Corticosteroid therapy in IgA nephropathy with minimal change-like lesions: a single-centre cohort study

Contemporary review of IgA nephropathy

IgA nephropathy (IgAN) is considered the most common primary glomerulonephritis worldwide with a predilection for Asian-Pacific populations and relative rarity in those of African descent. Perhaps 20%-50% of patients progress to kidney failure. The pathogenesis is incompletely understood. Mesangial deposition of immune complexes containing galactose-deficient IgA1 complexed with anti-glycan IgG or IgA antibodies results in mesangial cell activation and proliferation, inflammatory cell recruitment, complement activation, and podocyte damage. Diagnosis requires a biopsy interpreted by the Oxford criteria. Additional pathologic features include podocytopathy, thrombotic microangiopathy, and C4d staining. Biomarkers predicting adverse outcomes include proteinuria, reduced GFR, hypertension, and pathology. Acceptable surrogate endpoints for therapeutic trials include ongoing proteinuria and rate of eGFR decline. The significance of persisting hematuria remains uncertain. The mainstay of therapy is supportive, consisting of lifestyle modifications, renin-angiotensin inhibition (if hypertensive or proteinuric), sodium-glucose-transporter 2 inhibition (if GFR reduced or proteinuric), and endothelin-receptor antagonism (if proteinuric). Immunosuppression should be considered for those at high risk after maximal supportive care. Corticosteroids are controversial with the most positive results observed in Chinese. They carry a high risk of serious side effects. Similarly, mycophenolate may be most effective in Chinese. Other immunosuppressants are of uncertain benefit. Tonsillectomy appears efficacious in Japanese. Active areas of investigation include B-cell inhibition with agents targeting the survival factors BAFF and APRIL and complement inhibition with agents targeting the alternate pathway (Factors B and D), the lectin pathway (MASP-2), and the common pathway (C3 and C5). Hopefully soon, the who and the how of immunosuppression will be clarified, and kidney failure can be forestalled.

Treatment of IgA Nephropathy: A Rapidly Evolving Field

The pivotal event in the pathophysiology of IgA nephropathy is the binding of circulating IgA-containing immune complexes to mesangial cells, with secondary glomerular and tubulointerstitial inflammation and fibrosis. The paramount difficulty in the management of IgA nephropathy is the heterogeneity in its clinical presentation and prognosis, requiring an individualized treatment approach. Goal-directed supportive care remains the bedrock of therapy for all patients, regardless of risk of progression. Sodium-glucose transporter 2 inhibitors and sparsentan should be integral to contemporary supportive care, particularly in patients with chronic kidney damage. Pending the development of reliable biomarkers, it remains a challenge to identify patients prone to progression due to active disease and most likely to derive a net benefit from immunosuppression. The use of clinical parameters, including the degree of proteinuria, the presence of persistent microscopic hematuria, and the rate of eGFR loss, combined with the mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis, crescents score, is currently the best approach. Systemic glucocorticoids are indicated in high-risk patients, but the beneficial effects wane after withdrawal and come at the price of substantial treatment-associated toxicity. Therapies with direct effect on disease pathogenesis are increasingly becoming available. While targeted-release budesonide has garnered the most attention, anti-B-cell strategies and selective complement inhibition will most likely prove their added value. We propose a comprehensive approach that tackles the different targets in the pathophysiology of IgA nephropathy according to their relevance in the individual patient.

Mild mesangial proliferative IgA nephropathy with and without minimal change disease

Mild mesangial proliferative IgA nephropathy with minimal change disease (MCD-IgAN) and mild mesangial proliferative IgA nephropathy without minimal change disease (Non-MCD-IgAN) have similar characteristics on light microscopy. Nevertheless, their discrepancies in clinicopathological features and prognosis remain unknown. A total of 589 patients with biopsy-proven mild mesangial proliferative IgA nephropathy (M-IgAN) combined with light microscopy and immunofluorescence were enrolled. Firstly, the diagnoses of the patients by electron microscopy were recorded and used as the gold standard. We calculated the sensitivity and specificity using nephrotic syndrome (NS) as the diagnostic criteria to identify MCD-IgAN. Then, excluding patients with a 24-h urinary total protein less than 0.5 g/day, incomplete clinical data, or less than the six-month follow-up, we included 184 cases of non-MCD-IgAN and 98 cases of MCD-IgAN. The patients' clinicopathological and outcome data were collected and compared. Among the 589 patients, according to electron microscopy, 381 were diagnosed with non-MCD-IgAN, 167 with MCD-IgAN, and 41 with M-IgAN complicated by other glomerular diseases. Using NS as the diagnostic criteria to distinguish non-MCD-IgAN and MCD-IgAN, the sensitivity and specificity were 83.8% and 99.5%, respectively. The patients in the MCD-IgAN group tended to be younger, hypotensive, with lower urinary erythrocytes, and more likely to achieve complete remission, and fewer patients progressed to the endpoint than those in the non-MCD-IgAN group (all P < 0 .05). NS appears to be an objective indicator for differentiating MCD-IgAN from non-MCD-IgAN. Non-MCD-IgAN varies greatly from MCD-IgAN in clinicopathology and treatment response, with a poorer prognosis.

Oral glucocorticoids with intravenous cyclophosphamide or oral glucocorticoids alone in the treatment of IgA nephropathy present with nephrotic syndrome and mesangioproliferative glomerulonephritis

Background

Few studies have evaluated the treatment of immunoglobulin A nephropathy (IgAN) patients with nephrotic syndrome (NS) and mesangioproliferative glomerulonephritis (MPGN). The aim of this study was to compare the therapeutic effects of oral glucocorticoids (GCS) combined with intravenous cyclophosphamide (CTX) and oral GCS alone in the treatment of the MPGN-IgAN patients with NS.

Methods

Biopsy-proven primary IgAN patients who were aged ≥14 years at diagnosis, had coexistent NS and MPGN and estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m2, and were treated by oral GCS combined with intravenous CTX or oral GCS alone for 6-12 months were retrospectively included. The patients in the GCS + CTX (prednisone 0.6-0.8 mg/kg/day and intravenous CTX 0.6-1.0 g monthly) or GCS (prednisone 0.8-1 mg/kg/day) group were rather matched at a 1:1 ratio on key characteristics by propensity score matching. The primary outcome was defined as either complete remission or partial remission at Month 24. The secondary outcome was a composite renal endpoint defined as a 50% decline in eGFR, doubling of serum creatinine or progression to end-stage kidney disease.

Results

Among the 146 IgAN patients who met the inclusion criteria, 42 patients were enrolled in the GCS + CTX group, and 42 patients were enrolled in the GCS group after propensity score matching. The clinical and histological parameters were similar between the two groups. Remission occurred more frequently in the GCS + CTX group at Month 6 (88.1% vs 52.4%, P < 0.001), Month 12 (88.1% vs 56.1%, P = 0.001) and Month 24 (85.0% vs 47.5%, P < 0.001) than in the GCS group. Moreover, subgroup analysis revealed that the higher response rate at Month 24 in the GCS + CTX group than in the GCS group was also present in different subgroups defined by sex, age, eGFR or Oxford MEST-C. Notably, we found that eGFR decreased at a lower rate in patients from the GCS + CTX group than in patients from the GCS group [eGFR slope: 0.05(-3.09, 3.67) vs -2.56 (-11.30, 0.86) mL/min/1.73 m2/year, P = 0.03]. Based on multivariate Cox regression analysis, GCS + CTX treatment was found to be independently associated with a decrease in risk for the composite endpoint after adjusted by the International Risk Prediction Score with race (hazard ratio = 0.17, 95% confidence interval 0.04-0.83, P = .03). There was no significant difference in adverse events (50.0% vs 42.9%, P = 0.51) or serious adverse events (7.1% vs 11.9%, P = .71) between the two groups.

Conclusions

Oral GCS combined with intravenous CTX is superior to GCS alone in treating MPGN-IgAN patients combined with NS. As the retrospective design and small sample size, our findings need to be validated by a prospective study.

Key pathological features characterize minimal change disease-like IgA nephropathy

AIMS

A subset of IgA nephropathy (IgAN) patients exhibiting minimal change disease (MCD) like features present with nephrotic-range proteinuria and warrants immunosuppressive therapy (IST). However, the diagnosis of MCD-like IgAN varied by reports. We aimed to identify the key pathological features of MCD-like IgAN.

METHODS

In this cohort, 228 patients had biopsy-proven IgAN from 2009 to 2021, of which 44 without segmental sclerosis were enrolled. Patients were classified into segmental (< 50% glomerular capillary loop involvement) or global (> 50%) foot process effacement (FPE) groups. We further stratified them according to the usage of immunosuppressant therapy after biopsy. Clinical manifestations, treatment response, and renal outcome were compared.

RESULTS

26 cases (59.1%) were classified as segmental FPE group and 18 cases (40.9%) as global FPE group. The global FPE group had more severe proteinuria (11.48 [2.60, 15.29] vs. 0.97 [0.14, 1.67] g/g, p = 0.001) and had a higher proportion of complete remission (81.8% vs. 20%, p = 0.018). In the global FPE group, patients without IST experienced more rapid downward eGFR change than the IST-treated population (-0.38 [-1.24, 0.06] vs. 1.26 [-0.17, 3.20]mL/min/1.73 m2/month, p = 0.004).

CONCLUSIONS

The absence of segmental sclerosis and the presence of global FPE are valuable pathological features that assist in identifying MCD-like IgAN.

Corticosteroid Therapy in Immunoglobulin A Nephropathy: A Friend or Foe?

BACKGROUND

The administration of corticosteroids in addition to supportive care to delay progressive immunoglobulin A nephropathy (IgAN), the most common primary glomerulonephritis worldwide, remains controversial. This is partly due to the paucity of well-designed randomized controlled trials and well-known corticosteroid-related side effects. As a result, clinical equipoise in corticosteroid therapy exists depending on geographical regions and the clinician's preference.

SUMMARY

Better understanding around the pathogenesis of IgAN has prompted several clinical trials exploring the effects of immunosuppressive agents including corticosteroids. Earlier studies of corticosteroids were limited by suboptimal study designs, inadequate implementation of standard of care, and inconsistent adverse event data collection. Two well-designed, adequately powered, multi-centre randomized controlled trials, the STOP-IgAN and TESTING studies, have reported contrasting kidney outcomes that have further fuelled the clinical conundrum regarding the efficacy of corticosteroids. Both studies independently reported greater adverse events with corticosteroids. A novel targeted release formulation of budesonide, which has been hypothesized to reduce the adverse events associated with systemic corticosteroids, has shown promising results in the Phase 3 NefigaRD trial. Studies of treatments targeting B cells and the complement cascade are currently underway, and early data appear encouraging. This review provides an overview of the current literature around the understanding of the pathomechanisms and benefits and harm of corticosteroid use in IgAN.

KEY MESSAGES

Recent evidence suggests the use of corticosteroids in a selected cohort of people with IgAN at high risk of disease progression can improve kidney outcomes but comes with an associated risk of treatment-related adverse events, particularly with higher doses. Management decisions should therefore follow an informed patient-clinician discussion.

Characterization of patients with IgA nephropathy with and without associated minimal change disease

Introduction

Immunoglobulin A nephropathy (IgAN) presents various clinical manifestations and pathological phenotypes. Approximately 5% of patients with IgAN present with early onset nephrotic syndrome, mild mesangial lesions, and diffuse foot process effacement of podocytes, which resemble minimal change disease (MCD). These patients are defined as MCD-IgAN. Whether MCD-IgAN is a special type of IgAN or simply MCD accompanied by IgA deposition remains controversial.

Methods

A total of 51 patients diagnosed with MCD-IgAN at Beijing Anzhen Hospital from January 2010 to September 2022 were recruited. The clinical and pathological characteristics of IgA-MCD were analyzed. Patients with IgAN but without MCD (non-MCD-IgAN) and healthy participants were enrolled as controls. Galactose-deficient immunoglobulin A1 (Gd-IgA1) and complement C3 were detected both in the circulation and in renal tissues.

Results

We found that the levels of serum Gd-IgA1 were lower in participants with MCD-IgAN than in those with non-MCD-IgAN, but higher than in healthy participants. Gd-IgA1 was rarely deposited in the glomeruli of participants with MCD-IgAN, with a positive rate of only 13.7% (7/51); in contrast, the positive rate in participants with non-MCD-IgAN was 82.4% (42/51). Among renal Gd-IgA1-positive patients, Gd-IgA1 and immunoglobulin A (IgA) colocalized along the glomerular mesangial and capillary areas. Interestingly, we found that the circulating levels of complement C3 were significantly higher in participants with MCD-IgAN than in participants with non-MCD-IgAN. In addition, the intensity of C3c in glomeruli in participants with MCD-IgAN was significantly weaker than in participants with non-MCD-IgAN.

Conclusions

Our study suggests that, in MCD-IgAN, most of the IgA that is deposited on glomeruli is not the same pathogenic Gd-IgA1 as found in general IgAN. Complement activation both in the circulation and in the renal locality was much weaker in MCD-IgAN than in non-MCD-IgAN. Our study suggests that IgAN with MCD might be MCD with coincidental IgA deposition.

Immune Characteristics of IgA Nephropathy With Minimal Change Disease

Background: IgA nephropathy (IgAN) has a high degree of heterogeneity in clinical and pathological features. Among all subsets of IgAN, the pathogenesis of IgAN with minimal change disease (MCD-IgAN) remained controversial.

Methods: We analyzed the clinical and pathological characteristics of MCD-IgAN patients in a retrospective cohort. Patients diagnosed with IgAN, excluding MCD-IgAN, were randomly selected as controls. Levels of plasma galactose-deficient IgA1 (GdIgA1), IgG autoantibodies against GdIgA1, GdIgA1 deposition in the glomerulus, and inflammatory reactivity of circulating poly-IgA1 complexes to cultured mesangial cells were evaluated.

Results: Patients with MCD-IgAN had significantly higher levels of proteinuria and estimated glomerular filtration rate (eGFR), lower levels of albumin and urine blood cells, and milder histological lesions by a light microscope compared to IgAN patients, which bears a resemblance to MCD. Lower levels of GdIgA1 (3.41 ± 1.68 vs. 4.92 ± 2.30 μg/ml, p = 0.009) and IgG antiglycan autoantibodies (23.25 ± 22.59 vs. 76.58 ± 71.22 IU/ml, p < 0.001) were found in MCD-IgAN patients than those in IgAN controls. Meanwhile, weaker fluorescence intensities of both IgA and GdIgA1 were observed in the glomerulus of MCD-IgAN patients compared to those in IgAN patients. Furthermore, poly-IgA1 complexes from MCD-IgAN patients induced weaker inflammatory effects on cultured mesangial cells than those from IgAN patients in vitro.

Conclusion: The results demonstrated that MCD-IgAN cases represent a dual glomerulopathy, namely, mild IgAN with superimposed MCD, which furthermore provides substantial evidence for the corticosteroids therapy in MCD-IgAN patients as the guidelines recommended.

Immunoglobulin A (IgA) Nephropathy: A Clinicopathologic Study in a Tertiary Care Center in Saudi Arabia

Background: Immunoglobulin A nephropathy (IgAN) is the most common primary aetiology of glomerulonephritis worldwide, and it is the most important type in terms of morbidity and mortality. IgAN involves the deposition of immune bodies in the mesangial cells of the kidney, which causes renal glomerular damage, haematuria, proteinuria, and various other symptoms. Previous studies have mainly focused on the East Asian population, with few studies conducted in Saudi Arabia, particularly in the western region. The diagnosis requires a biopsy, which should be examined by an expert and classified according to the Oxford classification system.

Objectives: Analyze the clinical, pathological, and laboratory features of male and female patients diagnosed with IgAN at King Abdulaziz University Hospital (KAUH).

Methods and materials: This was a retrospective record review conducted at KAUH in Jeddah, Saudi Arabia between May-June 2021. The study included 18 patients diagnosed with IgAN by biopsy, and their clinical, laboratory and pathological data were evaluated and classified according to the Oxford classification system.

Results: Demographic data revealed a male predominance of 66.7%. The most common pathological finding was mesangial proliferation, and the most common presentation was haematuria. For treatment options, corticosteroids were the most prescribed drugs. A significant relationship was found between IgAN with increased serum creatinine and male sex (P = 0.017). Additionally, a significant relationship was observed between decreased estimated glomerular filtration rate (eGFR) in IgAN and the male sex (P = 0.006).

Conclusions: We found a difference in terms of pathological, clinical and laboratory presentations of IgAN between males and females. Men generally had worse kidney function at presentation and advanced Oxford classification in their kidney biopsies compared to women.

Clinical and pathological features of immunoglobulin A nephropathy patients with nephrotic syndrome

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide. The classic manifestation of IgAN is episodic hematuria and proteinuria. Nephrotic syndrome (NS) is not very common in IgAN, reported to occur in only 5-10% of IgAN patients. However, the clinical and pathological characteristics and long-term outcomes of patients with NS-IgAN at onset remain unknown. A retrospective study was conducted, enrolling 1165 patients with biopsy-proven IgAN from West China Hospital in 2008-2015. Patients with renal biopsy of minimal change disease with mesangial IgA deposits were excluded. The renal endpoint was defined as 50% decrease in eGFR or progressing into end-stage renal disease (ESRD). A total of 1165 patients were enrolled with average age of 34.58, and 171 (14.7%) patients were presented with NS. Comparing NS and non-NS groups, significance differences were shown in hypertension (HTN), 24-h urine protein, serum albumin, serum creatine, eGFR and uric acid. NS group had severe pathological changes such as endocapillary hypercellularity, tubular atrophy or interstitial fibrosis and crescent, but less segmental glomerulosclerosis or adhesion and global sclerosis. During the average follow-up of 44.27 months, 29.8% (51/171) NS patients and 15.8% (157/994) non-NS patients progressed to the renal endpoint. 5-year renal survival rates were 73.1% and 87.8% (P < 0.001) in NS and non-NS groups, respectively. This study demonstrated that IgAN patients with NS had higher serum creatine, lower eGFR, lower uric acid, more acute lesions and poor prognosis. NS was an independent risk factor for progression to the renal endpoint.

High renal DC-SIGN+ cell density is associated with severe renal lesions and poor prognosis in patients with immunoglobulin A nephropathy

BACKGROUND AND AIMS

In this observational cohort study, we assessed the prognostic value of DC-SIGN⁺ cells in the pathogenesis and progression of IgA nephropathy (IgAN).

METHODS AND RESULTS

A total of 139 adult IgAN patients were enrolled into this study from June 2009 to June 2010. We characterised DC-SIGN⁺ cells by immunohistochemistry or immunofluorescence in renal biopsy tissue. Correlations between the DC-SIGN, intercellular adhesion molecule 3 (ICAM-3), CD4 and CD8 were evaluated. Patients were classified into the DC-SIGN^high and DC-SIGN^low groups. Depending on an average of 100-month follow-up, the predictive value of DC-SIGN⁺ cells in IgAN progression was analysed. DC-SIGN⁺ cells were found frequently in IgAN kidneys while rarely observed in normal kidneys, and almost all DC-SIGN⁺ cells expressed MHC-II. We also found that DC-SIGN⁺ cells were adjacent to ICAM-3-positive CD4⁺ and CD8⁺ lymphocytes. The density of DC-SIGN⁺ cells was positively and linearly correlated with the density of ICAM-3⁺ cells, CD4⁺ cells and CD8⁺ cells in renal biopsy tissues. In the DC-SIGN^high group, the degree of renal lesion and inflammatory cell infiltration was more severe compared to the DC-SIGN^low group. Patients in the DC-SIGN^high group also had increased incidences of deteriorating renal function during the follow up compared to patients in the DC-SIGN^low group.

CONCLUSIONS

DC-SIGN⁺ cells probably served as a potential contributor to exacerbate local inflammatory response. The density of DC-SIGN⁺ cells was associated with the severity of renal lesions of the patients. High renal DC-SIGN⁺ cell density might be used as a predictor of poor prognosis in patients with IgAN.

Causes of nephrotic syndrome and nephrotic-range proteinuria are different in adult Chinese patients: A single centre study over 33 years

AIM

The reported causes of nephrotic syndrome (NS) varies between different countries. Less is known about the causes of nephrotic-range proteinuria (NPU). We aimed to evaluate the underlying causes of NS and NPU.

METHODS

This was a single-centre, retrospective study of adult patients who underwent renal biopsy between 1983 and 2015 in a tertiary referral hospital in Hong Kong. We determined the distribution of histopathological diagnoses with regard to the age subgroups and time periods.

RESULTS

Among 7456 patients who underwent renal biopsy, 982 and 838 patients had NS and NPU, respectively. The most common diagnosis in NS was minimal change disease (MCD) (33.3%), followed by membranous nephropathy (MN) (23.6%) and lupus nephritis (LN) (12.8%); whereas the most common diagnosis in NPU was LN (27.4%), followed by immunoglobulin A nephropathy (IgAN) (21.4%) and diabetic nephropathy (DN) (9.3%). In the NS group, MCD was the most common diagnosis in young adults while MN was the leading cause in the elderly. On the other hand, LN was the most common pathology in the NPU group until the age of 60. Over the past three decades, there was a trend of decrease in the proportion of IgAN in both NS and NPU group, while a combined pathology of hypertensive nephrosclerosis and diabetic nephropathy (HTNS and DN) increased significantly.

CONCLUSIONS

The causes of NS and NPU in Chinese adults were different and may represent two distinct pathological identities. The spectrum of renal histopathology among these two groups changed significantly over time.

IgA nephropathy clinicopathologic study following the Oxford classification: Progression peculiarities and gender-related differences

BACKGROUND AND AIM

Immunoglobulin A nephropathy (IgAN) is the most frequent glomerular disease worldwide and one of the main causes of chronic kidney disease. We aimed to investigate clinicopathological correlations in IgAN patients by gender.

MATERIALS AND METHODS

The study was based on a retrospective analysis of renal biopsy data and clinical manifestations of the disease. Consecutive 73 biopsy-proven IgAN cases of male (62%) and female (38%) patients were investigated. Renal biopsies were reviewed using the new Oxford classification assessing the MEST (mesangial hypercellularity, endocapillary hypercellularity, segmental sclerosis/adhesion, tubular atrophy/interstitial fibrosis) score. The most powerful IgAN prognostic risk factors, morphological (segmental glomerulosclerosis and tubular atrophy/interstitial fibrosis) as well as clinical (proteinuria and hypertension) were taken into account in the correlation analysis. The mean rate of renal function decline was expressed as a slope of eGFR during the follow-up (FU) dividing delta GFR with the FU years.

RESULTS

The mean age of the patients was 33.7 years (range, 16-76). Follow-up data were available for 64 patients with the mean follow-up of 4.1 years. The mean proteinuria at biopsy was 0.79g/24h. The mean arterial pressure (MAP) was 94.5±16.7mmHg and 7% of the patients were hypertensive. The initial mean estimated glomerular filtration rate (eGFR) was 94.9±30.7mL/min, at the end of the follow-up it was 86.2±27.1mL/min. The mean rate of renal function decline was -3.4±11.9mL/min/1.73m² per year in males (P<0.05) and -0.7±5.3mL/min/1.73m² per year in females. The Spearman correlation analysis confirmed a higher MEST score in the whole cohort and in males correlated with disease progression. In patients with proteinuria below 1.0g/24h, disease progression was faster in males.

CONCLUSIONS

According to the correlation analysis of the main prognostic risk factors, affecting the progression of IgAN, we can conclude that IgA nephropathy in males progresses more rapidly compared to females.

Long-term outcome of IgA nephropathy with minimal change disease: a comparison between patients with and without minimal change disease

BACKGROUND

The clinicopathological characteristics, treatment response and long-term outcome of immunoglobulin (Ig)A nephropathy with minimal change disease (MCD-IgAN) are not well defined.

METHODS

Patients with biopsy-proven MCD-IgAN from the Jinling Hospital IgA nephropathy Registry were systematically reviewed and compared with those with IgA nephropathy without minimal change disease (Non-MCD-IgAN).

RESULTS

We compared data of 247 MCD-IgAN patients and 1,121 Non-MCD-IgAN patients. Compared to Non-MCD-IgAN, MCD-IgAN patients were younger,with male predominance, had higher levels of proteinuria, total cholesterol and estimated glomerular filtration rate (eGFR), lower incidence of hypertension and microhematuria, lower level of serum creatinine, and had less severe glomerular, tubulointerstitial and vascular lesions in renal pathology. In the Non-MCD-IgAN group, 157 patients (14.0 %) reached the renal endpoint and 103 patients (9.2 %) entered end-stage renal disease (ESRD). The 5-,10-, 15- and 20-year cumulative renal survival rates from ESRD, calculated by Kaplan-Meier method, were 95.0, 83.0, 72.9 and 65.4 %, respectively. In the MCD-IgAN group, no patients entered ESRD and only 4 (1.6 %) reached the renal endpoint. Patients with MCD-IgAN had a significantly better renal outcome than Non-MCD-IgAN (p < 0.01). At multivariate Cox analysis, proteinuria >1.0 g/day, hypertension, eGFR <60 ml/min/1.73 m(2), hypoproteinemia and hyperuricemia were independent risk factors of renal survival for Non-MCD-IgAN patients [hazard ratio (HR) 3.43, p < 0.001; HR 1.65, p < 0.05; HR 2.61, p < 0.001; HR 2.40, p < 0.001; HR 2.27, p < 0.001, respectively), but not for patients with MCD-IgAN.

CONCLUSIONS

The long-term outcome of patients with MCD-IgAN is significantly better than that of patients with Non-MCD-IgAN.

The Treatment of IgA Nephropathy

BACKGROUND

IgA nephropathy (IgAN) is a very common glomerulonephritis worldwide. Nevertheless, treatment options for primary IgAN are still largely based on opinion or weak evidence. There is a lack of large randomized controlled trials (RCT) that provide a definitive immunosuppressive protocol for IgAN. The recent KDIGO Clinical Practice Guidelines for Glomerulonephritis have assigned low levels of evidence for almost all recommendations and suggestions related to this nephropathy.

SUMMARY

In this article, we review different treatment options and emphasize that the key to therapeutic decision-making is the assessment of an individual's prognosis. The risk of disease progression is closely related to clinical parameters such as proteinuria, hypertension, and impaired glomerular filtration rate. For patients with minor urinary abnormalities, the mainstay of treatment is long-term regular follow-up to detect renal progression and hypertension. Optimized supportive care aiming to maintain proteinuria <1 g/day is preferred in the typical patient presenting with microhematuria, significant but nonnephrotic proteinuria, hypertension, and variable degrees of renal failure. The atypical patient with overt nephritic syndrome or rapidly progressive kidney injury that represents a vasculitic form of IgAN should be treated with immunosuppression. Finally, the variant of overlapping syndrome of IgAN and lipoid nephrosis that runs a good prognosis should be treated as lipoid nephrosis.

KEY MESSAGE

The treatment of IgAN should be structured according to the clinical scenario.

Reversal of active glomerular lesions after immunosuppressive therapy in patients with IgA nephropathy: a repeat-biopsy based observation

BACKGROUND

Reversal of active glomerular lesions after immunosuppressive treatment in patients with IgA nephropathy (IgAN) and their association with prognosis have not been well established.

METHODS

Sixty patients with IgAN who received repeat biopsies after immunosuppressive treatment were recruited. Reversal of renal pathological lesions was evaluated between the first and second biopsy. The end-point was defined as a 30% reduction in estimated glomerular filtration rate (eGFR) or end-stage renal disease after the second biopsy.

RESULTS

Active glomerular lesions, i.e. endocapillary hypercellularity (E), crescents (C) and necrosis (N) were markedly decreased at the second biopsy after immunosuppressive therapy (36.7 vs. 8.3%, p < 0.001; 85.0 vs. 25.0%, p < 0.001; and 51.7 vs. 3.3%, p < 0.001). Patients with E, C or N at the first biopsy but reversed at the second biopsy showed significantly decreased median levels of proteinuria and hematuria. Such clinical changes were not observed in those with active lesions at both biopsies. After a median follow-up of 32 months, 25.0% of patients reached the end-point. Repeat biopsy confirmed that only tubular atrophy/interstitial fibrosis was associated with the renal outcome.

CONCLUSIONS

Active glomerular lesions can be reversed by immunosuppressive treatment in patients with IgAN. The reversal is accompanied by improvement in proteinuria and hematuria. The reversal of these lesions during the disease process may explain the lack of significant correlation of these lesions with clinical outcomes in the present study as well as in previous evaluation studies of the Oxford classification of IgAN.

Correlation of proteinuria with podocyte foot process effacement in IgA nephropathy: an ultrastructural study

BACKGROUND

Proteinuria is an uncommon clinical manifestation of IgA nephropathy and is usually seen in cases with severe lesions like endocapillary proliferation. However, it is occasionally seen even with cases with mild glomerular manifestations and may even be of nephrotic range.

PREDICTOR

Podocyte foot process effacement.

OUTCOME

Severity of proteinuria.

MEASUREMENTS

Podocyte foot process effacement was measured. Morphometric analysis was performed on transmission electron microscope images using a computerized digital photomicrograph system (BioWizard 4.2 Image analysis software, New Delhi, India). Proteinuria was measured quantitatively assigned into five grades.

RESULTS

It was found that as the extent of proteinuria increased, the effacement ratio also increased, and this was most significant between "no" proteinuria and the rest of the categories.

CONCLUSION

Nephrotic presentation in IgA nephropathy is a known phenomenon and in certain cases may show near normal glomerular morphology with severe foot process effacement on EM being the only significant finding to explain the proteinuria. Proteinuria in these cases shows a significant correlation with degree of foot process effacement. Renal biopsy is important in these cases because they are known to have a better prognosis and are usually steroid responsive.

IgA nephropathy with minimal change disease

BACKGROUND AND OBJECTIVES

Patients with IgA nephropathy typically present with hematuria and subnephrotic proteinuria. Nephrotic syndrome is uncommon in IgA nephropathy, and when present, it is usually associated with severe histologic features, such as endocapillary proliferation, segmental sclerosis, and crescent formation. Rarely, patients with IgA nephropathy present with nephrotic syndrome and only mild mesangial disease. This study sought to better characterize these patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A retrospective review of cases of IgA nephropathy diagnosed from 2004 to 2011 identified patients with nephrotic range proteinuria and histologically mild IgA nephropathy. Specifically, using the Oxford Classification of IgA Nephropathy, we identified cases that lacked endocapillary proliferation or segmental sclerosis.

RESULTS

The cohort consisted of 17 patients, including 10 men and 15 adults. The median serum creatinine was 0.9 mg/dl (range=0.7-3.1), median 24-hour urine protein was 8.0 g/d (3.0-18.0 g), and 14 patients were fully nephrotic, whereas the remaining 3 patients fulfilled two of three criteria for nephrotic syndrome. Biopsies revealed IgA-dominant or codominant deposits accompanied by mesangial proliferation in 14 patients (82.4%). Electron microscopy showed mesangial deposits and extensive foot process effacement (median=90%). Initial treatment consisted of corticosteroids, although many patients required additional agents to maintain remission status. Over a median follow-up of 20 months (2.2-82 months), 14 patients experienced a complete response, and 3 patients showed a partial response, with a median response time of 2 months (0.5-27 months). At least one relapse of nephrotic syndrome occurred in nine patients (53%). All patients exhibited stable or improved renal function over the follow-up period.

CONCLUSIONS

The findings in this cohort and previous studies suggest that rare cases of mild IgA nephropathy with nephrotic range proteinuria exhibit a clinical presentation, biopsy findings, treatment response, and outcome more typical of IgA nephropathy with superimposed minimal change disease. This study favors the view that such cases represent a dual glomerulopathy.