Research Article: Idiopathic nephrotic syndrome in South African children

Date Published: December , 2017

Publisher: Makerere Medical School

Author(s): Yassir Mahgoub Bakhiet, Abdullahi Mudi, Tholang Khumalo, Glenda Moonsamy, Cecil Levy.

http://doi.org/10.4314/ahs.v17i4.22

Abstract

Different histo-pathological types and treatment response patterns of Idiopathic nephrotic syndrome (INS) have been associated with differences in ethnicity and geographical location.

To provide an update on the steroid response and renal histo-pathological pattern in children treated for INS.

Medical records of children with INS treated at the Charlotte Maxeke Johannesburg Academic Hospital were reviewed.

Mean age was 5.3 years ± 2.8. The majority (68.1%) of the 163 children were of the black racial group. The highest rate of INS was seen in the 2–6 year age group (71.2%). The black racial group had the highest rate (42/111; 37.8%) of focal segmental glomerulosclerosis (FSGS), and the white race had the highest rate (9/14; 64.3%) of minimal change disease (MCD). Ninety four (57.7%) patients were steroid sensitive (SSNS) while 69 patients (42.3%) were steroid resistant (SRNS). Minimal change disease was the most common histo-pathological type seen in SSNS (60%), while FSGS was the most common observed in patients who had SRNS (65.2%).

There appears to be a higher rate of FSGS in all the racial groups, and also a higher rate of MCD in the black race group, when compared to previous reports.

Partial Text

The spectrum of idiopathic nephrotic syndrome (INS) in African countries seems to be different from other parts of the world suggesting that an interaction of genetic and environmental factors plays an important role in the pathogenesis of INS1,2. Worldwide, a significant number of cases of INS are usually steroid sensitive, while some cases will be diagnosed as having steroid unresponsive disease3–5.

This retrospective study reviewed children (2–16 years) with INS treated by the Division of Paediatric Nephrology at Charlotte Maxeke Johannesburg Academic Hospital between January 2004 and December 2013. Only children who had at least 6 months of follow up after onset of the disease were included in the study. Children with evidence of chronic renal impairment prior to the diagnosis of INS (estimated glomerular filtration rate (eGFR) ≤60 mL/min/1.73 m2) were excluded from the study. Demographic and clinical information were obtained from the patients’ records.

All data were collated, checked and analysed using a computer based statistical package STATA version 13.1. Continuous parameters were reported as mean and standard deviation while categorical variables were presented as percentages and bar charts. Associations between groups were determined using chi-square testing and bilateral Fisher’s exact tests. A p value < 0.05 was regarded as statistically significant. The study was approved by the University of the Witwatersrand, Human Research Ethics Committee (Protocol M150234) and was conducted in conformance with the Helsinki Declaration, Good Clinical Practice and within the laws and regulations of South Africa. 1. Steroid response pattern17: Steroid sensitive nephrotic syndrome (SSNS) (initial responder): Attainment of remission within initial 4 weeks of corticosteroid therapy.Steroid dependent nephrotic syndrome (SDNS): Two consecutive relapses during corticosteroid therapy, or within 14 days of ceasing therapy.Steroid resistant nephrotic syndrome (SRNS) (initial non-responder/steroid resistance): Failure to achieve complete remission after 8 weeks of corticosteroid therapy. A total of 163 children who met the study criteria were recruited. There were 97 (59.5%) males and 66 (40.5%) females with a male to female ratio of 1.5:1. The mean age of the children at the time of presentation was 5.3 years ± 2.8. The mean follow-up period was 60 months ± 36.9. This study found a mean age at presentation that is similar to previous studies1,6,7,9,12,18,19, but lower than that previously reported by Bhimma et al in Durban, South Africa1. Although we expected our study cohort to have a similar age of presentation to that of the Durban study, the Durban study had a higher percentage of Asian patients in their cohort than we had in ours, and this may explain why their mean age of presentation was closer to that observed in studies from India and Pakistan than to that of our study18,20. This study provides an update on children with INS and also highlights the higher rate of FSGS in all racial groups when compared to previous studies. The main limitations of our study are that it is retrospective and that we could not compare the response rate to other agents used in SRNS. We found higher rates of MCD, and also of favourable steroid response patterns, in our black race group than have been previously reported from South Africa. Of concern is our finding of a higher rate of FSGS in all the racial groups when compared to previous studies and we are not sure if this represents a new trend that FSGS is increasing in our population. If our finding of a higher rate of FSGS when compared to previous South African studies is real, this may mean that in the future we might begin to see an increase in the rate of steroid resistance among South African children with INS.   Source: http://doi.org/10.4314/ahs.v17i4.22

 

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