Quantitative assessments of physiological and biological parameters in psoriatic lesions and its correlations to the clinical severity of psoriasis.

Abstract

Twenty-nine psoriatics were examined using a model with clinical, physiological and pathological assessment parameters. The three parts in this assessment model include: (1) clinical assessment: psoriasis area and severity index (PASI); (2) assessment of skin physiology and microcirculation: water content of stratum corneum, water-holding capacity of stratum corneum, transepidermal water loss, intravital dynamic videocapillaroscopy-measuring the capillary diameters and blood cell velocity in proximal nailfold of ring finger, and fluorescence angiography-measuring transcapillary Na-fluorescein(NAF) diffusion; and (3) immunohistochemistry examination: markers of proliferation (Ki67Ag), differentiation (involucrin), and inflammation (neutrophil elastase, intercellular adhesion molecule-1(ICAM-1), endothelial leukocyte adhesion molecule-1(ELAM-1)). Our results showed both the transcapillary diffusion of NAF and the expression of cell markers-dermal neutrophil elastase, epidermal ELAM-1 and Ki67Ag--correlated significantly to PASI scores (P < 0.05, linear regression). According to our results, the increased capillary permeability and inflammation markers, and enhanced expression of Ki67Ag correlated very well with PASI score. These markers could serve as alternative methods for assessment of the clinical severity of psoriatic patients.