Genetic insights into the mechanisms of proliferative glomerulonephritis.

Glomerular visceral epithelial cells (i.e., podocytes) are an essential component of the tripartite glomerular filtration barrier. Healthy podocytes are terminally differentiated cells with limited replicative capacity; however, inappropriate cell cycle reentry can be induced in podocytes by various injurious stimuli. In this issue of the JCI, Yamaguchi et al. report on a somatic mosaic gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic α subunit (p110α, encoded by PIK3CA). The study reveals that activating mutations of p110α can drive podocyte proliferation in PIK3CA-related overgrowth syndrome (PROS). They also showed that selective, small-molecule inhibitors of p110 may be useful for the treatment of proliferative glomerulonephritis.

Association Between Membranoproliferative Glomerulonephritis and Colorectal Cancer - A Case Report.

Membranoproliferative glomerulonephritis (MPGN) is a rare glomerular disease characterized by mesangial hypercellularity and thickening of the glomerular basement membrane (GBM). MPGN can be idiopathic or associated with malignancy, systemic immune complex disorders and chronic infections. It has rarely been associated with solid organ tumors, such as lung, gastric, breast or prostate cancer. We report a patient with MPGN and coexisting colorectal carcinoma. A 48-year-old man presented with anemia, loss of weight, hypertension, and nephrotic syndrome. The renal biopsy findings were compatible with type 1 MPGN. The antineutrophilic cytoplasmic antibodies, antinuclear antibodies, anti-GBM, serologic markers of hepatitis B and hepatitis C and tumor markers were negative. After ruling out the secondary causes of MPGN, the patient was treated with pulse doses of methylprednisolone and a single dose of cyclophosphamide. However, due to the worsening anemia and rectal bleeding, a colonoscopy was performed, which established a diagnosis of adenocarcinoma of the descending colon. The patient was treated with left hemicolectomy and oral corticosteroids. Within a year after the cancer treatment, the patient experienced a complete resolution of the proteinuria and improvement of the kidney function. Although rare, MPGN can be associated with hematologic malignancies and solid organ tumors. The most common causes of secondary MPGN should be ruled out before starting specific treatment. In our patient, cancer treatment has led to a subsequent remission of the nephrotic syndrome, which indicated that this association was not coincidental but rather causal. In patients with a tumor and concomitant glomerulopathy which is suspected to be paraneoplastic in etiology, the treatment of the underlying malignancy should be prioritized.

Membranoproliferative Glomerulonephritis Pattern of Injury.

Membranoproliferative glomerulonephritis (MPGN) is no longer a disease but a pattern of injury in various diseases. Characterized by electron-dense deposits, mesangial proliferation, and duplication of the glomerular basement membrane, MPGN was previously classified by findings seen by electron microscopy. However, recognizing complement dysfunction in relation to cases with the MPGN pattern of injury substantially changed our view of its pathogenesis. A new classification, including immune complex-mediated and complement-mediated MPGN, has become preferable and has been adopted by international guidelines. Despite these advancements, accurate diagnosis of MPGN remains a clinical challenge, given the pathological and clinical similarities between immune complex-mediated and complement-mediated MPGN. Additional testing, such as molecular and genetic testing, is often necessary. Here, we will summarize our current understanding of the MPGN pattern of injury from a pathology perspective as an introductory article in the following chapters.

Hydralazine use can be associated with IgM-dominated immune complex-mediated glomerulonephritis.

CONTEXT: IgM-dominant immune complex-mediated glomerulonephritis (IgM-dominant ICMGN) is a rare renal entity, characterized by a membranoproliferative pattern by light microscopy, dominant IgM staining by immunofluorescent staining, and subendothelial deposits by electron microscopy. This study was to investigate if some of IgM-ICMGN were associated with autoimmune disorders induced by hydralazine. DESIGN: Seven IgM-dominant ICMGN cases were identified over 8 years. Their pathologic phenotypes and clinical scenarios were analyzed in detail. RESULTS: Patients' ages ranged from 47 to 87 years old with 5 women and two men. Six of seven patients had drug-induced autoimmune phenomenon (hydralazine-induced positive ANCA and ANA). All of them had renal dysfunction and some proteinuria. Most pathologic features showed a membranoproliferative pattern of glomerulonephritis with dominant IgM deposits at subendothelial spaces. IgM nephropathy (a variant of focal segmental glomerulosclerosis), chronic thrombotic microangiopathy, and cryoglobulinemic glomerulopathy were ruled out in the cases. CONCLUSION: The hydralazine-induced autoimmune phenomenon can be seen in IgM-dominant ICMGN, which should be classified as a subtype of membranoproliferative glomerulonephritis.

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.

Apolipoprotein E is enriched in dense deposits and is a marker for dense deposit disease in C3 glomerulopathy.

C3 glomerulopathy (C3G) is a rare disease resulting from dysregulation of the alternative pathway of complement. C3G includes C3 glomerulonephritis (C3GN) and dense deposit disease (DDD), both of which are characterized by bright glomerular C3 staining on immunofluorescence studies. However, on electron microscopy (EM), DDD is characterized by dense osmiophilic mesangial and intramembranous deposits along the glomerular basement membranes (GBM), while the deposits of C3GN are not dense. Why the deposits appear dense in DDD and not in C3GN is not known. We performed laser microdissection (LCM) of glomeruli followed by mass spectrometry (MS) in 12 cases each of DDD, C3GN, and pretransplant kidney control biopsies. LCM/MS showed marked accumulation of complement proteins C3, C5, C6, C7, C8, C9 and complement regulating proteins CFHR5, CFHR1, and CFH in C3GN and DDD compared to controls. C3, CFH and CFHR proteins were comparable in C3GN and DDD. Yet, there were significant differences. First, there was a six-to-nine-fold increase of C5-9 in DDD compared to C3GN. Secondly, an unexpected finding was a nine-fold increase in apolipoprotein E (ApoE) in DDD compared to C3GN. Most importantly, immunohistochemical and confocal staining for ApoE mirrored the dense deposit staining in the GBM in DDD but not in C3GN or control cases. Validation studies using 31 C3G cases confirmed the diagnosis of C3GN and DDD in 80.6 % based on ApoE staining. Overall, there is a higher burden of terminal complement pathway proteins in DDD compared to C3GN. Thus, our study shows that dense deposits in DDD are enriched with ApoE compared to C3GN and control cases. Hence, ApoE staining may be used as an adjunct to EM for the diagnosis of DDD and might be valuable when EM is not available.

Comparison of Clinico-pathologic features and outcomes of ANCA negative and ANCA positive pauci immune crescentic glomerulonephritis: A single centre study.

Introduction: Pauci-immune crescentic glomerulonephritis (PICN) is an important cause of rapidly progressive renal failure. 10-40% of PICN cases have ANCA (antineutrophil cytoplasmic antibody) negative serology. The present study compared clinico-pathologic features, Brix's renal risk score, Berden's histopathological classes and differences in outcome between ANCAnegative vs ANCA positive PICN patients. Materials and Methods: Sixty-one patients of biopsy-proven PICN were studied. Biochemical findings and ANCA serology were recorded. Renal biopsy slides were reviewed along with direct immunofluorescence. Clinical and histological features were compared between ANCA negative and positive PICN using the Man Whitney U test and Chi-square test. Patients were compared for distribution in Berden's histological classes and Brix's renal risk categories. Patient and renal survival were compared using Kaplan-Meier survival analysis. Results: ANCA negative PICN patients were younger (44.9 ± 16.5 years vs 53.6 ± 15.1 years, P = 0.049). Nasal (0 vs 18%, P = 0.035) and pulmonary involvement (9% vs 38%, P = 0.014) were lower in ANCA negative group. Both ANCA groups had similar renal biochemical profiles, percentage normal glomeruli, 16.3 ± 18.2 vs 21.7 ± 20.4 and percentage glomeruli with crescents, 64.5 ± 28.1 vs 64.3 ± 27.1. Twenty-seven per cent of ANCA negative cases fell in the sclerotic class in Berden's classification vs just 2.5% in ANCA positive group (p = 0.037) without significant difference in Brix's renal risk categories (p = 0.329). Thirteen per cent of ANCA negative patients achieved complete remission on treatment compared to 33% in ANCA positive patients. Patient survival and overall probability of progressing to ESRD were similar in the two groups. Conclusion: ANCA negative PICN cases present at younger ages. Nasal and pulmonary involvement is uncommon in these patients. Patient survival and progression to ESRD are similar in both ANCA groups.

Membranoproliferative Glomerulonephritis Type I Associated with Intravenous Immunoglobulin Administration Arising in a Child with X-Linked Agammaglobulinemia: A Case Report and a Reappraisal.

In 1952, X-linked agammaglobulinemia (XLA) was discovered as a rare inherited disorder. It markedly compromises the ability of the body to combat infectious microorganisms. Membranoproliferative glomerulonephritis (MPGN) Type I is characterized by subendothelial immune complex deposits. Patients with XLA can rarely develop immune-complex-induced diseases. Here, we report a case of MPGN Type I in a 12-year-old male patient with a past and family history of XLA. The patient presented with fever, productive cough, vomiting, and lower limb edema. Clinical and radiological examinations established a diagnosis of bronchopneumonia. The laboratory findings revealed proteinuria and hematuria, and a renal biopsy was performed. The histological examination of this biopsy revealed mesangial hypercellularity and thickened basement membranes. Immunofluorescence studies showed mesangiocapillary staining for Complement 3 and Immunoglobulin (Ig) G and, to a lesser extent, for IgA, IgM, and Complement 1q. Ultrastructural studies revealed partly thick, double-contoured glomerular basement membranes, glomerular endothelial cells with swollen cell bodies, and podocytes with effaced foot processes. Small subendothelial and mesangial eosinophilic deposits were identified. The diagnosis of MPGN type I was established. The patient was started on prednisolone. To the best of our knowledge, this is a rare case of MPGN Type I in a patient with XLA. The pathogenetic mechanisms underlying the development of MPGN Type I were not apparent in our patient. However, residual humoral immunity may play a role in the development of MPGN.

Clinical and histological features of patients with membranoproliferative glomerulonephritis classified by immunofluorescence findings / Características clínicas e histológicas de pacientes com glomerulonefrite membranoproliferativa classificados por achados de imunofluorescência

Abstract Background: New classification for membranoproliferative glomerulonephritis has been proposed in the literature. The aim of this study was to compare the clinical, biochemical, etiology and renal biopsy findings of these patients grouped by immunofluorescence as proposed by the new classification. Methods: Patients with renal biopsy-proven membranoproliferative glomerulonephritis unrelated to systemic lupus erythematosus, diagnosed between 1999 and 2014. The patients were divided according to immunofluorescence: Immunoglobulin positive group, C3 positive only and negative immunofluorescence group. Results: We evaluated 92 patients, the majority of which were in the immunoglobulin positive group. Infectious diseases, hepatitis C virus and schistosomiasis, were the most frequent etiology. A negative immunofluorescence group had more vascular involvement in renal biopsy compare with others groups. Conclusions: The only difference between the groups was higher vascular involvement in renal biopsy in negative immunofluorescence group. These new classification was satisfactory for the finding of etiology in one part of the cases.

Resumo Introdução: Uma nova classificação para glomerulonefrite membranoproliferativa foi proposta na literatura. O objetivo deste estudo foi comparar os achados clínicos, bioquímicos, etiológicos e da biópsia renal desses pacientes agrupados por imunofluorescência, conforme proposto pela nova classificação. Métodos: Pacientes com glomerulonefrite membranoproliferativa comprovada por biópsia renal, não relacionada ao lúpus eritematoso sistêmico, diagnosticados entre 1999 e 2014. Os pacientes foram divididos de acordo com a imunofluorescência: grupo positivo por imunoglobulina, grupo positivo por C3 apenas e grupo com imunofluorescência negativa. Resultados: avaliamos 92 pacientes, a maioria dos quais estava no grupo de imunoglobulina positiva. Doenças infecciosas, o vírus da hepatite C e a esquistossomose, foram as etiologias mais frequentes. Um grupo com imunofluorescência negativa apresentou maior comprometimento vascular na biópsia renal quando comparado com os outros grupos. Conclusões: a única diferença entre os grupos foi o maior envolvimento vascular na biópsia renal no grupo de imunofluorescência negativa. Esta nova classificação foi satisfatória para a descoberta de etiologia em uma parte dos casos.

Shenhua Tablet inhibits mesangial cell proliferation in rats with chronic anti-Thy-1 nephritis

BACKGROUND: In China, mesangial proliferative glomerulonephritis (MsPGN) is one of the most common kidney diseases. In this study, we treated a rat model of chronic anti-Thy-1 MsPGN with Shenhua Tablet and evaluated whether the tablet was able to protect the kidney function. Thirty-six Wistar rats were randomly divided into six groups: (1) Sham surgery (Sham); (2) anti-Thy-1 nephritis model (Thy-1); (3) anti-Thy-1 nephritis model + irbesartan-treated (Irb); (4) anti-Thy-1 nephritis model + low-dose of Shenhua Tablet (SHL); (5) anti-Thy-1 nephritis model + medium-dose of Shenhua Tablet (SHM); (6) anti-Thy-1 nephritis model + high-dose of Shenhua Tablet (SHH). RESULTS: Thirteen weeks after drug treatment, urinary proteins were quantified and renal pathological changes were thoroughly examined at the time point of 24 h. Meanwhile, the expression levels of p-Erk1/2, cyclin D1 and p21 at the renal cortex were also tested. The levels of urinary proteins and total cholesterol in the blood were significantly reduced in rats treated with any drug tested in this study. The level of triglyceride was significantly reduced in all three Shenhua Tablet-treated groups. Renal pathomorphological scores were significantly improved in groups of Irb, SHM and SHH. Mesangial cell proliferation was significantly inhibited in any drug-treated group. p-Erk1/2 and cyclin D1 were downregulated whereas p21 was upregulated in the renal cortex. CONCLUSIONS: Our study indicated that Shenhua Tablet is able to inhibit the abnormal proliferation of mesangial cells and to prevent kidney damage, which is likely associated with downregulation of p-Erk1/2 and reduced activity of its downstream target-cyclin D1.

Schistosomal glomerulopathy and changes in the distribution of histological patterns of glomerular diseases in Bahia, Brazil

Distinct patterns of glomerular lesions, including membranoproliferative glomerulonephritis and focal segmental glomerulosclerosis, are associated with infection by Schistosoma mansoni or Schistosoma japonicum. Evidence suggests that immune complex deposition is the main mechanism underlying the different forms of schistosomal glomerulonephritis and that immune complex deposition may be intensified by portal hypertension. The relationship between focal segmental glomerulosclerosis and schistosomiasis remains poorly understood. A clinicopathologic classification of schistosomal glomerulopathies was proposed in 1992 by the African Association of Nephrology. In Brazil, mass treatment with oral medications has led to a decrease in the occurrence of schistosomal glomerulopathy. In a survey of renal biopsies performed in Salvador, Brazil, from 2003-2009, only 24 (4 percent) patients were identified as positive for S. mansoni infection. Among these patients, only one had the hepatosplenic form of the disease. Focal segmental glomerulosclerosis was found in seven patients and membranoproliferative glomerulonephritis was found in four patients. Although retrospective studies on the prevalence of renal diseases based on kidney biopsies may be influenced by many patient selection biases, a change in the distribution of glomerulopathies associated with nephrotic syndrome was observed along with a decline in the occurrence of severe forms of schistosomiasis.

Clinicopathological features of atypical nephrotic syndrome in jamaican children / Características clínico-patológicas del síndrome nefrótico atípico en los niños jamaicanos

OBJECTIVES: To document the histopathological spectrum of atypical nephrotic syndrome in Jamaican children and to make clinicopathological correlations which will assist physicians in identifying patients needing nephrology consultation. METHODS: This was a retrospective review of renal biopsy data of Jamaican children who were referred to the University Hospital of the West Indies and the Bustamante Hospital for Children between January 1985 and December 2008. The study population consisted of children < 12 years old with atypical nephrotic syndrome. RESULTS: Biopsies were done in 157 children - 85 males and 72 females (mean age 8.91 ± 3.44 years). Indications for biopsy were steroid resistance (35%), frequent relapses (8.9%) and other atypical presentations (56.1%). Overall, mesangial proliferative glomerulonephritis (MesGN) was the commonest histology (49/157, 31.2%), followed by minimal change disease (MCD) (36/157, 22.9%) and diffuse proliferative glomerulonephritis (DPGN) (26/157, 16.6%). Infection was present in 38/157 (24%) cases. Diffuse proli ferative glomerulonephritis was the predominant type associated with streptococcal infection (52.9%) while Hepatitis B was seen in 83% ofcases ofmembranous nephropathy. CONCLUSION: Mesangial proliferative glomerulonephritis is the commonest histology seen in Jamaican children with atypical nephrotic syndrome. Most membranous nephropathy is Hepatitis B related. Hypertension with hypocomplementaemia, renal failure and anaemia are features ofmore serious renal disease (eg membranoproliferative glomerulonephritis and crescentic nephritis) rather than MCNS and should warrant urgent nephrology consultation for renal biopsy.

OBJETIVOS: Documentar el espectro histopatológico del síndrome nefrótico atípico en los niños jamaicanos y hacer correlaciones clínico-patológicas que ayuden a los médicos a identificar pacientes que necesitan la consulta de nefrología.. MÉTODOS: Se trata de un estudio retrospectivo de datos de biopsias renales de niños jamaicanos remitidos al Hospital Universitario de West Indies y al Hospital Pediátrico Bustamante, entre enero de 1985 y diciembre de 2008. La población del estudio consistió en niños < 12 años de edad que padecían el síndrome nefrótico atípico. RESULTADOS: Se realizaron biopsias a 157 niños - 85 varones y 72 hembras (edad promedio 8.91 + 3.44 años). Las indicaciones para la biopsia se debieron a resistencia a los esteroides (35%), recaídas frecuentes (8.9%) y otras manifestaciones atípicas (56.1%). En general, la glomerulonefritis proliferativa mesangial (GNMes) fue la histología más común con 49/157 (31.2%), seguida por la enfermedad de cambio mínimo (ECM) con 36/157(22.9%) y la glomerulonefritis proliferativa difusa (GNPD) con 26/157 (16.6%). La infección estuvo presente en 38/157 (24%) de los casos. La glomerulonefritis proliferativa difusa fue el tipo predominante asociado con la infección estreptocóccica (52.9%), mientras que Hepatitis B fue observada en el 83% de los casos de nefropatía membranosa. CONCLUSIÓN: La glomerulonefritis proliferativa mesangial es la histología que con mayor frecuencia se observa en los niños jamaicanos que padecen el síndrome nefrótico atípico. La mayoría de los casos de nefropatía membranosa guardan relación con la hepatitis B. La hipertensión con hipocomplementemia, la insuficiencia renal y la anemia son rasgos más bien de enfermedades renales más serias (p.ej, glomerulonefritis membranoproliferativa, nefritis crescéntica) que del síndrome nefrótico de cambios mínimos (SNCM) y debe asegurarse la consulta urgente con el nefrólogo para se realice una biopsia renal.

Glomerulonefritis rapidamente progresiva en el niño: análisis de la casuística de un quinquenio 2004-2009: [revisión] / Rapidly progressive glomerulonephritis in children: analysis of the data of a five-year period 2004-2009: [review]

La glomerulonefritis rápidamente progresiva (GNRP) es una entidad poco frecuente; el diagnóstico precoz es importante con fines terapéuticos y pronósticos. El objetivo del presente trabajo es reportar la casuística del GNRP en el Servicio de Nefrología del Hospital de Niños "Jorge Lizarraga" entre enero 2004 y enero 2009. Estudio retrospectiva y descriptivo con la revisión de las historias clínicas de 8 pacientes con edades entre 3-13 años. Seis pacientes correspondieron al sexo femenino. La edad promedio fue de 11 ± 3.5 años. La mayoría presentó un foco infeccioso previo con mayor frecuencia en piel (6 casos), y en faringe un caso. Las manifestaciones clínicas y los hallazgos de laboratorio se caracterizaron por: edema, hipertensión, hematuria, retención azoada progresiva, proteinuria e hipocomplementaria. Se realizó biopsia renal en todos los casos, observandose glomerulonefritis proliferativa endo y extracapilar en 6 casos y glomerulonefritis membranoprolirativa en 2 casos. La terapéutica se basó en tratar la infección y el fallo renal agudo. Se aplicaron pulsos de metilprednisolona a todos los pacientes y 6 pacientes ameritaron diálisis peritoneal. Seis pacientes sobrevivieron (2 egresaron con función renal normal y 4 progresaron a enfermedad renal crónica) y 2 pacientes fallecieron. La GNRP es una condición que se presenta esporadicamente; su evolución depende de la severidad del compromiso renal, extensión de las lesiones histopatológicas y precocidad en la terapéutica farmacológica y dialítica. La mayoría de los pacientes sobrevive, un porcentaje importante progresa a enfermedad renal crónica, lo cual eventualmente amerita terapia substitutiva con dialisis y trasplante renal.

Rapidly progressive glomerulonephritis (RPGN) is a rate entity; early diagnosis is important for adequate and prompt treatment. The objetive of this paper is to report the casuistic of RPGN in the Department of Nephrology of the Hospital de Niños "Jorge Lizarraga" between January 2004 and January 2009. Retrospective and descriptive study collecting data of the medical records of 8 pantients, ages 3-13 years. Six patients were females and the average for age was 11 ± 3.5 years. The majority presented a previous infection (skin in 6 and pharynx in 1). Clinical manifestations and laboratory findings were: edema hypertensión, hematuria, progressive azotemic retentions, proteinuria and hypocomplementemia. Renal biopsy was performed in all patients with the following results: endo and extracapillary proliferative glomerulonephritis in 6 cases and membranoproliferative glomerulonephritis in 2. Therapeutic measures were aimed to the treatment of infection acute renal failure. Methylprednisolone boluses were indicated in all patients, 6 patients were submitted to peritoneal dialysis. Six patients survived (2 with normal renal function and 4 with progression to chronic kidney disease), and 2 died. RPGN is a condition that occurs sporadically: its evolution depends of the severity of renal involvement, the extension of histological lesions and the precocity with which pharmacological and dialytic treatment are installed. Most patients survive but a significant number progresss to chronic kidney disease.

Infección por virus de la hepatitis C y glomérulonefritis membranoproliferativa / Hepatitis C virus infection and membranoproliferative glomerulonephritis

Antecedentes y métodos. Recientemente se ha informado una posible asociación entre la infección por virus de hepatitis C (VHC) y las glomérulonefritis membranoproliferativa (GNMP) y membranosa. La fisipatogenia de esta entidad parece estar mediada por depósito de complejos inmunes en los glomérulos. El objetivo de este informe es describir las característias clínicas, de laboratorio e histopatológicas de tres pacientes con infección crónica por VHC, sin infección por virus de la hepatitis B ni enfermedades autoinmunes, y con evidencia de enfermedad glomerular. Resultados. Todos los pacientes presentaron estigmas de hepatopatía crónica, ascitis y edema periférico, y presión arterial normal. Los resultados de laboratorio no mostraron alteraciones significativas en pruebas de función hepática y en las cifras de elementos azoados; los tres casos presentaron hematuria microscópica, hipoalbuminemia y albuminuria de grado variable, sin hipercolesterolemia y factor reumatoide positivo. Sólo un paciente tuvo anticuerpos antinucleares y anticuerpos antimitocondriales positivos a títulos bajos, y otro más presentó niveles bajos de C3 y C4. En los tres casos, las biopsias de riñón fueron interpretadas como glomérulonefritis membranoproliferativa tipo I, y las de hígado como cirrosis. Conclusiones. Las evidencias presentadas apoyan la asociación de la enfermedad crónica por virus de la hepatitis C y la glomérulonefritis membranoproliferativa. Es necesario realizar otros estudios para establecer más firmemente la asociación, fisiopatogenia y causalidad entre estas entidades

Glomerulonefritis membranoproliferativa con semilunas y depósitos masivos de IgA asociada a HBsAg / Membranoproliferative glomerulonephritis with semilunar forms and massive deposits of IgA associated with HBsAg

Se presenta un joven coreano de 21 años con diagnóstico de ingreso al hospital de síndrome nefrótico, hipertensión arterial, microhematuria e insuficiencia renal, requiriendo hemodiálisis. El paciente era portador HBsAg y HBeAg sin enfermedad hepática clínica ni humoral, tampouco antecedentes de transfusiones ni adicción a drogas de uso intravenoso. Se le efectuó biopsia renal percutánea pudiendo diagnosticarse glomérulonefritis membrano-proliferativa en estado avanzado con formación de semilunas fibroepiteliales en el espacio de Bowman. La inmunofluorescencia mostró depósitos masivos de IgA con un patrón granular, en mesangio y capilares glomerulares. Mediante técnica de inmunoperoxidasas se comprobó depósitos de HBsAg en la pared de los capilares glomerulares, citoplasma de las células glomerulares, mesangio y túbulos renales. Se trataría del primer caso de glomérulonefritis membranoproliferativa con semilunas y depósitos masivos de IgA, insuficiencia renal progresiva con necesidad de hemodiálisis crónica, en un portador de HBsAg y HBeAg

Leprosy and glomerulonephritis: case report and review of the literature

Membranoproliferative glomerulonephritis (MPGN) is a common form of glomerulonephritis and frequently is associated with chronic infections. Leprosy, one of the most common infections worldwide, was found in conjunction with MPGN, type I, in a patient. Serological abnormalities typical of MPGN, improvement in renal function with therapy of acute complications of leprosy, and long-term renal improvement with antileprosy therapy all occurred in this patient. Others have found that MPGN is found in 11% to 43% of leprosy patients undergoing renal biopsy. Serological abnormalities typical of MPGN frequently are found in patients with lepromatous leprosy. The associations of MPGN and leprosy, and the susceptibility of the glomerulonephritis to therapy, should be emphasized.