Allergic contact dermatitis in psoriasis patients: typical, delayed, and non-interacting.

Psoriasis is characterized by an apoptosis-resistant and metabolic active epidermis, while a hallmark for allergic contact dermatitis (ACD) is T cell-induced keratinocyte apoptosis. Here, we induced ACD reactions in psoriasis patients sensitized to nickel (n = 14) to investigate underlying mechanisms of psoriasis and ACD simultaneously. All patients developed a clinically and histologically typical dermatitis upon nickel challenge even in close proximity to pre-existing psoriasis plaques.

Thymic stromal lymphopoietin links keratinocytes and dendritic cell-derived IL-23 in patients with psoriasis.

Background: Thymic stromal lymphopoietin (TSLP) is a major proallergic cytokine that promotes TH2 responses through dendritic cell (DC) activation. Whether it also plays a role in human autoimmune inflammation and associated pathways is not known.

Objective: In this study we investigated the potential role of several epithelium-derived factors, including TSLP, in inducing IL-23 production by human DCs.

In situ identification of CD44+/CD24- cancer cells in primary human breast carcinomas.

Breast cancer cells with the CD44+/CD24- phenotype have been reported to be tumourigenic due to their enhanced capacity for cancer development and their self-renewal potential. The identification of human tumourigenic breast cancer cells in surgical samples has recently received increased attention due to the implications for prognosis and treatment, although limitations exist in the interpretation of these studies. To better identify the CD44+/CD24- cells in routine surgical specimens, 56 primary breast carcinoma cases were analysed by immunofluorescence and confocal microscopy, and the results were compared using flow cytometry analysis to correlate the amount and distribution of the CD44+/CD24- population with clinicopathological features.

Lichenoid red tattoo reaction: histological and immunological perspectives.

As tattooing practices increase, delayed-type inflammatory reactions represent an uncommon adverse event to tattoo pigments. Different reaction patterns, such as eczematous, lichenoid, granulomatous and pseudolymphomatous reactions, have been previously reported, especially in association with metals contained in red tattoo pigments. We report a lichenoid papular reaction to an organic red tattoo ink, characterized by an intense mononuclear infiltrate dominated by CD8(+) T cells and CD56(+) lymphocytes and distributed in the superficial dermis around the red pigment and in the epidermis.