RESUMEN
Background: Alopecia areata is an autoimmune disease that occurs as a result of the loss of the inherent immune privilege of the hair follicle. It has been recently demonstrated that the interferon-γ/interleukin-15 feedback loop that signals via the Janus kinase–signal transducer and activator of transcription pathway is critical to the breakdown of this immune privilege. Aims: To evaluate the immunological distribution of CD4+ T-cells, CD8+ T-cells, phosphorylated signal transducer and activator of transcription 1 and study its relation with the clinical and histopathological findings of the disease. Materials and Methods: A total of 30 patients of alopecia areata were included in the study. Following a detailed history and clinical examination, a scalp biopsy was performed. Histopathology was studied and immunohistochemistry was done to demonstrate the positivity and distribution of CD4+ T-cells, CD8+ T-cells and phosphorylated signal transducer and activator of transcription 1. Results: The follicular count, number of anagen and terminal hair were found to be decreased, whereas the catagen, telogen and vellus hair were found to be increased in number. A peribulbar CD4+ T-cell infiltrate was seen in 70% cases, whereas a CD8+ T-cell infiltrate was seen in 83.3% cases. An intrabulbar CD4+ T-cell infiltrate was seen in 26.7% cases, whereas a CD8+ T-cell infiltrate was seen in 70% cases. Among the 25 hair follicles dermal papilla identified, 36.8% cases were found to be positive for phospho-signal transducer and activation of transcription-1. Limitations: The drawbacks of our study included a small sample size and the use of only vertical sectioning for the scalp biopsy samples. Conclusion: Phosphorylated signal transducer and activator of transcription 1 positivity as an indicator of signalling via the Janus kinase-1/2 pathway was seen in 36.8% of our cases highlighting the integral role of this pathway in the pathogenesis of alopecia areata.
RESUMEN
Background: Accurate preparation of recipient area is a critical step in melanocyte-keratinocyte transplantation procedure for vitiligo. It is an important potential step for adaptation in the quest to achieve better results and ablative lasers potentially offer excellent precision over margin and depth control in achieving that. Objective: To compare between the two techniques used for recipient site preparation: Er:YAG laser ablation and mechanical dermabrasion for melanocyte-keratinocyte transplantation procedure in terms of re-pigmentation achieved and adverse effects seen. Methods: A randomized comparative trial was performed among 32 patients of stable vitiligo undergoing melanocyte-keratinocyte transplantation procedure. In Group A (n = 15), recipient site preparation was done with Er:YAG laser, and in Group B (n = 17), it was done with a motorized dermabrader. Patients of both groups were objectively assessed for re-pigmentation at 1, 3 and 6 months. Results: A total of 253.696 cm2 of depigmented surface was operated upon and re-pigmentation of 125.359 cm2 (49.4%) was achieved. On comparison between two groups, no statistical difference was found with respect to total re-pigmentation achieved (Group A: 54.67% vs Group B: 48.841%, P = 0.663) and grades of re-pigmentation achieved (P = 0.796). Occurrence of adverse events was also statistically similar in both the groups. Conclusion: This study did not reveal any statistically different outcome (in terms of re-pigmentation and adverse effects) between the two methods of recipient site preparation – motorized dermabrasion and Er:YAG ablation. Limitations: This study is small and larger studies are needed to ascertain the benefit of Er:YAG for recipient site preparation. Future studies may also ascertain variables such as time taken to prepare the recipient area, nature of bleeding, postoperative healing, difficulties in specific area, cost of the procedure, patient comfort and ease of the surgeon, rather than comparing the re-pigmentation alone.
RESUMEN
Vitamin D, originally associated with rickets and osteomalacia, has recently been shown to have a role in a number of medical and dermatological diseases. It has been found that vitamin D receptors and the enzymatic machinery capable of converting circulating 25-hydroxyvitamin D [25(OH)D] to the active 1,25-hydroxyvitamin D [1,25(OH)D] is present in most cells in the body including the skin. It is well known that vitamin D analogs are effective in the treatment of psoriasis vulgaris because of their anti-proliferative and pro-differentiating effects on keratinocytes. However, new roles have been found for vitamin D in skin, such as immunomodulatory and anti-apoptotic effects thus raising a possibility of its use in conditions such as atopic dermatitis and infections. Increasing evidence now indicates that cutaneous vitamin D synthesis may help in prevention of skin malignancies and further, that cancer mortality may be reduced by oral supplementation of vitamin D. Various epidemiological studies have linked low levels of vitamin D to autoimmune diseases including vitiligo, and topical vitamin D has been used to treat vitiligo. This review focuses on a wide array of roles of vitamin D in various skin disorders with emphasis on both its well-established role as in psoriasis and the less characterized role in other disorders such as ichthyosis, tuberculosis or acne.