Age-based inter-subject variability in platelet and white blood cell concentrations of platelet-rich plasma prepared using a new application to blood separation system

Platelet-Rich Plasma: Advances and Controversies in Hair Restoration and Skin Rejuvenation

BACKGROUND

Platelet-rich plasma (PRP) and its combined therapeutic modalities have catalyzed new possibilities in dermatology; however, limitations in evidence and lack of consensus remain among clinicians regarding optimal composition, protocol, technique, and application.

OBJECTIVE

To provide an update and analysis of the evidence for PRP in hair restoration and skin rejuvenation through review of recent available data, highlighting controversies and expert insights to guide future studies, and stimulate discourse and innovations benefitting patients.

METHODS

A structured review and expert analysis of PubMed publications before October 2023, with a focus on recent literature from January 2020 through October 2023.

RESULTS AND CONCLUSION

Growing literature supports the utility and benefits of PRP and related autologous products for applications for skin and hair, with strongest evidence for androgenetic alopecia and skin rejuvenation. However, this is limited by lack of consensus regarding best practices and protocols. Randomized, controlled trials with uniform metrics comparing outcomes of various compositions of autologous blood products, preparation methods, dosimetry, and frequency of treatments are still required. This will allow the medical discourse to grow beyond the realm of expert opinion into consensus, standardization, and more wide spread adoption of best practices that will benefit patients.

Individual immune cell and cytokine profiles determine platelet-rich plasma composition

OBJECTIVE

Platelet-rich plasma (PRP) therapy is increasingly popular to treat musculoskeletal diseases, including tendinopathies and osteoarthritis (OA). To date, it remains unclear to which extent PRP compositions are determined by the immune cell and cytokine profile of individuals or by the preparation method. To investigate this, we compared leukocyte and cytokine distributions of different PRP products to donor blood samples and assessed the effect of pro-inflammatory cytokines on chondrocytes.

DESIGN

For each of three PRP preparations (ACP®, Angel™, and nSTRIDE® APS), products were derived using whole blood samples from twelve healthy donors. The cellular composition of PRP products was analyzed by flow cytometry using DURAClone antibody panels (DURAClone IM Phenotyping Basic and DURAClone IM T Cell Subsets). The MESO QuickPlex SQ 120 system was used to assess cytokine profiles (V-PLEX Proinflammatory Panel 1 Human Kit, Meso Scale Discovery). Primary human chondrocyte 2D and 3D in vitro cultures were exposed to recombinant IFN-γ and TNF-α. Proliferation and chondrogenic differentiation were quantitatively assessed.

RESULTS

All three PRP products showed elevated portions of leukocytes compared to baseline levels in donor blood. Furthermore, the pro-inflammatory cytokines IFN-γ and TNF-α were significantly increased in nSTRIDE® APS samples compared to donor blood and other PRP products. The characteristics of all other cytokines and immune cells from the donor blood, including pro-inflammatory T cell subsets, were maintained in all PRP products. Chondrocyte proliferation was impaired by IFN-γ and enhanced by TNF-α treatment. Differentiation and cartilage formation were compromised upon treatment with both cytokines, resulting in altered messenger ribonucleic acid (mRNA) expression of collagen type 1A1 (COL1A1), COL2A1, and aggrecan (ACAN) as well as reduced proteoglycan content.

CONCLUSIONS

Individuals with elevated levels of cells with pro-inflammatory properties maintain these in the final PRP products. The concentration of pro-inflammatory cytokines strongly varies between PRP products. These observations may help to unravel the previously described heterogeneous response to PRP in OA therapy, especially as IFN-γ and TNF-α impacted primary chondrocyte proliferation and their characteristic gene expression profile. Both the individual's immune profile and the concentration method appear to impact the final PRP product.

TRIAL REGISTRATION

This study was prospectively registered in the Deutsches Register Klinischer Studien (DRKS) on 4 November 2021 (registration number DRKS00026175).

A randomized control trial of platelet-rich plasma in supporting the recovery of postpartum levator ani muscle trauma

BACKGROUND Pelvic floor dysfunction (PFD) is mostly caused by childbirth levator ani muscle (LAM) trauma. We hypothesized that platelet-rich plasma (PRP) therapy could support the recovery of LAM in postpartum trauma. METHODS A prospective, single-blind, randomized control study was enrolled in primigravid women from November 2016 to July 2019 at 21 health facilities in Jakarta, Indonesia. Subjects were injected with autologous PRP or placebo at LAM during perineorrhaphy after childbirth. The primary outcome was regaining LAM strength and reducing levator hiatal area at 3 months postpartum. The LAM strength was examined by perineometer (cmH₂O), and levator hiatal area was examined by transperineal ultrasound (cm²) at antenatal and 3 months after delivery. Mann–Whitney U test and Wilcoxon signed-rank test were used for analysis. The study was registered in clinicaltrials.gov: NCT03021954. RESULTS Among 240 women, 58 were eligible for analysis. There were no differences in LAM strength and levator ani hiatal area at 3 months postpartum between the two groups (p = 0.583 and p = 0.185, respectively). CONCLUSIONS PRP therapy did not show a difference in the muscle recovery healing process.

Assessment of Characteristics and Methodological Quality of the Top 50 Most Cited Articles on Platelet-Rich Plasma in Musculoskeletal Medicine

Background:

The wide range of clinical applications and controversial scientific evidence associated with platelet-rich plasma (PRP) therapy in musculoskeletal medicine requires an examination of the most commonly cited studies within this field.

Purpose:

To identify the 50 most cited articles on PRP, assess their study design, and determine any correlations between the number of citations and level of evidence (LoE) or methodological quality.

Study Design:

Cross-sectional study.

Methods:

The Web of Science database was queried to identify the top 50 most cited articles on PRP in orthopaedic surgery. Bibliometric characteristics, number of citations, and LoE were recorded. Methodological quality was evaluated using the Modified Coleman Methodology Score (MCMS), Methodological Index for Non-randomized Studies (MINORS), and Minimum Information for Studies Evaluating Biologics in Orthopaedics (MIBO). The Pearson correlation coefficient and Spearman correlation coefficient (r_S) were used to determine the degree of correlation between the number of citations or citation density and LoE, MCMS, MINORS score, and MIBO score. Student t tests were performed for 2-group comparisons.

Results:

The top 50 articles were published between 2005 and 2016 in 21 journals. The mean number of citations and citation density were 241 ± 94 (range, 151-625) and 23 ± 8, respectively, and the mean LoE was 2.44 ± 1.67, with 15 studies classified as LoE 1. The mean MCMS, MINORS score, and MIBO score were 66.9 ± 12.6, 16 ± 4.7, and 12.4 ± 3.7, respectively. No correlation was observed between the number of citations or citation density and LoE, MCMS, MINORS score, and MIBO score. A significant difference (P = .02) was noted in LoE in articles from the United States (3.56 ± 1.7) versus outside the United States (2 ± 1.5). Seven of the 8 in vivo studies were published between 2005 and 2010, whereas 19 of the 25 clinical outcome investigations were published between 2011 and 2016. Studies that were published more recently were found to significantly correlate with number of citations (r_S = –0.38; P = .01), citation density (r_S = 0.36; P = .01), and higher LoE (r_S = 0.47; P = .01).

Conclusion:

The top 50 most cited articles on PRP consisted of high LoE and fair methodological quality. There was a temporal shift in research from in vivo animal studies toward investigations focused on clinical outcomes.