Detection of hair root miR-19a as a novel diagnostic marker for psoriasis

Background: Objective biomarkers that reflect the diagnosis and disease activity have not been in clinical use for psoriasis. Objectives: We investigated the hair root miR-19a levels, regulatory microRNA of TNF-alpha, and evaluated the possibility that miR-19a can be a biomarker of psoriasis. Materials and methods: microRNAs were extracted from hair roots of patients with psoriasis (n = 18) and healthy controls (n = 22). Samples from 10 atopic dermatitis patients and 4 dermatomyositis patients were also included as the disease controls. miR-19a levels were determined by quantitative real-time PCR. Results: Hair root levels of miR-19a were significantly up-regulated only in psoriasis compared with normal controls. In characteristics (ROC) curve analysis for hair root miR-19a, to distinguish psoriasis patients from normal subjects, the areas under curve (AUC) was 0.87. Relative miR-19a levels were inversely and significantly correlated with duration between symptom onset and the first visit to the hospital in psoriasis patients. Conclusions: Our results indicated hair root miR-19a levels are effective as a disease marker.