The most common HCV-related nephropathy is membranoproliferative glomerulonephritis (MPGN), usually in the context of cryoglobulinaemia. The treatment of this entity is not consensual and represents a challenge to clinicians. We report a case of membranoproliferative glomerulonephritis associated with cryoglobulinaemia type II in a 46-year-old Caucasian male recipient of a deceased kidney transplant in 2010. His baseline serum creatinine (SCr) was 1.1 mg/dl. After three years post-transplantation, he presented with nephritic syndrome in association with renal function impairment (SCr – 2.1 mg/dl). The laboratory tests revealed positive rheumatoid factor, hypocomplementaemia and a positive cryocrit with type II cryoglobulinaemia. Antinuclear autoantibodies and anti-double stranded DNA antibodies were negative. Despite the presence of anti-HCV antibodies, the viral load remained undetectable. The allograft biopsy showed lesions compatible with membranoproliferative glomerulonephritis, with staining in the immunofluorescence for granular IgM and C3 and no C4d. He was treated with methylprednisolone pulses followed by oral prednisolone in association with rituximab. Two months after the last dose of rituximab, the SCr improved to 1.27 mg/dl...
We describe a treatment made with interferon-alpha (IFN-alpha) plus ribavirin of two patients with membranoproliferative glomerulonephritis (MPGN) induced by hepatitis C virus (HCV): Case 1 was a 22-year-old woman with leg and facial edema, hypertension and proteinuria, whose liver biopsy revealed chronic active hepatitis; and Case 2 was a 42-year-old man with anasarca, hypertension and proteinuria, whose liver biopsy indicated cirrhosis. Both had anti-HCV, HCV-RNA and cryoglobulins. IFN-alpha (3 million units (MU), 3 times/week) and ribavirin (1 g/day) were administered for 12 months. The drugs were well tolerated by both patients. Serum alanine aminotransferase (ALT) levels normalized and HCV-RNA became negative. Cryoglobulins disappeared and an improvement in renal disease was seen after 6 months of therapy. However, after 9 months, Case 2 presented ALT elevation, and proteinuria was detected. Two years after the end of therapy, both patients were negative in repeated HCV-RNA and cryoglobulin tests. Case 1 was asymptomatic, with normal liver and renal tests, and Case 2 had normal blood pressure, with mild edema of the ankles. Based on the evolution of these two cases, the association of IFN-alpha and ribavirin may be a therapeutic option for patients with MPGN related to HCV.
We have recently described hereditary membranoproliferative glomerulonephritis type II in the pig. All affected animals had excessive complement activation, revealed as low plasma C3, elevated plasma terminal complement complex, and massive deposits of complement in the renal glomeruli, and eventually died of renal failure within 11 wk of birth. The aim of the present study was to investigate the cause of complement activation in this disease. Transfusion of normal porcine plasma to affected piglets inhibited complement activation and increased survival. Plasma was successively fractionated and the complement inhibitory effect of each fraction tested in vivo. A single chain 150-kD protein which showed the same complement inhibitory effect as whole plasma was finally isolated. Immunologic cross-reactivity, functional properties, and NH2-terminal sequence identified the protein as factor H. By Western blotting and enzyme immunoassay, membranoproliferative glomerulonephritis-affected piglets were demonstrated to be subtotally deficient in factor H. At 1 wk of age, median (range) factor H concentration was 1.6 mg/liter (1.1-2.3) in deficient animals (n = 13) and 51 mg/liter (26-98) in healthy littermates (n = 52). Our data show that hereditary porcine membrano-proliferative glomerulonephritis type II is caused by factor H deficiency.
Intraglomerular expression of complement receptors (CR) was investigated chronologically in 22 repeatedly biopsied patients with membranoproliferative glomerulonephritis (MPGN) type I by indirect immunoperoxidase staining using MoAbs. Patients were divided into two groups based on whether intraglomerular C3c deposition was decreased at the second biopsy (2nd Bx) (group A, n = 12), or not (group B, n = 10). At the first biopsy (1st Bx), the severity of glomerular injury and the degree of glomerular C3c deposition were compatible between the two groups. Four patterns of CR1 (CD35) expression on podocytes were recognized: normal; generally decreased; focally/segmentally lost; and completely lost. The numbers of CR3 (CD11b/CD18)- and CR4 (CD11c/CD18)-positive cells per glomerular cross-section were counted. At the 1st Bx, no significant difference was found in the number of CR3+ or CR4+ cells between the two groups. At the 2nd Bx, the numbers of both the CR3+ and CR4+ cells were significantly decreased only in group A (P < 0.01). The numbers of CR3+ and CR4+ cells were significantly higher in cases with moderate or marked C3c deposits than in those with no or mild C3c deposits. The intensity of CR1 expression in group B was less than that in group A at both the 1st and 2nd Bx (1st...
Detailed studies of the complement system were carried out in fifteen patients with membranoproliferative glomerulonephritis. The findings of reduced levels of C3 and C7 and of circulating breakdown products of C3 in fresh plasma suggested in vivo complement activation. Low C3 levels were associated with the presence of a serum factor (the C3 nephritic factor C3NeF) which was capable of breaking down C3 in normal serum in vitro. Metabolic studies using radioactive iodine labelled C3 showed no evidence of accelerated in vivo breakdown of parenterally administered C3 suggesting that hypocomplementaemia is either maintained by diminished C3 synthesis or that accelerated catabolism is occurring in a pool that does not freely exchange with parenterally given C3. The C3 nephritic factor has so far only been identified in patients with membranoproliferative nephritis and is therefore of major diagnostic significance in patients with glomerular disease.
Engagement of immunoglobulin-binding receptors (FcγR) on leukocytes and other cell types is one means by which immunoglobulins and immune complexes activate effector cells. One of these FcγRs, FcγRIIb, is thought to contribute to protection from autoimmune disease by down-regulation of B-cell responsiveness and myeloid cell activation. We assessed the role of FcγRIIb in a mouse model of cryoglobulin-associated membranoproliferative glomerulonephritis induced by overexpression of thymic stromal lymphopoietin (TSLP). TSLP transgenic mice were crossbred with animals deficient for FcγRIIb on the same genetic background (C57BL/6). Renal pathology was assessed in female and male animals (wild-type, FcγRIIb−/−, TSLP transgenic, and combined TSLP transgenic/FcγRIIb−/− mice) after 50 and 120 days, respectively. FcγRIIb−/− mice had no significant renal pathology, whereas overexpression of TSLP induced a membranoproliferative glomerulonephritis, as previously established. TSLP transgenic FcγRIIb−/− mice appeared sick with increased mortality. Kidney function was significantly impaired in male mice corresponding to aggravated glomerular pathology with increases in glomerular matrix and cellularity. This resulted from both a large influx of infiltrating macrophages and increased cellular proliferation. These results emphasize the important role of FcγRIIb in regulating immune responses and suggest that modulation of Fcγ receptor activation or expression may be a useful therapeutic approach for treating glomerular diseases.
Massive glomerular deposits of C3 and the terminal C5b-9 complement complex (TCC), but no immune complex deposits were detected by immunofluorescence in porcine membranoproliferative glomerulonephritis type II. TCC deposits were always observed with concomitant deposits of vitronectin (S-protein) in membranoproliferative glomerulonephritis, in contrast to a piglet with mesangial glomerulopathy where TCC was present without vitronectin co-deposition. Enzyme immunoassays revealed extensive systemic complement activation in 1-week-old affected piglets, observed by low plasma C3 (about 5% of normal) and high plasma TCC (about 10 x normal). Affected piglets revealed some plasma complement activation already at birth, 3 to 4 weeks before recognizable clinical disease. It is concluded that porcine membranoproliferative glomerulonephritis represents a nonimmune complex-mediated glomerulonephritis caused by unrestricted systemic complement activation with C3 consumption, TCC formation, and glomerular trapping of complement activation products. A pathogenetic mechanism of a defective or missing complement regulation protein is suggested.
Type II membranoproliferative glomerulonephritis (MPGN-II) is characterized by electron-dense intramembranous deposits (DIMD) in the basal laminae of the kidney. These deposits selectively bind the lectin wheat germ agglutinin (WGA) or its succinylated derivative. In renal tissue samples from normal controls, Type I membranoproliferative glomerulonephritis, and several other renal diseases, only a normal pattern of WGA binding was observed and no membrane-oriented deposits reacted with WGA. Additional attempts to stain the DIMD with any of eight other lectins or eight antisera to renal antigens were uniformly unsuccessful. Discrete WGA reactivity indicates that the deposits contain appreciable quantities of internally linked N-acetylglucosamine and may also provide a valuable adjunct in making the histologic diagnosis of MPGN-II.
Thymic stromal lymphopoietin (TSLP) transgenic mice develop cryoglobulin-associated membranoproliferative glomerulonephritis, characterized by renal monocyte/macrophage infiltration, marked expansion of extracellular matrix, and variable intraluminal and mesangial deposits of cryoglobulins. A microarray approach was used to study global gene expression in glomerular RNA obtained from these mice, as well as from combined TSLP transgenic and Fcγ receptor IIb null mice (TSLP/FcIIb−/−), which develop aggravated membranoproliferative glomerulonephritis. Protease nexin-1 (PN-1) and tissue plasminogen activator (tPA), two potential regulators of fibrosis that are involved in the fibrinolytic and coagulation pathways, were dramatically upregulated in TSLP mice compared with wild-type controls. In situ hybridization revealed minimal expression of PN-1 mRNA in the glomeruli of wild-type mice, increased expression in TSLP mice, and the greatest expression in the mesangial cells of TSLP/FcIIb−/− mice. Immunohistochemistry demonstrated greater expression of PN-1, tPA, and PAI-1 in the mesangial cells of TSLP mice compared with wild-type and the greatest in TSLP/FcIIb−/− mice. In cultured mesangial cells, incubation with cryoglobulins induced an upregulation of PN-1 mRNA; increased expression of PN-1...
Many types of glomerulonephritis are initiated by the deposition of immune complexes, which induce tissue injury via either engagement of Fc receptors on effector cells or via complement activation. Four murine Fcγ receptors (FcγRs) have been identified at present. Ligand binding to FcγRI, III, and IV induces cell activation via the immunoreceptor tyrosine-based activation motif on the common γ chain (FcRγ). In this study, FcRγ chain knockout (FcRγ−/−) mice were crossed with thymic stromal lymphopoietin transgenic (TSLPtg) mice, which develop cryoglobulinemic membranoproliferative glomerulonephritis (MPGN). Female mice were studied at 30 and 50 days of age, when MPGN is in early and fully developed stages, respectively. Both TSLPtg and TSLPtg/FcRγ−/− mice developed MPGN with massive glomerular immune deposits, mesangial cell proliferation, extensive mesangial matrix accumulation, and macrophage influx. TSLPtg/FcRγ−/− mice had more glomerular immune complex deposits and higher levels of circulating cryoglobulins, IgG2a, IgG2b, and IgM, compared with TSLPtg mice. TSLPtg and TSLPtg/FcRγ−/− mice developed similar levels of proteinuria. These results demonstrated that deletion of activating FcγRs does not confer protection in this model of immune complex-mediated MPGN. The findings contradict accepted paradigms on the role of activating FcγRs in promoting features of glomerulonephritis as seen in other model systems. We speculate engagement of FcγRs on cells such as monocytes/macrophages may be important for the clearance of deposited immune complexes and extracellular matrix proteins.
Background and objectives: Membranoproliferative glomerulonephritis (MPGN) is an immune complex–mediated glomerulonephritis characterized by subendothelial and mesangial deposition of immune complexes. Autoimmune diseases and chronic infections, such as hepatitis C, are commonly recognized causes of MPGN; however, monoclonal gammopathy is a less widely recognized cause of MPGN.
Membranoproliferative glomerulonephritis is an uncommon kidney disorder characterized by mesangial cell proliferation and structural changes in glomerular capillary walls. It can be subdivided into idiopathic and secondary forms, which are differentially diagnosed by a review of clinical features, laboratory data, and renal histopathology. Three types—I, II, and III—have been defined by pathologic features. All three types are associated with hypocomplementemia, but they manifest somewhat different mechanisms of complement activation. Type II, also known as “dense deposit disease”, is associated with the presence of C3-nephritic factor. Membranoproliferative glomerulonephritis primarily affects children and young adults, with patients presenting with nephrotic or nephritic syndrome or with asymptomatic renal disease. This type of glomerulonephritis often progresses slowly to end-stage renal disease, and it tends to recur after renal transplantation, especially type II. The efficacy of various forms of treatment remains controversial; however, long-term steroid treatment seems to be effective in children with nephrotic-range proteinuria. Improvement in renal outcomes largely relies on the evaluation of more selective agents in carefully controlled studies.
Inflammatory pseudotumour is a rare condition that can affect various organs. The clinical and histologic appearance of the pseudotumour may mimic haematological, lymphoproliferative, paraneoplastic or malignant processes. A previously healthy 39-year-old man presented with nephrotic syndrome. He had a history of headaches, nausea and swollen ankles. Computed tomography of the abdomen revealed a 6-cm mass in the spleen. Following a renal biopsy, a diagnosis of membranoproliferative glomerulonephritis (MPGN) type I was made. Splenectomy was performed and the examination revealed a mixed population of lymphocytes with predominantly T-cells, B-cells and lymphoplasmacytoid cells. Immunostaining confirmed that the small cells were mostly T-cells positive for all T-cell markers including CD2, CD3, CD4, CD5, CD7 and CD8. A diagnosis of inflammatory pseudotumour was established. The removal of the spleen was followed by remission of glomerulonephritis, but it was complicated by a subphrenic abscess and pneumonia. This association between an inflammatory pseudotumour of the spleen and MPGN has not been previously described. Abnormal immune response due to the inflammation leading to secondary glomerulonephritis might be the main pathogenic mechanism.
Mantle cell lymphoma (MCL) is a rare aggressive lymphoid neoplasm occurring in about 3–7 % of non-Hodgkin lymphomas in the United States and Europe. Although lymphomas infiltrations are recognized in about half of post-mortem studies, in available literature we found only eight cases of mantle cell lymphoma with renal involvement. Five of them present MCL related glomerulonephritis, two show renal MCL infiltration with acute kidney injury and the last one describes MCL infiltration with acute tubulo-intrerstitial nephritis. We present the first case of a patient with the coexistence of renal mantle cell lymphoma infiltration, subacute membranoproliferative glomerulonephritis and acute kidney injury.
IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, accounting for approximately 30–40% of patients undergoing renal biopsy in Asia. The characteristic and diagnostic lesion of IgAN is the deposition of glomerular IgA. The morphological lesions observed by light microscopy are extremely variable. A causal relationship between IgAN and burn injury has not been established, and the correlation between them is not clear if they appear at the same time. We have explored the cause of severe proteinuria of a Chinese patient with burns of 2nd or 3rd degree after a gas leakage accident 2 weeks ago. The diffuse proliferative glomerulonephritis of this patient revealed type I membranoproliferative glomerulonephritis-like symptoms. Moreover, this patient showed a sensitive response to prednisone. This case report demonstrates the intrinsic relationship between kidney disease and burn injury, which will facilitate a feasible treatment strategy for proteinuria after burn injury.
Idiopathic membranoproliferative glomerulonephritis (MPGN) is a rare cause of renal failure with a cumulative incidence of 0.3% of all ESRD and 4% of all primary glomerulonephritis for types I and II. Membranoproliferative glomerulonephritis type III is more uncommon and idiopathic de novo MPGN III in a renal transplant patient has not been reported. We present the case of a 57-year old white female with a diagnosis of lithium toxicity as cause of endstage renal disease (ESRD) who developed MPGN III in her allograft 6 years after a renal transplant. Despite treatment, she progressed to ESRD within 4 and a half years from the time of diagnosis.
We present a case of a 75-year-old man with nephrotic syndrome and renal insufficiency caused by immune complex-mediated secondary membranoproliferative glomerulonephritis. He developed hepatic encephalopathy. A congenital portosystemic shunt was identified, indicating a diagnosis of membranoproliferative glomerulonephritis with noncirrhotic portosystemic shunt. Proteinuria resolved after shunt ratio reduction by percutaneous transhepatic portal vein embolization. Renal function and histopathological findings improved without immunosuppressive therapy. This case emphasizes the role of a high shunt ratio and reduced hepatic clearance of circulating immune complexes in such nephropathy. Membranoproliferative glomerulonephritis with a shunt may cause refractory nephrotic syndrome, but embolization is effective.
Immunoglobulin A (IgA) dominant membranoproliferative glomerulonephritis (MPGN) is rare, described only as case reports. We report a rare case of an elderly man presenting with rapidly progressive renal failure and nephrotic range proteinuria with histological, immunofluorescence, and ultrastructural findings supporting a diagnosis of IgA dominant MPGN. Autoimmune disease, cryoglobulinemia and infection-associated glomerulonephritis were excluded. Remission was achieved within 3 months of treatment. This case highlights an uncommon diagnosis with a good response to therapy. The differential diagnosis of IgA nephropathy with MPGN-like pattern is discussed.
Homozygous complement C4B deficiency is described in a Southern European young female patient with Membranoproliferative Glomerulonephritis (MPGN) type III characterized by renal biopsies with strong complement C4 and IgG deposits. Low C4 levels were independent of clinical evolution or type of immunosuppression and were found in three other family members without renal disease or infections. HLA typing revealed that the patient has homozygous A*02, Cw*06, B*50 at the class I region, and DRB1*08 and DQB1*03 at the class II region. Genotypic and phenotypic studies demonstrated that the patient has homozygous monomodular RCCX in the HLA class III region, with single long C4A genes coding for C4A3 and complete C4B deficiency. Her father, mother, son and niece have heterozygous C4B deficiency. The patient's deceased brother had a history of Henoch-Schönlein Purpura (HSP), an immune complex-mediated proliferative glomerulonephritis. These findings challenge the putative pathophysiological roles of C4A and C4B and underscore the need to perform functional assays, C4 allotyping and genotyping on patients with persistently low serum levels of a classical pathway complement component and glomerulopathy associated with immune deposits.
The most common HCV-related nephropathy is glomerulonephritis (MPGN), usually in the context of cryoglobulinaemia. The treatment of this entity is not consensual and represents a challenge to clinicians. We report a case of membranoproliferative glomerulonephritis associated with type II in a 46-year-old Caucasian male recipient of a deceased kidney transplant in 2010. His baseline serum creatinine (SCr) was 1.1 mg/dl. After three years post-transplantation, he presented with nephritic syndrome in association with renal function impairment (SCr - 2.1 mg/dl). The laboratory tests revealed positive rheumatoid factor, hypocomplementaemia and a positive cryocrit with type II cryoglobulinaemia. Antinuclear autoantibodies and anti-double stranded DNA antibodies were negative. Despite the presence of anti-HCV antibodies, the viral load remained undetectable. The allograft biopsy showed lesions compatible with membranoproliferative , with staining in the immunofluorescence for granular IgM and C3 and no C4d. He was treated with methylprednisolone pulses followed by oral prednisolone in association with rituximab. Two months after the last dose of rituximab, the SCr improved to 1.27 mg/dl, the proteinuria decreased and serum C3 levels normalized. Cryogloglobulins and rheumatoid factor became negative and HCV RNA remained undetectable. The patient was lost for follow-up. In our case...