Differential proliferation of endothelial cells and keratinocytes in psoriasis and spongiotic dermatitis

Ex vivo fluorescence confocal microscopy for intraoperative, real-time diagnosis of cutaneous inflammatory diseases: A preliminary study

Ex vivo fluorescence confocal microscopy (FCM) is an innovative imaging tool that can be used intraoperatively to obtain real-time images of untreated excised tissue with almost histologic resolution. As inflammatory diseases often share overlapping clinical features, histopathology evaluation is required for dubious cases, delaying definitive diagnoses, and therefore therapy. This study identifies key-features at ex vivo FCM for differential diagnoses of cutaneous inflammatory diseases, in particular, psoriasis, eczema, lichen planus and discoid lupus erythematosus. Retrospective ex vivo FCM and histological evaluations with relevant diagnoses were correlated with prospectively reported histopathologic diagnoses, to evaluate agreement and the level of expertise required for correct diagnoses. We demonstrated that ex vivo FCM enabled the distinction of the main inflammatory features in most cases, providing a substantial concordance to histopathologic diagnoses. Moreover, ex vivo FCM and histological evaluations reached a substantial agreement with histopathologic diagnoses both for all raters and for each operator. After a yet to be defined learning curve, these preliminary results suggest that dermatologists may be able to satisfactorily interpret ex vivo FCM images for correct real-time diagnoses. Despite some limitations mainly related to the equipment of FCM with a single objective lens, our study suggests that ex vivo FCM seems a promising tool in assisting diagnoses of cutaneous inflammatory lesions, with a level of accuracy quite close to that offered by histopathology. This is the first study to investigate ex vivo FCM application in cutaneous inflammatory lesions, and to evaluate the diagnostic capability of this technology.

Hsp72 antigen expression in the proliferative compartment of involved psoriatic epidermis

Oxidative damage to growth regulatory proteins has been implicated in the aetiology of psoriasis. However, the transient synthesis of heat shock proteins has been shown to protect cells against the adverse effects of oxidative and other forms of physiological stress. This study has used an hsp72 monoclonal antibody to measure inducible 72 kDa heat shock protein expression in heat stressed normal human skin and established plaque psoriasis. Hsp72 was detected in the basal and suprabasal layer cells of heat-stressed normal skin, and in 12 involved psoriasis lesions. Hsp72 expression was not detected in unstressed normal skin or in 12 cases of uninvolved psoriasis. Immunoprecipitation and Western blotting of cell lysates from heat stressed normal skin and involved psoriasis lesions confirmed the presence of a 72 kDa polypeptide with hsp72 immunoreactivity. The MIB-1 monoclonal antibody was used to determine the proliferative fraction of normal and involved psoriastic epidermis. The Ki67 antigen was localised to the nuclei of basal and suprabasal layer cells of normal and involved psoriatic epidermis. Involved psoriatic epidermis contained a higher number of proliferating keratinocytes when compared with normal skin. The study has also demonstrated a strong correlation between hsp72 expression and keratinocyte proliferation in involved psoriatic epidermis (r=0.864, p<0.001). We believe that the 72 kDa inducible heat shock protein performs a protective function in the proliferative compartment of normal and involved psoriatic skin.