Anti-Inflammatory Effects of Novel Standardized Platelet Rich Plasma Releasates on Knee Osteoarthritic Chondrocytes and Cartilage in vitro

Platelet Rich plasma injection of the vocal folds in benign vocal pathologies

PURPOSE

There are few options for treatment of dysphonia secondary to vocal pathology related to lamina propria scar, atrophy, sulcus, or inflammatory disorders. Platelet rich plasma (PRP) may provide anti-inflammatory and regenerative properties seen with other tissue engineering therapies without the risks associated with these treatments. We evaluated vocal fold (VF) injection of PRP for feasibility, phonatory effects, patient satisfaction and durability.

METHODS

Patients with dysphonia secondary to vocal fold scar, atrophy, sulcus and inflammatory lesions were included. PRP injections were administered in office, to bilateral vocal folds. Patients were followed up at 1 week, 1 month, 3 months and 6 months to assess outcomes (GRBAS scale, maximum phonation time, vocal fatigue index (VFI), voice handicap index (VHI-10) and stroboscopy).

RESULTS

75 intracordal PRP injections were administered to 48 patients. All injections were completed, and no adverse reactions were experienced. Improvements in VHI-10 scores at 1,3,6 months were seen (mean VHI 21.73 at baseline, 15.62 at six months, p < 0.001). 72.3% rated improvement at 7 or above on Likert scale. 95.7% of patients would consider a future PRP injection. Secondary outcomes VFI, MPT, and GRBAS also demonstrated significant improvements over time. Patients receiving a single PRP injection (n = 26) still demonstrated significant VHI-10 improvements at 1,3 and 6 months.

CONCLUSIONS

VF office PRP injections are feasible and safe and can provide phonatory benefit and reduce vocal effort in benign VF disorders. A single PRP injection is sufficient to provide sustained benefit in some cases.

LEVEL OF EVIDENCE

Level III: prospective cohort study.

Novel Molecular Mechanisms Underlying the Ameliorative Effect of Platelet-Rich Plasma against Electron Radiation-Induced Premature Ovarian Failure

Radiotherapy is one of the risk factors for radiation-induced premature ovarian failure and infertility in cancer patients. The development of methods for ovarian radioprotection remains relevant. Moreover, electrons are a little-studied and promising method of radiation with the least toxic effect on normal tissues. The assessment of intracellular mechanisms regulating the protective effects of leukocyte-poor platelet-rich plasma in a model of radiation-induced premature ovarian failure caused by electron irradiation. Wistar rats were divided into four groups, namely a control group, irradiation group (electron exposure), irradiation + leukocyte-poor platelet-rich plasma group, and only leukocyte-poor platelet-rich plasma group. Fragments of ovaries were removed and hormonal, oxidant, histological, and morphometric studies were carried out. The cell cycle of ovarian follicles and the inflammatory and vascular response were assessed using immunohistochemistry. The activity of MAPK, ERK, and PI3K pathways was also assessed using the RT-qPCR. We found that electron irradiation causes a decrease in the functional activity of the ovaries and the death of follicular cells through apoptosis. The administration of LP-PRP led to a partial restoration of the cytokine balance. In addition, minor ovarian damage and mild inflammation were observed in this group. Leukocyte-poor platelet-rich plasma components have anti-inflammatory, angiogenetic, and radioprotective effects, reducing the activation of the NOX4, caspase and cytokine cascades, and inflammatory response severity through the MAPK/p38/JNK signaling pathway. This leads to the induction of endogenous antioxidant protection, the repair of post-radiation follicular damage, and slowing down the development of radiation-induced premature ovarian failure after electron irradiation.

Reparative potential of mesenchymal stem cells and platelet-rich plasma on irradiated submandibular glands of male albino rats

OBJECTIVE

To appraise and compare the reparative role of bone marrow-mesenchymal stem cells (BM-MSCs) and platelet-rich plasma (PRP) against irradiation damage on albino rats' submandibular gland.

DESIGN

Seventy four male albino rats were used, one for BM-MSCs harvesting, 10 for PRP preparation, seven as control group (Group 1). The remaining 56 rats were subjected to single dose (6 Gy) gamma irradiation and were divided into equal four groups; (Group 2): received no treatment, (Group 3): each rat was injected with 1 × 10⁵ BM-MSCs, (Group 4): each rat was injected with 0.5 ml/kg PRP, and (Group 5): each rat was injected with 1 × 10⁵ BM-MSCs and 0.5 ml/kg PRP. Each group was further subdivided into two subgroups in which rats sacrificed after one and two weeks from irradiation. Any structural changes were examined histopathologically, immunohistochemically using proliferating cell nuclear antigen (PCNA) and CD31 primary antibodies and histochemically using picrosirius red (PSR) stain, then analyzed statistically.

RESULTS

Histopathological examination of Group 2 showed atrophied acini, with nuclear changes and signs of degeneration in duct systems. Treated groups revealed signs of regeneration in form of uniform acini and regenerated duct systems especially in Group 5 and in a time depended manner. Immunohistochemical examination revealed increased immunoexpression of PCNA and CD31, while histochemical examination showed decreased PSR in all treated groups in relation to the irradiated group and this was proved statistically.

CONCLUSIONS

BM-MSCs and PRP are effective as treatment for irradiation-induced submandibular gland damage. However, the combined therapy is recommended over each one separately.

Platelet-Rich Plasma-Releasate (PRPr) for the Treatment of Discogenic Low Back Pain Patients: Long-Term Follow-Up Survey

Background and Objectives: Clinical studies of platelet-rich plasma (PRP) for the treatment of low back pain (LBP) have been reported; however, less is known about its long-term efficiency. Materials and Methods: This study was a long-term follow-up of a previous prospective clinical feasibility study for the use of PRP releasate (PRPr) to treat discogenic LBP patients. Among 14 patients, 11 patients were evaluated for a long-term survey. The efficacy was assessed by a visual analogue scale (VAS) for LBP intensity and the Roland-Morris Disability Questionnaire (RDQ) for LBP-related disability. Radiographic disc height was evaluated for seven patients. Results: Improvements in VAS and RDQ were sustained at an average of 5.9 years after the intradiscal injection of PRPr (p < 0.01 vs. baseline, respectively). Clinically meaningful improvements (more than 30% decrease from baseline) in VAS and RDQ were identified in 91% of patients at final survey. The radiographic measurement of disc height of PRPr-injected discs showed a mild decrease (13.8% decrease compared to baseline) during the average 5.9 years. Conclusions: The results of this study with a small number of patients suggest that the intradiscal injection of PRPr has a safe and efficacious effect on LBP improvement for more than 5 years after treatment. Further large-scale studies would be needed to confirm the clinical evidence for the use of PRPr for the treatment of patients with discogenic LBP.

Two or four injections of platelet-rich plasma for osteoarthritic knee did not change synovial biomarkers but similarly improved clinical outcomes

We compared two and four intra-articular injections of platelet-rich plasma (PRP) in terms of changes of synovial cytokines and clinical outcomes. One hundred twenty-five patients having knee osteoarthritis (OA) underwent PRP injections at a 6-week interval. Before each PRP injection, synovial fluid aspiration was collected for investigation. Patients were divided into two or four intra-articular PRP injections (group A and B, respectively). Changes in synovial biomarkers were compared with the baseline levels of both groups, and clinical outcomes were evaluated until one year. Ninety-four patients who had completed synovial fluid collection were included for final evaluation, 51 in group A and 43 in group B. There were no differences in mean age, gender, body mass index (BMI), and radiographic OA grading. The average platelet count and white blood cell count in PRP were 430,000/µL and 200/ µL, respectively. There were no changes of synovial inflammatory cytokines (IL-1β, IL-6, IA-17A, and TNF-alpha), anti-inflammatory cytokines (IL-4, IL-10, IL-13, and IL-1RA), and growth factors (TGF-B1, VEGF, PDGF-AA, and PDGF-BB) between baseline levels and six weeks in group A, and 18 weeks in group B. Both groups had significantly improved clinical outcomes from six weeks including visual analog scale (VAS), patient-reported outcome measures [PROMs; Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index and Short Form-12 (SF-12)], with a significant delayed improvement of performance-based measures [PBMs; time up and go (TUG), 5-time sit to stand test (5 × SST), and 3-min walk test (3-min WT)]. In conclusion, two- or four-PRP intra-articular injection at a 6-week interval for knee OA demonstrated no changes of synovial cytokines and growth factors but similarly improved clinical outcomes from 6 weeks until 1 year.

PRP Injections for the Treatment of Knee Osteoarthritis: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

To evaluate effectiveness, in terms of patient-reported outcome measures, of platelet-rich plasma (PRP) injections for knee osteoarthritis compared to placebo and other intraarticular treatments.

DESIGN

PubMed, Cochrane Library, Scopus, Embase, Web of Science, as well as the gray literature were searched on January 17, 2020. Randomized controlled trials (RCTs) comparing PRP injections with placebo or other injectable treatments, in any language, on humans, were included. Risk of bias was assessed following the Cochrane guidelines; quality of evidence was graded using the GRADE guidelines.

RESULTS

Thirty-four RCTs, including 1403 knees in PRP groups and 1426 in control groups, were selected. WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) score favored PRP, with a statistically and clinically significant difference versus placebo at 12-month follow-up (P = 0.02) and versus HA (hyaluronic acid) at 6-month (P < 0.001) and 12-month (P < 0.001) follow-ups. A clinically significant difference favoring PRP versus steroids was documented for VAS (Visual Analogue Scale) pain (P < 0.001), KOOS (Knee Injury and Osteoarthritis Outcome Score) pain (P < 0.001), function in daily activities (P = 0.001), and quality of life (P < 0.001) at 6-month follow-up. However, superiority of PRP did not reach the minimal clinically important difference for all outcomes, and quality of evidence was low.

CONCLUSIONS

The effect of platelet concentrates goes beyond its mere placebo effect, and PRP injections provide better results than other injectable options. This benefit increases over time, being not significant at earlier follow-ups but becoming clinically significant after 6 to 12 months. However, although substantial, the improvement remains partial and supported by low level of evidence. This finding urges further research to confirm benefits and identify the best formulation and indications for PRP injections in knee OA.

A single step, centrifuge-free method to harvest bone marrow highly concentrated in mesenchymal stem cells: results of a pilot trial

PURPOSE

The aims of the present study were: (1) to characterize the bone-marrow aspirate (BMA) obtained with a centrifuge-free process, employing a dedicated aspiration device; (2) to test the in vitro efficacy of BMA in a model of cartilage inflammation; and (3) to report the preliminary clinical results in a small cohort of patients affected by knee OA.

METHODS

Ten patients (4 M, 6 W; mean age: 51.9 ± 9.2 yy) affected by mild to moderate unicompartmental knee OA (KL grade 2-3) were treated by intra-articular and subchondral injections of BMA obtained by a centrifuge-free process. To evaluate the effectiveness of the device in harvesting mesenchymal stem cells (MSCs), samples of the obtained BMA were tested by flow cytometry before and after subculture; BMA ability to counteract inflammation was also tested in an in vitro model of cartilage cell inflammation, evaluating the expression of MMP1, MMP3, TGFβ and TIMP-1 by real-time PCR. Patients were also evaluated up to two years' follow-up by using: VAS for pain, IKDC-subjective and KOOS scores.

RESULTS

The laboratory analysis showed that BMSCs accounted for 0.011% of BMA cells, similar to what had been expected in native bone marrow. The paracrine activity of BMA was able to reduce in vitro the catabolic response of human chondrocyte, as shown by the decrease in metalloproteases concentration and increase in anti-inflammatory mediators. Moreover, the clinical evaluation showed significant improvements in all scores adopted, with stable results up to two years.

CONCLUSION

The present data showed the effectiveness of the study device to harvest pure bone marrow with minimal peripheral blood contamination. The relevant content of MSCs resulted in the ability to counteract the catabolic cascade through a paracrine action. The clinical outcomes in patients affected by unicompartmental knee OA were encouraging in terms of pain reduction and functional improvement up to mid-term evaluation.

Platelet Concentrates in Musculoskeletal Medicine

Platelet concentrates (PCs), mostly represented by platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are autologous biological blood-derived products that may combine plasma/platelet-derived bioactive components, together with fibrin-forming protein able to create a natural three-dimensional scaffold. These types of products are safely used in clinical applications due to the autologous-derived source and the minimally invasive application procedure. In this narrative review, we focus on three main topics concerning the use of platelet concentrate for treating musculoskeletal conditions: (a) the different procedures to prepare PCs, (b) the composition of PCs that is related to the type of methodological procedure adopted and (c) the clinical application in musculoskeletal medicine, efficacy and main limits of the different studies.