported incidence of thromboembolic complications in NS is 3% [32]. We reported an incidence of 11.8% (6/51) among our SRNS patients. When screened for abnormalities of thrombophilia, two of these patients were proven to have an abnormal thrombophilia profile and are currently on lifelong anticoagulants. Nevertheless, the incidence reported in our cases is high probably due to the prolonged duration of proteinuria in cases of steroid resistance, associated with a persistent hypercoagulable state.

A retrospective study performed in New Delhi, India, by Sharma et al. in SRNS patients, showed that the rate of CNI toxicity for both tacrolimus and cyclosporin in follow-up biopsies after an average of 30 months was 7.5% and 17.5%, respectively. They concluded that longer durations of proteinuria, higher doses of CNIs, concomitant HTN, as well as initial steroid resistance were associated with a significantly increased risk of CNI toxicity [33].

In this study, we fortunately reported a lower rate of CNI toxicity in 3 of the 19 patients who underwent re-biopsy (15.8%). To avoid nephrotoxicity even when remission was achieved with the help of cyclosporine, it was gradually replaced by a less nephrotoxic drug such as MMF. Periodic assessment of GFR is also performed, so that re-biopsy is considered in case of GFR affection or after completion of 2 years on cyclosporine regimen. Nevertheless, cyclosporine was also administered for an even shorter duration in patients who showed unremitting disease when it failed to induce remission.

There is no clear consensus regarding the interval for testing for ocular complications; however, we have adapted the practice of requesting full ophthalmological assessment at least annually or earlier if indicated for our patients. Complications were recorded 4 times, where 3 patients had PSC, and one of them suffered from glaucoma as well. Hence, ophthalmological complications were recorded in 3/51 patients (5.9%).

HbA1C and fasting blood sugar are performed at least every 6 months as advised by IPNA, especially in cushingoid patients, the finding that 1/51 of patients has glucose intolerance and another patient (1/51) developed type II DM is therefore a true representative of the magnitude of the problem [2].

We also found that the most frequently recorded complications in this study were drug-related rather than disease-related. The 2 most recorded complications were cushingoid appearance (17.6%) and suppressed growth velocity (17.6%). Short stature was recorded in 13.7% of the cases. A similar observation was found in a retrospective study done in Saudi Arabia by Kari et al. [34]. According to IPNA’s guidelines for the management of SRNS patients, height and weight measurements should be obtained and plotted on a growth chart at least every 3 months, an annual height velocity should also be calculated based on these measurements [2].

The mean duration of follow-up in this study was 5.67 ± 3.07 years. Surprisingly, the most common outcome in this study and in several other studies was remission [12, 13, 24], with complete remission still having the highest prevalence. However, AlHarthi in Saudi Arabia has described that more than half of SRNS patients in their study developed CKD [22]. Moreover, the mortality rate in this study (4.3%), was also lower than that recorded in other studies [12, 22]. We think that our studied group of patients had a better outcome because we excluded cases with a positive family history, those with secondary causes of NS and those with positive genetic studies.

In this study, the results show that initial results of renal pathology and the presence of hematuria are the strongest predictors of outcome. The most important predictive factor for remission in this study was MCNS on renal biopsy (p value = 0.043). There was a significant correlation between failure to achieve remission and patients with persistent hematuria whether gross or microscopic (p value = 0.045). Inaba et al. concluded that patients with FSGS on biopsy, especially those who did receive initial treatment with cyclophosphamide rather than cyclosporine had the lowest renal survival rate [13]. Mendonca et al. concluded that steroid resistance, along with hematuria at presentation, as well as age of onset were the prime factors predicting patients’ outcomes [35].