ABSTRACT Objective: The aim of this study was to assess the laboratory performance of periostin associated with a panel of biomarkers to identify the inflammatory phenotype of Brazilian asthma patients. Methods: We evaluated 103 Brazilian individuals, including 37 asthmatics and 66 nonasthmatic controls. Both groups underwent analyses for serum periostin, eosinophil levels in the peripheral blood, the fraction of exhaled nitric oxide (FeNO), total serum IgE, urinary leukotriene E4, and serum cytokines. Results: Higher levels of periostin (p = 0.005), blood eosinophils (p = 0.012), FeNO (p = 0.001), total IgE (p < 0.001), and IL-6 (p ≤ 0.001) were found in the asthmatic patients than the controls. Biomarker analyses by the ROC curve showed an AUC greater than 65%. Periostin (OR: 12,550; 95% CI: 2,498-63,063) and IL-6 (OR: 7,249; 95% CI: 1,737-30,262) revealed to be suitable asthma inflammation biomarkers. Blood eosinophils, FeNO, total IgE, IL-6, TNF, and IFN-g showed correlations with clinical severity characteristics in asthmatic patients. Periostin showed higher values in T2 asthma (p = 0.006) and TNF in non-T2 asthma (p = 0.029). Conclusion: The panel of biomarkers proposed for the identification of the inflammatory phenotype of asthmatic patients demonstrated good performance. Periostin proved to be an important biomarker for the identification of T2 asthma.

RESUMO Objetivo: O objetivo deste estudo foi de avaliar o desempenho laboratorial da periostina associada a um painel de biomarcadores para identificar o fenótipo inflamatório de pacientes brasileiros com asma. Métodos: Foram avaliados 103 indivíduos brasileiros, incluindo 37 asmáticos e 66 controles não asmáticos. Ambos os grupos foram submetidos a análises de periostina sérica, níveis de eosinófilos no sangue periférico, a fração exalada de óxido nítrico (FeNO), IgE sérica total, leucotrieno E4 urinário e citocinas séricas. Resultados: Maiores níveis de periostina (p = 0,005), eosinófilos periféricos (p = 0,012), FeNO (p = 0,001), IgE total (p < 0,001) e IL-6 (p ≤ 0,001) foram encontrados nos pacientes asmáticos do que nos controles. As análises de biomarcadores pela curva ROC mostraram uma AUC superior a 65%. A periostina (OR: 12.550; IC 95%: 2.498-63.063) e a IL-6 (OR: 7.249; IC 95%: 1.737-30.262) se mostraram biomarcadores adequados da inflamação da asma. Eosinófilos periféricos, FeNO, IgE total, IL-6, TNF e IFN-g apresentaram correlação com características clínicas de gravidade em pacientes asmáticos. A periostina teve valores mais elevados na asma T2 (p = 0,006) e o TNF na asma não T2 (p = 0,029). Conclusão: O painel de biomarcadores proposto para a identificação do fenótipo inflamatório de pacientes asmáticos demonstrou bom desempenho. A periostina provou ser um importante biomarcador para a identificação da asma T2.

Abstract Rheumatoid arthritis (RA) is an autoimmune/inflammatory disease affecting 0.5 to 1% of adults worldwide and frequently leads to joint destruction and disability. Early diagnosis and early and effective therapy may prevent joint damage and lead to better long-term results. Therefore, reliable biomarkers and outcome measures are needed. Refinement of the understanding of molecular pathways involved in disease pathogenesis have been achieved by combining knowledge on RA-associated genes, environmental factors and the presence of serological elements. The presence of autoantibodies is a distinctive feature of RA. Rheumatoid Factor and Anti-Citrullinated Protein Antibodies are the two most remarkable autoantibodies in RA and provide different clinical and pathophysiological information. They precede the onset of disease symptoms and predict a more severe disease course, indicating a pathogenetic role in RA. Therefore, they promote a more accurate prognosis and contribute for a better disease management. Several RA-associated autoantibody systems have been identified: Anti-Carbamylated Antibodies, Anti-BRAF, Anti-Acetylated, Anti-PAD4 antibodies and others. Hopefully, the characterization of a comprehensive array of novel autoantibody systems in RA will provide unique pathogenic insights of relevance for the development of diagnostic and prognostic approaches compatible with an effective personalized medicine.