Quite frankly, I wasn't sure I would ever have the opportunity to write about an actual laboratory test for fibromyalgia in my lifetime. But before I organize a parade to celebrate, I have a few questions that are as yet unanswered.
The test––called the FM/a® test––was developed by EpicGenetics, a privately-held biomedical company “dedicated to developing conclusive diagnostic medical tests for complex medical conditions where no definitive testing is available.” EpicGenetics calls it “the first test to objectively diagnose fibromyalgia via a simple blood test.”
How the FM/a® Test Works
According to the developers, “FM/a® is a multiple biomarker-based test, which measures protein molecules called cytokines within white blood cells, a key part of your immune system. People with significantly lower cytokine levels have fibromyalgia. It uses a 1-100 point scoring system to determine diagnosis, and it calculates a positive fibromyalgia diagnosis as a score between 50 and 100 points.”
They say that FM/a is more than 93% sensitive, a sensitivity comparable to the HIV blood test. By comparison the rheumatoid arthritis blood test is only 65% sensitive. No medical test is 100% accurate.
The Research Behind the Test
The FM/a test was developed as part of an 18-month long study comparing cytokine responses in 110 FM patients and 91 healthy controls. The research, published in BMC Clinical Pathology in December 2012, concluded, “The cytokine responses to mitogenic activators of peripheral blood mononuclear cells isolated from patients with FM were significantly lower than those of healthy individuals, implying that cell-mediated immunity is impaired in FM patients. This novel cytokine assay reveals unique and valuable immunologic traits, which, when combined with clinical patterns, can offer a diagnostic methodology in FM.”
One of the most interesting things I found in this study was a statement at the end of the authors' discussion. “In the past, FM was claimed to be a rheumatologic, neurologic or psychiatric disease despite the fact that there were no objective links to any of those pathways. Our findings uncovered evidence that FM is instead an immunologic disorder. They prove that the immunologic basis of FM occurs independently of any subjective features. Hence, this illustrates the very strong clinical value of our test protocol. The fact that individual cytokines exhibited similar dynamics in patient samples reveals that the FM patients are uniform in regard to their cellular immunologic responses.”
The full text of the journal article is available for free here: Unique immunologic patterns in fibromyalgia.
My Unanswered Questions
While this study is impressive and the results encouraging, I still have a few questions regarding the test:
In the study, the test was only used to distinguish between FM patients and healthy controls. How would the test fare when trying to distinguish FM from other pain-related disorders?
Patients with any rheumatologic, autoimmune, immunologic, inflammatory, infectious or neoplastic disorder were excluded from the study. Would the test identify FM if a patient has another illness as well?
Study participants were not allowed to take any FDA-approved medications for FM, nor were they allowed to take anti-inflammatory or other medications that affect the immune system. Will patients be required to discontinue their medications before taking the FM test in order to get an accurate result?
Until these questions are answered, I'll remain cautiously optimistic.