Platelet-Rich Plasma Monotherapies for Androgenetic Alopecia: A Network Meta-Analysis and Meta-Regression Study

September 2022 | Volume 21 | Issue 9 | 943 | Copyright © September 2022


Published online August 16, 2022

Aditya K. Gupta MD PhD FAAD FRCPCa,b, Mary A. Bamimore PhDa

aMediprobe Research Inc., London, Ontario, Canada
bDivision of Dermatology, Department of Medicine, University of Toronto School of Medicine, Toronto, Ontario, Canada

Abstract
Introduction: Platelet-rich plasma (PRP) is a commonly used therapeutic option for androgenetic alopecia (AGA). Evidence syntheses for the impact of PRP on AGA has been handicapped by non-standardized protocols for its administration. We quantitatively synthesized the evidence base to determine the relative efficacy of PRP regimens with different frequencies of administration. We defined frequency as a vector of the (i) number of sessions and (ii) time interval between the sessions.
Methods: We systematically reviewed the peer-reviewed literature to obtain relevant data; we then conducted a multivariable meta-regression and network meta-analyses (NMAs).
Results: Twenty-five trials met our eligibility criteria; 10 unique PRP regimens were ultimately identified for use in our analyses. Our NMAs produced surface under the cumulative ranking curve (SUCRA) values that corroborated the findings of our multivariable meta-regression. The frequency of PRP sessions, chemical activation, number of centrifugations, the age and sex of the patient, and the design of PRP administration (ie, whole-head vs split-scalp) are correlated with the efficacy of PRP insofar as the mean change in total hair density at 6 months from baseline.
Conclusions: For the most part, regimens’ SUCRA rankings and relative effects support that the efficacy of PRP administration increases when: (i) the number of sessions increases and (ii) the time interval between sessions decreases; we found that chemically-activated PRP (vs inactivated), double centrifugation (vs single), younger (vs older) age of treated patients, female (vs male) sex, and whole-head (vs split-scalp) administration is associated with improved PRP efficacy. Our approach rules out much confounding as the analysis of our outcome was exclusive to monotherapy at a singular timepoint. Our results may reconcile discrepant findings among previous studies and may be helpful in updating clinical practice guidelines.
 
J Drugs Dermatol. 2022;21(9):943-952. doi:10.36849/JDD.6948

INTRODUCTION

Many individuals worldwide are negatively affected by androgenetic alopecia (AGA), a form of hair loss whose etiology involves abnormal androgen biochemistry.1-3 The Food and Drug Administration (FDA)-approved treatments are oral finasteride, topical minoxidil (2% and 5% concentrations), and low-level laser therapy (LLLT).1,2 Platelet-rich plasma (PRP) is a recent therapeutic option for AGA3; however, it is not FDA-approved for treating the condition. There is a general technique for administering PRP to persons with AGA: in short, blood is drawn from the patient, centrifuged to increase platelet concentration, and then injected into the scalp. This technique is currently not standardized as PRP regimens may vary in their parameters including the number of PRP sessions and interval between the sessions.4 This lack of homogeneity may explain the variation in clinical results reported throughout the literature. The lack of standardization may be attributed in part to the fact that PRP, an autologous therapy, is not FDA-regulated.4

The objective of the current study was 2-fold: we first wanted to identify patient- and protocol-related factors that may be associated with the efficacy of PRP monotherapy using a multivariable meta-regression; we then determined the relative efficacy of ‘different PRP regimens’ using Bayesian network meta-analyses (NMAs).

In this paper, regimen corresponds to the composite of (i) number of PRP sessions, (ii) the interval (ie, time lag) between the sessions, and (iii) other factors that can be associated with PRP’s efficacy including number of spins.

MATERIALS AND METHODS

The protocol for our work was registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY) (registration number: INPLASY202170088).5 We searched the peer-reviewed literature through the CINAHL, EMBASE (Ovid), PubMed, Scopus, and Web of Science databases on July 27, 2021. Searches were followed by removal of duplicates, followed by screening of title and abstracts; then, full texts were reviewed. Studies that were eligible for quantitative analyses were trials on PRP monotherapy for AGA that were published in English, used objective clinical endpoints,