Thiols as a Marker of Inflammatory Bowel Disease Activity: A Systematic Review with Meta-analysis

Abstract

Background Evidence indicates that inflammation in Inflammatory Bowel Disease (IBD) is associated with increased systemic levels of reactive oxygen species. Systemic oxidative stress has been associated with reduced levels of plasma thiols. Less invasive tests capable of reflecting and predicting IBD activity are increasingly sought after. In this sense, we sought to systematically review the evidence inherent in serum thiol levels as a marker of Crohn's Disease and Ulcerative Colitis activity (PROSPERO: CRD42021255521). Methods The highest quality documents for systematic reviews and meta-analyses standards were used as reference. The highest quality documents for systematic reviews and meta-analyses standards were used as reference. Articles were searched on Medline via PubMed and via Central, VHL, LILACS, WOS, EMBASE, SCOPUS, COCHRANE, CINAHL, OVID, CTGOV, WHO/ICTRP, OPENGREY, BDTD and CAPES, between August and September/2021. Descriptors were defined according to the Medical Subject Heading.The articles were searched between August and September/2021. Of the 11 articles selected for full reading, 7 were included in the review. Of these, 4 were combinable studies and were included in the meta-analysis. Results The findings of the individual studies included suggest an association between disease activity and systemic oxidation, as measured by serum thiol levels, however, the pooled analysis did not identify a significant association between the parameters evaluated. The limitations identified in this meta-analysis made it impossible to weigh the results of individual studies, which, associated with potential confounding factors, may have interfered with the results of the grouped assessment. Conclusions We recommend conducting randomized clinical trials, with individuals of both phenotypes and in different stages of IBD, involving larger numbers of participants, using standardization of the technique for measuring serum thiols, in order to confirm whether thiols can be a good parameter of monitoring the clinical course of these intestinal diseases and the degree of clinical applicability.