Establishing Nitric Oxide Levels as a Biomarker for Fibromyalgia and Rheumatoid Arthritis Diagnosis

Abstract

Fibromyalgia (FM) is a chronic, hyperalgesic disorder leaving musculoskeletal pain throughout the body without tissue damage, ultimately affecting about 1 in 25 to 1 in 50 people in the United States. Although prevalent, its diagnosis is complicated and long due to its ambiguity of official signs of its presence. Patients wait an estimated 2.3 years and see about 3.7 physicians on average before being diagnosed with this disorder. But in recent years, the FM/a blood test, which analyzes unusual patterns of immune responses has allowed for more accurate and timely diagnosis, boasts a 93% sensitivity rate and 89% specificity rate. Although an advancement, the FM/a test was found to have a false positive rate of 29% and 31% for patients with SLE and RA, respectively. To combat the lack of secure physiological ways to determine Fibromyalgia in patients, measuring nitric oxide (NO) levels in the body and exhaled breath appears to be a promising biomarker to distinguish RA from FM upon diagnosis. Nitric oxide works as a vasodilator and signal for localized inflammation. FM is a non-inflammatory disorder, so NO levels are heightened in both the blood and exhaled breath due to a lack of arginase, a competitive inhibitor of NO production. On the other hand, RA is an inflammatory autoimmune disorder that presents similarly in behavior to FM, but it leaves less NO in the blood because of the increased activity of arginase.