Cartilage regeneration and inflammation modulation in knee osteoarthritis following injection of allogeneic adipose-derived mesenchymal stromal cells: a phase II, triple-blinded, placebo controlled, randomized trial

Abstract

Background: Intra-articular injection of mesenchymal stromal cells (MSCs) with immunomodulatory features and their paracrine secretion of regenerative factors proposed a noninvasive therapeutic modality for cartilage regeneration in knee osteoarthritis (KOA).

Methods: Total number of 40 patients with KOA enrolled in two groups. Twenty patients received intra-articular injection of 100 × 10⁶ allogeneic adipose-derived mesenchymal stromal cells (AD-MSCs), and 20 patients as control group received placebo (normal saline). Questionnaire-based measurements, certain serum biomarkers, and some cell surface markers were evaluated for 1 year. Magnetic resonance imaging (MRI) before and 1 year after injection was performed to measure possible changes in the articular cartilage.

Results: Forty patients allocated including 4 men (10%) and 36 women (90%) with average age of 56.1 ± 7.2 years in control group and 52.8 ± 7.5 years in AD-MSCs group. Four patients (two patients from AD-MSCs group and two patients from the control group) excluded during the study. Clinical outcome measures showed improvement in AD-MSCs group. Hyaluronic acid and cartilage oligomeric matrix protein levels in blood serum decreased significantly in patients who received AD-MSCs (P < 0.05). Although IL-10 level significantly increased after 1 week (P < 0.05), the serum level of inflammatory markers dramatically decreased after 3 months (P < 0.001). Expressions of CD3, CD4, and CD8 have a decreasing trend during 6-month follow-up (P < 0.05), (P < 0.001), and (P < 0.001), respectively. However, the number of CD25⁺ cells increased remarkably in the treatment group 3 months after intervention (P < 0.005). MRI findings showed a slight increase in the thickness of tibial and femoral articular cartilages in AD-MSCs group. The changes were significant in the medial posterior and medial anterior areas of ​​the tibia with P < 0.01 and P < 0.05, respectively.

Conclusion: Inter-articular injection of AD-MSCs in patients with KOA is safe. Laboratory data, MRI findings, and clinical examination of patients at different time points showed notable articular cartilage regeneration and significant improvement in the treatment group.

Trial registration: Iranian registry of clinical trials (IRCT, https://en.irct.ir/trial/46 ), IRCT20080728001031N23. Registered 24 April 2018.

Keywords: Cartilage regeneration; Cell-based therapy; Knee osteoarthritis; Liquid biomarkers; Mesenchymal stromal cells; Regenerative medicine.

Fig. 1

Patients flow diagram and follow-up timeline of the phase II study

Fig. 2

Comparison of the WOMAC (P < 0.001) between A AD-MSCs and B control groups and VAS (P < 0.001) between C AD-MSCs and D control groups during the 12-month follow-up after injection. WOMAC Western Ontario and McMaster Universities Osteoarthritis index, VAS visual analog scale, AD-MSCs adipose-derived mesenchymal stromal cells. Data markers represent means; error bars, 95% confidence interval; and statistical analysis conducted by the one-way repeated measures analysis of variance (ANOVA)

Fig. 3

Comparison of the KOOS between AD-MSCs and control groups during 12-month follow-up. A KOOS, pain (P < 0.001); B KOOS, symptom (P < 0.001); C KOOS, daily function (P < 0.001); D KOOS, sport and recreation (P < 0.001); E KOOS, quality of life (P < 0.001); and F total KOOS (P < 0.001). KOOS Knee injury and Osteoarthritis Outcome Score, AD-MSCs adipose-derived mesenchymal stromal cells. Data markers represent means; error bars, 95% confidence interval; and statistical analysis conducted by the one-way repeated measures analysis of variance (ANOVA)

Fig. 4

SF-36 outcomes in AD-MSCs and control groups during the 12-month follow-up. PF physical functioning (P < 0.001), RP role physical (P < 0.001), BP body pain (P < 0.001), GH general health (P < 0.001), VT vitality (P < 0.001), SF social functioning (P < 0.001), RE role emotional (P < 0.001), MH mental health (P < 0.001). SF-36 36-Item Short Form Survey, AD-MSCs adipose-derived mesenchymal stromal cells. Data markers represent means; error bars, 95% confidence interval; and statistical analysis conducted by the one-way repeated measures analysis of variance (ANOVA)

Fig. 5

MRI analysis of femural condyle cartilage before and 48 weeks after AD-MSCs injection. A lateral radiograph indicates enhancement in anterior, posterior, and central area of femoral condyle cartilage. B Medial radiograph revealed increase in the thickness of femoral condyle cartilage in anterior, posterior, and central area. MRI magnetic resonance imaging, FLC Femur lateral central, FLP femur lateral posterior, FLA femur lateral anterior, FMC femur medial central, FMP femur medial posterior, FMA femur medial anterior, AD-MSCs adipose-derived mesenchymal stromal cells

Fig. 6

MRI analysis of tibial condyle cartilage before and 48 weeks after AD-MSCs injection. A Lateral radiograph indicates enhancement in anterior, posterior, and central area of tibial condyle cartilage. B Medial radiograph revealed increase in the thickness of tibial condyle cartilage in anterior, posterior, and central area. MRI magnetic resonance imaging, TLA tibia lateral anterior, TLC tibia lateral central, TLP tibia lateral posterior, TMA tibia medial anterior, TMC tibia medial central, TMP tibia medial posterior, AD-MSCs adipose-derived mesenchymal stromal cells

Fig. 7

MRI findings. A Tibial condyle cartilage thickness. B Femoral condyle cartilage thickness. Data markers represent means; error bars, 95% confidence interval; *P < 0.05, between and within groups; and one-way repeated measures analysis of variance (ANOVA). MRI magnetic resonance imaging, FLC femur lateral central, FLP femur lateral posterior, FLA femur lateral anterior, FMC femur medial central, FMP femur medial posterior, FMA femur medial anterior, TLA tibia lateral anterior, TLC tibia lateral central, TLP tibia lateral posterior, TMA tibia medial anterior, TMC tibia medial central, TMP tibia medial posterior, AD-MSCs adipose-derived mesenchymal stromal cells, m months, F/U follow-up

Fig. 8

Serum level of biomarkers. A HA levels decreased significantly in AD-MSCs group after 3 months (P < 0.05). B Levels of COMP declined remarkably in AD-MSCs group after 3 months (P < 0.05). C Level of MMP-3 does not change remarkably in AD-MSCs in comparison with the control group. Data markers represent means; error bars, 95% confidence interval; *P < 0.05, ns: not significant, between and within groups; and one-way repeated measures analysis of variance (ANOVA)

Fig. 9

Determination of inflammatory biomarkers in blood serum. A The level of IL-6 reduced significantly after 12 weeks of the injection in AD-MSCs group (P < 0.001). B IL-10 increased during the first week of injection (P < 0.05) and then decreased significantly 12 weeks after injection (P < 0.001). Data markers represent mean values; error bars, 95% confidence interval; *P < 0.05, ***P < 0.001, between and within groups; and one-way repeated measures analysis of variance (ANOVA)

Fig. 10

Cell surface CD marker expression during the 6-month follow-up. A The percentage of cells expressing CD3 decreased significantly in AD-MSCs group (P < 0.005). Surface expression percentages of B CD4 and C CD8 followed a noticeable decreasing trend during the 6-month follow-up in AD-MSCs group (P < 0.001). D CD25 expression increased dramatically in AD-MSCs group in comparison with the control group (P < 0.005). Data markers represent means; error bars, 95% confidence interval; and statistical analysis conducted by the one-way repeated measures analysis of variance (ANOVA)