Circulating Mir-140 and leptin improve the accuracy of the differential diagnosis between psoriatic arthritis and rheumatoid arthritis: a case-control study

Abstract

The differential diagnosis of psoriatic arthritis (PsA) and rheumatoid arthritis (RA) is difficult because of the lack of diagnostic clinical signs and reliable biomarkers. This study investigated microRNAs (miRNA) and adipokines as potential additional markers to discriminate PsA from RA. The expression profile of miRNA (miR-21, miR-140, miR-146a, miR-155, miR-181b, miR-223, miR-let-7e) and inflammatory cytokines (IL-1β, IL-6, IL-17a, IL-23a, TNF-α) from peripheral blood mononuclear cells of PsA and RA patients compared to healthy controls (HC) were evaluated by real-time PCR, and serum adipokines (adiponectin, chemerin, leptin, resistin, visfatin) and cytokines by ELISA assay. Univariable binary logistic regression was used to find the association between PsA and potential predictors. The gene expression of miRNA and cytokines and the serum levels of adipokines were found significantly different in PsA and RA patients compared to HC, as well as in PsA versus RA. MiR-140 gene expression resulted up-regulated in PsA patients and reduced in RA in comparison to HC, and, for the first time, significantly higher in PsA compared with RA. Serum levels of IL-23a and leptin were significantly increased in PsA and RA populations than in HC, as well as in PsA versus RA. Furthermore, circulating TNF-α was up-regulated in PsA and RA in comparison to controls, while resulted higher in RA than in PsA. Univariable binary logistic regression analysis found the above-mentioned markers associated to PsA versus RA. Our results first demonstrated an increased expression of circulating miR-140 and serum leptin in PsA patients compared to RA, which were identified as potential additional biomarkers to discriminate PsA from RA. Since the differential diagnosis of PsA and RA poses challenges in clinical practice, our data may help to enhance the diagnostic performance of PsA in daily practice.

Keywords: ACPA = anti‐cyclic citrullinated peptide antibodies; ACR = American college of rheumatology; ACTB = actin beta; BMI = body mass index; CRP = C-reactive protein; CV = cardiovascular; DAPSA = disease activity in psoriatic arthritis; DAS28 = disease activity score 28; DMARDs = disease-modifying anti-rheumatic drugs; ESR = erythrocyte sedimentation rate; EULAR = European league against rheumatism; HAQ = health assessment questionnaire; HC = healthy controls; HDL = high density lipoprotein; HMW = high molecular weight; IGF = insulin-like growth factor; IL = interleukin; LDL = low density lipoprotein; LMW = low molecular weight; MAPK = mitogen-activated protein kinase; MMW = medium molecular weight; NF‐κB = nuclear factor κB; NSAIDs = non-steroidal anti-inflammatory drugs; OA = osteoarthritis; PASI = psoriasis area severity index; PBMCs = peripheral blood mononuclear cells; PsA = psoriatic arthritis; RA = rheumatoid arthritis; RF = rheumatoid factor; SIRT‐1 = silencing the gene for sirtuin; SNORD-25 = small nucleolar RNA = C/D Box 25; TGF-β = activity and in transforming growth factor; TNF = tumor necrosis factor; VAS = visual analogue scale; VEGF = vascular endothelial growth factor; miRNA = microRNA.