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

Association of PLCE1 (rs7922612) and COL4A3 (rs375290088) Genetic Variants with the Risk of Nephrotic Syndrome in Egyptian Pediatric Patients

Nephrotic syndrome is one of the most prevalent pediatric kidney illnesses seen in pediatric nephrology clinics. Steroid resistance in children with nephrotic syndrome is a primary cause of renal failure and is characterized by nephrotic range proteinuria that does not respond to conventional steroid therapy. The current work was intended to investigate the possible role of the Phospholipase C epsilon 1 (rs7922612) and collagen4 alpha 3 (rs375290088) single nucleotide polymorphisms as risk factors for developing nephrotic syndrome among Egyptian children. The study was conducted on 100 children with nephrotic syndrome and 100 age- and sex-matched healthy individuals. Geno typing was performed by two methods of polymerase chain reaction for the analysis of PLCE1 (rs7922612) and COL4A3 (rs375290088) variants. We observed a higher percentage of the heterozygous and homozygous variant genotypes of PLCE1 (rs7922612) SNP in NS patients in comparison with the controls (P < 0.001 for both). The frequencies of the PLCE1 (rs7922612) variant showed a statistically significant elevated risk of NS using several genetic models, including the dominant (OR = 9.12), recessive (OR = 2.31), and allelic (OR = 1.62) models (P < 0.001 for each). In addition, the PLCE1 (rs7922612) genotypes and alleles frequencies did not differ significantly between SRNS compared to SSNS cases. Furthermore, there was no significant difference regarding COL4A3 (rs375290088) polymorphism, neither between the NS and control groups nor between SDNS and SRNS. PLCE1 (rs7922612) is considered an independent risk factor for nephrotic syndrome in Egyptian pediatrics.COL4A3 (rs375290088) polymorphism is not correlated to Egyptian NS patients.

Relation between interleukin-13 and annexin-V levels and carotid intima-media thickness in nephrotic syndrome

Background and aim

The aim of the current study is to assess the relation between carotid intima-media thickness (CIMT) measurements, renal Doppler resistive index (RI) and serum levels of interleukin-13 (IL-13) and annexin-V (An-V) in children with idiopathic nephrotic syndrome (INS).

Materials and methods

The present case-control study was conducted on 60 children with INS and 60 age- and sex-matched healthy children. All participants were subjected to evaluation of serum levels of IL-13 and An-V and ultrasound Doppler measurement of CIMT and renal RI.

Results

Patients expressed significantly higher An-V (5.9 ± 2.6 vs. 2.1 ± 0.8 ng/mL, p<0.001) and IL-13 (19.2 ± 7.6 vs. 3.4 ± 1.4 ng/L) levels when compared with healthy counterparts. Moreover, it was shown that patients had significantly higher CIMT (0.49 ± 0.06 vs. 0.35 ± 0.03, p<0.001) as compared to controls. No significant differences were noted between the studied groups regarding right or left RIs. Correlation analysis identified significant direct correlation between serum An-V levels and albumin/creatinine ratio (ACR) (r = 0.55), cholesterol (r = 0.48), triglycerides (r = 0.36), IL-13 (r = 0.92) and CIMT (r = 0.53). Similar correlations could be found between serum IL-13 levels and CIMT measurements and the corresponding parameters.

Conclusions

The present study suggests an association between higher early atherosclerosis expressed as elevated CIMT measurements in children with INS and elevated serum levels of An-V and IL-13.

Prevalence and distribution of primary glomerular diseases in Africa: a systematic review and meta-analysis of observational studies

Glomerulonephritis (GN) is a predominant cause of kidney failure in Africa. The prevalence of primary GNs varies widely across Africa depending on the relative proportion of secondary GNs and genetic predispositions. We assessed the overall and sub-regional prevalence of primary GN and its histologic subtypes in Africa. We searched PubMed, EMBASE and African Journals Online for studies of biopsy-proven primary GNs across all age groups in Africa published between 2010 and 2022. Data for primary GNs [minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), mesangioproliferative GN (MesPGN), membranoproliferative GN (MPGN), post-infectious GN (PIGN), IgA Nephropathy (IgAN), and crescentic GN (CresGN)] were extracted. Pooled prevalence was determined using the random effects model. Seventeen eligible articles (n = 6,494 individuals) from 8 African countries met the inclusion criteria. The overall pooled prevalence of FSGS, MCD, MN, MPGN, MesPGN, PIGN, IgAN and CresGN was 26.10%, 22.40%, 8.40%, 6.40%, 6.40%, 2.60%, 2.60%, 1.40%, respectively. Only 4 studies (23.5%) used light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM) for diagnosis. There were significant differences in the distribution of histologic subtypes in the paediatric compared to the adult population and across geographic sub-regions, with West Africa having a higher prevalence of FSGS. Overall, the dominance of FSGS across most regions and age groups has implications for disease diagnosis and ongoing care. Research efforts to understand the impact of this trend on kidney disease outcomes and efforts to improve kidney biopsy practice as a means of early disease detection are needed in Africa.

Hiding in plain sight: genetics of childhood steroid-resistant nephrotic syndrome in Sub-Saharan Africa

Steroid-resistant nephrotic syndrome (SRNS) is the most severe form of childhood nephrotic syndrome with an increased risk of progression to chronic kidney disease stage 5. Research endeavors to date have identified more than 80 genes that are associated with SRNS. Most of these genes regulate the structure and function of the podocyte, the visceral epithelial cells of the glomerulus. Although individuals of African ancestry have the highest prevalence of SRNS, especially those from Sub-Saharan Africa (SSA), with rates as high as 30-40% of all cases of nephrotic syndrome, studies focusing on the characterization and understanding of the genetic basis of SRNS in the region are negligible compared with Europe and North America. Therefore, it remains unclear if some of the variants in SRNS genes that are deemed pathogenic for SRNS are truly disease causing, and if the leading causes of monogenic nephrotic syndrome in other populations are the same for children in SSA with SRNS. Other implications of this lack of genetic data for SRNS in the region include the exclusion of children from the region from clinical trials aimed at identifying potential novel therapeutic agents for this severe form of nephrotic syndrome. This review underlines a need for concerted efforts to advance the genetic basis of SRNS in children in SSA. Such endeavors will complement global efforts at understanding the genetic basis of nephrotic syndrome.

Childhood Nephrotic Syndrome in Africa: Epidemiology, Treatment Trends, and Outcomes

Nephrotic syndrome is a common childhood glomerular disease that is associated with massive proteinuria and edema. Children with nephrotic syndrome are at risk of chronic kidney disease, disease-related complications, and treatment-related complications. Patients with frequently relapsing disease or steroid toxicity may require newer immunosuppressive medications. However, access to these medications is limited in many African countries owing to prohibitive cost, the need for frequent therapeutic drug monitoring, and a lack of appropriate facilities. This narrative review examines the epidemiology of childhood nephrotic syndrome in Africa, including trends in treatment and patient outcomes. In most of North Africa, as well as among White and Indian populations in South Africa, the epidemiology and treatment of childhood nephrotic syndrome closely resembles that of European and North American populations. Historically, secondary causes of nephrotic syndrome (eg, quartan malaria nephropathy and hepatitis B-associated nephropathy) were predominant among Blacks in Africa. Over time, the proportion of secondary cases has decreased, along with rates of steroid resistance. However, focal segmental glomerulosclerosis increasingly has been reported among patients with steroid resistance. There is a need for consensus guidelines for the management of childhood nephrotic syndrome in Africa. Furthermore, establishing an African nephrotic syndrome registry could facilitate monitoring of disease and treatment trends, and provide opportunities for advocacy and research to improve patient outcomes.

Long-Term Efficacy and Safety of Repeated Rituximab to Maintain Remission in Idiopathic Childhood Nephrotic Syndrome: An International Study

BACKGROUND

Long-term outcomes after multiple courses of rituximab among children with frequently relapsing, steroid-dependent nephrotic syndrome (FRSDNS) are unknown.

METHODS

A retrospective cohort study at 16 pediatric nephrology centers from ten countries in Asia, Europe, and North America included children with FRSDNS who received two or more courses of rituximab. Primary outcomes were relapse-free survival and adverse events.

RESULTS

A total of 346 children (age, 9.8 years; IQR, 6.6-13.5 years; 73% boys) received 1149 courses of rituximab. A total of 145, 83, 50, 28, 22, and 18 children received two, three, four, five, six, and seven or more courses, respectively. Median (IQR) follow-up was 5.9 (4.3-7.7) years. Relapse-free survival differed by treatment courses (clustered log-rank test P<0.001). Compared with the first course (10.0 months; 95% CI, 9.0 to 10.7 months), relapse-free period and relapse risk progressively improved after subsequent courses (12.0-16.0 months; HRadj, 0.03-0.13; 95% CI, 0.01 to 0.18; P<0.001). The duration of B-cell depletion remained similar with repeated treatments (6.1 months; 95% CI, 6.0 to 6.3 months). Adverse events were mostly mild; the most common adverse events were hypogammaglobulinemia (50.9%), infection (4.5%), and neutropenia (3.7%). Side effects did not increase with more treatment courses nor a higher cumulative dose. Only 78 of the 353 episodes of hypogammaglobulinemia were clinically significant. Younger age at presentation (2.8 versus 3.3 years; P=0.05), age at first rituximab treatment (8.0 versus 10.0 years; P=0.01), and history of steroid resistance (28% versus 18%; P=0.01) were associated with significant hypogammaglobulinemia. All 53 infective episodes resolved, except for one patient with hepatitis B infection and another with EBV infection. There were 42 episodes of neutropenia, associated with history of steroid resistance (30% versus 20%; P=0.04). Upon last follow-up, 332 children (96%) had normal kidney function.

CONCLUSIONS

Children receiving repeated courses of rituximab for FRSDNS experience an improving clinical response. Side effects appear acceptable, but significant complications can occur. These findings support repeated rituximab use in FRSDNS.