Letter to the Editor concerning "Low virulence bacterial infections in cervical intervertebral discs: a prospective case series" by Chen Y, Wang X, Zhang X, et al. (Eur Spine J; 2018: doi:10.1007/s00586-018-5582-4)

Chronic low back pain, Modic changes and low-grade virulent infection: efficacy of antibiotic treatment

Chronic low back pain (CLBP) has consistently been associated with the longest number of years lived with a disability in global studies, while commonly used treatments for CLBP are largely ineffective. In 2013 a randomized, double-blind, controlled study demonstrated significant improvements in CLBP patients demonstrating Modic changes type 1 on their MRI scans and undergoing long-term oral antibiotic treatment (100 days). Much of the ensuing debate has focused on whether this was a true infection or contamination. Newer and more advanced technologies clearly point to an ongoing low-grade infection. We have reviewed all of the clinical trials published in the recent past and conclude that there is compelling evidence for the effect of long-term oral antibiotic treatment for this patient group.

New insights link low-virulent disc infections to the etiology of severe disc degeneration and Modic changes

Within the last 5 years, international research collaborations including those of several research groups skilled in microbiology, immunology and pathophysiology, have identified a low-virulent intradiscal infection with the ability to provoke gradual and progressive disc degeneration, end-plate disruption, Modic changes and persistent clinical lower-back pain. Certain strains of the Propionibacterium acne bacterium seem able to invade, colonize and develop a protective biofilm inside the disc. The interaction of P. acne, disc tissues and mononuclear cells of the bone marrow are shown to trigger a relevant immunological response and an ensuing destructive inflammation of the disc and adjacent vertebrae. This process presents on MRI as Modic changes. Recent proof-of-concept data provide compelling evidence for this bacterial disc infection hypothesis.