Uma breve contextualização sobre a nefrite tubulo-intersticial por IgG4 com base em um relato de caso no sul do Brasil / A brief contextualization on IgG4 tubulointerstitial nephritis based on a case report in south Brazil

Resumo A Doença relacionada a IgG4 (IgG4RD) é um processo inflamatório recente de etiologia supostamente autoimune, que se caracteriza por níveis séricos elevados de IgG4, um denso infiltrado mononuclear rico em plasmócitos IgG4 positivos e fibrose estoriforme. A nefrite túbulo-intersticial é a manifestação renal mais comum, com diferentes graus de disfunção renal e achados clínicos variáveis. Aqui, os autores descrevem um novo caso de nefrite túbulo-intersticial associada a IgG4 (NTIgG4), e discutem critérios clínicos e patológicos. Paciente masculino, 72 anos, foi admitido no serviço hospitalar com queixa clínica de astenia, perda de força, emagrecimento e anosmia. A história prévia incluía Diabetes mellitus tipo 2. Os dados laboratoriais incluíam anemia normocrômica, proteinúria e elevação da creatinina. A ultrassonografia/tomografia computadorizada renal bilateral revelou um parênquima heterogêneo, com zonas densas e difusas irregulares, áreas de fibrose nos polos superiores e hidronefrose. A biópsia renal mostrou um infiltrado mononuclear intersticial denso, com mais de 50 plasmócitos por campo de grande aumento, áreas irregulares de fibrose fibroblástica e colagênica, tubulite focal e glomérulos normais. A imunofluorescência revelou deposição granular leve de IgG e C3c na membrana basal tubular. A imuno-histoquímica foi positiva para CD138, cadeias leves Kappa e lambda, e IgG4 (cerca de quarenta e cinco plasmócitos IgG4 positivos por campo de grande aumento). O nível sérico de IgG4 estava aumentado. O diagnóstico de NTIgG4 foi então estabelecido. O paciente recebeu corticoterapia e controle rigoroso da glicemia com insulina, com melhoria significativa dos sintomas e dos níveis de creatinina.

Abstract IgG4-related disease (IgG4RD) is a recent inflammatory process of supposed autoimmune etiology, which is characterized by elevated serum IgG4 levels, dense lymphoplasmacytic infiltration rich in IgG4-positive plasma cells and storiform fibrosis. Tubulointerstitial nephritis is the most common renal manifestation, with different degrees of kidney dysfunction and variable clinical findings. Herein, the authors describe a new case of IgG4 tubulointerstitial nephritis (IgG4TN), and discuss clinic and pathologic criteria. Male patient, 72 years-old, was admitted on hospital service with clinical complaint of asthenia, loss of strength, emaciation, and anosmia. Previous history included type 2 diabetes mellitus. Laboratorial data included normochromic anemia, proteinuria, and creatinine elevation. Bilateral kidney ultrassonography/computed tomography revealed a heterogenous parenchyma, with diffuse irregular dense zones, areas of fibrosis on upper poles, and hydronephrosys. Kidney biopsy showed a dense interstitial lymphoplasmacytic infiltrate, with more than 50 plasma cell per high power field, irregular areas of fibroblastic and collagenous fibrosis, focal tubulitis, and normal glomeruli. Immunofluorescence revealed mild granular deposition of C3c and IgG in the tubular basement membrane. Immunohistochemestry was positive for CD138, lambda and Kappa light chains, and IgG4 (around forty five IgG4 positive plasma cells per high power field). IgG4 serum level was increased. The diagnosis of IgG4TN was then established. The patient received corticotherapy and strict control of glycemia with insulin, with marked improvement of symptoms and creatinine levels.

Crescentic glomerulonephritis: a clinicopathologic analysis of 17 cases with emphasis on glomerular and interstitial neutrophil infiltration

In order to determine the extent to which specific forms of glomerulonephritis (GN) contribute to the pool of crescentic GN, renal tissues from 17 crescentic GN patients were examined with special attention to glomerular and interstitial neutrophil infiltration. Renal tissues from five normal kidneys served as normal controls. Renal biopsy tissues from five patients with postinfectious GN in which crescent formation was not observed were also examined as disease controls. The patients were put into both three groups according to immunofluorescence findings and two groups according to the active or inactive phase of the crescents: group 1 with anti-glomerular basement membrane crescentic GN, one case; group 2 with immune complex crescentic GN, ten cases; and group 3 with pauci-immune crescentic GN, six cases. Four of the nine individuals tested were positive for anti-neutrophil cytoplasmic antibody (44.4%). Glomerular and interstitial neutrophil infiltrations were prominent in both the active and inactive phase groups, compared to normal controls (p<.05). Glomerular neutrophil infiltration was significantly prominent in the active phase group, compared to the inactive phase group (p<.001). In both the active and inactive phase groups, interstitial neutrophil infiltration was prominent, compared to disease control groups (p<.05). These results support the concept of the participation of periglomerular leukocytes in the renal tissue damage of crescentic GN, although the role of neutrophils was not examined.

Anticuerpos anticitoplasma de neutrófilos (ANCA) en pacientes con enfermedades renales / Anti-neutrophil cytoplasmic antibodies (ANCA) in patients presenting with renal diseases

Se investiga la presencia de anticuerpos anticitoplasma de neutrófilos (ANCA) en 90 pacientes con enfermedades renales: 35 con glomerulonefritis progresiva idiopática (GPI), 25 con nefritis intersticial (NI) y 30 con nefropatías obstructivas (NO), tanto los inducidos por la proteinasa 3 (c-ANCA) como aquéllos específicos a la mieloperoxidasa (p-ANCA), mediante un ensayo inmunoenzimático. Se demostró un aumento significativo de p-ANCA en los grupos de pacientes GPI y NI al compararlos con los controles normales. Los niveles de c-ANCA fueron normales en todos los pacientes estudiados. Nuestros resultados sugieren la posibilidad de una activación de los neutrófilos por parte de los p-ANCA con amplificación del daño endotelial en estas enfermedades

Características do infiltrado inflamatório renal na nefropatia de refluxo / Characteristics of the renal inflamatory infiltrates in reflux nephropathy

Este trabalho objetivou caracterizar, in situ, o infiltrado inflamatório da nefropatia de refluxo. Para tal, estudamos rins de ratos infectados experimentalmente com Escherichia coli e espécimes renais humanos obtidos por biópsia renal ou nefrectomia. A caracterizaçäo das células mononucleares foi feita pela técnica de imunoperoxidase em quatro etapas, utilizando-se anticorpos monoclonais na primeira etapa. Observamos que a nefrite tubulointersticial era constituída de 72,1% de linfocitos T, dos quais 79,7 - 88,2% eram células T auxiliares e 11, 7-20,3% linfócitos T citotóxicos supressores. O restante do infiltrado inflamatório (27,9%) constituiu-se de monócitos-macrófagos (18%) e linfócitos B e/ou células "nulas" (10%)

Algunas nefropatias tubulointersticiales (I) / Some tubule interstitial nephropaties (I)

Las lesiones tubulares e intersticiales capaces de producir una insuficiencia renal importante se originan siempre en multiples factores. La simple supresion de los agentes causales, a veces subestimados en la medicina corriente, garantiza muy a menudo una curacion notoria y rapida