The Clinical Utility of a Chemokine-Cytokine Multiplex Assay in Fibromyalgia Diagnosis at an Academic Medical Center

Abstract Introduction/Objective: To assess the clinical utility of the FM/a® chemokine-cytokine assay in diagnosing fibromyalgia at an academic medical center. Methods: We performed a cross-sectional study on 50 patients diagnosed with fibromyalgia at a specialty fibromyalgia clinic between January 1, 2021 through July 31, 2021. Patients completed questionnaires and provided a venous blood sample sent to EpicGenetics, to complete the FM/a® test. Demographic, symptom, and historical data was obtained from chart review. Statistical analysis was performed. Results: Of 50 patients with a clinical diagnosis of fibromyalgia, the FM/a® test was positive in 45 (90%). Performance of the FM/a® test compared to the 2016 ACR criteria yielded an odds ratio of 3.5 with sensitivity of 0.91, specificity of 0.25. Univariate regression demonstrated an area under the curve (AUC) of 0.7337, which improved to 0.89 when adjusted for age, gender, and race. When compared to the 1990 ACR criteria, a positive FM/a® test had an odds ratio of 2.33 with sensitivity 0.92 and specificity 0.17. Univariate regression analysis demonstrated an AUC of 0.571, when adjusted for age, gender and race, AUC was similar at 0.585. Conclusion: The FM/a® test performed well overall, though inferiorly compared to the 1990 and 2016 ACR diagnostic criteria. When adjusted for age, gender, and race the test performed almost equivalently to the 2016 ACR criteria. The FM/a® test may be useful in general clinical practices to differentiate patients who are more likely to have FM.