Glycosaminoglycans as disease biomarkers: a systematic review

Objective: To identify glycosaminoglycans (GAGs) as biomarkers predictive of normal biological processes, pathological processes, and non-invasive diagnostic interventions. Methods: Searches were performed in the databases Acervo+ Index base, Scopus, MEDLINE, Web of Science, SciELO and LILACS, and experimental and review studies addressing the use of GAGs as biomarkers in diagnoses of diseases were included. For the critical analysis of the selected studies, the QUADAS-2 method was applied as a tool for evaluating methodological quality. Results: We selected 66 potentially relevant articles, 20 of which met the eligibility criteria. After evaluating the methodological quality, 10 studies classified with low risk of bias for narrative synthesis and 1 experimental article that studied the mechanism of GAGs in hepatic fibrosis were included. Final considerations: The present systematic review identified that the use of GAGs as biomarkers presents good reproducibility, can be used in non-invasive procedures (blood or urine), be performed in most laboratories, and allow for the evaluation of progress and pathophysiological processes. However, it still has limitations to differentiate intermediate stages in some diseases.