Corticosteroid Treatment Influences TA-Proteinuria and Renal Survival in IgA Nephropathy

Blood and urine biomarkers of disease progression in IgA nephropathy

The prognosis of patients with IgA nephropathy (IgAN) is variable but overall not good. Almost all patients with IgAN are at risk of developing end-stage renal disease within their expected lifetime. The models presently available for prediction of the risk of progression of IgAN, including the International IgA Nephropathy Prediction Tool, consist of traditional clinical, pathological, and therapeutic indicators. Finding biomarkers to improve the existing risk prediction models or replace pathological indicators is important for clinical practice. Many studies have attempted to identify biomarkers for prediction of progression of IgAN, such as galactose-deficient IgA1, complement, a spectrum of protein biomarkers, non-coding RNA, and shedding cells. This article reviews the biomarkers of progression of IgAN identified in recent years, with a focus on those with clinical value, in particular the combination of multiple biomarkers into a biomarker spectrum. Future research should focus on establishing a model based primarily on biomarkers that can predict progression of IgAN and testing it in various patient cohorts.

Effect of pulsed intravenous methylprednisolone with alternative low-dose prednisone on high-risk IgA nephropathy: a 18-month prospective clinical trial

Full-dose prednisone (FP) regimen in the treatment of high-risk immunoglobulin A nephropathy (IgAN) patients, is still controversial. The pulsed intravenous methylprednisolone combined with alternative low-dose prednisone (MCALP) might have a more favorable safety profile, which has not been fully investigated. Eighty-seven biopsy-proven IgAN adult patients and proteinuria between 1 and 3.5 g/24 h after ACEI/ARB for at least 90 days were randomly assigned to 6-month therapy: (1) MCALP group: 0.5 g of methylprednisolone intravenously for three consecutive days at the beginning of the course and 3rd month respectively, oral prednisone at a dose of 15 mg every other day for 6 months. (2) FP group: 0.8-1.0 mg/kg/days of prednisone (maximum 70 mg/day) for 2 months, then tapered by 5 mg every 10 days for the next 4 months. All patients were followed up for another 12 months. The primary outcome was complete remission (CR) of proteinuria at 12 months. The percentage of CR at 12th and 18th month were similar in the MCALP and FP groups (51% vs 58%, P = 0.490, at 12th month; 60% vs 56%, P = 0.714, at 18th month). The cumulative dosages of glucocorticoid were less in the MCALP group than FP group (4.31 ± 0.26 g vs 7.34 ± 1.21 g, P < 0.001). The analysis of the correlation between kidney biopsy Oxford MEST-C scores with clinical outcomes indicated the percentages of total remission was similar between two groups with or without M1, E1, S1, T1/T2, and C1/C2. More patients in the FP group presented infections (8% in MCALP vs 21% in FP), weight gain (4% in MCALP vs 19% in FP) and Cushing syndrome (3% in MCALP vs 18% in FP). These data indicated that MCALP maybe one of the choices for IgAN patients with a high risk for progression into ESKD.Trial registration: The study approved by the Chinese Clinical Trial Registry (registration date 13/01/2018, approval number ChiCTR1800014442, https://www.chictr.org.cn/ ).

Long term outcome of immunoglobulin A (IgA) nephropathy: A single center experience

INTRODUCTION

IgA nephropathy (IgAN) has a heterogeneous presentation and the progression to end stage renal disease (ESRD) is often influenced by demographics, ethnicity, as well as choice of treatment regimen. In this study, we investigated the long term survival of IgAN patients in our center and the factors affecting it.

METHODS

This study included all biopsy-proven IgAN patients with ≥ 1year follow-up. Patients with diabetes mellitus at diagnosis and secondary IgAN were excluded. Medical records were reviewed for demographics, clinical presentation, blood pressure, 24-hour urine protein, serum creatinine, renal biopsy and treatment received. The primary outcome was defined as combined event of 50% estimated glomerular filtration rate (eGFR) reduction or ESRD.

RESULTS

We included 130 (74 females; 56 males) patients of mean age 38.0 ± 14.0 years and median eGFR of 75.2 (interquartile range (IQR) 49.3-101.4) ml/min/1.73m2. Eighty-four (64.6%) were hypertensive at presentation, 35 (26.9%) had nephrotic syndrome and 57 (43.8%) had nephrotic range proteinuria (NRP). Median follow-up duration was 7.5 (IQR 4.0-13.0) years. It was noted that 18 (13.8%) developed ESRD and 34 (26.2%) reached the primary outcome. Annual eGFR decline was -2.1 (IQR -5.3 to -0.1) ml/min/1.73m2/year, with median survival of 20 years. Survival rates from the combined event (50% decrease in eGFR or ESRD) at 10, 20 and 30 years were 80%, 53% and 25%, while survival from ESRD were 87%, 73% and 65%, respectively. In the univariate analysis, time-average proteinuria (hazard ratio (HR) = 2.41, 95% CI 1.77-3.30), eGFR <45ml/min/1.73m2 at biopsy (HR = 2.35, 95% CI 1.03-5.32), hypertension (HR = 2.81, 95% CI 1.16-6.80), mean arterial pressure (HR = 1.02, 95% CI 1.01-1.04), tubular atrophy/interstitial fibrosis score (HR = 3.77, 95% CI 1.84-7.73), and cellular/fibrocellular crescent score (HR = 2.44, 95% CI 1.19-5.00) were found to be significant. Whereas only time-average proteinuria (TA-proteinuria) remained as a significant predictor in the multivariate analysis (HR = 2.23, 95% CI 1.57-3.16).

CONCLUSION

In our cohort, TA-proteinuria was the most important predictor in the progression of IgAN, irrespective of degree of proteinuria at presentation.

Long-term blood pressure behavior and progression to end-stage renal disease in patients with immunoglobulin A nephropathy: a single-center observational study in Italy

BACKGROUND

Antihypertensive treatment by the use of RAAS inhibitors (RAAS-is) is of paramount importance in the management of slowly progressive IgA nephropathy (IgAN). With the aim of better understanding the relationship between BP behavior and progression, we looked at time-averaged SBP and time-averaged proteinuria and renal outcome in a single-center cohort of IgAN patients.

METHODS

Among 248 consecutive patients referred to the Clinic of Nephrology of San Martino Hospital from 1996 to 2018 for native renal biopsy with a diagnosis of IgAN, we retrospectively analyzed 145 with available data at baseline and during follow-up. All patients received Supportive Care, 39% were on RAAS-is alone, 45% plus steroids, and 16% plus steroids and immunosuppressors. Renal replacing treatment (RRT) was the primary endpoint.

RESULTS

During a mean follow-up of 67 ± 6 months, 23% of study patients (n = 33) progressed to RRT and 6% (n = 9) died. Patients who reached the renal endpoint, had lower baseline eGFR and higher proteinuria and proteinuria indexed at baseline. Moreover, they had higher TA-SBP (139 ± 17 vs. 130 ± 13, P = 0.0016). The incidence of RRT was higher in IgAN patients in the highest time-averaged SBP tertile as compared with the others (32 vs. 23 vs. 9%, χ 6.8, P = 0.033). After adjusting for baseline SBP, baseline and time-averaged proteinuria indexed, MEST-C score, and treatment, the association between TA-SBP and RRT persisted.

CONCLUSION

Time-averaged low BP values were independently associated to a decreased risk of renal progression in IgAN with no evidence of a J-curve relationship even at SBP levels below 125 mmHg.

Efficacy and safety of immunosuppressive therapies in the treatment of high-risk IgA nephropathy: A network meta-analysis

BACKGROUND

IgA nephropathy (IgAN) is one of the significant contributing factors of end-stage renal disease (ESRD). It is reported that over half of patients with IgAN accompany multiple high-risk factors, which increase the risk of ESRD progression. Studies have shown that immunosuppressive agents were beneficial in high-risk IgAN, but the efficacy and safety have not been fully demonstrated yet. The present study aims to elucidate the efficacy of commonly used immunosuppressants in high-risk IgAN and their relative safety profiles via a network meta-analysis strategy.

METHODS

Randomized controlled trials (RCTs) eligible for this network meta-analysis were included to evaluate the efficacy and safety of different immunosuppressants for high-risk IgAN. Main outcomes and measures include incidence of renal composite end point, the rate of total remission, adverse events, and proteinuria. Besides, subgroup analysis and cluster analysis were carried out.

RESULTS

This network meta-analysis of 37 RCTs involving 3012 participants found that Mycophenolate mofetil (MMF) combined with corticosteroids (CS) was superior to other interventions in end point events and proteinuria. Cyclosporine A (CsA) plus CS was the best option for clinical remission rate, and supportive care (SC) was the safest treatment. Cluster analysis showed that MMF+CS and Leflunomide (LEF)+CS were best protocols in efficacy and safety. Subgroup analysis indicated the best benefits of MMF were presented among the Asian population, and the benefits increased with the increase of follow-up duration. The effect of Cyclophosphamide (CTX) +CS on crescent IgAN was better than that of other risk factors. Moreover, the increasing follow-up duration was negatively associated with the effect.

CONCLUSIONS

MMF+CS and LEF+CS appear to serve as the best choice for treating high-risk IgAN than other immunosuppressive therapies.

Clinical and histological features and therapeutic strategies for IgA nephropathy

Chronic glomerulonephritis is the second most common reason, after diabetic nephropathy, for initiation of dialysis in Japan and IgA nephropathy (IgAN) is the most prevalent form of chronic glomerulonephritis. In the half century since IgAN was initially reported, our understanding of the long-term prognosis, clinical and histological features, pathogenesis of onset and progression, risk factors for progression, and appropriate treatment under different clinical and histological conditions, has steadily increased. Strong experimental and clinical evidence, the Clinical Practice Guidelines for IgA Nephropathy in Japan, the Oxford Classification, and the Kidney Disease Improving Global Outcomes guidelines have all contributed to the appropriate treatment of IgAN. Several intensive therapies, such as tonsillectomy, steroid therapy, and their combinations, can result in clinical remission, and prevent the progression to end stage renal disease (ESRD). However, some IgAN patients still progress to ESRD even when treated with intensive therapies. In this review, we discuss the clinical and histological features of IgAN, focusing primarily on our previous reports, and our opinions on therapeutic strategies for IgAN.

Albuminuria during treatment with angiotensin type II receptor blocker is a predictor for GFR decline among non-diabetic hypertensive CKD patients

BACKGROUND

Albuminuria is a predictor of disease progression in patients with chronic kidney disease (CKD). However, the ability of proteinuria parameters measured at various time periods to predict renal outcomes is unclear.

METHOD

This observational cohort study included 165 non-diabetic hypertensive CKD patients who took olmesartan medoxomil. We measured the albuminuria at five different time points (0, 2, 4, 26, and 38 months) and the mean levels. The mean albuminuria levels were calculated during 0-4 months, 0-26 months, and 0-38 months. The renal outcome was defined as a decline in eGFR ≥ 40% during the entire study period.

RESULT

The albuminuria at five different time points and the mean albuminuria levels were independent risk factors for a worse renal outcome after adjusting for age, sex, and estimated glomerular filtration rate (eGFR) at enrollment and were able to predict the renal outcome, although the performance of the estimation tended to be more effective using the mean albuminuria level at the 38-month follow-up time point. The risk of a decline in eGFR ≥ 40% was increased by 1.690-folds [95% CI 1.110-2.572, P = 0.014] per 500 mg/day increase in the mean albuminuria at 38 months. With a cut-off value of 897 mg/day for mean albuminuria at 38 months after treatment, a decline in eGFR ≥ 40% was predicted with a sensitivity of 88.9% and specificity of 81.3%. The ability of albuminuria to predict a renal event at different measurement points does not differ in CKD patients.

CONCLUSION

The time-averaged albuminuria cut-off of 900 mg/day during the 3-year follow-up period showed high sensitivity and specificity for predicting a decline in eGFR ≥ 40% in CKD patients, although the albuminuria at different measurement points did not predict a worse renal outcome.

Inflammation in IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the most frequently occurring primary glomerulonephritis in Caucasian and Asian populations. Nonetheless, therapeutic recommendations are based on weak evidence, large controlled trials are scarce and, in particular, the additional value of immunosuppression beyond comprehensive supportive measures is not well-established. The use of immunosuppressants is supported by experimental insights into IgAN pathogenesis that suggest an autoimmune component in disease development. The so-called "multi-hit" theory comprises multiple steps, starting with defective glycosylation of IgA subclass IgA1 that results in overproduction of galactose-deficient IgA1 (Gd-IgA1), occurrence of anti-Gd-IgA1 autoantibodies, and mesangial deposition of nephritogenic immune complexes. This eventually results in an increased mesangial cell proliferation, inflammatory responses, and complement activation. Recent genome-wide association studies have identified several susceptibility genes, many of which support the "multi-hit" concept. In light of these discoveries, it is astonishing that the vast majority of adult IgAN patients obviously do not need and/or benefit from immunosuppressive therapies in the first place. In fact, a number of supportive measures are highly effective in reducing the risk for disease progression in many patients. These measures need to be optimized before immunosuppression should be considered at all. In this review we focus on the underlying pathogenetic cornerstones and the central question of whether systemic inflammation in adult IgAN patients should be treated. Treatment options in children with IgAN are also discussed.

Treatment of IgA nephropathy

The therapy of IgA nephropathy (IgAN) is cause for debate among nephrologists. Since the early 1980s, many therapeutic attempts have been proposed, but most of them did not prove efficacy. The recent KDIGO Clinical Practice Guideline for Glomerulonephritis recommend long-term ACE-I or ARB treatment when proteinuria is more than 1 g/day, with up-titration of the drug. For patients with GFR >50 ml/min and proteinuria persistently higher than 1 g/day, they suggest a 6-month course of corticosteroid therapy. Based on our experience and the results of the literature, we propose a progressive treatment, which takes into account the time the IgAN is recognized and the clinical conditions present at that time. The treatment can be summarize as follows: (1) in patients with macro-microscopic haematuria, in case with proteinuria less than 0.3 g/day, only annual controls; (2) in patients with proteinuria between 0.3 and 0.9 g/day, ACE-I and/or ARB, with titration of the drugs; (3) in patients with proteinuria higher than 1 g/day, in case with the presence of arterial hypertension and GFR up to 30 ml/min, 6 months course of corticosteroids, in addition to ACE-I and/or ARB; (4) in patients with GFR less than 30 ml/min, ACE-I/ARB, dialysis and kidney transplantation; corticosteroids should be in case considered for patients with persistently high or increasing proteinuria; (5) the immunosuppressants (cyclophosphamide and azathioprine) should be reserved for patients with progressive renal insufficiency or with vasculitic lesions on renal biopsy.