Although the symptoms of low back pain are obvious enough to anyone who suffers from it, diagnosing the cause remains a challenge for doctors. Researchers have now found evidence that levels of key substances in the blood may serve as useful markers for diagnosing low back pain.
Scientists discovered that levels of a cytokine called interleukin-6 (IL-6) were significantly higher in patients with low back pain than in control subjects. The findings were published online in January 2016 in Arthritis Research & Therapy.
Cytokines are small proteins secreted by cells of the immune system. Levels of matrix metalloproteinase, one of a group of enzymes that work to break down proteins, were found to be significantly lower in the patients being studied.
In addition, these substances, or biomarkers, were also associated with specific forms of low back pain. Levels of IL-6 were higher in patients who had spinal stenosis and degenerative disc disease, compared with those who had herniated discs (control subjects).
Biomarkers have already been identified for many different types of conditions—for example, measuring serum low-density lipoprotein (LDL) to diagnose high cholesterol.
Researchers don’t yet know whether the biomarkers identified in the current study, which are linked to inflammation, are a cause or an effect of the damage to discs. As they learn more, they hope that a simple blood test might eventually help doctors diagnose low back pain more accurately.