Following historical "tracks" of hair follicle miniaturisation in patterned hair loss: Are elastin bodies the forgotten aetiology?

Signaling pathways in hair aging

Hair follicle (HF) homeostasis is regulated by various signaling pathways. Disruption of such homeostasis leads to HF disorders, such as alopecia, pigment loss, and hair aging, which is causing severe health problems and aesthetic concerns. Among these disorders, hair aging is characterized by hair graying, hair loss, hair follicle miniaturization (HFM), and structural changes to the hair shaft. Hair aging occurs under physiological conditions, while premature hair aging is often associated with certain pathological conditions. Numerous investigations have been made to determine the mechanisms and explore treatments to prevent hair aging. The most well-known hypotheses about hair aging include oxidative stress, hormonal disorders, inflammation, as well as DNA damage and repair defects. Ultimately, these factors pose threats to HF cells, especially stem cells such as hair follicle stem cells, melanocyte stem cells, and mesenchymal stem cells, which hamper hair regeneration and pigmentation. Here, we summarize previous studies investigating the above mechanisms and the existing therapeutic methods for hair aging. We also provide insights into hair aging research and discuss the limitations and outlook.

Vellus-to-terminal Hair Follicle Reconversion Occurs in Male Pattern Balding and is Promoted by Minoxidil and Platelet-rich Plasma: In Vivo Evidence from a New Humanized Mouse Model of Androgenetic Alopecia

Abstract is missing (Short communication)

Human Stem Cell Use in Androgenetic Alopecia: A Systematic Review

Androgenetic alopecia is a condition that results in hair loss in both men and women. This can have a significant impact on a person's psychological well-being, which can lead to a decreased quality of life. We conducted a systematic review to evaluate the efficacy of using stem cells in androgenic alopecia. The search was conducted in MEDLINE via PubMed, Web of Science, and Scopus databases. The review was performed on data pertaining to the efficacy of using different types of stem cells in androgenic alopecia: quantitative results of stem cell usage were compared to the control treatment or, different types of treatment for female and male androgenetic alopecia. Of the outcomes, the density of hair was analyzed. Fourteen articles were selected for this review. During and after treatment with stem cells, no major side effects were reported by patients with alopecia. The use of stem cells in androgenic alopecia seems to be a promising alternative to the standard treatment or it could play the role of complementary therapy to improve the effect of primary treatment. However, these results should be interpreted with caution until they can be reproduced in larger and more representative samples.

Hair regrowth treatment efficacy and resistance in androgenetic alopecia: A systematic review and continuous Bayesian network meta-analysis

Background

Androgenetic alopecia (AGA) affects almost half the population, and several treatments intending to regenerate a normal scalp hair phenotype are used. This is the first study comparing treatment efficacy response and resistance using standardized continuous outcomes.

Objective

To systematically compare the relative efficacy of treatments used for terminal hair (TH) regrowth in women and men with AGA.

Methods

A systematic literature review was conducted (from inception to August 11, 2021) to identify randomized, Placebo-controlled trials with ≥ 20 patients and reporting changes in TH density after 24 weeks. Efficacy was analyzed by sex at 12 and 24 weeks using Bayesian network meta-analysis (B-NMA) and compared to frequentist and continuous outcomes profiles.

Results

The search identified 2,314 unique articles. Ninety-eight were included for full-text review, and 17 articles met the inclusion criteria for data extraction and analyses. Eligible treatments included ALRV5XR, Dutasteride 0.5 mg/day, Finasteride 1 mg/day, low-level laser comb treatment (LLLT), Minoxidil 2% and 5%, Nutrafol, and Viviscal. At 24 weeks, the B-NMA regrowth efficacy in TH/cm² and significance (^**) in women were ALRV5XR: 30.09^**, LLLT: 16.62^**, Minoxidil 2%: 12.13^**, Minoxidil 5%: 10.82^**, and Nutrafol: 7.32^**, and in men; ALRV5XR: 21.03^**, LLLT: 18.75^**, Dutasteride: 18.37^**, Viviscal: 13.23, Minoxidil 5%: 13.13^**, Finasteride: 12.38, and Minoxidil 2%: 10.54. Two distinct TH regrowth response profiles were found; Continuous: ALRV5XR regrowth rates were linear in men and accelerated in women; Resistant: after 12 weeks, LLLT, Nutrafol, and Viviscal regrowth rates attenuated while Dutasteride and Finasteride plateaued; Minoxidil 2% and 5% lost some regrowth. There were no statistical differences for the same treatment between women and men. B-NMA provided more accurate, statistically relevant, and conservative results than the frequentist-NMA.

Conclusion

Some TH regrowth can be expected from most AGA treatments with less variability in women than men. Responses to drug treatments were rapid, showing strong early efficacy followed by the greatest resistance effects from flatlining to loss of regrowth after 12-16 weeks. Finasteride, Minoxidil 2% and Viviscal in men were not statistically different from Placebo. LLLT appeared more efficacious than pharmaceuticals. The natural product formulation ALRV5XR showed better efficacy in all tested parameters without signs of treatment resistance (see Graphical abstract).

Systematic review registration

www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42021268040, identifier CRD42021268040.

Case report: Two individuals with AEBP1-related classical-like EDS: Further clinical characterisation and description of novel AEBP1 variants

Introduction: AEBP1-related classical-like EDS (clEDS type 2) is a rare type of Ehlers-Danlos syndrome (EDS) that was first reported in 2016. There are overlapping clinical features with TNXB-related classical-like EDS (or clEDS type 1), including skin hyperextensibility, joint hypermobility, and easy bruising. There are currently nine reported individuals with AEBP1-related clEDS type 2. This report confirms previous findings and provides additional clinical and molecular data on this group of individuals. Materials and methods: Two individuals (P1 and P2), with features of a rare type of EDS, were clinically assessed in the London national EDS service and underwent genetic testing. Results: Genetic testing in P1 revealed likely pathogenic AEBP1 variants: c.821del:p. (Pro274Leufs*18) and c.2248T>C:p. (Trp750Arg). In P2 pathogenic AEBP1 variants, c.1012G>T:p. (Glu338*) and c.1930C>T:p. (Arg644*) were identified. Discussion: These two individuals increased the reported number of individuals with AEBP1-related clEDS to 11 (six females and five males). There are shared features with previously reported individuals, including hypermobility (11/11), skin hyperextensibility (11/11), presence of atrophic scarring (9/11), and easy bruising (10/11). In P1, a chronic right vertebral artery dissection, mild dilatation of the splenic artery, aberrant subclavian artery, and tortuous iliac arteries were observed at the age of 63 years. Cardiovascular disease has been reported, including mitral valve prolapse (4/11), peripheral arterial disease (1/11), and aortic root aneurysm requiring surgical intervention (1/11). Hair loss has been reported in 6/11 individuals (five females and one male), only one of which was documented to have a formal diagnosis of androgenetic alopecia, while other individuals were described as having thinning of hair, male pattern hair loss, or unspecified alopecia. Conclusion: The clinical features of individuals with AEBP1-related EDS have not been fully elucidated yet. Hair loss is present in 6/11 individuals with AEBP1-related clEDS and appears to be a feature of this condition. This is the first time hair loss has been formally reported as a characteristic feature in a rare type of EDS. Cardiovascular surveillance seems warranted in this condition because 2/11 individuals have evidence of arterial aneurysm and/or dissection. Further descriptions of affected individuals are necessary to update diagnostic criteria and management guidelines.

Sex differences in clinical trials of ALRV5XR treatment of androgenetic alopecia and telogen effluvium

Introduction

ALRV5XR treatment of androgenetic alopecia (AGA) and telogen effluvium (TE) has early evidence of regenerating a normal scalp hair phenotype in both sexes.

Design

We performed two 24-week double-blinded placebo-controlled comparison trials, one in each sex, on the ALRV5XR treatment effect on hair regeneration, in AGA and TE, in 92 AGA subjects (24 also had TE). Forty-six women (age 24–64 years) and 46 men (age 22–63 years) were randomized 1:1 to either ALRV5XR or placebo regimens (one b.i.d. oral capsule and daily administration of shampoo, conditioner, and follicle serum).

Evaluation

Primary outcomes: Absolute and relative changes in terminal hair (TH) density. Secondary outcomes: Response rate, changes in vellus hair (VH) density, TH/VH ratio, hair diameter, growth, and shedding rate.

Results

Forty-one women (20 ALRV5XR, 21 placebo) and 36 men (17 ALRV5XR, 19 placebo) completed the trials. TH outcome was evaluable for 18 and 21 women and 11 and 11 men (ALRV5XR, placebo, respectively). Efficacy in women: 30.1 THs/cm2 (p = 0.0002) and 19.7% (p = 0.0016). Efficacy in men: 21.0 THs/cm2 (p = 0.0014) and 16.4% (p = 0.0012). 66.7% of women and 100% of men responded to ALRV5XR. TH/VH ratio for men increased 33.0% (p = 0.0033). Growth rate in women increased by 30.7 μm/24 h (p < 0.0001) and 10.0% (p < 0.0001). There were no adverse events reported.

Conclusion and relevance

ALRV5XR induced significant regrowth of TH. Accelerating regrowth by reactivation of dormant telogen follicles were the dominant effects in women. Thickening of miniaturized hair and regrowth of dormant telogen follicles contributed equally to the increased TH seen in men (see Graphical Abstract).