Intradiscal Injection of Iron-Labeled Autologous Mesenchymal Stromal Cells in Patients With Chronic Low Back Pain: A Feasibility Study With 2 Years Follow-Up

Purpose: Degeneration of the intervertebral disc is considered to be central in pain pathogenesis in patients suffering from chronic low back pain (LBP). In recent years, the injection of mesenchymal stromal cells (MSCs) into the disc to arrest or reverse the degenerative process has been proposed as an alternative therapy. The aim of the present study was to investigate the feasibility of using iron-labeled MSCs for intradiscal injection in patients with long-standing LBP. Methods: Ten patients (7 men, 3 women, mean age 40 years, range 26-53) with chronic LBP and confirmed disc degeneration on magnetic resonance imaging (MRI) were recruited from the waiting list for planned surgery. Injection of autologous, expanded, and iron-labeled bone marrow-derived MSCs (BM-MSCs) into 1 or 2 disc levels was undertaken. Follow-up consisted of monitoring of adverse events, regular MRI examinations, and collection of patient-reported outcome measures (PROMs) for a minimum of 2 years. Results: No complications could be detected, neither clinically nor on MRI. No statistically significant improvement was seen for PROMs on a group level up to 2 years postinjection. Three of 10 patients opted to proceed with the initially planned surgery within the first year and 2 more within 3 years postinjection. Conclusion: Results from this pilot cohort study show that injection of autologous expanded iron-labeled BM-MSCs is a safe procedure, in accordance with the existing body of evidence. The clinical result warrants further larger studies.