Time to remission of proteinuria and incidence of relapse in patients with steroid-sensitive minimal change disease and focal segmental glomerulosclerosis: the Japan Nephrotic Syndrome Cohort Study

A nomogram to predict the risk of relapse in patients with minimal change disease: a retrospective cohort study

BACKGROUND

Minimal change disease (MCD) is a common pathological type of nephrotic syndrome. Relapses of MCD present a significant challenge for patients. This study aims to develop a predictive model for evaluating the probability of relapse in patients with MCD.

METHODS

This study enrolled 152 patients with biopsy-confirmed MCD, all of whom received exclusive glucocorticoid treatment at the First Affiliated Hospital of Zhejiang University in Hangzhou, China, between October 2012 and April 2021. The Cox regression analysis was utilized to identify the risk factors associated with the relapse in MCD, and a nomogram was constructed to predict the probability of relapse.

RESULTS

The results demonstrated that serum immunoglobulin E (IgE) levels > 936 IU/mL, age ≤ 30 years old, estimated glomerular filtration rate (eGFR) < 90 mL/(min × 1.73 m2), serum total cholesterol (TCh) levels > 12.3 mmol/L, and time to remission were independent risk factors associated with relapses in patients with MCD. A nomogram was established and achieved a concordance index of 0.726 (95% CI = 0.659-0.793). The receiver operating characteristic curves demonstrated areas under the curve of 0.771, 0.853, and 0.811 for the prediction of relapse at 1-, 2-, and 3-year intervals after achieving remission in MCD patients respectively. These findings along with the calibration curves indicated the good discrimination and calibration performance of the nomogram in this cohort.

The established nomogram provides a valuable tool for the identification of patients with MCD who are at risk of relapse, which may facilitate prompt treatment for these patients.

Relationship between time to clinical remission and relapse in adults with steroid-sensitive minimal change disease: a retrospective cohort study

OBJECTIVE

Minimal change disease (MCD) is a common nephrotic syndrome that is usually steroid-sensitive and has high relapse rate. The aim of this study was to investigate the relationship between time to clinical remission and recurrence after the initial steroid therapy.

METHODS

Among 305 adult patients diagnosed with MCD via light and electron microscopy, sensitive to steroids, and hospitalized for nephrotic syndrome in the Department of Nephrology of the Affiliated Hospital of Guangdong Medical University in China, 88 were included in this retrospective cohort study. Cox regression analysis was performed with time to clinical remission and 24-hour urine protein quantification (24 hUTP), absolute basophil (BA) and basophil percentage (BA%) as independent variables. Independent variables with significant differences and the time to remission were used to construct a Cox regression model to exclude the influence of confounding factors. The receiver operating characteristic (ROC) curve was plotted according to the independent variable of time to clinical remission.

RESULTS

No significant differences were found between the relapse and non-relapse groups in terms of sex, age at onset, or prevalent hypertension. There were significant differences in time to clinical remission, 24 hUTP, BA and BA% between the relapse and non-relapse groups. The risk of recurrence was significantly higher in patients with clinical remission of 15-21, 22-28 and 29-56 days than in those who had clinical remission of 1-7 days. In addition, patients with clinical remission of >26.5 days had a significantly higher risk of recurrence than those in the other groups.

CONCLUSIONS

Overall, the time of clinical remission is a potential factor for predicting the recurrence of steroid-sensitive MCD in adults.

High Albumin Clearance Predicts the Minimal Change Nephrotic Syndrome Relapse

Key Points

Albumin kinetics not only reflected the pathophysiology of minimal change nephrotic syndrome but was also a predictor of relapse. The high estimated 24-hour albumin clearance predicts the minimal change nephrotic syndrome relapse. The 24-hour albumin clearance can easily be calculated from only serum albumin and urinary protein excretion, which are routine laboratory measurements.

Background

Although albuminuria leakage that occurs in minimal change nephrotic syndrome (MCNS) may be related to the disease state, albumin kinetics in MCNS has never been evaluated. In this study, we investigated albumin kinetics in adult Japanese patients with MCNS by the estimated 24-hour albumin clearance (eCALB) and examined the association between eCALB and relapse.

Methods

We retrospectively identified 103 adult patients with a histological diagnosis of MCNS from four hospitals in Japan (2010–2020). The primary outcome is the first relapse in 2 years after complete remission after corticosteroid therapy. The eCALB [µ l/min] was defined as (2.71828(0.0445+0.9488×log(urinary protein) [g/24 hours])/(serum albumin [g/dl]×1440 [min/24 hours]) for women and (2.71828(-0.1522+0.9742×log(urinary protein) [g/24 hours])/(serum albumin [g/dl]×1440 [min/24 hours]) for men.

Results

Relapse was observed in 44 patients (103 kidney biopsy samples; 42.7%). The mean patient age was 41.0 years. Patients had an eGFR of 71.0 ml/min per 1.73 m2, urinary protein excretion of 6.8 g/d, serum albumin of 1.4 g/dl, and eCALB of 2.27 μ l/min. eCALB was strongly associated with hypoalbuminemia, severe proteinuria, lipid abnormalities, and coagulopathy. In the multivariable analysis, a high eCALB was significantly associated with relapse after adjusting for age, eGFR, time to complete remission, and urinary protein excretion (adjusted hazard ratio, 5.027; 95% confidence interval, 1.88 to 13.47; P = 0.001).

Conclusions

This study revealed that eCALB, which could substitute albumin kinetics, reflected the severity of MCNS, and a high eCALB was associated with recurrence.

Predictors of early remission of proteinuria in adult patients with minimal change disease: a retrospective cohort study

Previous studies reported conflicting results regarding an association between serum albumin concentration and the cumulative incidence of remission of proteinuria in adult patients with minimal change disease (MCD). The present study aimed to clarify the clinical impact of serum albumin concentration and the cumulative incidence of remission and relapse of proteinuria in 108 adult patients with MCD at 40 hospitals in Japan, who were enrolled in a 5-year prospective cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study (JNSCS). The association between serum albumin concentration before initiation of immunosuppressive treatment (IST) and the cumulative incidence of remission and relapse were assessed using multivariable-adjusted Cox proportional hazards models. Remission defined as urinary protein < 0.3 g/day (or g/gCr) was observed in 104 (96.3%) patients. Of 97 patients with remission within 6 month of IST, 42 (43.3%) developed relapse defined as ≥ 1.0 g/day (or g/gCr) or dipstick urinary protein of ≥ 2+. Serum albumin concentration was significantly associated with remission (multivariable-adjusted hazard ratio [95% confidence interval] per 1.0 g/dL, 0.57 [0.37, 0.87]), along with eGFR (per 30 mL/min/1.73 m²: 1.43 [1.08, 1.90]), whereas they were not associated with relapse. A multivariable-adjusted model showed that patients with high eGFR level (≥ 60 mL/min/1.73 m²) and low albumin concentration (≤ 1.5 g/dL) achieved significantly early remission, whereas those with low eGFR (< 60 mL/min/1.73 m²) and high albumin concentration (> 1.5 g/dL) showed significantly slow remission. In conclusion, lower serum albumin concentration and higher eGFR were associated with earlier remission in MCD, but not with relapse.