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.
Subject(s)
Immunoglobulin G , Nephritis, Interstitial/diagnosis , Nephritis, Interstitial/immunology , Aged , Brazil , Humans , MaleABSTRACT
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.