[Platelet-rich plasma (PRP) and disc lesions: A review of the literature]

Leukoreduced PRP enhanced proliferation and ECM production yet inhibited senescence, inflammation, and multi-differentiation potential of AFSCs by downregulating HMGB1

BACKGROUND

This study assessed the role and potential mechanism of platelet-rich plasma (PRP) in the progression of intervertebral disk degeneration (IVDD).

METHODS

Annulus fibrosus (AF)-derived stem cells (AFSCs) from New Zealand white rabbits received the transfection with high mobility group box 1 (HMGB1) plasmids and the subsequent treatment with bleomycin, 10% leukoreduced PRP or leukoconcentrated PRP. Dying cells were indicated by immunocytochemistry analysis for senescence-associated β-galactosidase (SA-β-gal) staining. The proliferation of these cells was evaluated based on the population doubling time (PDT). The expressions of HMGB1, pro-aging and anti-aging molecules, extracellular matrix (ECM)-related catabolic/anabolic factors, and inflammatory genes at the molecular or transcriptional levels were quantified via Western blot or reverse transcription-quantitative PCR (RT-qPCR). Besides, the adipocytes, osteocytes, and chondrocytes were separately dyed by Oil Red O, Alizarin Red S, and Safranin O staining.

RESULTS

Bleomycin enhanced the senescent morphological changes and increased the PDT and the expressions of SA-β-gal, pro-aging molecules, ECM-related catabolic factors, inflammatory genes, and HMGB1 while suppressing the expressions of anti-aging and anabolic molecules. Leukoreduced PRP reversed the effects of bleomycin and inhibited the differentiation of AFSCs into adipocytes, osteocytes, and chondrocytes. Besides, HMGB1 overexpression offset the roles of leukoreduced PRP in AFSCs.

CONCLUSION

Leukoreduced PRP promotes cell proliferation and ECM production of AFSCs, while inhibiting their senescence, inflammation, and multi-differentiation potentials via downregulating HMGB1 expression.

Intervertebral disc therapies for non-specific chronic low back pain: a systematic review and meta-analysis

Objectives

We aim to evaluate the benefits and harms of intervertebral disc therapies (IDTs) in people with non-specific chronic low back pain (NScLBP).

Methods

We conducted a systematic review and meta-analysis of randomized trials of IDTs versus placebo interventions, active comparators or usual care. EMBASE, MEDLINE, CENTRAL and CINHAL databases and conference abstracts were searched from inception to June 2020. Two independent investigators extracted data. The primary outcome was LBP intensity at short term (1 week-3 months), intermediate term (3-6 months) and long term (after 6 months).

Results

Of 18 eligible trials (among 1396 citations), five assessed glucocorticoids (GCs) IDTs and were included in a quantitative synthesis; 13 assessed other products including etanercept (n = 2), tocilizumab (n = 1), methylene blue (n = 2), ozone (n = 2), chymopapaine (n = 1), glycerol (n = 1), stem cells (n = 1), platelet-rich plasma (n = 1) and recombinant human growth and differentiation factor-5 (n = 2), and were included in a narrative synthesis. Standardized mean differences (95% CI) for GC IDTs for LBP intensity and activity limitations were -1.33 (-2.34; -0.32) and -0.76 (-1.85; 0.34) at short term, -2.22 (-5.34; 0.90) and -1.60 (-3.51; 0.32) at intermediate term and -1.11 (-2.91; 0.70) and -0.63 (-1.68; 0.42) at long term, respectively. Odds ratios (95% CI) for serious and minor adverse events with GC IDTs were 1.09 (0.25; 4.65) and 0.97 (0.49; 1.91).

Conclusion

GC IDTs are associated with a reduction in LBP intensity at short term in people with NScLBP. Positive effects are not sustained. IDTs have no effect on activity limitations. Our conclusions are limited by high heterogeneity and a limited methodological quality across studies.

Registration

PROSPERO: CRD42019106336.

Risks of Intradiscal Orthobiologic Injections: A Review of the Literature and Case Series Presentation

BACKGROUND

Intervertebral disc disease (IDD) is responsible for a large portion of back pain with historically suboptimal treatments for long-term improvement. IDD pathogenesis is thought to arise at a cellular and biochemical level, making biologically based injections an area of clinical interest. Although human studies have shown promise, emerging data suggest there may be risks inherent to such injections that were previously unrecognized. The aim of this review is to summarize the known risks to date and provide mitigation steps to reduce potential complications in the future. In addition, we present a small case series of serious adverse events (SAEs) from our clinical practice.

METHODS

A literature review was performed to identify human intradiscal autologous biologic injection studies to date, including mesenchymal signaling cells (MSCs) and platelet-rich plasma (PRP) preparations, which were reviewed for complications. Cases of complication following intradiscal orthobiologic injection were identified from a single outpatient center and reviewed.

RESULTS

Publications of MSC-based intradiscal injection documented 136 total patients treated with two SAEs reported, one infection and one progressive disc herniation. Publications of PRP intradiscal injection included 194 patients with one SAE reported. We also review three cases of previously unpublished SAEs, including one case of confirmed infection with Cutibacterium acnes (C acnes) and two presumed cases of discitis without pathogen confirmation. Bone marrow concentrate was the injectate in all three cases.

CONCLUSIONS

Although biologic intradiscal injection shows promise for the treatment of discogenic back pain, there are inherent risks to be considered and mitigated. We currently recommend a leukocyte-rich PRP and a two-needle delivery technique coupled with intradiscal gentamicin to mitigate the risk of postinjection spondylodiscitis. Further research is needed using large registries to not only track clinical outcomes but also complication rates.

308-nm Excimer Laser Plus Platelet-Rich Plasma for Treatment of Stable Vitiligo: A Prospective, Randomized Case-Control Study

Purpose

308-nm excimer laser has a confirmed treatment effect on vitiligo. Platelet-rich plasma (PRP) is an autologous preparation which contains a variety of growth factors. The effect of 308-nm excimer laser combined with PRP on vitiligo has been rarely reported. This study investigated the effect of PRP combined with 308-nm excimer laser on stable vitiligo.

Patients and Methods

A total of 60 patients with localized stable vitiligo who received treatment at Beijing Friendship Hospital and Xi’an Vitiligo Specialist Hospital between May 2019 and January 2020 were consecutively enrolled. They were equally randomized into three groups according to different treatment methods: intradermal PRP injection (group I), 308-nm excimer laser alone (group II), and 308-nm excimer laser plus PRP injection (group III). All treatments lasted for 3 months. At 3 months after treatment, clinical assessments were performed in terms of the visual analogue scale (VAS) score, repigmentation response and side effects.

Results

The VAS scores showed significant differences among the three groups (P<0.001), with the highest score in group III, followed by group II and then group I. Repigmentation responses also showed significant differences among the groups (P<0.001), and the best effect was observed in group III. No side effects were reported in any of the groups.

Conclusion

The effect of PRP combined with 308-nm excimer laser on stable vitiligo is significantly better than that of PRP and 308-nm excimer laser alone. It is safe and satisfactorily tolerant.

Efficacy and tolerability of injectable collagen-containing products in comparison to trimecaine in patients with acute lumbar spine pain (Study FUTURE-MD-Back Pain)

Low back pain (LBP) represents an important subgroup of vertebrogenic pain with estimated prevalence around 80 %. Locally acting injectable collagen for topical application has recently extended the limited range of treatment options. The aim of the study was to evaluate the efficacy and safety of injectable collagen in patients with LBP. Patients suffering from LBP (< three months) were enrolled. They were administered either collagen 4 ml or trimecaine 1 % 4 ml in the form of subcutaneous paravertebral injections into eight pre-specified points (0.5 ml per each point) in the following schedule: two administrations in the first and second week, one in the third week. The pain intensity, Thomayer distance, Oswestry disability index, Lasseque test, quality of life, consumption of rescue medication and safety were evaluated. Exertional and rest pain, evaluated by a visual analogue scale, gradually decreased in both groups. Both treatments showed a statistically significant improvement in mobility and quality of life. The consumption of paracetamol as a rescue medication was significantly lower in patients treated with collagen than in the group treated with trimecaine (p=0.048). The analgesic efficacy of locally acting injectable collagen, as well as an analgesic sparing effect when compared to local anesthetics were demonstrated.

Efficacy of Platelet-Rich Plasma Containing Xenogenic Adipose Tissue-Derived Stromal Cells on Restoring Intervertebral Disc Degeneration: A Preclinical Study in a Rabbit Model

Objective

Platelet-rich plasma (PRP) containing multiple growth factors is a promising strategy for disc degeneration. Thus, this study hypothesizes that the combination of PRP and adipose tissue-derived stromal cells (ADSCs) may repair degenerative disc more effectively than using each one of them alone.

Methods

The model of early intervertebral disc degeneration was induced by annular puncture in the New Zealand rabbit. Autologous PRP was extracted from fresh arterial blood by using two centrifugation techniques. ADSC was offered by the Center for Clinic Stem Cell Research. Four weeks after the first experiment, PRP or ADSCs or a combination of PRP and ADSCs was injected into the punctured intervertebral disc. Four weeks later, disc height and signal intensity on T2-weighted magnetic resonance imaging (MRI) were assessed.

Results

One month after puncture, we detected relatively narrow discs and lower signal intensity in MRI T2-weighted images. At four weeks after injection, the PRP-ADSC group statistically significantly restored discs, compared with PRP, ADSCs, or negative control group.

Conclusions

The combination of PRP and ADSCs shows an effective potential to restore degenerated intervertebral discs in the rabbit.

EVALUATION OF CENTRIFUGING REGIMES FOR THE PURPOSE OF OPTIMIZING THE PLATELET RICH PLASMA HARVESTING PROTOCOL

Aim: Based on the classical principles, to determine the optimal conditions for centrifugation, PRP harvesing (platelet-rich plasma). To conduct a quantitative assessment of the substrate obtained under different conditions of centrifugation. Materials and methods. Based on the basic principles of obtaining platelet-rich plasma (PRP) by centrifuging in containers with an anticoagulant followed by phase separation to obtain the final substrate, the efficiency of the technique under the conditions of single and double centrifugation as well as under different conditions of acceleration and centrifugation was evaluated. Blood for follow-up was collected from 20 healthy volunteers (11 men, 9 women) average 25.3±4.1 in syringes of LuerLock design with ACD-A anticoagulant solution, and centrifuged. Centrifugation was carried out under controlled conditions using a centrifuge with rotating bowls of the rotor. Centrifugation was performed at an acceleration of 100-400g in time intervals up to 20 minutes. Activation of the substrate was performed with calcium chloride solution. Quantitative evaluation of platelets of whole blood and the final substrate of PRP was carried out with a semi-automatic analyzer. Results. The obtained results demonstrate the maximum level of harvesting efficiency when performing double centrifugation in the 150g×15 min+250g×10 min mode. Subject to this centrifugation protocol, it is possible to obtain a substrate that complies with the standardized requirements for PRP. The maximum level of an increase in the number of platelets in the substrate in comparison with whole blood is determined at the level of ×4.36 with concentration (volume reduction) x5 in comparison with the volume of whole blood. Conclusions. This study demonstrated the advantage of double centrifuging modes over single modes. According to the results of the study, it was possible to determine the conditions for an optimal double-centrifugation mode (acceleration and duration), which allows us to achieve the most efficient concentration of the substrate.