Mesangiocapillary glomerulonephritis type II (dense-deposit disease): clinical features of progressive disease

Clinical characteristics and outcomes of immune-complex membranoproliferative glomerulonephritis and C3 glomerulopathy in Japanese children

BACKGROUND

Membranoproliferative glomerulonephritis (MPGN) can be divided into immune-complex MPGN (IC-MPGN) and C3 glomerulopathy (C3G), which includes dense deposit disease (DDD) and C3 glomerulonephritis (C3GN). These conditions result from abnormalities in different complement pathways and may lead to different prognoses. However, there are limited studies describing the respective clinical courses.

METHODS

In this study, Japanese pediatric patients diagnosed with MPGN based on kidney biopsies conducted between February 2002 and December 2022 were reclassified as having IC-MPGN or C3G (DDD or C3GN). We retrospectively analyzed the clinical characteristics and outcomes of these patients.

RESULTS

Out of 25 patients with MPGN, three (12.0%) were diagnosed with DDD, 20 (80.0%) with C3GN, and two (8.0%) with IC-MPGN. There were 13 (65.0%) patients and one (33.3%) patient in remission after treatment for C3GN and DDD, respectively, and no patients with IC-MPGN achieved remission. The median follow-up period was 5.3 (2.5-8.9) years, and none of the patients in either group progressed to an estimated glomerular filtration rate < 15 ml/min/1.73 m2. Patients with C3GN presenting mild to moderate proteinuria (n = 8) received a renin-angiotensin system inhibitor (RAS-I) alone, and these patients exhibited a significant decrease in the urinary protein creatinine ratio and a notable increase in serum C3 levels at the last follow-up.

CONCLUSIONS

Most patients with MPGN were diagnosed with C3GN. The remission rate for C3GN was high, and no patients developed kidney failure during the approximately 5-year follow-up. Additionally, patients with C3GN with mild to moderate proteinuria had good outcomes with RAS-I alone, but continued vigilance is necessary to determine long-term prognosis.

Membranoproliferative Glomerulonephritis in Pregnancy

BACKGROUND

Membranoproliferative glomerulonephritis (MPGN) is an uncommon form of glomerulonephritis and it can be particularly difficult to predict outcomes and manage women with this disorder during pregnancy.

MATERIALS AND METHODS

The management of 3 successful pregnancies in women with MPGN from 1 center and previously described cases from the world literature are reviewed. This includes a number of large studies of pregnancy in women with underlying glomerular disease as well as small case series and individual reports. Courses of these pregnancies, maternal and fetal outcomes, and management, when described, were included in this review.

RESULTS

Some successful outcomes used antiplatelet therapy and plasmapheresis, but high-dose intravenous, followed by oral, corticosteroid therapy was used most frequently in patients with successful outcomes.

CONCLUSIONS

The data provided is meant as a guide for clinicians who provide care for women with MPGN who are considering pregnancy or women who present with this disorder while pregnant.

C3 glomerulopathy associated to multiple myeloma successfully treated by autologous stem cell transplant

A 32-year-old male presented with advanced renal failure and nephrotic proteinuria due to lambda light chain multiple myeloma. Renal biopsy showed a proliferative glomerulonephritis with isolated C3 deposits. Renal recovery was obtained after chemotherapy and autologous stem cell transplant. We review previously described cases of C3 glomerulopathy associated with monoclonal gammopathy.

Understanding the complement-mediated glomerular diseases: focus on membranoproliferative glomerulonephritis and C3 glomerulopathies

An enhanced understanding of the role of complement in the pathogenesis of membranoproliferative glomerulonephritis has led to reclassification of the latter into immunoglobulin-mediated and non-immunoglobulin-mediated disease. The new classification schema resulted in improved diagnostic clinical algorithms, while it brought into light again the diseases, which are characterized by the presence of glomerular deposits, composed predominantly by C3, in the absence of significant amounts of immunoglobulins in renal biopsy, namely, C3 glomerulopathies (dense deposit disease and C3 glomerulonephritis). Despite the lack of randomized controlled trials following the advances in the understanding of the pathogenetic pathways involved in membranoproliferative glomerulonephritis, it is important that the new mechanistic approach has opened new roads for the exploration and discovery of targeted therapies.

Histopathology of MPGN and C3 glomerulopathies

'Membranoproliferative' describes glomerular injury characterized by capillary wall thickening and mesangial expansion owing to increased matrix deposition and hypercellularity. The presence of immune deposits is indicative of membranoproliferative glomerulonephritis (MPGN). Historically, MPGN was further classified into three types according to the appearance and site of the electron-dense deposits seen by electron microscopy, but it is now recognized that many cases show only deposition of the complement component C3, owing to abnormal control of the alternative pathway of complement activation-these cases are now classified as C3 glomerulopathies. Not all cases of C3 glomerulopathy, however, show an MPGN pattern. C3 glomerulopathies include dense deposit disease, which shows dense osmiophilic deposits, and C3 glomerulonephritis, which shows isolated deposits. In many cases, the genetic mutations or autoantibodies responsible for C3 deposition have been identified. Some patients in whom complement control is abnormal will accumulate small amounts of immunoglobulin in their glomeruli and so, in everyday practice, the morphological diagnosis of 'glomerulonephritis with dominant C3' is useful for identifying patients who require investigation of the complement pathway. The recognition that many cases of MPGN are C3 glomerulopathies and that the underlying cause can often be identified in immunoglobulin-associated cases means that the diagnosis of idiopathic MPGN is now very uncommon.

Reanalysis of membranoproliferative glomerulonephritis patients according to the new classification: a multicenter study

BACKGROUND

All types of membranoproliferative glomerulonephritis (MPGN) are progressive diseases with poor prognoses. Recently, a newly proposed classification of these diseases separated them into immune complex- and complement-mediated diseases. We investigated the frequency of C3 glomerulonephritis among previously diagnosed MPGN patients.

METHODS

We conducted a retrospective study of patients diagnosed with MPGN at three tertiary care institutions between 2001 and 2010. We investigated the incidence of complement-mediated disease among patients diagnosed with MPGN. Progressive renal dysfunction was defined as a 50% reduction in the glomerular filtration rate or the need for renal replacement therapy.

RESULTS

Among the 3,294 renal biopsy patients, 77 (2.3%) were diagnosed with MPGN; 31 cases were excluded, of which seven were diagnosed with systemic lupus nephritis, and the others were not followed for a minimum of 12 months after biopsy. Based on the new classification, complement-mediated MPGN was diagnosed in two patients (4.3%); only one patient developed progressive renal dysfunction. Among the immune complex-mediated MPGN patients, 17 patients developed progressive renal dysfunction. Serum albumin and creatinine levels at the time of MPGN diagnosis were risk factors of renal deterioration, after adjusting for low C3 levels and nephrotic syndrome.

CONCLUSION

Complement-mediated glomerulonephritis was present in 4.3% of patients previously diagnosed with MPGN.

C3 nephritic factor associated with C3 glomerulopathy in children

BACKGROUND

C3 glomerulopathy (C3G) is characterized by predominant C3 deposits in glomeruli and dysregulation of the alternative pathway of complement. Half of C3G patients have a C3 nephritic factor (C3NeF). C3G incorporated entities with a range of features on microscopy including dense deposit diseases (DDD) and C3 glomerulonephritis (C3GN). The aim of this work was to study children cases of C3G associated with C3NeF.

METHODS

We reviewed 18 cases of C3G with a childhood onset associated with C3NeF without identified mutations in CFH, CFI, and MCP genes.

RESULTS

Clinical histories started with recurrent hematuria for seven patients, nephrotic syndrome for four, acute post-infectious glomerulonephritis for three and acute renal failure for four. Twelve patients had a low C3 at first investigation. Kidney biopsy showed ten C3GN and eight DDD. Twenty-three percent of the patients tested presented elevated sC5b9. Seven patients relapsed 3 to 6 years after the onset. At the end of follow-up, two patients were under dialysis, 11 had a persistent proteinuria, five had none; four patients did not follow any treatment. Steroids were first used in 80 % of cases.

CONCLUSIONS

C3NeF associated C3G has a heterogeneous presentation and outcome. Anti-proteinuric agents may control the disease during follow-up, even after nephrotic syndrome at the onset. The efficiency of immunosuppressive therapy remains questionable.

Dense deposit disease and C3 glomerulopathy

C3 glomerulopathy refers to those renal lesions characterized histologically by predominant C3 accumulation within the glomerulus, and pathogenetically by aberrant regulation of the alternative pathway of complement. Dense deposit disease is distinguished from other forms of C3 glomerulopathy by its characteristic appearance on electron microscopy. The extent to which dense deposit disease also differs from other forms of C3 glomerulopathy in terms of clinical features, natural history, and outcomes of treatment including renal transplantation is less clear. We discuss the pathophysiology of C3 glomerulopathy, with evidence for alternative pathway dysregulation obtained from affected individuals and complement factor H (Cfh)-deficient animal models. Recent linkage studies in familial C3 glomerulopathy have shown genomic rearrangements in the Cfh-related genes, for which the novel pathophysiologic concept of Cfh deregulation has been proposed.

Dense deposit disease in Korean children: a multicenter clinicopathologic study

The purpose of this study was to investigate the clinical, laboratory, and pathologic characteristics of dense deposit disease (DDD) in Korean children and to determine whether these characteristics differ between Korean and American children with DDD. In 2010, we sent a structured protocol about DDD to pediatric nephrologists throughout Korea. The data collected were compared with previously published data on 14 American children with DDD. Korean children had lower 24-hr urine protein excretion and higher serum albumin levels than American children. The light microscopic findings revealed that a higher percentage of Korean children had membranoproliferative glomerulonephritis patterns (Korean, 77.8%; American, 28.6%, P = 0.036), whereas a higher percentage of American children had crescents (Korean, 0%; American, 78.6%, P < 0.001). The findings from the electron microscopy revealed that Korean children were more likely to have segmental electron dense deposits in the lamina densa of the glomerular basement membrane (Korean, 100%; American, 28.6%, P = 0.002); mesangial deposit was more frequent in American children (Korean, 66.7%; American, 100%, P = 0.047). The histological findings revealed that Korean children with DDD were more likely to show membranoproliferative glomerulonephritis patterns than American children. The degree of proteinuria and hypoalbuminemia was milder in Korean children than American children.

Dense deposit disease: clinicopathologic study of 32 pediatric and adult patients

BACKGROUND AND OBJECTIVES

Dense deposit disease (DDD) is a rare disorder that most commonly affects children. This study reports the largest North American series addressing clinicopathologic and outcome differences in children and adults.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Thirty-two patients with DDD were analyzed from the archives of Columbia University between 1977 and 2007. Characteristic intramembranous electron-dense deposits defined all diagnoses.

RESULTS

The cohort included 14 children (<16 yr) and 18 adults, with 39% of adults >60 yr. The female/male ratio was 1.9. At presentation, the mean 24-h urine protein was 4.6 g, nephrotic syndrome was present in 33%, renal insufficiency in 59%, and hematuria in 87% of patients. Compared with adults, children had lower incidence of renal insufficiency and were more likely to have reduced C3. Histologic pattern included membranoproliferative, mesangial, endocapillary, and crescentic glomerulonephritis. Treatment included immunosuppression (IS) alone in seven, renin angiotensin system (RAS) blockade alone in six, and combined IS/RAS blockade in 11. On follow-up (mean 63 mo) available in 27 patients, 26% had complete response, 48% had persistent renal dysfunction, and 26% had ESRD. Correlates of ESRD were older age and higher creatinine at biopsy, the absence of combined IS/RAS blockade therapy and the presence of subepithelial humps, but not histologic pattern. On multivariate analysis, age and creatinine emerged as the only independent predictors of ESRD.

CONCLUSIONS

DDD is clinically and pathologically heterogeneous. Adults have worse outcome than children, despite similar treatment. Combined IS/RAS blockade appears superior to either agent alone.

Nephritic factor and recurrence in the renal transplant of membranoproliferative glomerulonephritis type II

Animal models suggest a role for nephritic factor in the pathogenesis of glomerular disease, but evidence for a role in human disease is lacking. To assess its role, we applied a recently developed method that allows measurement of low levels of nephritic factor activity to stored serum specimens from three patients who had membranoproliferative glomerulonephritis (MPGN) type II. All three had had renal transplants, and one lost two of three transplants from recurrent disease. Evidence for a role for nephritic factor in human disease was a positive correlation between the level of nephritic factor activity and both the severity of recurrence and an increase in serum creatinine concentration. However, the hypocomplementemia was never severe; C3 levels of 49-76 mg/dl and nephritic factor levels of 89 U/ml were associated with severe recurrences. We have previously seen severe disease with mild hypocomplementemia. In contrast, patients with partial lipodystrophy often have severe hypocomplementemia and, presumably, high levels of nephritic factor yet have a mild glomerulonephritis. Disease severity and nephritic factor levels thus appear to be inversely related. The disease is progressive when only moderate amounts of nephritic factor have been circulating and C3 only mildly depressed.

Dense deposit disease is not a membranoproliferative glomerulonephritis

Dense deposit disease (first reported in 1962) was classified as subtype II of membranoproliferative glomerulonephritis in the early 1970s. Over the last 30 years, marked differences in etiology and pathogenesis between type I membranoproliferative glomerulonephritis and dense deposit disease have become apparent. The sporadic observation that dense deposit disease can be seen with markedly different light microscopy appearances prompted this study. The goal was to examine a large number of renal biopsies from around the world to characterize the histopathologic features of dense deposit disease. Eighty-one cases of dense deposit disease were received from centers across North America, Europe and Japan. Biopsy reports, light microscopy materials and electron photomicrographs were reviewed and histopathologic features scored. Sixty-nine cases were acceptable for review. Five patterns were seen: (1) membranoproliferative n=17; (2) mesangial proliferative n=30; (3) crescentic n=12; (4) acute proliferative and exudative n=8 and (5) unclassified n=2. The age range was 3-67 years, with 74% in the range of 3-20 years; 15% 21-30 years and 11% over 30 years. Males accounted for 54% and females 46%. All patients with either crescentic dense deposit disease or acute proliferative dense deposit disease were between the ages of 3 and 18 years. The essential diagnostic feature of dense deposit disease is not the membranoproliferative pattern but the presence of electron dense transformation of the glomerular basement membranes. Based upon this study and the extensive data developed over the past 30 years, dense deposit disease is clinically distinct from membranoproliferative glomerulonephritis and is morphologically heterogeneous with only a minority of cases having a membranoproliferative pattern. Therefore, dense deposit disease should no longer be regarded as a subtype of membranoproliferative glomerulonephritis.

Dense deposit disease: new insights

PURPOSE OF REVIEW

Dense deposit disease is a rare but devastating disease primarily affecting children. This review focuses on new information regarding the pathophysiology of dense deposit disease, its appearance histopathologically, its relationship to other diseases including macular degeneration and acquired partial lipodystrophy and potential new therapies.

RECENT FINDINGS

The microscopic features of dense deposit disease have been separated into five patterns with only about 25% of patients showing membranoproliferative features. The subtle interplay between genetic changes in complement regulatory proteins and dysregulation of the alternative pathway of complement is now more evident. Haplotype mapping has shown at-risk phenotypes of complement factor H associated with the development of dense deposit disease. Treatment protocols are empiric and not very effective. New information on complement inhibitors and plasma exchange, however, has brought hope for new therapies in the near future.

SUMMARY

Understanding of the pathology and the pathophysiology of dense deposit disease has advanced rapidly in the last decade. New efforts in genetic mapping along with the development of novel inhibitors of the complement system will lead to improved care for patients afflicted with this uncommon condition.

Recurrence of membranoproliferative glomerulonephritis type II in renal allografts: The North American Pediatric Renal Transplant Cooperative Study experience

Membranoproliferative glomerulonephritis type II (MPGN II) is an uncommon form of complement-dependent acquired renal disease. Although it has been recognized since the 1970s that MPGN II recurs almost universally in renal transplants, data regarding the long-term consequences of disease recurrence are limited. Therefore, a retrospective comparative analysis of 75 patients with MPGN II contained in the North American Pediatric Renal Transplant Cooperative Study transplantation database was performed. Five-year graft survival for patients with MPGN II was significantly worse (50.0 +/- 7.5%) compared with the database as a whole (74.3 +/- 0.6%; P < 0.001). Living related donor organs had a significantly better 5-yr survival (65.9 +/- 10.7%) compared with cadaveric donor organs (34.1 +/- 9.8%; P = 0.004). The primary cause of graft failure in 11 (14.7%) patients was recurrent disease. Supplemental surveys were obtained on 29 (38%) of 75 patients. Analysis of these data indicated that recurrent disease occurred in 12 (67%) of the 18 patients with posttransplantation biopsies. Although there was no correlation between pretransplantation presentation, pre- or posttransplantation C3 levels, and either disease recurrence or graft failure, there was a strong association between heavy proteinuria and disease recurrence. The presence of glomerular crescents in allograft biopsies had a significant negative correlation with graft survival. At last follow-up, patients with recurrent disease had significantly higher serum creatinine and qualitatively more proteinuria than patients without biopsy-proven disease. These data indicate that recurrent MPGN II has a significant negative impact on renal allograft function and survival.

Membranoproliferative glomerulonephritis type II (dense deposit disease): an update

Membranoproliferative glomerulonephritis type II (MPGN II) is a rare disease characterized by the deposition of abnormal electron-dense material within the glomerular basement membrane of the kidney and often within Bruch's membrane in the eye. The diagnosis is made in most patients between the ages of 5 and 15 yr, and within 10 yr, approximately half progress to end-stage renal disease, occasionally with the late comorbidity of visual impairment. The pathophysiologic basis of MPGN II is associated with the uncontrolled systemic activation of the alternative pathway (AP) of the complement cascade. In most patients, loss of complement regulation is caused by C3 nephritic factor, an autoantibody directed against the C3 convertase of the AP, but in some patients, mutations in the factor H gene have been identified. For the latter patients, plasma replacement therapy prevents renal failure, but for the majority of patients, there is no proven effective treatment. The disease recurs in virtually all renal allografts, and a high percentage of these ultimately fail. The development of molecular diagnostic tools and new therapies directed at controlling the AP of the complement cascade either locally in the kidney or at the systemic level may lead to effective treatments for MPGN II.

Management of membranoproliferative glomerulonephritis: evidence-based recommendations

Idiopathic membranoproliferative glomerulonephritis (MPGN) is one of the least common types of GN. This article critically evaluates the literature and generates evidence-based recommendations for the management of idiopathic MPGN. For all age groups, for idiopathic MPGN with normal renal function and asymptomatic nonnephrotic range proteinuria, no specific therapy is necessary (grades B and C). Close follow-up every three to four months, with specific attention to renal function, proteinuria, and blood pressure control, is recommended. In children with MPGN and nephrotic syndrome and/or impaired renal function, a trial of steroids is warranted (grade A). The best data suggest high-dose, alternate-day steroids for a period of 6 to 12 months (40 mg/m2 on alternate days). If no benefit is seen, discontinuation with close follow-up and attention to conservative treatment (that is, blood pressure control, use of agents to reduce proteinuria, and correction of metabolic abnormalities) is recommended. In adults with MPGN, impaired renal function, and/or nephrotic-range proteinuria, a trial of aspirin (325 mg daily), dipyridamole (75 to 100 mg tid), or a combination of the two for 12 months is reasonable (grade B). Again, if no benefits are seen, the treatment should be stopped. Attention to factors known to delay the progression of renal decline and close follow-up should be part of the treatment plan (grades B and C).

Glomerulonephritis

The differential diagnosis of glomerulonephritis without systemic disease includes poststreptococcal glomerulonephritis, IgA nephropathy, rapidly progressive glomerulonephritis (RPGN), and membranoproliferative glomerulonephritis (MPGN). Glomerular inflammation is probably induced directly by a nephritogenic streptococcal protein in poststreptococcal glomerulonephritis, and by mesangial deposition of abnormally glycosylated IgA1-containing immune aggregates in IgA nephropathy. In crescentic RPGN the role of cellular rather than humoral immune mechanisms is now becoming clear. Many patients with MPGN have chronic hepatitis C infection. There is no effective disease-specific therapy for poststreptococcal glomerulonephritis or IgA nephropathy. RPGN benefits from high-dose steroids and cytotoxic drug therapy with the addition of plasma exchange in disease induced by antibody to glomerular basement membrane. Antiviral therapies reduce the severity of MPGN due to hepatitis C virus. However, various new therapies directed at specific cytokines, growth factors, fibrin deposition, and other mediators of injury are being developed, as well as more specific and less toxic forms of immunotherapy.

Long-term prognosis in idiopathic membranoproliferative glomerulonephritis

The following results were obtained in a long-term follow-up investigation including 37 patients who suffered from idiopathic membranoproliferative glomerulonephritis. The mean follow-up period was 51 months (median 32 months). 1) Renal survival was 35% at 5 years and 16% at 10 years. 2) Univariate analysis indicated significant (p < or = 0.10) association between poor prognosis and the two following parameters a) high age b) elevated blood pressure. 3) Using a Cox-analysis including a) gender b) age at kidney biopsy c) square of age (age age) at biopsy d) presence of nephrotic syndrome e) presence of elevated blood pressure, the following p-values were found: 0.56; 0.02; 0.04; 0.50; 0.09. Thus at the 10% level age, the square of age and elevated blood pressure were significant and independently associated with poor prognosis.

Fundamental concepts and immunosuppressive treatment in the various forms of glomerulonephritis

Immunosuppressive treatment in glomerulonephritis (GN) is still controversial. Most of the secondary forms of glomerulonephritis have the histologic features of one of the primary types of glomerulonephritis. Eight histologic expressions of primary glomerulonephritis can be distinguished and ordered in terms of severity of symptoms and prognosis: endocapillary GN, minimal change GN, mesangioproliferative GN, membranous GN, focal-sclerosing GN, membranoproliferative GN, focal-necrotizing GN, and rapidly progressive GN. Agreement exists only to the extent that immunosuppression is not required in endocapillary glomerulonephritis, although it is recommended in the other extreme of rapidly progressive GN. Primarily, an indication for immunosuppression is given by the severity of symptoms with a urinary protein excretion > 3.5 g per day and/or serum creatinine > 150 mumol per liter. As for anti-GBM, the type of glomerulonephritis is more important than the severity of symptoms in guiding therapy, whereas for IgA nephropathy it is controversial whether the prospective prognosis of even inexorably deteriorating renal function justifies immunosuppression. Renal biopsy is required to identify the type of glomerulonephritis so as to establish the specific immunosuppressive concept with different intensity and duration of treatment. Immunosuppression can reduce urinary protein excretion and improve deterioration of renal function; however, the proportion of patients responding varies with and depends on the different forms of GN.

Specific controversies concerning the natural history of renal disease in pregnancy

Whether or not pregnancy adversely affects the natural course of underlying primary renal disease, and whether fetal outcome is influenced by the type of renal disease per se are controversial issues. We retrospectively analyzed the fetal and maternal outcome in 148 women with various, biopsy-proven histological types of primary chronic glomerulonephritis (GN), including IgA GN (52 patients), membranous GN ([MGN] 20 patients), membranoproliferative type 1 GN ([MPGN] 58 patients), focal and segmental glomerulosclerosis ([FSGS] 13 patients), and minimal change nephrotic syndrome ([MCNS] 22 patients), who were pregnant (with a total of 290 pregnancies) after the clinical onset of GN, and in 104 women with reflux nephropathy (with a total of 254 pregnancies). Fetal outcome was poor in the presence of uncontrolled hypertension, nephrotic range proteinuria, and/or impaired renal function at conception or early in gestation, whatever the type of renal disease. An accelerated, more rapid than expected, worsening of maternal renal function was observed in five GN patients of whom four (two IgA, two MPGN) had serum creatinine (Scr) levels greater than 160 mumol/L (1.8 mg/dL) early in gestation, and in five patients with reflux nephropathy whose Scr at conception ranged from 180 to 490 mumol/L (2.0 to 5.5 mg/dL).(ABSTRACT TRUNCATED AT 250 WORDS)