Efficacy of Serum BDNF for the Evaluation of Depressive Neurological Symptoms in Patients with Refractory Ulcerative Colitis.

Background/Aims: Numerous patients with ulcerative colitis (UC) become mentally unstable after experiencing a long-standing, physically painful life, and their long-term prognosis is poorer than that of those who are mentally stable. The current study aimed to evaluate serum biomarkers for predicting mental instability, which is challenging to objectively quantify. Methods: In total, 29 refractory UC patients newly treated with filgotinib underwent measurements of blood parameters associated with depression and a quantitative assessment of quality of life using the Inflammatory Bowel Disease Questionnaire (IBDQ) before and after treatment initiation with a 12-week interval. The data collected were examined in relation to each other. Results: The induction of remission treatment with filgotinib resulted in a clinical response rate of 89.7% and a clinical remission rate of 86.2%, with all eight extraintestinal manifestations resolved. No adverse events were observed. The serum zinc, high-density lipoprotein cholesterol, mature brain-derived neurotrophic factor (BDNF) concentrations, and the IBDQ psychiatric subscores increased significantly after treatment (p < 0.05). Among these parameters, the mature-BDNF concentration and the IBDQ psychiatric subscore had the strongest positive correlation (R = 0.29, p = 0.08). Based on the logistic regression analysis, the mature-BDNF concentration (cutoff value: 20.5 ng/mL) had a sensitivity of 68.2%, specificity of 64.7%, and area under the curve of 0.67 for predicting psychiatric remission (subscore > 42.5) (p = 0.04). Conclusions: While it is not easy to objectively predict the degree of psychiatric instability in patients with refractory UC, serum mature-BDNF levels can be a useful biomarker.