What’s new in hair — April 2015 | Dr. Claire A. Higgins
High Relapse Rates Despite Early Intervention with Intravenous Methylprednisolone Pulse Therapy for Severe Childhood Alopecia Areata.
Pediatr Dermatol. 2015 Apr 15. doi: 10.1111/pde.12578.
Alopecia areata is an autoimmune disease of the hair follicle, where onset is typically observed in patients under the age of 30. It is also common in adolescents, where the median age of onset is 10 years old. Intravenous methylprednisolone pulse therapy (IV-MPPT) has been suggested as a possible treatment for adolescents with severe alopecia, as it is both safe and effective. In this paper, Smith et al retrospectively evaluated 18 children (younger than 17) who had severe alopecia areata, and had been treated with IV-MPPT. They found that 7 months after treatment 10 of the 18 children had responded well and had hair regrowth. Unfortunately, they found that 7 of these 10 responders experienced relapse starting 8 months after treatment. They concluded that while IV-MPPT may modify the initial course of the disease, it does not impact the long-term outcome.
Int J Trichology. 2015 Jan-Mar;7(1):26-8. doi: 10.4103/0974-7753.153454.
Alopecia areata is an autoimmune disease, which results in inflammation induced hair loss. Triggering events result in a breakdown of immune privilege in the follicle, and infiltration of immune cells. In this paper, Bhardwaj and Trüeb describe a case of acute diffuse and total alopecia, a subtype of areata, which co-occurs with a Borrelia infection. They propose that this infection may have contributed to the auto immune reaction which underlies onset of alopecia. The patient was prescribed a course of intravenous ceftriaxone, topical clobetasol propionate, thyroid supplementation therapy and vitamin D3, and showed complete remission after 10 months.
Analysis of unique mutations in the LPAR6 gene identified in a Japanese family with autosomal recessive woolly hair/hypotrichosis: Establishment of a useful assay system for LPA.
J Dermatol Sci. 2015 Mar 18. doi: 10.1016/j.jdermsci.2015.03.006.
Woolly hair/hypotrichosis is a very rare hair disease that results in short and thin tightly curled hair. It is caused by mutations in either LIPH or LPAR6, which are both expressed in the inner root sheath of the hair follicle. The inner root sheath provides structural support and guidance to the hair shaft, and thus mutations in the inner root sheath can impact hair shaft structure. LIPH encodes phospholipase A, which produces LPA from phosphatidic acid, while LPAR6 codes for LPA6, which is an LPA receptor. In this paper, Hayashi et al describe a Japanese patient with a unique compound heterozygous mutation in LPAR6, causing woolly hair/hypotrichosis. They also developed a sensitive assay to evaluate LPA6 activation, to assess the impact of mutations on the LPAR6 on protein function.
Nature. 2015 Apr 6. doi: 10.1038/nature14306.
Hair follicles go through periods of growth (anagen), and degeneration (catagen), where there is controlled cell death within the epithelial portion of the follicle. Previously, the Greco group has shown that during growth, highly mitotic cells fuel downward movement of the basal epithelium. In this manuscript, they used several elegant transgenic mouse models to assess degeneration in the follicle. Mesa et al show that TGFβ signalling initiating from the dermal papilla induces cell death in the basal epithelium and onset of catagen. They go on to demonstrate that epithelial apoptotic debris is not removed by professional phagocytes, but rather by surviving basal epithelial cells, which act as phagocytes, supporting a model of epithelial self-clearance.
Enhancing hair follicle regeneration by nonablative fractional laser: Assessment of irradiation parameters and tissue response.
Wu YF, Wang SH, Wu PS, Fan SM, Chiu HY, Tsai TH, Lin SJ.
Lasers Surg Med. 2015 Apr;47(4):331-41. doi: 10.1002/lsm.22330.
In recent years, non-ablative laser treatment has been suggested as a therapy for hair loss. In this paper, Wu et al evaluated the effect of a 1550nm erbium glass laser on the telogen to anagen hair transition in mouse skin. The authors shaved eight week old mice, who have hair follicles in telogen, and treated them once with the laser inducing low levels of thermal injury in the skin. They found that at a beam density of 1048MTZ/cm2, and an energy of 15mJ, they could induce premature anagen re-entry in mice. The authors found that 1-3 days after laser treatment there was inflammation around the follicle, which later subsided. By 5 days they could observe proliferation in hair germs, followed 2 days later by proliferation in bulge stem cells. One theory related to plucking induced hair growth in mice is that injury and apoptosis in the hair germ can cause bulge stem cell activation. Perhaps low levels of thermal injury in the skin can have a similar effect, enabling premature anagen re-entry, like that observed here after non-ablative laser treatment.
Int J Trichology. 2015 Jan-Mar;7(1):16-23. doi: 10.4103/0974-7753.153451.
Hair follicle transplantation surgery was pioneered back in 1959 by Orentreich, and works because of a concept known as ‘donor dominance’. Essentially, the donor skin graft is dominant over the graft site, and thus retains its donor site characteristics. In this paper, Azar et al demonstrate that there is also a previously untold influence of the recipient tissue on the donor follicle. They analysed follicles taken from three donor sites; occipital scalp, beard and chest, which were transplanted into frontal scalp. Initially after transplantation, it is well known that hair follicles enter a dystrophic catagen, followed by a telogen phase prior to re-entry into anagen. Six months after grafting the authors theorized that the grafted follicles would have been in anagen for at least 2 months, and that any immune response from the transplant would have subsided. They analysed grafted follicles six months after transplanting, and compared them to native follicles. They found that both dermal papilla size, and the full length of transplanted follicles was significantly less than native follicles from the donor site. There were also large numbers of immune cell infiltrate around the grafted follicles, which the authors postulate may have an involvement in adapting the size of the follicle. It may be that the dystrophic catagen has more of an impact than previously anticipated on the follicle, or alternatively, that there are site driven changes that result in decreased papilla size, and a reduced follicle length after transplantation into frontal scalp.