[Influenza A: H1N1 post-viral membranoproliferative glomerulonephritis occurring in aggressive systemic mastocytosis: Case report and literature review]. / Glomérulonéphrite membrano-proliférative post-grippale chez un patient atteint de mastocytose systémique agressive : observation commentée et revue de la littérature.

Systemic mastocytosis is characterised by tissular infiltration and a cytokine storm due to mast cells excessive proliferation and activation. Herein, we report an extraordinary case of AH1N1 influenza post-viral glomerulonephritis occurring in the course of an aggressive systemic mastocytosis with an associated hematological neoplasm. Because of a multisystemic involvement including the liver and lungs, we treated mastocytosis with midostaurin (multiple inhibitor of kinase protein), anti H1/H2 blockers and dexamethasone as first line treatment. One month later and despite vaccination, he developed a severe acute lung injury with respiratory distress due to AH1N1 influenza in association with the nephrotic syndrome. Kidney biopsy disclosed a membranoproliferative glomerulonephritis that was successfully treated with mycophenolate mofetil. Only a few cases of influenza post-viral or post-vaccination glomerulonephritis are documented in the medical literature. This is an exceptional association of uncommon conditions occurring within only a few months in the same patient.

Rare Case of C3 Glomerulopathy in a Patient of Type 1 Diabetes Mellitus.

Complement component 3 glomerulopathy (C3G) is a recently defined entity comprising dense deposit disease and C3 glomerulonephritis. It is associated with nonrenal diseases such as diabetes mellitus (DM) type 1, ocular drusen, acquired partial lipodystrophy, and monoclonal gammopathy of undetermined significance. We describe a case of 13-year-old boy of the known case of type 1 DM, who developed proteinuria, and swelling over his face, and lower limbs, which on renal biopsy, was diagnosed as a case of C3G.

C3 Glomerulopathy and Related Disorders in Children: Etiology-Phenotype Correlation and Outcomes.

BACKGROUND AND OBJECTIVES: Membranoproliferative GN and C3 glomerulopathy are rare and overlapping disorders associated with dysregulation of the alternative complement pathway. Specific etiologic data for pediatric membranoproliferative GN/C3 glomerulopathy are lacking, and outcome data are based on retrospective studies without etiologic data. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 80 prevalent pediatric patients with membranoproliferative GN/C3 glomerulopathy underwent detailed phenotyping and long-term follow-up within the National Registry of Rare Kidney Diseases (RaDaR). Risk factors for kidney survival were determined using a Cox proportional hazards model. Kidney and transplant graft survival was determined using the Kaplan-Meier method. RESULTS: Central histology review determined 39 patients with C3 glomerulopathy, 31 with immune-complex membranoproliferative GN, and ten with immune-complex GN. Patients were aged 2-15 (median, 9; interquartile range, 7-11) years. Median complement C3 and C4 levels were 0.31 g/L and 0.14 g/L, respectively; acquired (anticomplement autoantibodies) or genetic alternative pathway abnormalities were detected in 46% and 9% of patients, respectively, across all groups, including those with immune-complex GN. Median follow-up was 5.18 (interquartile range, 2.13-8.08) years. Eleven patients (14%) progressed to kidney failure, with nine transplants performed in eight patients, two of which failed due to recurrent disease. Presence of >50% crescents on the initial biopsy specimen was the sole variable associated with kidney failure in multivariable analysis (hazard ratio, 6.2; 95% confidence interval, 1.05 to 36.6; P<0.05). Three distinct C3 glomerulopathy prognostic groups were identified according to presenting eGFR and >50% crescents on the initial biopsy specimen. CONCLUSIONS: Crescentic disease was a key risk factor associated with kidney failure in a national cohort of pediatric patients with membranoproliferative GN/C3 glomerulopathy and immune-complex GN. Presenting eGFR and crescentic disease help define prognostic groups in pediatric C3 glomerulopathy. Acquired abnormalities of the alternative pathway were commonly identified but not a risk factor for kidney failure.

Fulminant type I cryoglobulinemic glomerulonephritis with unique ultrastructural plugs: a case report.

INTRODUCTION:  Type I cryoglobulinemia is a rare disease which affects the skin, central nervous system and kidneys. It is usually associated with lymphoproliferative disorders such as multiple myeloma, lymphoma and monoclonal gammopathy of renal significance. Proteinuria and membranoproliferative glomerulonephritis are the most common renal manifestations; Case presentation: Here we report the case of a female patient in her late 40 s who had proteinuria accompanied by Raynaud's phenomenon, high blood and plasma viscosity, hearing loss, and cardiac and central nervous system involvement. Monoclonal immunoglobulin G-λ protein was detected and serum was positive for cryoglobulin. Renal biopsy revealed massive cryo-plugs with unique ultrastructural appearance in the glomerular and peritubular capillary lumina. Immunofluorescence showed predominant IgG3/λ deposition in cryo-plugs. As reported, the clinical manifestations of this patient resulted from cryoprecipitate and hyperviscosity syndrome; Conclusion: Cryoglobulinemia should be considered as a possible diagnosis in patients with Raynaud's phenomenon, hyperviscosity syndrome and monoclonal immunoglobulin.

Clinical and morphologic spectrum of renal involvement in idiopathic hypereosinophilic syndrome.

BACKGROUND: To explore the clinical and pathological features of renal lesions in patients with kidney involvement in idiopathic hypereosinophilic syndrome (IHES). METHODS: The demographic, clinical, and pathological characteristics and the treatment and follow-up data were analyzed. RESULTS: We identified 18 patients with IHES and renal involvement. Eleven patients presented with nephrotic syndrome, and 6 patients had impaired renal function. 15 patients underwent renal biopsy, and the pathological findings included the following: membranoproliferative glomerulonephritis in 3 patients; minimal-change disease in 3; mesangial proliferative nephritis in two; IgA nephropathy in 2; membranous nephropathy in two; chronic interstitial nephritis in two; focal segmental sclerosis in one; and eosinophil infiltration into the renal interstitium in 11 and into the glomerulus in 3. After treatment with glucocorticoids, the eosinophil count decreased. 15 patients were followed up, and 14 showed a decrease in urinary protein or renal function recovery. When glucocorticoids were discontinued, eosinophil increased (8 cases), urine protein increased (1 case), and 1 patient progressed to end-stage renal disease. CONCLUSIONS: Nephrotic syndrome with or without renal insufficiency is the main clinical manifestation. A wide spectrum of renal lesions can be observed in patients with IHES. Eosinophil infiltration into the renal interstitium was common in these patients. Most patients have a good prognosis after glucocorticoid therapy.

Renal pathological analysis using galactose-deficient IgA1-specific monoclonal antibody is a strong tool for differentiation of primary IgA nephropathy from secondary IgA nephropathy.

In several cases with IgA nephropathy (IgAN), differential diagnosis is difficult due to the complication with other systemic diseases which can induce secondary IgAN. Recently, we demonstrated that immunostaining with galactose-deficient IgA1-specific monoclonal antibody (KM55 mAb) specifically showed positive in primary IgAN cases. Here, we report four cases which we could make definitive diagnosis by immunohistological analysis using KM55 mAb. The underlying systemic diseases are rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), hepatitis C (HCV) and Crohn's disease (CD). Renal pathological findings in the four cases revealed mesangial proliferative glomerulonephritis with IgA and C3 deposits. Immunostaining with KM55 mAb was positive for three cases complicated with RA, SLE and CD, respectively. Thus, these three cases were diagnosed as primary IgAN and treated with tonsillectomy and steroid pulse therapy. These three cases finally achieved clinical remission. On the other hand, the case with HCV showed negative for KM55. Finally, we diagnosed as HCV-related nephropathy and successfully treated by antiviral agents. These cases suggested KM55 mAb is a strong tool to differentiate primary IgAN from secondary IgAN.

Systemic Bartonellosis Manifesting With Endocarditis and Membranoproliferative Glomerulonephritis.

Cat scratch disease caused by Bartonella species is mostly benign and self-limiting condition. Systemic infection is uncommon in immunocompetent host. We describe the case of a 66-year-old male who presented with sudden painless left eye blindness and brown-colored urine. Laboratory findings revealed progressively rising serum creatinine in association with nephrotic-range proteinuria at 7 g/day and glomerular hematuria on urinalysis. An echocardiogram demonstrated mitral and tricuspid valve vegetations despite multiple negative blood cultures. The left eye blindness was attributed to retinal artery occlusion from septic valvular embolus. Kidney biopsy showed membranoproliferative glomerulonephritis pattern of injury with "full house" pattern on immunofluorescent staining with subendothelial deposits on electron microscopy. Markedly elevated IgG (immunoglobulin G) titers for B henselae and B quintana were discovered. The patient had several cats at home. Kidney failure rapidly progressed to require hemodialysis. Once the diagnosis of systemic bartonellosis was confirmed, doxycycline (for 4 months) with rifampicin (for 3 months) were initiated. Repeat echocardiogram in 4 months demonstrated a resolution of valvular vegetations; however, the left eye blindness was permanent. In the present case the correct diagnosis of systemic bartonellosis allowed institution of appropriate antibiotic therapy and to also achieve a partial recovery of renal function and to discontinue hemodialysis.

A case of proliferative glomerulonephritis with immunoglobulin A1-lambda deposits successfully treated by chemotherapy.

A 74-year-old man presented with nephrotic syndrome and kidney insufficiency. Laboratory tests revealed monoclonal gammopathy of immunoglobulin A-lambda. Renal biopsy revealed diffuse mesangial proliferation and double-contoured basement membranes. Immunofluorescent analyses showed granular deposition of immunoglobulin A and C3 at the capillary walls and mesangial regions. Immunohistochemistry suggested monoclonal deposition of immunoglobulin A1-lambda. Electron microscopic analyses showed finely granular electron-dense deposits at mesangial and subendothelial areas. These findings suggested immunoglobulin A-type proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Based on the results of bone marrow aspiration, multiple myeloma was diagnosed. Because the renal manifestation was considered to be affected by monoclonal gammopathy, chemotherapy was initiated rather than immunomodulatory therapy. Although bortezomib and dexamethasone proved ineffective, second chemotherapy with elotuzumab, lenalidomide, and dexamethasone was successful, and kidney function recovered. Effective treatments for proliferative glomerulonephritis with monoclonal immunoglobulin deposits have not been established. This represents the first description of a patient successfully treated for proliferative glomerulonephritis with monoclonal immunoglobulin deposits by chemotherapy using elotuzumab.

Schistosomiasis-associated glomerulopathy: Clinical aspects, pathological characteristics, and renal outcomes
.

BACKGROUND: In Brazil, schistosomiasis is caused only by Schistosoma mansoni, occurring in the northeastern and southeastern regions. Schistosomiasis primarily affects the liver and gastrointestinal tract, although the kidneys can also be affected, mainly in the form of glomerulopathies. Here, we describe the characteristics of patients with schistosomiasis-associated glomerulopathies, including treatment and renal outcomes. MATERIALS AND METHODS: This was a retrospective analysis of patients diagnosed with schistosomiasis-associated glomerulopathy between 2002 and 2017. Clinical, biochemical, and histopathological (kidney biopsy) data were evaluated. RESULTS: Of the 24 patients evaluated, 19 (79.1%) were male and 16 (66.4%) were White. The mean age was 38.58 ± 9.83 years. We observed the hepatosplenic form of schistosomiasis in 15 patients (68.1%), nephrotic-nephritic syndrome in 13 (54.1%), hematuria in 20 (83.3%), and hypertension in 18 (75.0%). Renal histology showed a predominance of membranoproliferative pattern (n = 17/70.8%). On immunofluorescence, 19 patients (82.6%) showed immunoglobulin M (IgM) expression, 10 (43.4%) showed IgM+IgG expression, and 1 (4.3%) showed a "full house" pattern. The median follow-up time was 59.70 months, by the end of which 9 patients (37.5%) had developed end-stage renal disease (ESRD). Baseline serum creatinine was higher among the patients who developed ESRD than among those who did not (1.99 ± 1.08 vs. 1.34 ± 0.46 mg/dL, p = 0.05). CONCLUSION: Our study is one of the rare clinical studies on schistosomiasis-associated glomerulopathy with a long follow-up and renal endpoints, showing that one third of our patients, independent of their histological form, progress to dialysis.
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Membranoproliferative glomerulonephritis related to a streptococcal infection in a girl with IgA deficiency: a case report.

BACKGROUND: IgA deficiency associated with glomerulonephritis is rare. In particular, there is no prior report regarding the association between IgA deficiency and membranoproliferative glomerulonephritis (MPGN) in children. Herein, we describe the case of a 5-year-old girl with selective IgA deficiency and MPGN. CASE PRESENTATION: The patient presented with persisting urinary abnormality and hypocomplementemia following a group A treptococcal infection. Renal biopsy revealed the presence of diffuse mesangial hypercellularity, endocapillary proliferation, and focal thickening of the walls of the glomerular capillaries using light microscopy, with IgG and moderate C3 deposits observed using immunofluorescence. Electron microscopy images revealed nodular deposits in the subendothelial areas, with hump-shaped subepithelial deposits. The pathological diagnosis was confirmed as MPGN. Treatment using oral prednisolone (PSL), mizoribine (MZR), and angiotensin-converting enzyme inhibitors reduced the proteinuria. The PSL dose was gradually tapered, with the low dose of PSL and MZR continued for 4 years. Histological findings were improved on repeated renal biopsy, and PSL and MZR administration was discontinued. CONCLUSIONS: We report a rare case of MPGN related to a streptococcal infection in a child. The clinical presentation included selective IgAD, with several pathological findings and a clinical course typical of glomerulopathy. The patient was successfully treated using multidrug therapy.

HHV-8-negative multicentric Castleman disease presenting as a crescentic immune complexes membranoproliferative glomerulonephritis.

Multicentric Castleman disease is a rare polyclonal lymphoproliferative disorder mainly associated with two renal manifestations: thrombotic microangiopathy and amyloidosis. Nevertheless, we report here a case of human herpes virus-8 negative multicentric Castleman disease with membranous proliferative glomerulonephritis and extracapillary proliferation. A patient was successfully treated with corticosteroids, anti-CD20 and cyclophosphamide therapy.

A Narrative Review on C3 Glomerulopathy: A Rare Renal Disease.

In April 2012, a group of nephrologists organized a consensus conference in Cambridge (UK) on type II membranoproliferative glomerulonephritis and decided to use a new terminology, "C3 glomerulopathy" (C3 GP). Further knowledge on the complement system and on kidney biopsy contributed toward distinguishing this disease into three subgroups: dense deposit disease (DDD), C3 glomerulonephritis (C3 GN), and the CFHR5 nephropathy. The persistent presence of microhematuria with or without light or heavy proteinuria after an infection episode suggests the potential onset of C3 GP. These nephritides are characterized by abnormal activation of the complement alternative pathway, abnormal deposition of C3 in the glomeruli, and progression of renal damage to end-stage kidney disease. The diagnosis is based on studying the complement system, relative genetics, and kidney biopsies. The treatment gap derives from the absence of a robust understanding of their natural outcome. Therefore, a specific treatment for the different types of C3 GP has not been established. Recommendations have been obtained from case series and observational studies because no randomized clinical trials have been conducted. Current treatment is based on corticosteroids and antiproliferative drugs (cyclophosphamide, mycophenolate mofetil), monoclonal antibodies (rituximab) or complement inhibitors (eculizumab). In some cases, it is suggested to include sessions of plasma exchange.

Proliferative Glomerulonephritis with Monoclonal Immunoglobulin Deposits without Conspicuous Mesangial Proliferation, Complicated with Squamous Cell Lung Carcinoma.

We performed a renal biopsy for nephrotic syndrome in a patient with squamous cell lung carcinoma, which can worsen the prognosis. Chemoradiation therapy was effective for the cancer and proteinuria; we thus inferred that the nephrotic syndrome had been closely associated with the carcinoma. A pathological analysis of the kidney showed monoclonality for λ chain, satisfying the diagnostic criteria of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID); however, conspicuous mesangial proliferation was not observed. This is the first case of PGNMID complicated with lung carcinoma; furthermore, our findings underscore the importance of examining renal lesions and assessing monoclonality in cancer patients.

Complement dysregulation in glomerulonephritis.

Glomerulonephritis (GN) refers to a group of renal diseases affecting the glomeruli due to the damage mediated by immunological mechanisms. A large proportion of the disease manifestations are caused by disturbances in the complement system. They can be due to genetic errors, autoimmunity, microbes or abnormal immunoglobulins, like modified IgA or paraproteins. The common denominator in most of the problems is an overactive or misdirected alternative pathway complement activation. An assessment of kidney function, amount of proteinuria and hematuria are crucial elements to evaluate, when glomerulonephritis is suspected. However, the cornerstones of the diagnoses are renal biopsy and careful examination of the complement abnormality. Differential diagnostics between the various forms of GN is not possible based on clinical features, as they may vary greatly. This review describes the known mechanisms of complement dysfunction leading to different forms of primary GN (like IgA glomerulonephritis, dense deposit disease, C3 glomerulonephritis, post-infectious GN, membranous GN) and differences to atypical hemolytic uremic syndrome. It also covers the basic elements of etiology-directed therapy and prognosis of the most common forms of GN. Common principles in the management of GN include treatment of hypertension and reduction of proteinuria, some require immunomodulating treatment. Complement inhibition is an emerging treatment option. A thorough understanding of the basic disease mechanism and a careful follow-up are needed for optimal therapy.

Diffuse membranoproliferative glomerulonephritis with focal sclerosis and renal amyloidosis in an adult male with autosomal dominant dystrophic epidermolysis bullosa: a case report.

Previous reports of glomerular disease in adult patients with autosomal dominant dystrophic epidermolysis bullosa (EB) are limited and include post-infectious glomerulonephritis, IgA nephropathy, amyloidosis, and leukocytoclastic vasculitis. To our knowledge, membranoproliferative glomerulonephritis (MPGN) has not been described before. We report a case of a 39-year-old male with autosomal dominant dystrophic EB, presenting with bilateral leg swelling of one-week duration. There was no other significant past medical history. The physical examination was remarkable for scars and erosions over all body areas, with all extremities with blisters and ulcers covered, absent finger and toenails and bilateral lower extremity edema. Serum creatinine was 0.9 mg/dL, albumin 1.3 g/dL and urine protein excretion 3.7 g/24 h. Viral markers (hepatitis-B, C, and HIV), complement c3 and c4 levels and auto-immune antibody profile all remained negative or within normal limits. Renal ultrasound and echocardiogram were normal. Renal biopsy recovered 14 glomeruli, all with proliferation of mesangial and endothelial cells as well as an expansion of the mesangial matrix, focal segmental sclerosis and amorphous homogeneous deposits demonstrating apple-green birefringence under polarized light with Congo red stain. Our observation emphasizes the importance of recognizing MPGN and secondary amyloidosis in patients with EB, especially with the availability of newer treatment modalities.

A case report of recurrent membranoproliferative glomerulonephritis after kidney transplantation due to ventriculoatrial shunt infection.

BACKGROUND: Transplant failure requires the consideration of numerous potential causes including rejection, acute tubular necrosis, infection, and recurrence of the original kidney disease. Kidney biopsy is generally required to approach these differential diagnoses. However, the histopathological findings on their own do not always lead to a definite diagnosis. Consequently, it is crucial to integrate them with clinical findings and patient history when discussing histopathological patterns of injury. The histopathologic finding of a membranoproliferative glomerulonephritis (MPGN) is one of the most challenging constellations since it does not refer to a specific disease entity but rather reflects a pattern of injury that is the result of many different causes. Whilst MPGN is occasionally classified as immune complex mediated, careful evaluation usually reveals an underlying disorder such as chronic infection, plasma cell dyscrasia, complement disorders, and autoimmune disease. CASE PRESENTATION: We describe the case of a 43-year-old woman who was referred to us because of a slowly rising serum creatinine 4 years after kidney transplantation. As in the native kidney, the biopsy revealed an MPGN pattern of injury. The cause of this finding had not been established prior to transplantation leading to a classification as idiopathic MPGN in the past. Further workup at the time of presentation and allograft failure revealed chronic infection of a ventriculoatrial shunt as the most probable cause. CONCLUSION: This case underlines the fact that MPGN is not a disease but a histopathological description. Consequently, the causative disorder needs to be identified to avoid kidney failure and recurrence after transplantation.

[Membranoproliferative glomerulonephritis with relapsing episodes of acute kidney injury in the Schnitzler syndrome].

The Schnitzler syndrome (SS) is a rare and underdiagnosed entity that associates a chronic urticarial rash, monoclonal IgM (or sometimes IgG) gammopathy and signs and symptoms of systemic inflammation. During the past 45 years the SS has evolved from an elusive, little-known disorder to the paradigm of a late-onset auto-inflammatory acquired syndrome. Though there is no definite proof of its precise pathogenesis, it should be considered as an acquired disease involving abnormal stimulation of the innate immune system, which can be reversed by the interleukin 1 (IL-1) receptor antagonist anakinra. Here we describe the case of a 56-year-old male Caucasian patient affected by SS and hospitalized several times in our unit because of relapsing episodes of acute kidney injury. He underwent an ultrasound-guided percutaneous kidney biopsy in September 2012, which showed the histologic picture of type I membranoproliferative glomerulonephritis. He has undergone conventional therapies, including nonsteroidal anti-inflammatory drugs, steroids and immunosuppressive drugs; more recently, the IL-1 receptor antagonist anakinra has been prescribed, with striking clinical improvement. Although the literature regarding kidney involvement in the SS is lacking, it can however be so severe, as in the case reported here, to lead us to recommend the systematic search of nephropathy markers in the SS.

Cryoglobulinemia in a moroccan nephrology department.

Cryoglobulinemia is a rare cause of kidney disease that occurs in patients with various diseases. Renal involvement often occurs after appearance of various clinical manifestations dominated by purpura and neuropathy. The aim of this study is to describe clinical, biological, and pathological characteristics of cryoglobulinemic glomerulonephritis (GN), as well as treatment and outcome. This is a retrospective study including all patients with positive cryoglobulin test and biopsy-proven GN secondary to cryoglobulinemia. Fourteen patients with cryoglobulinemic GN were collected. Their mean age was 46.92 ± 15.82 years with male predominance (64.28%). Weight loss, fever (71.42%), and purpuric rash (57.14%) were the main extrarenal manifestations. Eight patients presented with nephrotic syndrome (NS), associated with renal impairment in three patients. Four patients had rapidly progressive GN and two patients had acute kidney injury. Renal biopsy, performed in all patients, revealed membranoproliferative GN with glomerular thrombi in all patients. Crescents and necrotizing vasculitis were present in four patients. Hepatitis C virus (HCV) infection was the most common etiology. Antivirals and steroids or other immunosuppressive agents were used in most of the patients. During follow-up, complete response was observed in three patients and partial response was observed in four patients. Five patients had no response with renal injury requiring hemodialysis. NS with hematuria and renal insufficiency were the main clinical manifestations of cryoglobulinemic GN. In our study, HCV infection dominated the etiologies, although not well described earlier. A half of our patients had poor outcome even after antiviral and immunosuppressive therapy.

Effectiveness of cryofiltration and mizoribine combination with oral steroid therapy in a patient with membranoproliferative glomerulonephritis due to essential cryoglobulinemia.

A 65-year-old male patient with nephrotic syndrome was admitted to our hospital due to worsening systemic edema and purpura on the limbs. He had an impaired renal function, low serum complement level, and elevated rheumatoid factor level. He was positive for cryoglobulin (monoclonal IgM-κ and polyclonal mixed-type IgG), and the results of his kidney biopsy showed a tissue profile of membranoproliferative glomerulonephritis (MPGN). Due to the fact that the secondary cause was unclear, he was diagnosed with MPGN due to essential mixed cryoglobulinemia. On hospital day 20, he was initiated on 50 mg/day prednisolone (PSL). On hospital day 43, oral mizoribine (MZR) at a dose of 150 mg/day was prescribed. On hospital day 49, cryofiltration was performed because the disease was steroid resistant. The treatment promptly decreased urine protein levels. Serum albumin and serum complement levels increased, and complete remission was achieved approximately three months after the initiation of treatment. The PSL and MZR doses were gradually reduced to 2 mg/day and 100 mg/day, respectively, without any reemergence of the symptoms of cryoglobulinemia or relapse of the nephrotic syndrome for three years. Here, we report this case with essential mixed cryoglobulinemia in whom we could achieve complete remission of the disease by adding cryofiltration to the oral corticosteroid and immunosuppressant therapy with mizoribine and could maintain for a long time.