Plasma Cytokine Profiling to Predict Steroid Resistance in Pediatric Nephrotic Syndrome

Serum tumour necrosis factor-alpha as a marker of disease activity in children with nephrotic syndrome

Idiopathic nephrotic syndrome (NS) is a common glomerular disease in children throughout the world; however, the exact pathogenesis of the disease remains unknown. Several studies have shown that tumour necrosis factor-alpha (TNF-α), a proinflammatory cytokine, plays a significant role in the pathogenesis of NS. The literature lacks sufficient data to establish the relationship between TNF-α and NS. This prospective study was conducted on children aged 1-14 years diagnosed with idiopathic NS. All enrolled individuals were followed up from disease onset or relapse of NS until remission or at least 42 days with steroid therapy if remission was not achieved. Serum TNF-α levels were measured at presentation and remission or after 42 days of steroid therapy if remission was not achieved. The role of TNF-α levels in response to steroid therapy in NS was also assessed. One hundred and twelve children (68% boys) with idiopathic NS were enrolled. The median age (interquartile range) at enrolment was 58.5 (37-84.7) months, while the median age at symptom onset was 47.5 (24-60.7) months. The median TNF-α level at presentation was 7.5 (3.5-12.1) pg/ml, and that at remission was 5.25 (1.62-8.8) pg/ml. The median TNF-α levels among first-episode NS at presentation were 3.98 pg/ml and 1.88 pg/ml (P = .04) at remission, whereas in steroid-resistant NS, it was 6.59 pg/ml at presentation and 9.02 pg/ml at 42 days (P = .45). There was a significant negative correlation between the duration of steroid therapy and TNF-α levels, with a correlation factor of -0.021 and R2 of 0.154 (P≤.001). Serum TNF-α levels decrease with steroid therapy in children with steroid-sensitive NS, which correlates clinically with the achievement of remission.

Swollen Feet: Considering the Paradoxical Roles of Interleukins in Nephrotic Syndrome

Interleukins are a family of 40 bioactive peptides that act through cell surface receptors to induce a variety of intracellular responses. While interleukins are most commonly associated with destructive, pro-inflammatory signaling in cells, some also play a role in promoting cellular resilience and survival. This review will highlight recent evidence of the cytoprotective actions of the interleukin 1 receptor (IL-1R)- and common gamma chain receptor (IL-Rγc)-signaling cytokines in nephrotic syndrome (NS). NS results from the injury or loss of glomerular visceral epithelial cells (i.e., podocytes). Although the causes of podocyte dysfunction vary, it is clear that pro-inflammatory cytokines play a significant role in regulating the propagation, duration and severity of disease. Pro-inflammatory cytokines signaling through IL-1R and IL-Rγc have been shown to exert anti-apoptotic effects in podocytes through the phosphoinositol-3-kinase (PI-3K)/AKT pathway, highlighting the potential utility of IL-1R- and IL-Rγc-signaling interleukins for the treatment of podocytopathy in NS. The paradoxical role of interleukins as drivers and mitigators of podocyte injury is complex and ill-defined. Emerging evidence of the cytoprotective role of some interleukins in NS highlights the urgent need for a nuanced understanding of their pro-survival benefits and reveals their potential as podocyte-sparing therapeutics for NS.

Nephrotic syndrome sera induce different transcriptomes in podocytes based on the steroid response

As the molecular mechanism of nephrotic syndrome remains largely undiscovered, patients continue to be exposed to the pros and cons of uniform glucocorticoid treatment. We explored whether the exposure of in vitro-cultivated podocytes to sera from children with steroid-sensitive or steroid-resistant nephrotic syndrome induces differences in gene expression profiles, which could help to elucidate the pathogenesis of the steroid response. Human immortalized podocytes were cultivated with patient sera for 3 days. After cell lysis, RNA extraction, 3'-mRNA libraries were prepared and sequenced. There were 34 significantly upregulated and 14 downregulated genes (fold difference <0.5 and >2.0, respectively, and false discovery rate-corrected p < 0.05) and 22 significantly upregulated and 6 downregulated pathways (false discovery rate-corrected p < 0.01) in the steroid-sensitive (n = 9) versus steroid-resistant group (n = 4). The observed pathways included upregulated redox reactions, DNA repair, mitosis, protein translation and downregulated cholesterol biosynthesis. Sera from children with nephrotic syndrome induce disease subtype-specific transcriptome changes in human podocytes in vitro. However, further exploration of a larger cohort is needed to verify whether clinically distinct types of nephrotic syndrome or disease activity may be differentiated by specific transcriptomic profiles and whether this information may help to elucidate the pathogenesis of the steroid response.

The Role of Cytokines in Nephrotic Syndrome

Idiopathic nephrotic syndrome (INS) is an important primary glomerular disease characterized by severe proteinuria. Evidence supports a role for T cell dysfunction in the pathogenesis of INS. Glucocorticoids are the primary therapy for INS; however, steroid-resistant NS (SRNS) patients are at a higher risk of drug-induced side effects and harbor poor prognosis. Although the exact mechanism of the resistance is unknown, the imbalances of T helper subtype 1 (Th1), Th2, and regulatory T cells (Tregs) and their cytokines may be involved in the pathogenesis of glucocorticoid responsiveness. Up to now, no confirmed biomarkers have been able to predict SRNS; however, a panel of cytokines may predict responsiveness and identify SRNS patients. Thus, the introduction of distinctive cytokines as novel biomarkers of SRNS enables both preventions of drug-related toxicity and earlier switch to more effective therapies. This review highlights the impacts of T cell population imbalances and their downstream cytokines on response to glucocorticoid responsiveness state in INS.

Effect of Huaiqihuang Granules Combined with Comprehensive Nursing on Children with Primary Nephrotic Syndrome

Background

To observe the effect of Huaiqihuang granules combined with comprehensive nursing intervention on children with primary nephrotic syndrome (PNS) and its effect on renal function index.

Methods

A total of 104 patients were included, and the patients were randomly divided into two groups, with 52 cases in each group. The control group was treated with glucocorticoid, and the study group was treated with Huaiqihuang granules. The clinical efficacy of the two groups was observed. The levels of TG, TC, EGFR, 24 h UTP, BUN, Scr, IgA, IgG, IgM, IFN-γ and TNF-α were compared between two groups before and after treatment. The incidence of adverse reactions and recurrence rate after treatment were compared between the two groups.

Results

The effective rate of the study group (94.23%) was significantly higher than that of the control group (78.85%). Before treatment, there was no significant difference in TG and TC levels between the two groups. After treatment, the levels of TG and TC in both groups were decreased, and the decrease was more obvious in the study group. Compared with before treatment, the levels of 24 h UTP, BUN, Scr, IFN-γ, and TNF-α in both groups were significantly decreased after treatment, while EGFR, IgA, IgG, and IgM levels were significantly increased. Compared with the control group, the changes of each index in the study group were more obvious after treatment. After treatment, the incidence of adverse reactions and recurrence rate in the study group were significantly lower than those in the control group.

Conclusions

Huaiqihuang granules combined with comprehensive nursing treatment in children with PNS can reduce the occurrence of recent recurrence and adverse reactions and improve the cellular immune function and renal function.

Later Response to Corticosteroids in Adults With Primary Focal Segmental Glomerular Sclerosis Is Associated With Favorable Outcomes

INTRODUCTION

Guidelines advise initial therapy with corticosteroids (CSs) in patients with presumed primary focal segmental glomerular sclerosis (pFSGS). Many patients do not achieve complete remission (CR) after 8 or 16 weeks. Although these patients are considered steroid resistant, clinical outcomes are ill defined.

METHODS

A retrospective cohort study of patients with pFSGS who were referred between January 1995 and December 2014. Data of clinical presentation until last follow-up were collected from patient records.

RESULTS

A total of 51 patients (median age 47 years, 20 female/31 male) were included (median follow-up 7.1 years). There were 10 patients who achieved partial response (PR) at 8 weeks. High-dose CS monotherapy was continued for a median of 17 weeks (interquartile range [IQR] 11-21 weeks) (total duration 56 weeks [IQR 28-83 weeks]). With CSs, the cumulative incidence of CR + PR was 18% and 35%, respectively. Of 24 patients with persistent nephrotic-range proteinuria, 22 received additional immunosuppressive (IS) therapy, resulting in CR in 3 (14%) and PR in 11 patients (50%). A decrease of >20% of proteinuria at 8 weeks predicted response. In addition, 8 patients (36%) were considered primary nonresponders. A genetic cause was found in 2 patients. Proteinuria at end of follow-up was 1.2 g (IQR 0.4-3.0 g/24 hours or g/10 mmol creatinine). Renal survival at 3, 5, and 10 years was 92%, 87%, and 64%, respectively.

CONCLUSION

Patients with presumed pFSGS often respond late to IS therapy. A decrease in proteinuria of >20% after 8 weeks of therapy is a predictor of responsiveness. Regardless of CR in some patients, improved biomarkers are needed to predict response/outcomes in patients with pFSGS.

Sulfatase 2 Is Associated with Steroid Resistance in Childhood Nephrotic Syndrome

Glucocorticoid (GC) resistance complicates the treatment of ~10-20% of children with nephrotic syndrome (NS), yet the molecular basis for resistance remains unclear. We used RNAseq analysis and in silico algorithm-based approaches on peripheral blood leukocytes from 12 children both at initial NS presentation and after ~7 weeks of GC therapy to identify a 12-gene panel able to differentiate steroid resistant NS (SRNS) from steroid-sensitive NS (SSNS). Among this panel, subsequent validation and analyses of one biologically relevant candidate, sulfatase 2 (SULF2), in up to a total of 66 children, revealed that both SULF2 leukocyte expression and plasma arylsulfatase activity Post/Pre therapy ratios were greater in SSNS vs. SRNS. However, neither plasma SULF2 endosulfatase activity (measured by VEGF binding activity) nor plasma VEGF levels, distinguished SSNS from SRNS, despite VEGF's reported role as a downstream mediator of SULF2's effects in glomeruli. Experimental studies of NS-related injury in both rat glomeruli and cultured podocytes also revealed decreased SULF2 expression, which were partially reversible by GC treatment of podocytes. These findings together suggest that SULF2 levels and activity are associated with GC resistance in NS, and that SULF2 may play a protective role in NS via the modulation of downstream mediators distinct from VEGF.