Age and donor site do not affect cell growth and biologic...

Age and donor site do not affect cell growth and biologic activity in Autologous Tendon-cell Implantation (OrthoATI™) for treatment of patellar tendon and palmaris longus tendon

Katie Wang MD 1, Allan Wang MD, PhD 2, Tak Sum Cheng PhD 2, Euphemie Landao-Bassonga MMsc 2, Clair Lee PhD 2, Andrew Tai PhD 2, Maurizio Damiani MBBS 3, Ming Hao Zheng MD, PhD 2

Published: May 14, 2024
DOI: https://doi.org/10.1016/j.jisako.2024.05.007

Abstract

Objectives

Autologous tendon cell implantation (OrthoATI™) therapy has demonstrated efficacy in treating patients with tendinopathy at various anatomical sites. This study evaluates the effect of patient age, gender and tendon biopsy site on morphology, growth and gene expression of autologous tendon cells used to treat chronic tendinopathy.

Methods

Patients undergoing OrthoATI™ for tendinopathies between 2020 and 2022 were initially treated by biopsies taken from patella tendon (PT) or palmaris longus tendon (PL). Autologous tenocytes were treated at a Good Manufacturing Practice (GMP) cell laboratory where they were isolated, cultured and expanded for four to six weeks. Cell morphology was assessed using phase contrast microscopy. Droplet digital PCR (ddPCR) was utilised for gene expression analysis. Dichotomous results were compared between groups using x2 or Fisher’s exact tests with no adjustment for multiple comparisons. The non-parametric Mann–Whitney U and Kruskal–Wallis tests were utilised for the sex and age (<35y, 35-44y, 45-54y, >55y) analyses respectively. All analyses were performed using IBM SPSS v27, and a two-tailed P-value of <0.05 was considered statistically significant.

Results

149 patients were included in the analysis. The PT was biopsied in 63 patients, and PL in 86 patients. There were no observer effects for age and gender between PT and PL groups. There was no statistical significance between the PT and PL tendons for cell morphology, average cell population doubling time (PDT) (PT 83.9 vs PL 82.7 hours, p=0.482), cellular yield (PT 16.2 vs PL 15.2×106 , p=0.099), and cell viability (PT 98.7 vs PL 99.0%, p=0.277). Additionally, ddPCR analyses showed no statistical significance found in tenogenic gene expression including collagen type I (COL1, p=0.86), tenomodulin (TNMD, p=0.837) and scleraxis (SCX, p=0.331) between PT- and PL-derived tendon cells. An age stratification analysis found no effect on growth and gene expression. COL1 was found to be higher in males when compared to females (P<0.001), but otherwise no difference was seen in growth and gene expression in the gender analysis. No post-biopsy clinical complications were reported for either group.

Conclusion

This study has shown that the growth and bioactivities of tendon cells from tendon biopsies for OrthoATI™ are not affected by tendon donor site and age.

Level of evidence
IV

WHAT ARE THE NEW FINDINGS?

•Tendon tissue acquisition for autologous tendon cell implantation is not affected by tendon donor site and gender.
•Patients from the older age groups (> 60 years) have equivalent cell culture times as younger patients.

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