Caracterización de enfermedades glomerulares: análisis de 22 años de biopsias renales / Frequency of glomerular diseases in an analysis of 550 kidney biopsies

BACKGROUND: The frequency of glomerular diseases is dynamic and varies according to geographic area. AIM: To evaluate the frequency of primary and secondary glomerulopathies, their demographic profile and main clinical characteristics. MATERIAL AND METHODS: Renal biopsies from native kidneys performed between 1999 and 2020 were retrospectively reviewed. Demographic characteristics, clinical presentation, most relevant laboratory tests, frequency of primary and secondary glomerulopathies were analyzed. RESULTS: We analyzed 550 kidney biopsies from patients with a median age of 48 years (64% females). Nephrotic syndrome was the main indication for renal biopsy. Primary and secondary glomerulopathies occurred with similar frequency. Within the primary glomerulopathies, membranous nephropathy (34.1%) was the most common, followed by IgA nephropathy (31.1%) and focal segmental glomerulosclerosis (14.1%). Among the secondary glomerulopathies, lupus nephropathy was the most common (41.7%), followed by pauciimmune glomerulonephritis (27.1%) and diabetic nephropathy (6.4%). When comparing the results with other regions, significant differences were observed with reported frequencies in United States, Europe, Asia and the rest of Latin America. CONCLUSIONS: The most common primary glomerulopathies were membranous nephropathy and IgA nephropathy. Among the secondary glomerulopathies lupus nephropathy and pauci-immune glomerulonephritis were the most common. Compared to international registries, we observed a high proportion of membranous nephropathy and pauci-immune glomerulonephritis.

The Oxford Classification predictors of chronic kidney disease in pediatric patients with IgA nephropathy / Preditores da doença renal crônica segundo a Classificação de Oxford em pacientes pediátricos com nefropatia por IgA

Abstract Objective: The Oxford Classification for Immunoglobulin A nephropathy (IgAN) identifies pathological variables that may predict the decline of renal function. This study aimed to evaluate the Oxford Classification variables as predictors of renal dysfunction in a cohort of Brazilian children and adolescents with IgAN. Methods: A total of 54 patients with IgAN biopsied from 1982 to 2010 were assessed. Biopsies were re-evaluated and classified according to the Oxford Classification. Multivariate analysis of laboratory and pathological data was performed. The primary outcomes were decline of baseline estimated glomerular filtration rate (eGFR) greater than or equal to 50%. Results: Mean follow-up was 7.6 ± 5.0 years. Mean renal survival was 13.5 ± 0.8 years and probability of decline ≥50% in baseline eGFR was 8% at five years of follow-up and 15% at ten years. Ten children (18.5%) had a decline of baseline eGFR ≥ 50% and five (9.3%) evolved to end-stage renal disease. Kaplan-Meier analysis showed that baseline proteinuria, proteinuria during follow-up, endocapillary proliferation, and tubular atrophy/interstitial fibrosis were associated with the primary outcome. Multivariate Cox analysis showed that only baseline proteinuria (HR, 1.73; 95% CI, 1.20-2.50, p = 0.003) and endocapillary hypercellularity (HR, 37.18; 95% CI, 3.85-358.94, p = 0.002) were independent predictors of renal dysfunction. No other pathological variable was associated with eGFR decline in the multivariate analysis. Conclusion: This is the first cohort study that evaluated the predictive role of the Oxford Classification in pediatric patients with IgAN from South America. Endocapillary proliferation was the unique pathological feature that independently predicted renal outcome.

Resumo Objetivo: A Classificação Oxford para a Nefropatia por Imunoglobulina A (IgAN) identificou variáveis patológicas de risco para disfunção renal. O presente estudo teve como objetivo avaliar as variáveis da Classificação de Oxford como preditores de disfunção renal em crianças brasileiras com IgAN. Métodos: Foram analisados 54 pacientes com diagnóstico de IgAN entre 1982-2010. As biópsias renais foram reavaliadas pela Classificação de Oxford. Foram feitas análises uni e multivariada das variáveis clínicas e patológicas. O desfecho primário foi queda da taxa de filtração glomerular (TFG) ≥ 50% da filtração basal. Resultados: O acompanhamento médio foi de 7,6 ± 5,0 anos. A sobrevida renal média foi de 13,5 ± 0,8 anos e a probabilidade de atingir o desfecho primário foi de 8% em cinco anos e 15% em 10 anos de seguimento. Dez crianças (18,5%) apresentaram queda na TFG basal ≥ 50% e cinco (9,3%) evoluíram para doença renal crônica terminal. A análise de Kaplan-Meier mostrou que a proteinúria basal e de seguimento, a proliferação endocapilar e a atrofia tubular/fibrose intersticial foram associadas com o desfecho primário. A análise multivariada de Cox mostrou que a proteinúria basal (HR = 1,73; IC95% 1,20-2,50, p = 0,003) e a proliferação endocapilar (HR = 37,18; IC95% 3,85-358,94, p = 0,002) foram preditores independentes de disfunção renal. Nenhuma outra variável patológica foi associada com declínio da TFG na análise multivariada. Conclusão: Este é o primeiro estudo brasileiro que avaliou a Classificação Oxford em crianças com IgAN. A proliferação endocapilar foi a única característica patológica capaz de predizer independentemente o declínio da função renal.

Evaluation of TGF-beta1 and MCP-1 expression and tubulointerstitial fibrosis in children with Henoch-Schönlein purpura nephritis and IgA nephropathy: A clinical correlation

OBJECTIVES: Henoch-Schönlein purpura nephritis and immunoglobulin A nephropathy are two diseases with similar clinical presentations but very different prognoses. Transforming growth factor β1 and monocyte chemoattractant protein-1 have been associated with the development of tissue fibrosis. We examined the development of tubulointerstitial fibrosis and its relationship with Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in these patients. METHODS: Renal tissue samples were collected by renal biopsy from 50 children with Henoch-Schönlein purpura nephritis and 50 children with immunoglobulin A nephropathy. Hematoxylin and eosin and Masson's trichrome-stained tissues were examined using light microscopy. Tubulointerstitial fibrosis was graded using the method described by Bohle et al. (1). The immunohistochemical detection of Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was correlated with the tubulointerstitial fibrosis grade. Clinical Trial registration number: ZJCH-2012-0105. RESULTS: Transforming growth factor β1 and monocyte chemoattractant protein-1 expression in the renal tissues was significantly greater in the patients with immunoglobulin A nephropathy than in the patients with Henoch-Schönlein purpura nephritis (both p<0.001). The immunoglobulin A nephropathy patients had a higher tubulointerstitial fibrosis grade than the Henoch-Schönlein purpura nephritis patients (p<0.001). The tubulointerstitial fibrosis grade was in accordance with the Transforming growth factor β1 and monocyte chemoattractant protein-1 expression levels in both diseases (both p<0.001). CONCLUSION: Transforming growth factor β1 and monocyte chemoattractant protein-1 expression was associated with the development of immunoglobulin A nephropathy and Henoch-Schönlein purpura nephritis. Further studies are needed to better evaluate this association.

An update on pathology of IgA nephropathy / Atualização em nefropatia da IgA

Abstract IgA Nephropathy (IgAN) is the commonest of the glomerular diseases in the world. Its progression rate of 30-40% of the cases em 20-30 years makes IgAN an important healthcare issue in Nephrology. Diagnosis of IgAN depends on biopsy findings, particularly at immunofluorescence microscopy. The frequence of IgAN diagnosis is variable in different populations and depends on screening and biopsy indication policies. IgAN pathogenesis is considered multifactorial; its primordial defect is the production of galactosis-deficient IgA molecules. This review paper discusses the most uptodate aspects of the pathogenesis, pathological classification and clinical implications of IgAN.

Resumo A Nefropatia da IgA (IgAN) é a mais comum das doenças glomerulares no mundo. Sua taxa de progressão de 30-40% em 20-30 anos torna a IgAN uma importante preocupação em saúde pública na area da Nefrologia. O diagnóstico da IgAN depende dos achados de biópsia, particularmente de microscopia de imunofluorescência. A frequência do diagnóstico é variável em diferentes populações e depende do rastreamento de hematúria e da indicação de biopsia. A IgAN é uma doença multifatorial: o defeito primordial é a produção de moléculas de IgA deficientes em galactose. Esta revisão discute aspectos atualizados da patogênese e classificação patológica da IgAN e suas implicações clínicas.

La nefropatía IgA, la glomerulopatía más frecuente en el mundo / IgA nephropathy, the most common glomerulopathy worldwide

La nefropatía inmunoglobulina A es una glomerulonefritis mediada por inmunocomplejos caracterizada por el depósito de inmunoglobulina A1 en el mesangio glomerular. Es la forma más frecuente de glomerulonefritis primaria en el mundo. La probabilidad de deterioro de la función renal a largo plazo, está aumentada por los hallazgos siguientes: hipertensión arterial, hematuria microscópica persistente, proteinuria mayor de 0,5 g/día, descenso de la función renal al comenzar las manifestaciones o hallazgos en la biopsia renal de esclerosis glomerular, esclerosis vascular, fibrosis intersticial, atrofia tubular, formación de crecientes o distribución de IgA en la pared de los capilares glomerulares en la inmunofluorescencia. Son manifestaciones clínicas en la nefropatía inmunoglobulina A la hematuria macroscópica en aproximadamente la mitad de los pacientes al primero o segundo día del inicio de síntomas de infección respiratoria, y está asociada con dolor en el flanco en pacientes menores de 40 años. En los más viejos, la hematuria microscópica es generalmente asintomática, y en ocasiones, detectada en análisis de orina de pesquisa. Entre 10 y 20 % de los pacientes, por lo general aquellos que tienen hematuria y proteinuria ligera, pueden lograr remisión espontánea; pero, entre 25 y 30 % pueden mostrar progresión hacia la enfermedad renal crónica terminal, y la progresión por lo general es lenta (5-20 años). La biopsia renal es la única prueba específica para confirmar el diagnóstico. Los pacientes con hematuria y proteinuria menor de 0,3 g/día que están normotensos, no requieren tratamiento específico con medicamentos, pero necesitan ser controlados periódicamente con análisis de orina, creatinina sérica y medida de la tensión arterial. Los pacientes con proteinuria o hipertensión deben ser tratados enérgicamente con inhibidores de la enzima convertidora. La hipertensión, la proteinuria significativa (> 0,5 g/día), la glomerulonefritis rápidamente progresiva (rara) y el síndrome nefrótico necesitan ser tratados inmediatamente. La amigdalectomía, frecuentemente realizada en Japón, puede ser de beneficio para los que se presentan con hematuria macroscópica y amigdalitis. Se consultaron varias fuentes para esta revisión.

IgA nephropathy is immunocomplex-mediated glomerulonephritis that is characterized by the A1 immunoglobulin deposition in the glomerular mesangium. It is the most frequent form of primary glomerulonephritis worldwide. The probabilities of long-term renal function deterioration increased due to the following findings: blood hypertension, persistent microscopic hematuria, proteinuria greater than 0.5 g/day, decrease of renal function when manifestations or findings of glomerular sclerosis are observed in the renal biopsy; vascular sclerosis, interstitial fibrosis, tubular atrophy, formation or distribution of IgA in the glomerular capillary walls in the immunofluorescence test. Among the clinical manifestations of IgA nephropathy is macroscopic hematuria in roughly half of patients in the first or second day after onset of the respiratory infection symptoms and is associated to flank pain in patients less than 40 years. In the oldest people, macroscopic hematuria is generally asymptomatic and occasionally detected in screening urinalysis. Ten to twenty percent of patients with mild proteinuria and hematuria may reach spontaneous remission, but 25 to 30 % of them may also progress into the terminal chronic renal disease at a general slow rate (5 to 20 years). Renal biopsy is the only specific test to confirm diagnosis. Those patients with hematuria and proteinuria of less than 0.3 g/day, whose blood pressure is normal, do not require specific drug treatment but they need to be systematically controlled through urinalysis, serum creatinine and blood hypertension taking. The patients suffering from proteinuria and hypertension must be strictly treated with converting enzyme inhibitors. Hypertension, significant proteinuria (0.5 g/day), rapidly progressive glomerulonephritis (rare) and nephrotic syndrome must be immediately managed. Tonsillectomy, frequent method in Japan, could be beneficial for those patients presenting with macroscopic hematuria and tonsillitis. Several sources were consulted to make this review.

Association of proteinuria with various clinical findings and morphologic variables of oxford classification in immunoglobulin a nephropathy patients

Immunoglobulin A nephropathy [IgAN] with nephrotic syndrome is an uncommon form of IgAN. Clinical and morphological characteristics of proteinuria in IgAN, especially when is in nephrotic range have not yet been fully examined. This study was aimed to correlate morphologic variables of the Oxford classification, and various clinical data with proteinuria in IgAN patients. We also aimed to demonstrate the significance of prevention of proteinuria as one of the important factors in progression of this disease. In an observational study conducted on IgAN patients, total of 114 biopsies were entered in the study. IgAN was diagnosed by light and immunofluorescence study. Of 114 patients 70.2% were male. Mean age of patients was 37.7 +/- 13.6 years. The mean of proteinuria was 1742 +/- 1324 mg/day. Also mean of serum creatinine [Cr] was 1.6 +/- 1.5 mg/dL. Of 114 patients, 11[9.6%] had nephrotic range proteinuria. In this study, there was a positive correlation between proteinuria and serum Cr, peri-glomerular fibrosis or interstitial fibrosis. There was a positive association between proteinuria and totally sclerotic glomeruli too. There was also a positive association between the amount of fibrous crescents and the level of proteinuria. Nephrotic proteinuria could just be seen in male patients. Also, nephrotic syndrome had a positive association with the number of crescents. Our findings firstly support the prognostic value of crescent due to its association with proteinuria and secondly imply the importance of treatment of proteinuria to prevent progression of IgAN

Renal macrophage infiltration is associated with a poor outcome in IgA nephropathy

OBJECTIVES: The objectives of our study were as follows: 1) to analyze the prognostic value of macrophage infiltration in primary IgA nephropathy (IgAN) and 2) to study the relationship between macrophages and other factors associated with the development of renal fibrosis, including mast cells, TGF-β1, α-SMA and NF-kB. METHODS: We analyzed 62 patients who had been diagnosed with IgAN between 1987 and 2003. Immunohistochemical staining was performed with monoclonal antibodies against CD68 and mast cell tryptase and polyclonal antibodies against TGF-β1, α-SMA and NF-kB p65. We also used Southwestern histochemistry for the in situ detection of activated NF-kB. RESULTS: The infiltration of macrophages into the tubulointerstitial compartment correlated with unfavorable clinical and histological parameters, and a worse clinical course of IgAN was significantly associated with the number of tubulointerstitial macrophages. Kaplan-Meier curves demonstrated that increased macrophage infiltration was associated with decreased renal survival. Moreover, the presence of macrophages was associated with mast cells, tubulointerstitial α-SMA expression and NF-kB activation (IH and Southwestern histochemistry). In the multivariate analysis, the two parameters that correlated with macrophage infiltration, proteinuria and tubulointerstitial injury, were independently associated with an unfavorable clinical course. CONCLUSION: An increased number of macrophages in the tubulointerstitial area may serve as a predictive factor for poor prognosis in patients with IgAN, and these cells were also associated with the expression of pro-fibrotic factors.

Nefropatia por IgA: análise histológica e correlação clínico-morfológica em pacientes do Estado de Minas Gerais / IgA nephropathy: histological analysis and clinicomorfological correlation in patients from Minas Gerais State

INTRODUÇÃO: A Nefropatia por IgA (NIgA) é a glomerulopatia primária mais comum. OBJETIVO: Classificar a NIgA segundo a nova proposta de Classificação de Oxford. MÉTODOS: Foram analisadas biópsias do Serviço de Nefropatologia da UFTM, no período de 1996 a 2010, com diagnóstico de NIgA. Foram avaliados gênero, idade, presença de hematúria, padrões/intensidade das lesões, deposições de IgA, IgG, IgM, Kappa, Lambda, C3, C1q e fibrinogênio. Histologicamente, as biópsias foram caracterizadas conforme a Classificação de Oxford, e realizou-se a correlação clínico-morfológica. RESULTADOS: Das 164 biópsias avaliadas, houve predomínio do gênero masculino (53,7%) e adulto (93,3%). Caracterizando os pacientes conforme a classificação de Oxford, obtivemos predominância M0 (85,3%), S1 (53,1%), E0 (65,2%) e T0 (70,1%). À correção clínico-morfológica, observamos maior proteinúria M1 em relação a M0 (p < 0,008), menor taxa de filtração glomerular estimada (p < 0,001) e maior frequência de hipertensão (p < 0,001) comparando-se T0,T1 e T2. À imunofluorescência, predominância de IgA (100% dos casos), com codeposição de C3 (99,37% dos casos), Kappa (96,25%), Lambda (91,25%) e IgM (76,92%). Foi observada correlação entre a intensidade de deposição de IgA com C3, Kappa e Lambda. CONCLUSÃO: No presente estudo, a NIgA foi predominante em homens, mais comuns foram os padrões M0, S1, E0 e T0, com maior proteinúria e aumento da hipercelularidade mesangial, além de maior prevalência de hipertensão/pior função renal conforme a gravidade das repercussões túbulo-intersticiais.

INTRODUCTION: IgA nephropathy (IgAN) is the most common primary glomerulopathy. OBJECTIVE: Classify IgAN according to the new Oxford's classification. METHODS: We analyzed the renal biopsies from the Nephropathology Service of UFTM, among 1996 to 2010, with a diagnosis of IgAN. We assessed gender, age, presence of hematuria, patterns/intensity of the lesions, deposition of IgA, IgG, IgM, Kappa, Lambda, C3, C1q and fibrinogen. Based on the histological alterations, the biopsies were characterized according to the Oxford Classification, and the clinicomorfological correlation was made. Significative results for p < 0,05. RESULTS: A total of 164 cases biopsies, predominantly male (53.7%) and adults (93.3%). We characterized the patients according Oxford Classification, there was a predominance of the pattern M0 (85,3%), S1 (53,1%), E0 (65,2%) e T0 (70,1%). About the clinicomorfological correlation, we observed more severe proteinuria comparing M1 to M0 (p < 0,008), low estimated GFR (p < 0,001) and more frequent hypertension (p < 0,001) comparing T0, T1 e T2. On immunofluorescence, there is a predominance of IgA (100% of cases), with codeposition of C3 (99.37% of cases), Kappa (96.25%), Lambda (91.25%) and IgM (76.92%). Correlation was found between IgA intensity and C3, Kappa and Lambda. CONCLUSION: In this study, IgA nephropathy was predominant in males, the more frequent patterns were the M0, S1, E0 and T0, with more severe proteinuria and the enhance of mesangial hypercellularity, besides larger prevalence of hypertension/worse kidney function according the tubulo-interstitial injuries.

A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

OBJECTIVES: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. METHODS: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. RESULTS: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-Inositol, lactate, L6 lipids ( = CH-CH2-CH = O), L5 lipids (-CH2-C = O), and L3 lipids (-CH2-CH2-C = O) as well as lower levels of β -glucose, α-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. CONCLUSIONS: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high-risk groups in our research. These results offer new, sensitive and specific, noninvasive approaches that may be of great benefit to immunoglobulin A nephropathy patients by enabling earlier diagnosis.

Caso clínico-anatomopatológico: las diversas presentaciones de la nefropatía por IgA / Clinicopathological case: the various presentations of IgA nephropathy

Se trata de una paciente de 58 años, sexo femenino, que se presenta con hematuria, proteinuria severa y función renal normal. Pocas semanas después, ella desarrolla una trombosis de vena renal, embolia pulmonar secundaria y un episodio de insuficiencia renal aguda. Este caso clínico ilustra las distintas presentaciones clínicas de una nefropatía por IgA grave, incluyendo hematuria, síndrome nefrótico y trombosis de vena renal. Además muestra otras complicaciones serias, como embolia pulmonar y falla renal aguda. La paciente fue sometida a 2 biopsias renales, que permitieron una correlación adecuada entre las manifestaciones clínicas y la patología renal.

This is a female, 58 years old patient, who presented with hematuria, heavy proteinuria and normal kidney function. Few weeks later she developed a renal venous thrombosis, pulmonary embolism and acute kidney injury. This clinical case illustrates the variable presenting features of a severe IgA nephropathy including hematuria, nephrotic syndrome and renal venous thrombosis. Further it shows its possible severe complications such as lung embolism and acute renal failure. The patient was kidney biopsied in two opportunities, which allows assessing the correlation between the variable clinical characteristics and the renal pathology.

Prediction of tubulo-interstitial injury by Doppler ultrasound in glomerular diseases: value of resistive and atrophic indices.

BACKGROUND: Doppler ultrasound is increasingly used in Nephrology for diagnosis of renovascular hypertension and evaluation of allograft dysfunction. However, its utility in glomerular disease remains controversial. OBJECTIVES: Using Doppler Ultrasound, we prospectively tested the role of resistive and atrophic indices in predicting tubulointerstitial lesions in patients with glomerular disease as demonstrated by renal biopsy. METHODS: Seventy one patients with primary or secondary glomerular diseases were examined by Doppler ultrasonography immediately before renalbiopsy. The resistive and atrophic indices (RI & AI) were calculated and compared with histologic changes in biopsy specimen. RESULTS: Receiver Operator Characteristics analysis showed RI of 0.60 as an optimal value for discriminating tubulointerstitial changes with sensitivity of 82.7% and specificity of 92%. An AI of 0.65 was shown to be optimal for discriminating tubulointerstitial injury with sensitivity of 69.2% and specificity of 85%. The combination of the two indices had not been found to be superior to either index alone. There was a significant correlation between atrophic and resistive indices. (r=0.358, p< 0.01). It was observed that older age, smoking, elevated AI and RI, low GFR, high serum cholesterol and Hypertension were found to be significantly associated with the presence of tubulointerstitial injury in the univariate analysis whereas only elevated AI and RI were found to predict tubulointerstitial injury in multivariate analysis. CONCLUSION: Measurement of RI by Doppler ultrasound can be considered as a supplementary diagnostic tool in glomerular diseases to predict the severity of tubulointerstitial injury.

Dual renin-angiotensin system blockade plus oral methylprednisone for the treatment of proteinuria in IgA nephropathy / Doble bloqueo del sistema renina-angiotensina más metilprednisona oral para el tratamiento de la proteinuria en la nefropatía por IgA

Renin-angiotensin system inhibition is a widely accepted approach to initially deal with proteinuria in IgA nephropathy, while the role of immunosuppressants remains controversial in many instances. A prospective, uncontrolled, open-label trial was undertaken in patients with biopsy-proven IgA nephropathy with proteinuria more than 0.5 g/day and normal renal function to assess the efficacy of a combination treatment of angiotensin converting enzyme inhibitors plus angiotensin receptor blockers enalapril valsartan coupled with methylprednisone to decrease proteinuria to levels below 0.5 g/day. Twenty patients were included: Age 37.45 more or less 13.26 years (50% male); 7 patients (35%) were hypertensive; proteinuria 2.2 more or less 1.86 g/day; serum creatinine 1.07 more or less 0.29 mg/dl; mean follow-up 60.10 more or less 31.47 months. IgA nephropathy was subclassified according to Haas criteria. Twelve patients (60%) were class II; seven (35%) were class III and one (5%) class V. All patients received dual reninangiotensin system blockade as tolerated. Oral methylprednisone was started at 0.5 mg/kg/day for the initial 8 weeks and subsequently tapered bi-weekly until the maintenance dose of 4 mg was reached. Oral steroids were discontinued after 24 weeks (6 months) of therapy but renin-angiotensin inhibition remained unchanged. At 10 weeks of therapy proteinuria decreased to 0.15 more or less 0.07 g/day (P less than 0.001) while serum creatinine did not vary: 1.07 ± 0.28 mg/dl (P=ns). After a mean follow-up of 42.36 more or less 21.56 months urinary protein excretion (0.12 more or less 0.06 g/day) and renal function (serum creatinine 1.06 more or less 0.27 mg/dl) remained stable. No major side effects were reported during the study. Renin-angiotensin blockade plus oral steroids proved useful to significantly decrease proteinuria to less than 0.5 g/day in patients with IgA nephropathy without changes in renal function.

El doble bloqueo del sistema renina-angiotensina con inhibidores de la enzima convertidora de angiotensina junto a bloqueadores del receptor tipo I de angiotensina II es aceptado como tratamiento en la proteinuria de la nefropatía por IgA, ya que el rol de los inmunosupresores continúa siendo controvertido. Estudio prospectivo, no controlado, abierto para pacientes con nefropatía por IgA con proteinurias major que 0.5 g/día y creatininas séricas menor que 1.4 mg/dl, para evaluar la eficacia de tratamiento de enalapril más valsartán asociado a metilprednisona vía oral para disminuir las proteinurias a menor que 0.5 g/día. Fueron incluidos 20 pacientes: Edad: 37.45 más o menos 13.3 años (50% hombres); 7 pacientes (35%) eran hipertensos; proteinuria inicial 2.2 más o menos 1.86 g/día; creatinina inicial 1.07 más o menos 0.29 mg/dl; seguimiento promedio: 60.10 más o menos 31.47 meses (5 más o menos 2.62 años). La nefropatía por IgA fue subclasificada según Haas: 12 pacientes (60%) clase II; 7 (35%) clase III y 1 (5%) clase V. Todos recibieron enalapril más valsartán según tolerancia más metilprednisona vía oral en dosis de 0.5 mg/kg/día durante las primeras 8 semanas y subsecuentemente se redujo cada dos semanas hasta llegar a 4 mg. Se discontinuaron los esteroides luego de 24 semanas (6 meses). La inhibición del sistema renina angiotensina prosiguió indefinidamente. A las 10 semanas la proteinuria disminuyó de 2.2 más o menos 1.86 g/día a 0.15 más o menos 0.7 g/día (p menor que 0.001); la creatinina no varió significativamente (1.07 más o menos 0.29 mg/dl vs. 1.07 más o menos 0.28 mg/dl) (P=ns). Luego de 10 semanas y con un seguimiento de 42.36 más o menos 21.56 meses la proteinuria (0.12 más o menos 0.006 g/día) y la función renal (creatinina 1.06 más o menos 0.27mg/dl) permanecieron estables. No se informaron efectos adversos durante el estudio. El doble bloqueo del sistema renina angiotensina más bajas dosis de metilprednisona resultó útil para reducir...

Genetic potential for an acute inflammatory response in IgA glomerulonephritis in mice

Mice selected on the basis of an acute inflammatory response (AIR) can provide information about the immunopathological mechanisms of glomerulonephritis. We studied the differences between mice selected for a maximal AIR (AIRmax that attract more polymorphonuclear cells to the site of injury) or a minimal AIR (AIRmin that attract more mononuclear cells) in an experimental model of IgA nephropathy in order to investigate the effect of genetic background on glomerular disease progression and the participation of the monocyte chemoattractant protein-1 (MCP-1) chemokine. IgA nephropathy was induced by intraperitoneal ovalbumin injection and bile duct ligation in AIRmax and AIRmin mice. Histological changes, urinary protein/creatinine ratio, serum IgA levels, immunofluorescence for IgA, IgG and complement C3 fraction, immunohistochemistry for macrophages and MCP-1, and MCP-1 levels in macerated kidney were determined. Mesangial IgA deposition was seen only in AIRmin mice, which presented more renal lesions. Increased serum IgA levels (1.5 ± 0.4 vs 0.3 ± 0.1 mg/mL, P < 0.001), high glomerular MCP-1 expression and decreased monocyte/macrophage infiltration in the interstitial area (0.3 ± 0.3 vs 1.1 ± 0.9 macrophages/field, P < 0.05) were detected in AIRmin mice compared to AIRmax mice. No glomerular monocyte/macrophage infiltration was detected in either strain. In spite of the absence of IgA deposition, AIRmax mice presented discrete or absent mesangial proliferation. The study showed that there are differences between mice selected for AIRmax and AIRmin with respect to serum IgA levels, histological damage and MCP-1 chemokine production after ovalbumin injection in combination with bile duct ligation.

Primary IgA nephropathy in children: association of clinical and pathological findings with prognosis.

Primary IgA nephropathy is a disease characterized by recurrent macroscopic or microscopic hematuria and diffuse mesangial IgA deposition. Although IgA nephropathy had previously been suggested to have a benign prognosis, long term follow-up of the patients revealed that it might lead to chronic renal failure. In this study, the association of the initial clinical and laboratory findings with the renal histological changes was evaluated in 14 cases with primary IgA nephropathy who were at follow-up with a mean duration of 43.07 +/- 16.88 months. Finally the correlation between the clinicopathological findings and prognosis was investigated. In 92.8% of the patients, macroscopic hematuria was the presenting complaint. Proteinuria was detected in 42.9% of the cases mild proteinuria in 14.3% and moderate in 28.6%. Renal biopsy specimens, evaluated according to Churg-Sobin's classification, showed grade 1 changes in 35.7% cases, grade 2 in 35.7%, grade 3 in 14.3% and grade 4 in 14.3%. Both the patients with grade 4 histology had moderate proteinuria, and developed chronic renal failure requiring hemodialysis. Prognosis was found to be associated with the degree of proteinuria and the severity of the histopathological findings.

Nefropatía por IGA / IgA nephropathy

Se realizó una revisión bibliográfica. La bibliografía correspondiente a los últimos años se consultó con el objetivo de profundizar en el estudio de la nefropatía IgA y se revisaron las características patogénicas y clinicopatogénicas de la enfermedad, así como su abordaje terapéutico. La nefropatía IgA se reconoce como la causa más común de enfermedad glomerular y fueron la hematuria recurrente y la presencia de depósitos de IgA en el mesangio, los signos clínicos y patológicos más característicos de esta enfermedad. La nefropatía IgA no es una afección benigna, su evolución es crónica y progresiva. La proteinuria es un indicador de mal pronóstico y no existe un tratamiento específico eficaz para ella por lo que constituye un reto para el futuro

Immunoglobulin A nephropathy in patients with non-insulin dependent diabetes mellitus

The occurrence of immunoglobulin A nephropathy (IgAN) in patients with noninsulin dependent diabetes mellitus (NIDDM) is a rare event and of pathogenetic interest. It is not clear whether this is merely coincidence. We report here five patients with IgAN in NIDDM associated with or without diabetic glomerulosclerosis. All of the patients were Korean males. In three patients, diabetes mellitus was diagnosed at the same time with diagnosis of IgAN, and the known duration of the diabetes in the other two patients were three and seven years, respectively. There was no evidence of diabetic retinopathy in four patients, but it was found in one patient. In all cases, the diagnosis of IgAN was made by immunohistology.

Análisis clínico e histopatológico de la nefropatía a IgA / Clinical and pathological analysis in IgA nephropathy

La nefropatía a IgA (NIgA) es considerada la glomerulopatía primaria más frecuente en el mundo. En el Registro Uruguayo de Glomerulopatías su frecuencia aumentó en los últimos años. Estudiamos 50 pacientes con diagnóstico inmunohistológico de N IgA, 68 hombres con una edad de 28.9+-23,8 años. La presentación clínica más frecuente fue la hematuria macroscópica en 58 por ciento, seguida por las alteraciones del sedimento urinario en un 30 por ciento de los pacientes. El tiempo de seguimiento de los pacientes fue de 65 +- 49 meses. La sobrevida de la función renal fue de 87 por ciento a los 6 años. Ocho pacientes evolucionaron a la insuficiencia renal terminal. Nuestros resultados concuerdan con otras publicaciones, mostrando que una Creatinina más elevada, la presencia de una proteinuria mayor a 2g/litro, la menor edad, y la presencia de factores de riesgo para el desarrollo de insuficiencia renal en esta nefropatía

Primary IgA nephropathy in adults.

IgA nephropathy was found in 9.6% of 649 adults with primary glomerulonephritis. Hypertension was detected in 51.6% and renal failure in 32.3%. A nephrotic presentation was seen in 22.6% and recurrent macroscopic hematuria in 17.7%. On light microscopy, mesangial hypercellularity and an increase in mesangial matrix were frequently seen (74.2%). Immunofluorescence studies demonstrated IgA in all patients along with C3 in 61.3%, IgM in 27.4% and IgG in 11.3%. Followup was possible in 61.3% for mean period of 17.3 months. No clinical or biochemical abnormalities were detected on followup in 26.3%. Progression to end stage renal disease was noted in 7.9%.