RESUMO CONTEXTO: Os anticorpos citoplasmáticos anti-neutrófilos perinuclear (p-ANCA) e anticorpos anti-Saccharomyces cereviciae (ASCAs) são utilizados para diferenciar a doença de Crohn (DC) da colite ulcerativa (CU) e mais recentemente para correlacioná-los com o prognóstico da doença. OBJETIVO: 1) Determinar a acurácia diagnóstica dos marcadores sorológicos na identificação de DC e CU pediátrica em São Paulo, Brasil. 2) Correlacioná-los com as características demográficas e clínicas destas duas doenças. MÉTODOS: Estudo multicêntrico transversal em pacientes com diagnóstico estabelecido de doença inflamatória intestinal (DII) determinando a presença dos marcadores sorológicos ASCAs e p-ANCA, correlacionando seus resultados com os dados demográficos e clínicos, e também em pacientes controles isentos de doenças gastrointestinal. RESULTADOS: 122 pacientes, 74 com DII (46% masculinos) em quatro centros de referência em Gastroenterologia Pediátrica, média de idade 13±7 anos, 49 (66%) com DC e 25 (34%) com CU e 48 controles (54% masculinos). O marcador p-ANCA apresenta maior porcentagem de detecção na CU (69,6%), mas também na DC (30,4%) quando comparado ao grupo controle (P<0,001). Os marcadores ASCA IgA (76,2%) e IgG (94,4%) apresentam maiores porcentagens de detecção na DC, quando comparada ao controle (P<0,001) e que a positividade do marcador esteve relacionada ao uso de medicações em pacientes portadores de DC que realizaram cirurgia (26,86±17,99; P=0,032). CONCLUSÃO: Os resultados dos testes sorológicos em crianças com DII em São Paulo, Brasil, foram altamente específicos, mas pouco sensíveis para auxiliar no diagnóstico, embora com correlação positiva com a gravidade da doença.

ABSTRACT BACKGROUND: Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCAs) have long been used to differentiate between Crohn’s disease (CD) and ulcerative colitis (UC), more recently having been used as prognostic indicators. OBJECTIVE: To determine the diagnostic accuracy of serological markers in the identification of pediatric CD and UC in Sao Paulo, Brazil, as well as to correlate those markers with characteristics demographic and clinical of these two diseases. METHODS: Retrospective cross-sectional multi-center study involving pediatric patients with inflammatory bowel disease (IBD). We identified ASCAs serological markers and p-ANCA, correlating their presence with demographic and clinical data, not only in the patients with IBD but also in a group of age-matched gastrointestinal disease-free controls. RESULTS: A total of 122 patients, 74 with IBD (46% males), treated at four pediatric gastroenterology referral centers, the mean age of 13±7 years, 49 (66%) with CD, and 25 (34%) with UC. The control Group comprised 48 patients (54% males). The proportion of patients testing positive for p-ANCA was significantly higher in the UC group (69.9%) compared to the CD group (30.4%), as well as being significantly higher in the CD group versus the control Group (P<0.001 for both). The proportion of patients testing positive for ASCA IgA (76.2%) and ASCA IgG (94.4%) markers was also significantly higher in the CD group than in the control Group (P<0.001), and such positivity correlated significantly with the use of immunomodulatory medications such as azathioprine and anti-tumor necrosis factor agents (azathioprine 38.9%, anti-TNF 55.6%; P=0.002). In the CD group, the proportion of patients testing positive for the ASCA IgA was significantly higher among those who underwent surgery than among those who did not (26.86±17.99; P=0.032). CONCLUSION: In pediatric patients with IBD in Sao Paulo, Brazil, serological tests proving to be highly specific, although not very sensitive, for the diagnosis of IBD. However, the serological markers showed a positive correlation with the severity of the disease.