Characterization of follicular minoxidil sulfotransferase activity in a cohort of pattern hair loss patients from the Indian Subcontinent

Recent Advances in Understanding of the Etiopathogenesis, Diagnosis, and Management of Hair Loss Diseases

Hair-loss diseases comprise heterogenous conditions with respective pathophysiology and clinicopathological characteristics. Major breakthroughs in hair follicle biology and immunology have led to the elucidation of etiopathogenesis of non-scarring alopecia (e.g., alopecia areata, AA) and cicatricial alopecia (e.g., lichen planopilaris, LPP). High-throughput genetic analyses revealed molecular mechanism underlying the disease susceptibility of hair loss conditions, such as androgenetic alopecia (AGA) and female pattern hair loss (FPHL). Hair loss attracted public interest during the COVID-19 pandemic. The knowledge of hair loss diseases is robustly expanding and thus requires timely updates. In this review, the diagnostic and measurement methodologies applied to hair loss diseases are updated. Of note, novel criteria and classification/scoring systems published in the last decade are reviewed, highlighting their advantages over conventional ones. Emerging diagnostic techniques are itemized with clinical pearls enabling efficient utilization. Recent advances in understanding the etiopathogenesis and management for representative hair diseases, namely AGA, FPHL, AA, and major primary cicatricial alopecia, including LPP, are comprehensively summarized, focusing on causative factors, genetic predisposition, new disease entity, and novel therapeutic options. Lastly, the association between COVID-19 and hair loss is discussed to delineate telogen effluvium as the predominating pathomechanism accounting for this sequela.

Pharmacological Management of Pattern Hair Loss

Pattern hair loss (PHL) is a condition that worsens with time and the only way it can be slowed down is with pharmacological intervention. Pharmacological treatments for PHL, from an evidenced-based perspective with respect to safety and efficacy, are limited to only two drugs, minoxidil and finasteride. However, there are a host of drugs being used, off-label with limited evidence. This article attempts to review the literature on this topic, and the authors add to this, with their experience of over two decades on incorporating pharmacologic treatments along with hair transplantation in their management of PHL.

SULT1A1 (Minoxidil Sulfotransferase) enzyme booster significantly improves response to topical minoxidil for hair regrowth

BACKGROUND

Minoxidil is a widely used over-the-counter topical treatment for hair loss. The response rate for topical minoxidil is relatively low. Minoxidil is a pro-drug, converted to its active form, minoxidil sulfate, by SULT1A1 enzymes located in the scalp. Recently, a novel topical formula that increases the activity of SULT1A1 in hair follicles was reported.

AIMS

To evaluate any benefit of applying the SULT1A1 enzyme booster prior to daily 5% minoxidil treatment.

METHODS

Male androgenic alopecia patients were recruited to a randomized blinded placebo-controlled study. Patients were randomized to receive 5% topical minoxidil plus the novel formula or minoxidil plus a sham adjuvant. Patient's hair growth was monitored using global photography over 60 days.

RESULTS

Twenty-four males with androgenic alopecia (Norwood scale average 4.4, range 2-6) were randomized and completed the trial: 12 in the active arm and 12 in placebo. 75% of the subjects who used the SULT1A1 adjuvant with their daily minoxidil treatments for 60 days regrew hair versus 33% of those using the placebo adjuvant (p = 0.023).

CONCLUSIONS

In a small cohort of androgenetic alopecia men, adding the SULT1A1 adjuvant to their daily minoxidil treatment regimen improved hair regrowth.

Low-level laser therapy and narrative review of other treatment modalities in androgenetic alopecia

Androgenetic alopecia (AGA), also termed as androgenic alopecia or common baldness, is a condition where there is androgen mediated conversion of susceptible terminal hair into vellus hair. Although it is reported more commonly in males, it also affects females but the incidence is relatively unknown. AGA tremendously affects the psychology of the patient due to its chronicity of treatment and cosmetic implications. There are numerous treatment options available for AGA but the choice of treatment has to often be tailored according to the patient's needs, affordability, and compliance. This review focusses on the various treatment options available, with special emphasis on the role of low-level laser therapy (LLLT) in the management of AGA. The literature research considered published journal articles (clinical trials or scientific reviews). Studies were identified by searching electronic databases (MEDLINE and PubMed) and reference lists of respective articles. Only articles available in English were considered for this review.

Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes

Minoxidil sulfate is the active metabolite required to exert the vasodilatory and hair growing effects of minoxidil. For hair growth, sulfotransferase enzymes expressed in outer root sheath of the hair follicle sulfonate minoxidil. The large intra-subject variability in follicular sulfotransferase was found to predict minoxidil response and thus explain the low response rate to topical minoxidil in the treatment of androgenetic alopecia. A method to increase minoxidil response would be of significant clinical utility. Retinoids have been reported to increase minoxidil response. The purported mechanism of action was retinoid modulation of skin permeation to minoxidil; however, evidence to the contrary supports retinoids increase dermal thickness. In order to elucidate the effect of topical retinoids on minoxidil response, we studied the effect of topical tretinoin on follicular sulfotransferase. In this study, we demonstrate that topical tretinoin application influences the expression of follicular sulfotransferase. Of clinical significance, in our cohort, 43% of subjects initially predicted to be nonresponders to minoxidil were converted to responders following 5 days of topical tretinoin application. To the best of our knowledge, this is the first study to elucidate the interaction mechanism between topical minoxidil and retinoids and thus provides a pathway for the development of future androgenetic alopecia treatments.