AB0664 EFFICACY OF PLASMA PHOSPHOETHANOLAMINE AS A NOVEL BIOMARKER FOR RHEUMATOID ARTHRITIS-ASSOCIATED DEPRESSION
Authors: Y. Miwa, Y. Miwa, H. Tomioka, M. Hosaka
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> It has been reported that about 15% of patients with rheumatoid arthritis (RA) have depression, and most of these studies have used questionnaire methods. Diagnosis of depression is based on an interview. Phosphoethanolamine (PEA), a plasma biomarker, has been reported to be a useful diagnostic biomarker for depression. <h3>Objectives:</h3> We examined the efficacy of PEA as a biomarker for RA-associated depression. <h3>Methods:</h3> This study included 123 registered RA patients recruited between 2020 and 2022. The following background factors were investigated: age, sex, and disease duration. RA disease activity was evaluated using the SDAI. The psychiatrist was blinded to the questionnaire results and conducted a structured interview in a separate room. The psychiatrist's diagnosis was defined as the Gold Standard. Questionnaires for depression (using the Center for epidemiologic studies depression scale (CES-D)), anxiety (using State-trait Anxiety Inventory (STAI), and ego (using Tokyo University ego gram (TEG)-Ⅱ) were also performed. Items of this questionnaire were converted into Scale A (depression/anxiety scale including CES-D and STAI) and Scale B (adaptation scale including TEG-Ⅱ). Plasma PEA levels were measured using a capillary electrophoresis triple-quadrupole mass spectrometer in the Human Metabolome Technologies laboratories. <h3>Results:</h3> Twenty-three patients were excluded. Seven patients disagreed and withdrew their consent, and 16 could not adjust their schedules. The psychiatrist's diagnosis was abnormal in 15 patients. This included one patient with major depression, two patients with moderate depression, five patients with minor depression, two patients with adjustment disorder, two patients with neurosis, one with anxiety, one with insomnia, and one with mental retardation. The patients were divided into two groups according to the presence or absence of psychiatric disorders. 1 No significant difference was noted between the groups for the plasma PEA concentration (p = 0.09). 2 The Scale A score was significantly high among patients with depression (p &lt; 0.001), and the ratio of Scale A score to PEA was significantly high (p &lt;0.001) among patients. 3 The Scale B score was significantly high among patients with depression (p&lt;0.001). 4 The Receiver Operating Characteristic curve produced the following cutoff values. A score of 1.44 or more on the PEA, 7 or more on Scale A, 5.607 or more on the Scale A to PEA ratio, and 2 or more on Scale B was considered a cutoff. The serum PEA had a specificity of 48.1%, a sensitivity of 26.3%, and the area under the curve (AUC) was 0.586 (95%CI 0.467-0.705). The Scale A had a specificity of 80.2%, a sensitivity of 84.2%, and an AUC was 0.842 (95%CI 0.721-0.963). The Scale A to PEA ratio had a specificity of 84.0%, a sensitivity of 84.2%, and an AUC was 0.845 (95%CI 0.725-0.965). The Scale B had a specificity of 75.3%, a sensitivity of 68.4%, and an AUC was 0.75 (95%CI 0.621-0.88). <h3>Conclusion:</h3> Plasma PEA alone presents a weak performance as a diagnostic biomarker for depression in patients with RA. However, a composite measure for diagnosing depression, including questionnaires for depression, anxiety, and ego, may be used as an auxiliary diagnosis. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> Human Metabolome Technologies, Inc. and Yoshiaki Ohashi, Fermecutes, Inc. <h3>Disclosure of Interests:</h3> YUSUKE MIWA Pfizer Japan Inc.,, Yuko Miwa: None declared, Hiroi Tomioka: None declared, Michio Hosaka: None declared.