TPI1 and TPM4 are strong candidate RNA biomarkers for systemic sclerosis.

BACKGROUND: Systemic Sclerosis (SSc) is an autoimmune rheumatic disease (ARD) with unclear aetiopathogenesis. Disease prognosis, diagnosis, and treatment are challenging, thus mandating the discovery of reliable biomarkers to improve patient care. Candidate biomarkers have been proposed in the literature, and this study aimed to validate some of them in an easily accessible tissue. METHODS: We collected peripheral blood samples from patients with SSc and other rheumatic diseases, and extracted total RNA. We assessed the expression levels of selected molecules with real-time PCR and performed statistical analysis to identify significant differential expression of molecules among the study groups. Enrichr Web server was used for pathway analysis of differentially expressed molecules. RESULTS: We confirmed the overexpression of two molecules (Triosephosphate isomerase (TPI1) and Tropomyosin alpha-4 chain (TPM4)) in patients with SSc compared to healthy controls or individuals with other rheumatic diseases. We further used the Enrichr Web server for pathway analysis, which revealed that these molecules are implicated in pathways that might be involved in disease pathogenesis. CONCLUSIONS: We conclude that TPI1 and TPM4 are reliable and specific biomarkers for SSc, and can be measured in blood samples with minimal risk to patients, thereby facilitating a cost-effective and timely diagnosis.