Oral Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

Off-the-shelf NP cell therapy for canine disc degeneration at different severity levels (#MP-13c)

Jordy Schol 1 , Takayuki Warita 1 2 , Erika Matsushita 1 , Asami Kawachi 1 2 , Shota Tamagawa 1 3 , Yuto Otani 1 , Daisuke Sakai 1 , Masato Sato 1 , Masahiko Watanabe 1
  1. Tokai University School of Medicine, Isehara, Japan
  2. TUNZ Pharma Inc., Osaka, Japan
  3. Juntendo University School of Medicine, Tokyo, Japan

INTRODUCTION

Intervertebral disc (IVD) degeneration poses significant challenges, impacting quality of life and socioeconomic factors. Cell therapy has emerged as a promising avenue for mitigating IVD degeneration, though debates persist regarding its effectiveness, especially in severe cases where cell retention and nutritional support pose challenges.1-3 To address these uncertainties, our study aimed to establish a canine model inducing mild and severe disc degeneration, enabling evaluation of nucleus pulposus (NP) cell injection's efficacy across different degenerative stages.

 

METHODS

Human NP cells were cultured from surgical waste tissue (obtained following informed consents (#17R173)), optimizing their potency through FGF2 supplementation promoting Tie2-positivty following previous methods4. Off-the-shelf NP cell suspensions were cryopreserved for injection. Chondrodystrophic beagles (#223014) were randomly assigned for mild (n=7) and severe degeneration (n=7) induction in specific discs, with sham saline or NP cell injections. Mild degeneration involved NP tissue aspiration using a 18G needle5, while severe degeneration utilized a surgical punch. For each dog L3/4-L5/6 were employed. Within each degeneration cohort, dogs were assigned to Cell-treatment (n=4) or Sham-injection (n=3) and involving intradiscal injection of either 100 µL of 1x106 NP cells in (1:1) 0.5% (w/v) HA/CS10 suspension (Cell) or 100 µL saline (Sham). Canines underwent a 3-month observation period, assessing disc height index, T2WI MRI imaging (3T Phillips, The Netherlands), body weight, and pain assessment. Afterwards, canines were sacrificed and the three discs were explanted for histological examination using the ORS Spine histological classification scheme.6 Statistical analysis was conducted using GraphPad Prism through either one-way or two-way ANOVA.

 

RESULTS

Procedures were complication-free. On average, 28.2 (±8.3) mg or 41.9 (±7.7) mg NP tissue was extracted in the Mild or Severe cohorts. Mild degeneration resulted in approximately 16% DHI loss, while severe cases showed 26% loss. NP cell-treated discs exhibited DHI improvement, particularly, both the mild and severe discs promoted disc height regeneration condition to a final 95.2% and 91.4% DHI at 12 weeks, respectively, resulting in significant improvements to baseline and corresponding Sham controls. T2 intensity images also revealed significantly enhanced intensities comparing Cell-treated versus Sham-treated cohorts at final follow-up. Overall, pain scores were slightly worse for sham-treated dogs. Histological analysis confirmed DHI findings, revealing a significantly enhanced outcomes for cell treated discs compared to Sham-controls, with both Mild and Severe conditions showing similar final scores.

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DISCUSSION

Our study utilized chondrodystrophic dogs to mimic human IVD degeneration.7 We successfully induced mild and severe states and observed comparable NP cell therapy outcomes for DHI and histology in both cases. Despite incomplete recovery, cell therapy showed regenerative potential even in more severe degeneration, suggesting its wider applicability. Limitations include uncontrolled disc inflammation, warranting further investigation into its impact on severely degenerated discs and their response to treatment. This study underscores the potential of NP cell therapy in addressing both mild and severe IVD degeneration, suggesting a more wide range effectiveness, even in more severe cases of disc degeneration.

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