Autoanticorpos nas doenças hepáticas autoimunes : relevância no diagnóstico, prognóstico e triagem de co-morbidades

Abstract

Resumo: A investigacao e correta interpretacao dos autoanticorpos e indispensavel para o diagnostico adequado de doencas autoimunes (DAI) do figado. O diagnostico precoce e fundamental para o correto tratamento e reducao das consequencias da doenca. Pacientes com essas doencas apresentam alto risco de desenvolver outras DAI concomitantes. O presente estudo teve como objetivo realizar um amplo painel de autoanticorpos em pacientes com hepatopatias autoimunes e associar com dados clinicos, demograficos e presenca de outras DAI Fo am analisadas amost as de so o de 60 pacientes com DAI hepatica (43 Š, 17 ‰; idade media 42,7 anos; 19-72 anos), sendo 23 com hepatite autoimune (HAI), 7 com cirrose biliar primaria (CBP), 15 com colangite esclerosante primaria (CEP) e 15 com sindrome de sobreposicao (SSP). Grupo controle: 100 individuos sadios da mesma area geografica. Foram avaliados os anticorpos relacionados ao diagnostico das DAI hepaticas: anti-musculo liso (AML), anti-mitocondria (AMA), anti-microssoma de figado e rim (LKM), anti-nuclear (FAN) e anti-citoplasma de neutrofilos (ANCA); anticorpos relacionados ao prognostico: anticorpos anti-glicoproteina 210 (gp210) e anti-centromero; e anticorpos relacionados as co-morbidades: anti-endomisio (EmA-IgA), anti-celula gastrica parietal (CGP), anti-transglutaminase (tTG), anti-peptidio ciclico citrulinado (CCP), fator reumatoide (FR), anti-dsDNA (dsDNA), anti-cromatina, perfil ENA/confirmatorios. Estes foram investigados por imunofluorescencia indireta, ensaio de imunoadsorcao ligado a enzima (ELISA) e/ou aglutinacao em latex, utilizando substratos adequados e kits especificos para cada reacao. Os resultados mostraram aumento significativo na positividade total (86,7%) e especifica de cada anticorpo relacionado ao diagnostico nos pacientes em relacao ao grupo controle (0%; p<0,001). Foram detectados autoanticorpos em 78,3% dos casos de HAI, 93,3% de CEP, 71,4% de CBP e em 100% nos de SSP. A positividade dos anticorpos nao diferiu em relacao ao sexo, faixa etaria e idade de diagnostico dos pacientes. Foi detectado aumento significativo na faixa de 0-2 anos de duracao de doenca (p=0,039). A significante correlacao entre AMA e FAN HEp-2 padrao citoplasmatico pontilhado reticulado (R=0,636; p<0,001) foi dado pioneiro nesta populacao e caracterizou real contribuicao no diagnostico de CBP e SSP (HAI/CBP). A positividade de 52,2% do p-ANCA atipico na HAI e 73,3% na SSP ressalta seu valor diagnostico na HAI, mesmo na ausencia de AML. A associacao clinico-laboratorial destacou a necessidade de realizar o painel completo de autoanticorpos e a analise conjunta dos dados para correto diagnostico das hepatopatias. A confirmacao histopatologica de SSP em 6 pacientes corrobora o papel dos biomarcadores. Frequencia elevada de anticorpos relacionados as co-morbidade orgao especificas e/ou sistemicas nos pacientes em relacao aos controles (p<0,001), independente do sexo, faixa etaria, idade ao diagnostico e duracao da doenca mostrou a importancia de investigar outras DAI concomitantes, inclusive na ausencia de sintomas. A associacao clinico-laboratorial atraves da analise dos biomarcadores relacionados as co-morbidades sugeriu outra DAI em 18 pacientes. Em cinco pacientes obteve-se confirmacao do diagnostico previo. Concluindo, os resultados ressaltam o papel dos autoanticorpos nos pacientes com DAI do figado como marcadores precoces da doenca, bem como ferramenta de diagnostico para associacao com co-morbidades. O alto indice de SSP e autoanticorpos relacionados a outras DAI nos pacientes com hepatopatias autoimunes do sul do Brasil sugere forte influencia genetica e de fatores ambientais no desenvolvimento das mesmas.

Abstract: Research and correct interpretation of autoantibodies is essential for the appropriate diagnosis of autoimmune liver diseases (ALD). Early diagnosis is crucial to the correct treatment and reduction of disease consequences. Patients with such diseases have a high risk of developing other concomitant autoimmune disease (AD). The present study aimed to evaluate a broad spectrum of autoantibodies in patients with ALD, and associate with clinical and demographic data of the disease and presence of other concomitant AD. Serum samples of 60 ALD patients (43 Š, 17 ‰, mean age 42,7 yea s, 19-72 years) were evaluated: 23 with autoimmune hepatitis (AIH), 7 with primary biliary cirrhosis (PBC), 15 with primary sclerosing cholangitis (PSC) and 15 with overlap syndrome (OLS). Control group: 100 healthy individuals from the same region. Antibodies related to the diagnosis of ALD were evaluated: smooth muscle antibody (SMA), antimitochondrial (AMA), liver kidney microsomal (anti-LKM), anti-nuclear (ANA) and anti-neutrophil cytoplasmatic (ANCA). Antibodies related with prognosis: glycoprotein 210 antibody (gp210) and anti-centromere; and antibodies related with comorbidity: anti-endomysial (IgA-EmA) antibody, anti-parietal cell (PCA), anti-tissue transglutaminase antibodies (anti-tTG), anti-cyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), anti-dsDNA (dsDNA), anti-chromatin and ENA/confirmatory. These autoantibodies were investigated by indirect immunofluorescence, enzyme linked immunosorbent assay (ELISA) and latex agglutination, using appropriate substrates and specific kits for each reaction. The results showed a significant increase in total (86.7%) and specific positivity of each antibody related to the diagnosis of patients in relation to the control group (0%, p <0.001). Autoantibodies were detected in 78,3% of AIH cases, 93,3% of PSC, 71,4 of PBC end 100% of OLS. The positivity did not differ regarding gender, age and age at the diagnosis of patients. A significant increase in the range of 0-2 years of duration of illness was detected (p=0,039). The significant correlation between AMA and ANA HEp-2 reticulated speckled cytoplasmic pattern (R=0,636; p<0,001) was pioneer in this population and featured real contribution to the diagnosis of PBC and OLS (AIH/PBC). The positivity of 52,2% of atypical p-ANCA in AIH and 73,3% in OLS emphasizes its diagnostic value in AIH, even in the absence of SMA. The clinical and laboratory association highlighted the need to evaluate a full panel of antibodies and simultaneous analysis of data for correct diagnosis of liver diseases. The histopathologic confirmation of OLS in 6 patients corroborates the role of biomarkers. Higher frequency of antibodies related to organ-specific and/or systemic co-morbidities in patients than controls (p<0,001), regardless of sex, age, age at diagnosis and duration of disease showed the value of investigating other concomitant AD, even in the absence of symptoms. The clinical and laboratory association by analysis of biomarkers related to comorbidities suggested other AD in 18 patients. Confirmation of a previous diagnosis in five patients was obtained. In conclusion, the results emphasize the role of antibodies in patients with ALD as early markers of disease, as well as a diagnostic tool for association with comorbidities. The high rate of OLS and antibodies related to other AD in patients with ALD in southern Brazil suggest a strong genetic influence and environmental factors in their development.