An overlapping syndrome of IgA nephropathy and lipoid nephrosis

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.

A Case of a Pregnant Woman with IgA Nephropathy Showing Histological Preeclampsia Findings without Hypertension Treated with Steroids: A Case Report and Literature Review

A 35-year-old woman pregnant with twins developed nephrotic syndrome (NS) at 33 weeks' gestation, but her blood pressure remained within the normal range throughout gestation and puerperium. At 34 weeks' gestation, she delivered healthy twins via Caesarean section. After delivery, she developed massive proteinuria (21.1 g/day) and severe hypoalbuminemia (1.0 g/dL). A renal biopsy performed 19 days after delivery revealed IgA nephropathy (IgAN) and preeclampsia. She was treated with steroids, and the NS gradually resolved. This is a rare case of massive gestational proteinuria with IgAN and preeclampsia pathologically that did not meet the clinical criteria for preeclampsia.

Exosomal miR-4639 and miR-210 in Plasma and Urine as Biomarkers in IgA Nephropathy

BACKGROUND

It has been widely recognized that exosomal miRNAs can participate in the pathogenesis of different renal disorders and serve as disease biomarkers. Although kidney biopsy is still the gold standard for diagnosing and monitoring immunoglobulin A nephropathy (IgAN), it is highly required to identify new and effective noninvasive biomarkers for IgAN, the most frequently detected primary glomerulonephritis worldwide.

METHODS

Plasma and urinary exosomes were extracted by PEG precipitation. Size and morphological characteristics of plasma and urinary exosomes were observed by transmission electron microscopy and nanoparticle tracking analysis. The levels of plasma and urinary exosomes were revealed by Western blotting. The expressions of target miRNAs were revealed by in situ hybridization and qRT-PCR.

RESULTS

The levels of plasma and urinary exosomes were remarkably enhanced in IgAN patients compared with healthy controls (HCs). The expressions of miR-4639 and miR-210 in IgAN patients were significantly higher in contrast to the individuals with membranous nephropathy, minimal change nephrosis, diabetic nephropathy, or HC. These also played a valuable role in assessing the kidney function and the level of proteinuria. Furthermore, plasma and urinary exosomal miR-4639 expression was associated with more serious and active histological activity (mesangial hypercellularity, crescent, and C3 complement deposition). With an average follow-up of 8 months, miR-4639 and miR-210 expressions in plasma and urinary exosomes were higher in patients with progressive IgAN. Plasma exosomal miR-4639 and miR-210 were better than proteinuria (g/24 h) to estimate renal outcomes.

CONCLUSION

Exosomal miR-4639 and miR-210 could be used as valid biomarkers to assist in diagnosis, evaluate severity, and assess disease development of IgAN.

IgA Nephropathy: An Interesting Autoimmune Kidney Disease

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. It is a leading cause of chronic kidney disease and progresses to end-stage kidney disease in up to 40% of patients about 20 years after diagnosis. Additionally, IgAN is associated with significant mortality. The diagnosis currently necessitates a kidney biopsy, as no biomarker sufficiently specific and sensitive is available to supplant the procedure. Patients display significant heterogeneity in the epidemiology, clinical manifestations, renal progression, and long-term outcomes across diverse racial and ethnic populations. Recent advances in understanding the underlying pathophysiology of the disease have led to the proposal of a four-hit hypothesis supporting an autoimmune process. To date, there is no disease-specific treatment but, with a better understanding of the disease pathogenesis, new therapeutic approaches are currently being tested in clinical trials. In this review, we examine the multiple facets and most recent advances of this interesting disease.

Characterization of IgA Deposition in the Kidney of Patients with IgA Nephropathy and Minimal Change

Approximately 5% of patients with IgA nephropathy (IgAN) exhibit mild mesangial lesions with acute onset nephrotic syndrome and diffuse foot process effacement representative of minimal change disease (MCD). It is not clear whether these unusual cases of IgAN with MCD (IgAN-MCD) are variant types of IgAN or coincidental deposition of IgA in patients with MCD. In a retrospective multicenter cohort study of 18 hospitals in Korea, we analyzed 46 patients with IgAN-MCD. Patients with endocapillary proliferation, segmental sclerosis, and crescent were excluded, and the clinical features and prognosis of IgAN-MCD were compared with those of pure MCD. In addition, we performed galactose-deficient IgA1 (KM55) staining to characterize IgAN-MCD. Among the 21,697 patients with glomerulonephritis enrolled in the database, 46 patients (0.21%) were diagnosed with IgAN-MCD, and 1610 patients (7.4%) with pure MCD. The 46 patients with IgAN-MCD accounted for 0.6% of primary IgAN patients (n = 7584). There was no difference in prognosis between patients with IgAN-MCD and those with only MCD. IgA and KM55 showed double positivity in all patients with IgAN-MCD (n = 4) or primary IgAN (n = 5) under double immunofluorescent staining. However, in four patients with lupus nephritis, mesangial IgA was deposited, but galactose-deficient-IgA1 (Gd-IgA1) was not. These findings suggest that IgAN-MCD is a dual glomerulopathy in which MCD was superimposed on possibly indolent IgAN. We confirmed by KM55 staining that IgAN-MCD is true IgAN, enabling better characterizations of the disease. Furthermore, IgAN-MCD shows a good prognosis when treated according to the usual MCD treatment modality.

Recent advances in risk prediction, therapeutics and pathogenesis of IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the world's commonest primary glomerular disease with variable clinical presentation and progression rates that are dependent on clinical-pathologic phenotype and duration of follow-up. Overall 4-40% of patients progress to end-stage kidney disease (ESKD) by 10 years. Treatment decisions remain a challenge due to these variations. The ultimate goal of management is to prevent progression to ESKD and of vital importance is the potential reversible early detection of active glomerular inflammation prior to scarring. IgAN is globally, is the most common biopsy proven glomerulonephritis and a leading cause of ESKD. The Oxford pathological classification was devised by a collaborative pathology and nephrology network to provide an evidence-based scoring system with reproducible independent pathology features of predictive value. Clinical variables that alter prognosis include male sex, increasing age, increased body weight, smoking, Pacific Asian ethnicity, hypertension, proteinuria, and complement deficiency. Excellent conservative therapy is the cornerstone of therapy with tight blood control, renin-angiotensin system inhibition, and statin therapy. The role of immunosuppressive therapy including corticosteroids in IgAN remains open with ongoing clinical trials of low dose oral corticosteroids and enteric coated budesonide. Complement activation contributes to the pathogenic process of IgAN with evidence from genetic, serological, histological and in-vitro studies. This knowledge has translated to clinical trials of investigational agents directly targeting the alternative pathway.

The Emerging Role of Pathogenesis of IgA Nephropathy

IgA nephropathy is an autoimmune disease induced by fthe ormation of galactose-deficient IgA1 and anti-glycans autoantibody. A multi-hit hypothesis was promoted to explain full expression of IgA nephropathy. The deposition of immune complex resulted in activation of the complement, increasing oxidative stress, promoting inflammatory cascade, and inducing cell apoptosis via mesangio-podocytic-tubular crosstalk. The interlinked signaling pathways of immune-complex-mediated inflammation can offer a novel target for therapeutic approaches. Treatments of IgA nephropathy are also summarized in our review article. In this article, we provide an overview of the recent basic and clinical studies in cell molecular regulation of IgAN for further treatment interventions.

IgA nephropathy: common nephritis leading to end-stage renal failure

IgA nephropathy (IgAN) characterized by mesangial proliferative glomerulonephritis with predominant mesangial IgA deposition is the commonest glomerulonephritis worldwide. In contrast to the initial report indicated a favorable prognosis, subsequent reports have shown a highly variable outcome leading to end-stage renal failure (ESRF) in a significant proportion of patients. Many centers report a high incidence (ranging from 10-22%) of patients with idiopathic IgAN amongst the total population of patients on maintenance dialysis. Most of these patients develop ESRF at their middle-age and hence, will pose a significant and important workload in the dialysis and transplantation programme. Because IgAN is a disease with a variable rate of progression leading to chronic renal failure amongst younger patients and with neither effective nor specific treatment, identification of the clinical and pathologic prognostic indicators for these patients is of paramount importance in planning the long-term renal replacement program.

Efficacy of mycophenolate treatment in adults with steroid-dependent/frequently relapsing idiopathic nephrotic syndrome

BACKGROUND

This study assessed the efficacy of therapy with mycophenolate (MF) and reduced doses of steroids in adults with steroid-dependent/frequently relapsing idiopathic nephrotic syndrome (SD/FR-INS).

METHODS

Twenty-nine nephrotic patients (including 16 males and 13 females; mean age: 40 years, range: 18-74) were treated. Starting doses of MF were 2000 mg/day for mofetil MF (1500 mg/day in one patient) or 1440 mg/day for sodium MF. The initial prednisone (PDN) dose was 10 mg/day in 14 patients, 5 mg/day in two patients and no steroids in one patient. In the remaining 12 patients, moderate initial doses of PDN were administered (mean: 23.7 mg/day, range: 15-40), tapering to 10 mg/day after 1 month.

RESULTS

Nephrotic syndrome remission was achieved in 27/29 cases (93.1%) (25 complete, 2 partial). Two patients showed resistance to the prescribed schedule. The first cycle of MF therapy was concluded in 20 patients after a mean (range) of 16.9 months (12-49). Maintenance of remission was observed in 11 of these 20 cases (55%) after a mean follow-up of 32.8 months (12-108). In nine patients with nephrotic syndrome relapse after tapering of MF (MF dependency), the same MF-PDN schedule was restarted, leading again to remission in all nine. The remaining seven MF-sensitive patients are still receiving their first therapeutic cycle. To date, the mean time under therapy in the 27 MF-sensitive patients is 38 months (4-216). Regarding complications, only minor digestive disorders and a slight decrease in blood haemoglobin levels were observed in a few patients.

CONCLUSIONS

MF plus reduced doses of PDN is an effective and well-tolerated therapy for adult SD/FR-INS. Though MF dependence is observed, its low toxicity could allow long periods of therapy if it is required to maintain nephrotic syndrome remission.

IgA Nephropathy

IgA nephropathy (IgAN) is a leading cause of CKD and renal failure. Recent international collaborative efforts have led to important discoveries that have improved our understanding of some of the key steps involved in the immunopathogenesis of IgAN. Furthermore, establishment of multicenter networks has contributed to rigorous design and execution of clinical trials that have provided important insights regarding immunotherapy in IgAN. In this article, we review emerging developments in clinical and translational IgAN research and describe how these novel findings will influence future strategies to improve the outcome of patients with IgAN.

IgA nephropathy

Globally, IgA nephropathy (IgAN) is the most common primary glomerulonephritis that can progress to renal failure. The exact pathogenesis of IgAN is not well defined, but current biochemical and genetic data implicate overproduction of aberrantly glycosylated IgA1. These aberrant immunoglobulins are characterized by galactose deficiency of some hinge-region O-linked glycans. However, aberrant glycosylation alone is insufficient to induce renal injury: the participation of glycan-specific IgA and IgG autoantibodies that recognize the undergalactosylated IgA1 molecule is required. Glomerular deposits of immune complexes containing undergalactosylated IgA1 activate mesangial cells, leading to the local overproduction of cytokines, chemokines and complement. Emerging data indicate that mesangial-derived mediators that are released following mesangial deposition of IgA1 lead to podocyte and tubulointerstitial injury via humoral crosstalk. Patients can present with a range of signs and symptoms, from asymptomatic microscopic haematuria to macroscopic haematuria. The clinical progression varies, with 30-40% of patients reaching end-stage renal disease 20-30 years after the first clinical presentation. Currently, no IgAN-specific therapies are available and patients are managed with the aim of controlling blood pressure and maintaining renal function. However, new therapeutic approaches are being developed, building upon our ever-improving understanding of disease pathogenesis.

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.

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.

Minimal change disease and IgA deposition: separate entities or common pathophysiology?

Introduction. Minimal Change Disease (MCD) is the most common cause of nephrotic syndrome in children, while IgA nephropathy is the most common cause of glomerulonephritis worldwide. MCD is responsive to glucocorticoids, while the role of steroids in IgA nephropathy remains unclear. We describe a case of two distinct clinical and pathological findings, raising the question of whether MCD and IgA nephropathy are separate entities or if there is a common pathophysiology. Case Report. A 19-year old man with no medical history presented to the Emergency Department with a 20-day history of anasarca and frothy urine, BUN 68 mg/dL, Cr 2.3 mg/dL, urinalysis 3+ RBCs, 3+ protein, and urine protein : creatinine ratio 6.4. Renal biopsy revealed hypertrophic podocytes on light microscopy, podocyte foot process effacement on electron microscopy, and immunofluorescent mesangial staining for IgA. The patient was started on prednisone and exhibited dramatic improvement. Discussion. MCD typically has an overwhelming improvement with glucocorticoids, while the resolution of IgA nephropathy is rare. Our patient presented with MCD with the uncharacteristic finding of hematuria. Given the improvement with glucocorticoids, we raise the question of whether there is a shared pathophysiologic component of these two distinct clinical diseases that represents a clinical variant.

KDOQI US commentary on the 2012 KDIGO clinical practice guideline for glomerulonephritis

Glomerulonephritis (GN) is an important cause of morbidity and mortality in patients of all ages throughout the world. Because these disorders are relatively rare, it is difficult to perform randomized clinical trials to define optimal treatment for many of the specific glomerulopathies. In the absence of high-grade evidence to guide the care of glomerular diseases, in June 2012, KDIGO (Kidney Disease: Improving Global Outcomes) published an international clinical guideline for GN. The Work Group report represents an important review of the literature in this area and offers valid and useful guidelines for the most common situations that arise in the management of patients with glomerular disease. This commentary, developed by a panel of clinical experts convened by the National Kidney Foundation, attempts to put the GN guideline into the context of the US health care system. Overall, we support the vast majority of the recommendations and highlight select areas in which epidemiological factors and medical practice patterns in this country justify modifications and adjustments in order to achieve favorable outcomes. There remain large gaps in our knowledge of the best approaches to treat glomerular disease and we strongly endorse an expanded clinical research effort to improve the health and long-term outcomes of children and adults with GN.

A case of minimal change nephrotic syndrome with immunoglobulin A nephropathy transitioned to focal segmental glomerulosclerosis

A 50-year-old woman with a 1-month history of lower extremity edema and a 5 kg weight increase was admitted to our hospital with suspected nephrotic syndrome in October 1999. Urine protein level was 3.5 g per day, 10-15 erythrocytes in urine per high-power field, and serum albumin level 2.5 g/dl. Furthermore, an accumulation of pleural effusion was confirmed by chest X-ray. The results of a renal biopsy indicated slight mesangial proliferation in the glomeruli by light microscopy, and an immunofluorescence study confirmed the deposition of immunoglobulin (Ig) A and C3 in the mesangial area. Diffuse attenuation of foot processes and dense deposits in the mesangial area were observed by electron microscopy. Treatment with 40 mg/day of prednisolone was effective, and proteinuria was negative 1 month later. Because of this course, we diagnosed minimal change nephrotic syndrome complicated by mild-proliferative IgA nephropathy. In November 2000, there was a relapse of nephrotic syndrome, which was believed to be induced by an influenza vaccination, but response to increased steroid treatment was favorable, and proteinuria disappeared on day 13 of steroid increase. A second relapse in May 2001, showed steroid resistance with renal insufficiency, and an increase in the selectivity index to 0.195. Light microscopy revealed focal sclerotic lesions of the glomeruli, and an immunofluorescence study revealed attenuation of mesangial IgA and C3 deposition. These findings led to the diagnosis that minimal change nephrotic syndrome had transitioned to focal segmental glomerulosclerosis, whereby mesangial IgA deposition was reduced by immunosuppressive treatment. Subsequently, her renal function gradually worsened to the point of end-stage renal failure by 27 months after the second relapse of nephrotic syndrome.

Clinical features and outcomes of IgA nephropathy with nephrotic syndrome

BACKGROUND AND OBJECTIVES

Nephrotic syndrome (NS) is a rare manifestation of IgA nephropathy (IgAN). Clinical characteristics and long-term outcomes of this condition have not yet been explored.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A multicenter observational study was conducted between January 2000 and September 2010 in 1076 patients with biopsy-proven IgAN from four medical centers in Korea. The primary outcome was a doubling of the baseline serum creatinine concentration.

RESULTS

Of the 1076 patients, 100 (10.2%) presented with NS; complete remission (CR), partial remission (PR), and no response (NR) occurred in 48 (48%), 32 (32%), and 20 (20%) patients, respectively. During the median follow-up of 45.2 months, 24 patients (24%) in the NS group reached the primary endpoint compared with 63 (7.1%) in the non-NS group (P<0.001). The risk of reaching the primary endpoint was significantly higher in the PR (P=0.04) and NR groups (P<0.001) than in the CR group. Among patients with NS, 24 (24%) underwent spontaneous remission (SR). SR occurred more frequently in female patients and in patients with serum creatinine levels ≤1.2 mg/dl and a >50% decrease in proteinuria within 3 months after NS onset. None of the patients with SR reached the primary endpoint and they had fewer relapses during follow-up.

CONCLUSIONS

This study demonstrated that the prognosis of NS in IgAN was not favorable unless PR or CR was achieved. In addition, SR was more common than expected, particularly in patients with preserved kidney function and spontaneous decrease in proteinuria shortly after NS onset.

[Therapy in IgA nephropathy--when and how to do it]

IgA nephropathy is the most common primary glomerulonephritis worldwide. The clinical spectrum covers a wide range of features from minor urinary abnormalities (asymptomatic hematuria and mild proteinuria with normal renal function) to acute and chronic renal insufficiency. Ideally, the goal of treatment would be to correct any defects in IgA1 glycosylation and to modify mesangial deposition or removal of IgA1 deposits. There are only a few randomized controlled trials in IgA nephropathy; for this reason most treatment options are largely based on expert opinion. Authors discuss therapeutic options of different clinical pictures and the optimized renoprotective treatment of all IgA nephropathy patients.

Spontaneous remission of nephrotic syndrome in patients with IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) can be complicated by nephrotic syndrome. Because the spontaneous resolution of heavy proteinuria is rare, corticosteroid therapy should be considered in such cases, particularly when IgAN is combined with minimal-change disease. Here, we report our experience of spontaneous remission of nephrotic syndrome in patients with IgAN and the long-term outcomes of these patients.

METHODS

Two hundred and thirty-three patients with biopsy-proven IgAN were enrolled between January 2001 and March 2009. Demographic, clinical and laboratory data were collected retrospectively based on medical records. In addition, pathologic findings were reviewed for glomerular and tubulointerstitial lesions. Outcome data for complete or partial remission, spontaneous remission, relapse, deterioration of renal function, and end-stage renal disease were recorded.

RESULTS

Twenty-four patients (10.3%) presented nephrotic syndrome. Among them, five patients underwent spontaneous remission within 6 months after the presentation of nephrotic syndrome. Interestingly, spontaneous remission occurred even in two patients who had elevated serum creatinine levels and advanced renal damage. During follow-up, neither recurrence nor relapse occurred, and no patients showed progressive deterioration of kidney function. Conclusions. This study suggests that spontaneous remission of nephrotic syndrome may occur in any stage of IgAN and carries a favourable long-term outcome without relapse. Given the possibility of under-reported cases, large-scale studies are required, and careful attention should be paid to such complicated cases.

Clinicopathologic characteristics of IgA nephropathy with steroid-responsive nephrotic syndrome

Nephrotic syndrome is an unusual manifestation of IgA Nephropathy (IgAN). Some cases respond to steroid treatment. Here we describe a case-series of IgAN patients with steroid-responsive nephrotic syndrome. Twelve patients with IgAN with steroid-responsive nephrotic syndrome were evaluated and followed up. All patients presented with generalized edema. Renal insufficiency was found in two patients. The renal biopsy of eight patients revealed wide foot process effacement in addition to the typical features of IgAN. They showed complete remission after steroid therapy. Seven relapses were reported in five patients; six of the relapsed cases responded to steroid therapy. Compared with steroid-non-responsive patients, the patients with steroid-responsive nephrotic syndrome had shorter symptom duration, more weight gain, more proteinuria, and lower histologic grade than did those that had steroid-non-responsive nephrotic syndrome at presentation. None of the responders progressed to end stage renal disease, whereas five (38%) non-responders required dialysis or renal transplantation. Patients with IgAN who have steroid-responsive nephrotic syndrome likely have both minimal change disease and IgAN. The clinical features of sudden onset of generalized edema, initial heavy proteinuria and initial severe hypoalbuminemia might help identify the subset of patients, especially in low grade IgAN.

Clinicopathologic correlation and outcome of C1q nephropathy

BACKGROUND AND OBJECTIVES

The number of patients with C1q nephropathy (C1qN) in previous reports is small and the duration of follow-up is short. Our study describes the clinicopathologic correlation and clinical outcome through the mean follow-up period of 7.2 yr in 61 patients.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

Sixty-one patients, 1 to 67 yr of age, with C1qN were enrolled in this study.

RESULTS

According to presentation at onset, patients were divided into two groups: asymptomatic urinary abnormalities (asymptomatic) (n = 36) and nephrotic syndrome (NS) (n = 25). Light microscopy showed minimal change disease (MCD) in 46 patients (75%), mesangial proliferative glomerulonephritis in 7 (12%), and focal segmental glomerulosclerosis (FSGS) in 8 (13%). The prevalence of MCD was higher in the NS group than in the asymptomatic group. Nine patients in the asymptomatic group and all patients in the NS group were treated with prednisolone and/or cyclosporine. Normal urinalysis was found in 10 patients in asymptomatic group and 8 in NS group during the follow-up. Thirteen patients in the NS group were frequent relapsers at the latest follow-up. Three patients with FSGS developed chronic renal failure 8 to 15 yr after the diagnosis. C1q deposits disappeared in 3 of 8 patients receiving repeat biopsy, and 2 of these 3 showed FSGS.

CONCLUSIONS

The prognosis of C1qN is good, associated with MCD in a large number. In some patients, C1q deposits disappear through the follow-up period. FSGS may develop in some patients on repeat biopsies. Further investigation is critically needed to settle this issue.

Clinicopathologic correlation in IgA nephropathy

IgA nephropathy is the most common biopsy-proven pattern of glomerulonephritis in the world. Many factors, both clinical and histologic, have been suggested to impact on prognosis. We review the wide variations in how patients with immunoglobulin A nephropathy can present and the important differences derived from the clinical pathologic setting through the description of 4 cases. These include the clinical scenarios of modest proteinuria, acute kidney injury, and the nephrotic syndrome.

Clinicopathologic correlation of C1q nephropathy in children

BACKGROUND

Clinicopathologic correlation of C1q nephropathy is clarified poorly. The aim of our study is to clarify clinicopathologic correlation in childhood C1q nephropathy.

METHODS

Thirty children aged 3 to 15 years who met criteria proposed by Jennette and Hipp were enrolled in this study.

RESULTS

According to their presentation at onset, children were divided into 2 groups: the asymptomatic urinary abnormalities (asymptomatic) group (n = 18) and the nephrotic syndrome (NS) group (n = 12). Light microscopy showed minimal change disease (MCD) in 22 children (73%), mesangial proliferative glomerulonephritis in 6 children (20%), and focal segmental glomerulosclerosis (FSGS) in 2 children (7%). Four children in the asymptomatic group and all children in the NS group were administered prednisolone and/or cyclosporine. Normal urinalysis results were found in 8 children in the asymptomatic group and 3 children in the NS group during the follow-up period of 3 to 15 years. Eight children in the NS group were frequent relapsers at the latest follow-up. Two children with FSGS (1 child, asymptomatic group; 1 child, NS group) received dialysis 10 and 15 years after the diagnosis. There were no differences in histological findings and clinical outcomes between the 2 groups. Four children with MCD in the NS group underwent a second biopsy. C1q deposits disappeared in 2 children, and 1 of these 2 children showed FSGS.

CONCLUSION

Childhood C1q nephropathy is found in a wide clinical spectrum. Some children showed disappearance of C1q deposits through the follow-up period. A large number of children with C1q nephropathy showed MCD. However, FSGS may develop in some children on repeated biopsy. Therefore, long-term follow-up is needed in children with C1q nephropathy.

Mechanisms of tubulointerstitial injury in IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) runs a highly variable clinical course, with frequent involvement of tubulointerstitial damage. A subgroup of IgAN with severe tubulointerstitial damage is often associated with the most rapid progression to end-stage renal failure. In IgAN, mesangial sclerosis and tubulointerstitial damage were found to be correlated with the increase in pore size of the glomerular barrier.

METHODS

The direct toxicity of proximal tubular epithelial cells (PTEC) by IgA in IgAN is still unresolved. Activation of PTEC by mediators released from infiltrating cells or resident kidney cells that induce tubular inflammation is the common final pathway in most chronic renal diseases. We hypothesize that mediators released from human mesangial cells (HMC) triggered by IgA deposition may lead to PTEC activation.

RESULTS

We found that IgA binding to PTEC was less than one tenth that of HMC. The binding was nonspecific and exhibited no increased cell proliferation or enhanced synthesis of cytokines or adhesion molecules. However, when PTEC were cultured with IgA-HMC spent medium prepared from IgAN patients, there was enhanced proliferation of PTEC and increased synthesis of cytokines and adhesion molecules.

CONCLUSION

These findings implicate a glomerulotubular cross-talk with mediators released from the mesangium, contributing to the pathogenesis of tubulointerstitial damage in IgAN. There are preliminary data to suggest that the expression of angiotensin II subtype-1 receptor and angiotensin II subtype-2 receptor in PTEC differs from that of HMC. These novel findings may provide clinicians new therapeutic approach for selective blockade of the tubulointerstitial injury in IgAN.

Controlled, prospective trial of steroid treatment in IgA nephropathy: a limitation of low-dose prednisolone therapy

BACKGROUND

No accepted therapy has been established for progressive immunoglobulin A (IgA) nephropathy.

METHODS

A prospective, randomized, controlled trial of low-dose prednisolone therapy was performed in patients with IgA nephropathy with moderate histological characteristics. Forty-three patients in the steroid group and 47 patients in the control group were included in the study. The initial dose of prednisolone was 20 mg/d, gradually tapered to 5 mg/d during 2 years.

RESULTS

Baseline urine protein-creatinine ratio (UP-UCR) was significantly greater in the steroid group than in controls. Follow-up duration was 65 +/- 25 months in the steroid group and 64 +/- 23 months in controls. Changes in UP-UCR from baseline, ie, UP-UCR at last follow-up minus UP-UCR at baseline, were significantly lower in the steroid group than in controls (steroid group, -0.84 +/- 1.78; controls, 0.26 +/- 1.65; P = 0.0034). Kidney survival was similar in both groups. Patients were divided into two subgroups according to clinical course. There were 28 improved patients and 15 unimproved patients in the steroid group and 27 improved patients and 20 unimproved patients in the control group. In the steroid group, UP-UCR was significantly greater in the unimproved than improved subgroup (3.1 +/- 2.6 versus 1.8 +/- 1.5).

CONCLUSION

These data suggest that our protocol had an antiproteinuric effect, but could not improve kidney survival. Because the effect of steroid therapy to prevent the progression of IgA nephropathy is believed to be linked closely to reduction in urinary protein, an insufficient dose of prednisolone in our protocol may be the reason for the discrepancy between the effect on proteinuria and kidney survival.

Chronic glomerulonephritis in childhood. Membranoproliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and IgA nephropathy

The chronic glomerulonephritides that lead to permanent loss of renal function may present with an acute nephritic syndrome, nephrotic syndrome, or asymptomatic hematuria and proteinuria. Membranoproliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and IgA nephropathy are common childhood glomerulonephritides that may lead to chronic renal failure. Their clinical manifestations, natural history, and long-term prognosis are distinct. This article reviews various presentations of these common childhood glomerulonephritides and an approach to management and potential therapy.

Spontaneous remission of nephrotic syndrome in a patient with IgA nephropathy

A patient with spontaneous remission of nephrotic syndrome (NS) associated with IgA nephropathy is described. The patient presented at the age of 8 years with asymptomatic proteinuria, and at the age of 11 years developed classical features of NS. A percutaneous renal biopsy showed mild mesangial prominence without significant hypercellularity, electron-dense deposits within the mesangium, and 3+ mesangial staining with IgA and IgG. NS resolved 6 weeks after onset without any form of therapy; absence of proteinuria persisted 6 months later. This report demonstrates clearly that patients with NS associated with IgA nephropathy may undergo spontaneous resolution of their proteinuria.

Mesangial IgA nephropathy with steroid-responsive nephrotic syndrome: disappearance of mesangial IgA deposits following steroid-induced remission

This report describes the clinical features and renal biopsy pathology in two patients with immunoglobulin A (IgA) nephropathy and nephrotic syndrome before and after steroid-induced remission. Apart from confirming the frequently relapsing course and mild glomerular changes observed in patients with IgA nephropathy and steroid-responsive nephrotic syndrome (SRNS), we were able to show that mesangial expansion and mesangial IgA deposits disappeared or were greatly reduced in repeat renal biopsies following steroid-induced remission. Because mesangial IgA deposits usually persist in repeat biopsies obtained from patients with typical IgA nephropathy, their resolution in our patients following steroid remission would support the proposal that the association of IgA nephropathy and SRNS may represent a distinct clinical syndrome. It is postulated that the presence of mesangial IgA deposits during nephrotic presentation and their disappearance following steroid-induced remission may result from increased mesangial sequestration of IgA circulating immune complexes (CIC) during the period of enhanced glomerular permeability and that the increased load of IgA CICs may reflect a common defect in mucosal immunity or immunoregulation in these patients.

Treatment of severe IgA nephropathy in children

We treated ten children with severe IgA nephropathy (IgAN) [proteinuria greater than 1 g/day, hypertension, renal insufficiency, segmental sclerosis, crescent formation and/or glomerular basement membrane (GBM) deposition of IgA] with prednisone and azathioprine for 1 year. Following the year of therapy, seven of the ten children underwent a repeat kidney biopsy. All biopsies were scored for activity (percentage of glomeruli demonstrating crescent formation, degree of mesangial proliferation and interstitial infiltrate; maximum score = 9) and chronicity (percentage of glomeruli demonstrating fibrous crescents, segmental sclerosis, global sclerosis, and degree of tubular atrophy and interstitial fibrosis; maximum score = 12). After 1 year of therapy, the protein excretion of all the children decreased significantly (P less than 0.01) from 4,052 +/- 3,190 mg/day to 1,692 +/- 1,634 mg/day. The activity score decreased significantly (P less than 0.01) from 4.35 +/- 0.94 prior to therapy to 2.28 +/- 0.75 after therapy while the chronicity score was unchanged (5.42 +/- 1.7 vs 5.85 +/- 2.0). The percentage of glomeruli demonstrating cellular crescents decreased (P less than 0.05) from 21.2 +/- 21.7% prior to therapy to 0.94 +/- 2.4% after therapy. Mesangial deposition of IgA persisted but GBM deposition of IgA was less prominent after therapy. During the follow-up period (mean 2.6 years, range 9 months-7.5 years), one child required brief retreatment for biopsy-confirmed recurrence of active disease, two children have developed renal insufficiency due to progressive scarring in the absence of inflammation, while the remaining seven are stable. We suggest that treatment with prednisone and azathioprine may be beneficial in children with severe IgAN and that a controlled clinical trial is warranted.

Immunotactoid glomerulopathy with fingerprint immune deposits. A variant of lupus nephritis?

Immunotactoid glomerulopathy is a distinct clinico-pathological entity which has recently been defined. The term immunotactoid refers to highly organized immune depositions appearing as rod-like microtubular structures in ultrastructural examination. We describe a patient with mixed connective tissue disease who demonstrates characteristic features of immunotactoid glomerulopathy. The diagnosis was made after excluding amyloidosis, cryoglobulinaemia and lupus nephritis. In addition to immunotactoid microtubules, ultrastructural examination also demonstrated presence of fingerprint depositions which were intimately mixed with immunotactoid structures. Fingerprint deposits have been described in lupus nephritis and cryoglobulin-related nephropathy, but rarely in other glomerulonephritis. These unique findings in our patient may suggest a previously unsuspected relationship between the syndrome of immunotactoid glomerulopathy and systemic lupus erythematosus.

IgA nephropathy: clinical features and natural history--a pediatric perspective

This review describes the spectrum of clinical features observed in pediatric patients with IgA nephropathy (IgAN) in different parts of the world. The typical clinical presentation consists of an episode of macroscopic hematuria within 24 to 48 hours of an upper respiratory infection. However, many children who present with macroscopic hematuria are subjected to a battery of urologic studies before the appropriate procedure is performed. This sequence highlights the lack of awareness of IgAN among pediatricians, family practitioners, and urologists. The finding of microscopic hematuria or, less commonly, proteinuria, in a urinalysis carried out as part of a school screening program is the most frequent "presentation" of IgAN in Japanese children. However, it is possible that many children with IgAN expressed as microscopic hematuria and/or mild proteinuria remain undiagnosed in this country because routine urinalysis is not done and many pediatric nephrologists are reluctant to perform renal biopsies when such children are identified. It is now recognized that some patients with IgAN and nephrotic range proteinuria exhibit a state of steroid responsiveness. The renal biopsy in such patients often reveals "minimal change." Several recent studies have shown progressive deterioration in approximately 10% of all pediatric patients found to have IgAN and in 15% to 30% of the subset of patients with more severe histologic findings. Hypertension and proteinuria are observed frequently in patients who progress to chronic renal failure. It is proposed that multicenter collaborative studies be designed to evaluate proposed therapies for children with IgAN associated with proliferative glomerular lesions, particularly those in whom hypertension, proteinuria, and depressed glomerular filtration rate are found.

Immunopathological findings in idiopathic nephrosis: clinical significance of glomerular "immune deposits"

Idiopathic nephrosis (IN), which includes minimal change (MCD), diffuse mesangial proliferation (DMP) and focal segmental glomerular sclerosis (FSGS), is classically characterized by the absence of significant deposits by immunofluorescence microscopy (IF), except for the focal lesions of segmental sclerosis and/or hyalinosis of FSGS, which fix IgM and C3 antiserums. Since IF is available in most centres, an increasing number of unexpected findings has been reported. In order to evaluate the clinical significance of the glomerular deposits revealed by IF in some instances, we reviewed the renal biopsy findings of 222 consecutive children presenting with IN and in whom IF microscopy was available. By light microscopy, 122 patients showed MCD, 10 DMP, and 90 FSGS with DMP (11 cases) or without (79 cases). By IF, 125 specimens were negative and served as controls; 54 showed mesangial IgM deposits, 24 mesangial IgG deposits (associated with Clq deposits in 16), 15 scattered granules of C3 and 4 predominant deposits of mesangial IgA. We correlated these findings with initial response to steroid therapy and outcome and could find no significant difference between the various categories defined by IF and the control group. Repeat biopsies, performed in 21 cases, showed the persistence of deposits in 11 and their transformation in 10. The particular problem raised by the patients who present with IN and mesangial IgA deposits is discussed. Our results demonstrate that patients presenting with IN and "positive IF", whether showing IgM, IgG and Clq, C3 or IgA, do not represent distinct clinicopathological entities.

The clinicopathological characteristics of IgA nephropathy in Hong Kong

The clinicopathologic data of 237 Chinese patients with IgA nephropathy from Hong Kong are reviewed in an attempt to identify the features pertinent to Chinese patients. Although the nephropathy is commonest in the 26-35 year age group, 11% of the IgA nephritic patients were children below 16 years. The male predilection reported in Caucasian populations is not observed and the male:female ratio is 0.94 in our series. The commonest renal manifestation is microscopic hematuria (25%) and 19% of the patients present with macroscopic hematuria, not infrequently synpharyngitic. Nephrotic syndrome occurs in 15% of our patients and proteinuria more than 1 gm/day is documented in 58% of these IgA nephritic patients. The degree of proteinuria does not correlate with prognosis. A small proportion of these nephrotic patients respond to steroid therapy, suggesting a variant of IgA nephropathy that resembles lipoid nephrosis in its steroid-responsiveness. Seventeen percent of the patients (18/104) are hepatitis B virus carriers and 61% of these patients demonstrate viral antigens in their renal biopsies, indicating that hepatitis B virus infection may sometimes play a pathogenetic role.

Cyclosporin treatment of IgA nephropathy: a short term controlled trial

Cyclosporin's known regulatory effects on the immune system suggest that it may be useful in treating patients with IgA nephropathy. A randomised prospective single blind study of 19 patients with IgA nephropathy and proteinuria (greater than 1.5 g/day) was conducted to determine the therapeutic value of cyclosporin. The patients were divided into two groups: nine patients were given oral cyclosporin (5 mg/kg/day) for 12 weeks and 10 patients a placebo. The two groups were comparable in age of presentation, ratio of men to women, plasma creatinine and serum IgA concentrations, creatinine clearance, daily urinary protein excretion, severity of renal histopathological changes, and prevalence of hypertension. A significant reduction of proteinuria and an increase of plasma albumin concentration was observed with treatment with cyclosporin. Nevertheless, a significant rise of plasma creatinine concentration and a fall in creatinine clearance was found in patients after six weeks' treatment with cyclosporin, although the plasma cyclosporin concentrations were maintained within a narrow therapeutic range. Serum IgA concentrations were reduced in seven patients. Renal function improved within eight weeks after treatment was stopped. Three months after treatment was stopped proteinuria remained less than half of the pretreatment values in three patients. No similar biochemical changes were observed in the controls. Short term cyclosporin therapy may be beneficial in reducing proteinuria in some patients with IgA nephropathy. As transient renal impairment was seen, despite cyclosporin concentrations being maintained within a narrow therapeutic range, indiscriminate use of cyclosporin in glomerulonephritis should be discouraged.

Pattern of glomerulonephritis in Hong Kong

A retrospective analysis of all renal biopsies (961) performed in two regional hospitals in Hong Kong during 1977-1985 revealed that IgA nephropathy was the most frequently encountered glomerulopathy. Lipoid nephrosis (minimal change nephrotic syndrome) remained the commonest cause of nephrotic syndrome in children. The frequencies of mesangiocapillary glomerulonephritis, focal glomerulosclerosis, and idiopathic membranous nephropathy were lower than in other populations. Membranous nephropathy was frequently associated with hepatitis B virus antigenemia, especially in children. Other chronic infections did not have a significant pathogenetic role in glomerular diseases. Lupus nephritis was the commonest secondary glomerular disease in our study, and over seventy percent of the renal biopsies showed advanced pathologies with either diffuse proliferative glomerulonephritis or membranous nephropathy.