Assessment of epidermal dendritic cell markers and T‐lymphocytes in psoriasis

Abstract

Epidermal dendritic and T-cell counts have been performed in lesional and non-lesional skin from 35 psoriatic patients. The aims were to investigate absolute changes and interrelationships between these cellular elements in psoriasis and to explain apparent discrepancies between these results and reports in the literature. In non-lesional skin, the most frequently expressed dendritic cell marker was CD1a. HLA-DR+ and alpha-mannosidase+ dendritic cells were approximately 50 per cent and S100+ cells were 25 per cent as frequent. T-lymphocytes were rare, CD4+ cells predominating. In lesional psoriatic epidermis, there was a definite increase (approximately two-fold) in the absolute number of CD1a+ dendritic cells. This differs from the conclusions from the majority of previous studies. However, when cell counts were expressed per unit area of vertical section, there was a decrease in CD1a+ cells in lesional skin, which is an explanation for this discrepancy. There was a greater increase in absolute HLA-DR+ cell counts, so that the numbers of cells expressing CD1a and HLA-DR were similar in lesional skin. S100 expression increased proportionately with CD1a+, but there was no absolute increase in alpha-mannosidase+ cells, which might represent a separate sub-population of dendritic cells. The greatest cellular increase was in T-lymphocytes, particularly CD8+. In lesional skin, direct correlations have been demonstrated between epidermal thickness, HLA-DR+ dendritic cells and T-lymphocytes, particularly CD8+ cells. We would suggest that the present method of quantification is of value for the analysis of absolute changes in epidermal infiltrates, particularly psoriasis, and could be applied to other epidermal pathologies.

Clinical immunology Density of Langerhans cells in chronic plaque psoriatic lesions before and after phototherapy

“…The number of LCs in lesional skin may differ depending on the phase of development of plaque, its time of duration, localization [21] and also a type of psoriasis (guttate or plaque) [8]. Different staining and counting methods, nonequivalent patients populations and differences in structure of healthy epidermis and acanthotic psoriatic epidermis may also influence the results [20,25,26].…”

“…The study group 25 individuals suffering from plaque psoriasis were included in the study, after giving written informed consent. They were randomly selected from patients referred to Phototherapy Unit of Dermatology Department of Medical University in Lodz, Poland.…”

A comparative study of psoriasis and psoriasiform lesion on basis of CD4 and CD8 cell infiltration

“…Studies investigating the pathogenesis of psoriasis conclude the essential role of CD8+ cells in psoriasis [5,6,14,18,21,22]. T lymphocytes in lesional skin showed CD8+ cell figured more strongly than C cells [23]. Psoriasiform lesions on the other hand have morphological features similar to psoriasis.…”

CD56brightCD16– NK cells accumulate in psoriatic skin in response to CXCL10 and CCL5 and exacerbate skin inflammation

“…In addition, activated NK cells are cytotoxic for immature but not mature dendritic cells, thus providing a critical checkpoint for induction of efficient immune responses. Dendritic cells are greatly increased in number in psoriatic skin [57][58][59][60][61]. In addition, psoriatic dendritic cells display maturation markers, such as abundant MHC class II, CD86 and CD83 [60,61].…”