Loss of melanocytes cells means loss of melanin, or pigmentation of the skin, the well-known characteristic of vitiligo, which shows up as patchy white smooth areas covering different parts of the face, torso and limbs. Melanocytes are found in skin, hair and eyes and their presence determines an individual’s coloration. They are also found in the inner ear, the eye and the leptomeninges of the brain. The melanocytes that cause white patches to appear on the skin surface are located in the immediate skin surface or epidermis.
It is not the number of cells that determines the final look and color of an individual, but the activity of the melanocyte cells. Minute structures known as melanosomes in each cell produce melanin and the darker the appearance of a person, the more melanin is present. It is the melanosomes that respond to light, such as UBV (ultraviolet rays) and usually form clusters at the center of the cell but quickly rearrange at the end of dendritic processes projecting from each cell. The melanocytes provide melanin to roughly thirty keratinocytes via the dendrite process. Loss of pigmentation is a result of a change in melanocytes cells and a decrease in the activity described. Vitiligo and other atopic skin disorders are a result of a decrease in production of melanin, whereas hyperpigmentation, which affects some women during pregnancy, is caused by an increase in melanocytes cell activity.
Melanoma or skin cancer is a common malignant tumor known to be a mutant melanocyte and can be found in all racial types but is more prevalent among people with fair skin of Caucasian origin. Most of these tumors look like dark moles that spread in irregular shapes. It is the substance, melanin, which is responsible for the color of the skin and also for protecting the skin from dangerous UVA and UVB rays. Skin cancers are associated with a fair complexion where melanocytes cells are less active.
In a recently developed vitiligo treatment, melanocytes cells are transplanted from healthy normal skin-colored sites of the vitiligo sufferer to the depigmented sites. The procedure takes approximately an hour and is performed under sterile conditions using aseptic techniques. Under local anaesthetic a small, thin area of skin is taken from an area where normal coloration still exists. The sample skin is processed to produce a pre-confluent mix of epidermal cells which is then applied to a prepared area of vitiligo. The melanocytes cells attach themselves to the prepared recipient site. The site of the transplant is then covered for at least a week.
One other transplant procedure includes removal of graft samples from the arm or forearm by electric vacuum suction. The top of the blister is transferred either to the prepared vitiligo area or used to externally produce autologous melanocyte cultures for later transplant to the white patches. In both transplant tests, whether a direct transplant or via a culture, the site of the transfer is covered with dressing for a minimum of a week. In spite of some technical limitations with the autologous melanocytes cell culture, when these transplants are combined with PUVA therapy this form of treatment shows good results. Observations at six months reveal one hundred percent repigmentation. The conclusions of this dermatological test reveals the need to develop multiple grafting sessions to treat the most stubborn patches of vitiligo.
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