Antígenos de histocompatibilidade humanos e dermatologia: da pesquisa para a prática clínica

Abstract

Abstract:The participation of the human histocompatibility system (HLA: human leukocyte antigens) in the pathogenesis of autoimmune diseases is well known. Situated on the short arm of chromosome 6, the HLA system is very polymorphic and has the capacity to confer susceptibility or resistance to different diseases. In Dermatology, this system has an important participation in the pathogenesis and natural course of various diseases. The strength and type of association differ with conditions and sometimes with the ethnic-racial group studied. The discovery of molecular methods to typify HLA alleles and recent updates in its nomenclature has contributed to a better understanding of this system. Unfortunately, this information has not been adequately transmitted in the literature, hindering identification of the association of the HLA with skin diseases. In this review, some aspects of the HLA system are discussed, such as methods of detection, nomenclature and association with vitiligo, pemphigus, psoriasis, lupus erythematosus, scabies, cutaneous leishmaniasis, leprosy, paracoccidiodomycosis and atopic dermatitis.

HLA molecules and nasal carriage of Staphylococcus aureus isolated from dialysis and kidney transplant patients at a hospital in Southern Brazil

“…Class II molecules are distributed less widely, being found primarily on the surface of cells linked directly to the immune response (such as macrophages, monocytes, dendritic cells, Langerhans cells, B lymphocytes, and activated T lymphocytes), with the purpose of presenting peptides to regulatory T cells (CD4 + ). The class III region does not encode histocompatibility molecules, but rather other molecules such as tumor necrosis factors, C4 and C2 proteins, complement factor B, heat shock protein, and 21-hydroxylase enzyme [9-12]. …”

HLA and skin cancer

“…Although studies that seek to establish a relationship between the presence of specific HLA antigens and the development of skin cancer are difficult to perform and prone to significant confusion bias, they are essential and need to be conducted. 38 Further research studies with different antigens in different populations are probably needed so that reliable results are obtained and transferred to clinical practice. ❑…”

Estudo comparativo entre reação de Mitsuda e antígenos leucocitários humanos em pacientes hansenianos

“…A discordância entre os resultados obtidos em nosso estudo com os dados da literatura pode ser justificada nas características peculiares que envolvem o complexo HLA, como o polimorfismo, herança genética, a variação da freqüência dos alelos observada entre as diferentes etnias 15 , além do pequeno número de pacientes envolvidos. Sendo assim, estudos neste contexto devem ser analisados individualmente para que suas particularidades sejam percebidas 1 . Quando analisados os grupos de acordo com a resposta ao teste de Mitsuda, no grupo com reação de Mitsuda negativa, foi possível detectar associação estatisticamente significante em nível descritivo de 0,002, pelo teste do Qui-quadrado, sugerindo o envolvimento do alelo HLA-DQ1 na resposta imune deficiente contra o M. leprae, corroborando os dados da literatura 3 15 .…”