Glomerular Immune Deposits Are Predictive of Poor Long-Term Outcome in Patients with Adult Biopsy-Proven Minimal Change Disease: A Cohort Study in Korea

CD80 Insights as Therapeutic Target in the Current and Future Treatment Options of Frequent-Relapse Minimal Change Disease

Minimal change disease (MCD) is the most common cause of idiopathic nephrotic syndrome in children, and it is well known for its multifactorial causes which are the manifestation of the disease. Proteinuria is an early consequence of podocyte injury and a typical sign of kidney disease. Steroid-sensitive patients react well with glucocorticoids, but there is a high chance of multiple relapses. CD80, also known as B7-1, is generally expressed on antigen-presenting cells (APCs) in steroid-sensitive MCD patients. Various glomerular disease models associated with proteinuria demonstrated that the detection of CD80 with the increase of urinary CD80 was strongly associated closely with frequent-relapse MCD patients. The role of CD80 in MCD became controversial because one contradicts finding. This review covers the treatment alternatives for MCD with the insight of CD80 as a potential therapeutic target. The promising effectiveness of CD20 (rituximab) antibody and CD80 inhibitor (abatacept) encourages further investigation of CD80 as a therapeutic target in frequent-relapse MCD patients. Therapeutic-based antibody towards CD80 (galiximab) had never been investigated in MCD or any kidney-related disease; hence, the role of CD80 is still undetermined. A new therapeutic approach towards MCD is essential to provide broader effective treatment options besides the general immunosuppressive agents with gruesome adverse effects.

End-Stage Renal Disease and Mortality Outcomes Across Different Glomerulonephropathies in a Large Diverse US Population

OBJECTIVE

To compare renal function decline, incident end-stage renal disease (ESRD), and mortality among patients with 5 common glomerular diseases in a large diverse population.

PATIENTS AND METHODS

A retrospective cohort study (between January 1, 2000, and December 31, 2011) of patients with glomerulonephropathy using the electronic health record of an integrated health system was performed. Estimated glomerular filtration rate (eGFR) change, incident ESRD, and mortality were compared among patients with biopsy-proven focal segmental glomerulosclerosis (FSGS), membranous glomerulonephritis (MN), minimal change disease (MCD), immunoglobulin A nephropathy (IgAN), and lupus nephritis (LN). Competing risk models were used to estimate hazard ratios for different glomerulonephropathies for incident ESRD, with mortality as a competing outcome after adjusting for potential confounders.

RESULTS

Of the 2350 patients with glomerulonephropathy (208 patients [9%] younger than 18 years) with a mean follow-up of 4.5±3.6 years, 497 (21%) progressed to ESRD and 195 (8%) died before ESRD. The median eGFR decline was 1.0 mL/min per 1.73 m² per year but varied across different glomerulonephropathies (P<.001). The highest ESRD incidence (per 100 person-years) was observed in FSGS 8.72 (95% CI, 3.93-16.72) followed by IgAN (4.54; 95% CI, 1.37-11.02), LN (2.38; 95% CI, 0.37-7.82), MN (2.15; 95% CI, 0.29-7.46), and MCD (1.67; 95% CI, 0.15-6.69). Compared with MCD, hazard ratios (95% CIs) for incident ESRD were 3.43 (2.32-5.08) and 2.35 (1.46-3.81), 1.28 (0.79-2.07), and 1.02 (0.62-1.68) for FSGS, IgAN, LN, and MN, respectively. No significant association between glomerulonephropathy types and mortality was detected (P=.24).

CONCLUSION

Our findings from a real-world clinical environment revealed significant differences in eGFR decline and ESRD risk among patients with 5 glomerulonephropathies. These variations in presentation and outcomes warrant different management strategies and expectations.

Increased PD-1+CD154+ Tfh cells are possibly the most important functional subset of PD-1+ T follicular helper cells in adult patients with minimal change disease

T follicular helper (Tfh) cells, especially programmed cell death protein 1 (PD-1)+ Tfh cells, exert important functions in the normal immune response. The purpose of this study was to determine the frequency of different subsets of PD-1+ Tfh cells and their functional effects in adult patients with minimal change disease (MCD). The frequencies of circulating PD-1+, PD-1+CD154+, and PD-1+interleukin (IL)-21+ Tfh cells, and CD38+CD19+ and CD38+CD19+CD40+ B cells, as well as serum IL-2, IL-4, IL-17A, IL-6, IL-21, and interferon (IFN)-γ were significantly increased in the MCD patients compared with the healthy controls (HCs) (P < 0.05). However, no significant difference was found in PD-1+BCL-6+ or PD-1+ICOS+ Tfh cells. Furthermore, the percentages of PD-1+ Tfh and PD-1+CD154+ Tfh cells were negatively correlated with the estimated glomerular filtration rate (eGFR), but positively correlated with the 24-h urinary protein concentration and serum IL-21 level. The percentages of PD-1+ Tfh and PD-1+CD154+ Tfh cells were positively correlated with the percentages of CD38+ plasma cells and active CD38+CD40+ plasma cells, respectively. After an 8-12-week treatment with prednisolone, the percentages of PD-1+, PD-1+CD154+, and PD-1+IL-21+ Tfh cells as well as the serum level of IL-21 were significantly reduced; in contrast, the serum levels of IL-4 and IL-10 were increased (P < 0.05). We conclude that increased PD-1+CD154+ Tfh cells are possibly the most important functional subset of PD-1+ Tfh cells and may contribute towards the pathogenesis of MCD.

Nephrin Loss Can Be Used to Predict Remission and Long-term Renal Outcome in Patients With Minimal Change Disease

Introduction

Minimal change disease is a common cause of nephrotic syndrome. In general, patients with minimal change disease respond to corticosteroids and have excellent long-term renal survival. However, some patients have less favorable outcome. These patients are often thought to have progressed to focal segmental glomerulosclerosis. We previously reported that a segmental loss of podocyte markers is present before the development of focal segmental glomerulosclerosis in a rat model. Here, we investigated whether loss of podocyte marker nephrin can serve as a biomarker for predicting poor outcome in patients with minimal change disease.

Methods

We obtained 47 kidney biopsy samples from patients diagnosed with minimal change disease and stained sections with periodic acid−Schiff and for nephrin. Nephrin loss was scored by 2 independent researchers who were blinded to clinical outcome. Clinical data were collected retrospectively, and nephrin loss was correlated with clinical follow-up data.

Results

Nephrin loss was present in 34% of the biopsy samples. During follow-up, patients with nephrin loss achieved remission less frequently (61%) compared to patients without (96%) (P = 0.002). Moreover, 5-year eGFR was lower in the patients with renal nephrin loss. The risk of eGFR decreasing to < 60 ml/min per 1.73m² increased with each percentage of glomeruli with nephrin loss (hazard ratio = 1.044, 95% confidence interval = 1.02−1.07).

Conclusion

These results indicate that nephrin loss in patients with minimal change disease can help predict both remission and long-term renal outcome.

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.