Circulating microRNAs as biomarkers of adult Crohn's disease.

ABSTRACT

OBJECTIVE: Previous studies have found a differential expression of microRNAs (miRNAs) in the blood of patients with Crohn's disease (CD) compared with healthy controls. The aim of this study was to identify circulating miRNAs expressed in CD and assess their performance as biomarkers in patients with clinically suspected or known CD. METHODS: The study consisted of two parts (a) miRNA profiling The miRNA expression pattern was examined in six patients with CD and six controls using OpenArray miRNA profiling, and the best miRNAs were selected according to their P-value. (b) Validation cohort In a well-characterized cohort of 102 patients with suspected or known CD, miRNAs identified by miRNA profiling or selected from previously published studies (hsa-miR-16, hsa-miR-21, hsa-miR-106a, and hsa-miR-140-3p) were measured in plasma using reverse transcription PCR. RESULTS: miRNA profiling hsa-miR-369-3p, hsa-miR-376a, hsa-miR-376, hsa-miR-411#, hsa-miR-411, and mmu-miR-379 were downregulated in CD patients compared with the controls; hsa-miR-200c, hsa-miR-181-2#, and hsa-miR-125a-5p were upregulated (P<0.05). Validation cohort Only hsa-miR-16 was significantly downregulated in patients with CD compared with patients without CD (fold change 0.83, P=0.02). Receiver operating characteristic analyses showed an area under the curve of 0.65. miRNAs could not discriminate inflammatory from stricturing CD or small bowel CD from CD involving the colon. CONCLUSION: In a clinically relevant cohort of patients, miRNAs in plasma identified in the present and previous studies were inadequate biomarkers for the diagnosis of CD.