Vitiligo: analysis of grafting versus curettage alone, using melanocyte morphology and reverse transcriptase polymerase chain reaction for tyrosinase mRNA

Abstract

Metabolically inactive or dormant melanocytes are probably present within vitiligo areas, and may be activated by exogenous or endogenous stimuli.

Gene expression analysis of melanocortin system in vitiligo

“…Tyrosinase (TYR) and tyrosinase-related proteins (TRP1 and DCT) are closely related melanocytespecific gene products involved in melanogenesis and in the biology of melanocytes. Down-regulation of TYR mRNA expression has been documented in lesional skin of vitiligo patients [36]. Accordingly, in our previous study, a statistically significant decrease in TYR expression was observed in lesional skin compared to non-lesional skin of vitiligo patients and healthy control subjects (both p < 0.0001) [31].…”

“…In addition, levels of two genes encoding enzymes concerned with melanogenesis -tyrosinase-related protein-1 (TRP1) and dopachrome tautomerase (DCT) -were measured. The presence of mRNA expression of examined genes in skin of healthy controls and vitiligo patients became evident in QRT-PCR with a relatively large number (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) of amplification cycles.…”

MYG1, novel melanocyte related gene, has elevated expression in vitiligo

“…mRNA expression of tyrosinase, an essential marker for melanogenesis, was determined in the skin samples of the same patients to ensure that the samples faithfully represent melanocyte specific differences between lesional and nonlesional skin. Down-regulation of tyrosinase mRNA expression has been documented in lesional skin of vitiligo patients [9]. Accordingly, a statistically significant decrease in tyrosinase expression was observed in lesional skin of vitiligo patients (DCT = 0.2) compared to nonlesional skin of vitiligo patients (DCT = 2.8) and healthy control subjects (DCT = 1.7, both p < 0.0001).…”

Imuno-histoquímica para o diagnóstico precoce de vitiligo

“…Alguns autores acreditam que melanócitos permaneçam no vitiligo, mas sem atividade melanogênica (4,10,15,19) , porém Montes et al (13) , por microscopia eletrônica, e Le Poole et al (6) , por imuno-histoquímica, demonstraram ausência de melanócitos nas áreas despigmentadas do vitiligo. Em nosso estudo, o caso 3 mostra na pele lesada células localizadas na camada basal da epiderme lembrando melanócitos, porém não imunomarcadas pelo HMB-45 (Figura 2B) nem pelo Melan-A; acreditamos que essas células correspondam a melanócitos, porém apoptóticos, e por isso não apresentam imunomarcação.…”