Trends in the epidemiology of childhood nephrotic syndrome in Africa: A systematic review

Abstract

Background: Childhood nephrotic syndrome, if left untreated, leads to progressive kidney disease or death. We quantified the prevalence of steroid-sensitive nephrotic syndrome, steroid-resistant nephrotic syndrome, and histological types as the epidemiology of nephrotic syndrome in Africa remains unknown, yet impacts outcomes.

Methods: We searched MEDLINE, Embase, African Journals Online, and WHO Global Health Library for articles in any language reporting on childhood nephrotic syndrome in Africa from January 1, 1946 to July 1, 2020. Primary outcomes included steroid response, biopsy defined minimal change disease, and focal segmental glomerulosclerosis (FSGS) by both pooled and individual proportions across regions and overall.

Findings: There were 81 papers from 17 countries included. Majority of 8131 children were steroid-sensitive (64% [95% CI: 63-66%]) and the remaining were steroid-resistant (34% [95% CI: 33-35%]). Of children biopsied, pathological findings were 38% [95% CI: 36-40%] minimal change, 24% [95% CI: 22-25%] FSGS, and 38% [95% CI: 36-40%] secondary causes of nephrotic syndrome.

Interpretation: Few African countries reported on the prevalence of childhood nephrotic syndrome. Steroid-sensitive disease is more common than steroid-resistant disease although prevalence of steroid-resistant nephrotic syndrome is higher than reported globally. Pathology findings suggest minimal change and secondary causes are common. Scarcity of data in Africa prevents appropriate healthcare resource allocation to diagnose and treat this treatable childhood kidney disease to prevent poor health outcomes.

Funding: Funding was provided by the Canadian Institute for Health Research (CIHR) and the National Institute of Health (NIH) for the H3 Africa Kidney Disease Research Network. This research was undertaken, in part, from the Canada Research Chairs program.

Fig. 1

PRISMA flow diagram displaying literature search method with included and excluded studies.

Fig. 2

Published data on childhood nephrotic syndrome among individual African counties and the years of study.

Fig. 3

Steroid response among children with nephrotic syndrome separated by African country calculated using pooled averages.

Fig. 4

Proportions of focal segmental glomerulosclerosis (FSGS) minimal change disease (MCD) and other histological types out of those biopsied from 1960 to 2018 in African countries calculated using pooled averages. ^aCote D'Ivoire had one study with one biopsy which showed Focal Segmental Glomerulosclerosis and was not included in this figure. ^bNumber biopsied for FSGS = 585. ^cNumber biopsied for MCD and other = 105. ^dNumber biopsied for MCD and FSGS = 1046. ^eNumber biopsied for Total MCD = 3477 and Total FSGS = 3514. ^fOther includes any of the following: membranous nephropathy, tropical extramembranous, mesangial proliferative glomerulonephritis, cyclosporine toxicity, likely FSGS, membranoproliferative glomerulonephritis, amyloidosis, diffuse mesangial proliferation, diffuse segmental glomerulonephritis, diffuse proliferative glomerulonephritis, IgA, dense deposit disease, IgM, post infectious glomerulonephritis, lupus nephritis, Alport's syndrome, tropical immune complex glomerulonephritis, immune complex glomerulonephritis and secondary FSGS, mesangiocapillary glomerulonephritis, diffuse global glomerulonephritis, diffuse mesangial hypercellularity, quartan malaria nephropathy, proliferative, extra capillary proliferation, mild mesangial hypercellularity, post-streptococcus glomerulonephritis, endocapillary glomerulonephritis, focal proliferative secondary to sickle cell, chronic glomerulonephritis, crescentic glomerulonephritis, congenital.