Systematic Review on Diagnostic and Prognostic Roles of microRNA and DNA Biomarkers in Non-Arthritic Human Diseases

Background: MicroRNA and DNA-based biomarkers have emerged as promising molecular tools for early diagnosis, prognostic stratification, and disease monitoring across non-arthritic human diseases. Their clinical translation remains limited by fragmented evidence, variation in biomarker type, study design, assay platform, disease population, and outcome reporting, creating a need for systematic synthesis. Objective: This systematic review aimed to evaluate the diagnostic and prognostic roles of microRNA and DNA biomarkers in human non-arthritic diseases, with emphasis on early detection, disease progression, recurrence, mortality, and clinical applicability. Methods: A systematic literature search was conducted across PubMed, Scopus, Web of Science, and the Cochrane Library. Eligible studies included human participants with non-arthritic conditions and evaluated microRNA or DNA-based biomarkers for diagnostic or prognostic purposes. Observational and experimental studies reporting outcomes such as sensitivity, specificity, predictive value, disease progression, recurrence, survival, mortality, or hazard ratios were considered. Non-English publications, animal studies, reviews, conference abstracts, unpublished data, and studies without relevant biomarker outcomes were excluded. Data were extracted using standardized forms, methodological quality was assessed using structured appraisal criteria, and findings were synthesized narratively because of heterogeneity in study designs, disease categories, biomarkers, and outcome measures. Results: Eight studies involving diverse non-arthritic disease populations met the inclusion criteria. MicroRNA biomarkers demonstrated diagnostic potential, particularly for early disease detection, with reported sensitivity ranging from 85% to 94% and specificity from 80% to 91%. DNA-based biomarkers, including methylation patterns and circulating DNA, were associated with prognostic outcomes, including disease progression, recurrence, and survival, with hazard ratios ranging from 1.8 to 3.2. Combined biomarker approaches showed improved diagnostic and prognostic performance compared with single-marker assessment. Conclusion: MicroRNA biomarkers appear most relevant for early diagnostic discrimination, whereas DNA-based biomarkers show stronger prognostic utility across non-arthritic diseases. Larger standardized multicenter validation studies are required before routine clinical implementation