Glomerular Hypertrophy Is a Risk Factor for Relapse in Minimal Change Disease Patients

Outcomes of minimal change disease without nephrotic range proteinuria

Minimal change disease (MCD) is characterized by edema and nephrotic range proteinuria (NS). However, the fate of MCD without nephrotic proteinuria requires elucidation. We retrospectively reviewed 79 adults diagnosed with primary MCD at their initial renal biopsy at a tertiary hospital between May 2003 and June 2017. Clinicopathologic features were compared between patients with and without NS. The frequency of flaring to nephrotic proteinuria and renal outcomes were assessed during follow-up. There were 20 and 59 patients in the Non-NS and NS groups, respectively. The Non-NS group had a lower frequency of acute kidney injury (AKI) during the follow-up period [5.0% vs. 59.3%, p <0.001]. The response rate to steroid treatment was 100% in the Non-NS group and 92.3% in the NS group (p = 1.000). Except for one patient, the Non-NS group was treated with steroids when their proteinuria increased to a nephrotic level. There were no differences in the frequency of the first relapse or the number of relapses among patients with initial remission from nephrotic range proteinuria. At the final visit, the complete remission rate was 73.4%. The estimated glomerular filtration rate during follow-up was significantly better in the NS group than the Non-NS group, given the higher rates of AKI at renal biopsy. The rates of renal events, end-stage renal disease, and mortality did not differ between the groups. Adult MCD patients with nephrotic and non-nephrotic range proteinuria showed similar outcomes. Accordingly, this population must be carefully managed, regardless of the amount of proteinuria at renal biopsy.

Contribution of IL-33/ILC2-mediated Th2 cytokines during the progression of minimal change disease

Minimal change disease (MCD) is a common type of nephrotic syndrome with high recurrence rate. This study aims to explore the impacts of interleukin (IL)-33 in MCD and to discuss its potential mechanism. In adriamycin (ADM) and puromycin aminonucleoside (PAN)-induced MCD rat model, IL-33 was used for treatment. H&E staining was applied for detecting histological changes. Critical proteins were examined by western blot. Corresponding commercial kits tested oxidative stress- and inflammation-related factors. Cell apoptosis was measured by TUNEL assay. ADM-induced podocyte injury model was establish to mimic MCD in vitro. Cell proliferation and apoptosis were detected by CCK-8 and TUNEL assays. Finally, podocyte was stimulated by innate lymphoid type-2 cells-secreted Th2 cytokines (ILC2s: IL-13 and IL-5 respectively), with or without incubation with M1 macrophage medium to further explore the immune-regulation of ILC2s behind the inflammatory environment of MCD. It was found that PAN-induced kidney jury, inflammation, oxidative stress and apoptosis were severer than ADM, and IL-33 treatment significantly alleviated the above injuries in PAN and ADM-induced MCD rat model. Moreover, IL-33 reversed the reduced viability and increased oxidative stress and apoptosis in ADM-induced podocyte injury model. Further, the capacities of IL-13 alone in inducing M1/M2 macrophage polarization, apoptosis, inflammation, kidney injury and reducing cell viability are stronger than IL-5. However, IL-13 reversed reduced cell viability and stimulated apoptosis, inflammation, kidney injury mediated by co-incubation with M1-conditioned medium. Collectively, IL-33 might protect against immunologic injury in MCD via mediating ILC2s-secreted IL-13.

Tubular B7-1 expression parallels proteinuria levels, but not clinical outcomes in adult minimal change disease patients

B7-1 is thought to play a pathogenic role in minimal-change disease (MCD). Recently, however, doubts have arisen regarding the role of B7-1 expression in MCD. Therefore, we aimed to identify the presence and clinical significance of B7-1 expression in MCD patients. The study participants included 28 adult MCD patients for whom kidney specimens were available. The intensity of B7-1 expression was assessed by two independent specialists. We analysed the association between the intensity of B7-1 expression and clinicopathological variables. No B7-1 expression in the glomeruli was observed in any of the 28 patients. Unexpectedly, however, 75.0% of the patients exhibited tubular B7-1 expression, with 35.7% demonstrating weak positive expressions and 39.3% demonstrating strong positive expressions. The level of proteinuria significantly increased as the intensity of tubular B7-1 expression increased. We also found trends of increasing blood urea nitrogen and serum creatinine levels with increased intensity of tubular B7-1 expression. However, we could not observe definite differences in long- and short-term clinical outcomes depending on the intensity of tubular B7-1 expression. In conclusion, B7-1 was expressed in renal tubular cells but not in glomeruli in adult MCD patients. The intensity of tubular B7-1 expression paralleled proteinuria levels, but not clinical outcomes.