In vivo reflectance confocal microscopy features of cutaneous microcirculation and epidermal and dermal changes in diffuse systemic sclerosis and correlation with histological and videocapillaroscopic findings.

Abstract

Videocapillaroscopy of the nail fold is the current gold standard to assess progressive changes of the capillary network in patients with systemic sclerosis (SSc). Reflectance confocal microscopy (RCM) is a non-invasive optical imaging tool that allows in vivo visualization of the skin structures and cutaneous microcirculation. To investigate qualitative and quantitative changes of the cutaneous microcirculation and dermal-epidermal alterations of SSc patients by RCM and to correlate the images with findings of videocapillaroscopy and histology. Ten patients affected by diffuse-type SSc with skin involvement and 10 healthy controls were enrolled. All subjects underwent RCM of the dorsal and ventral surfaces of the middle third of the left forearm and nailfold videocapillaroscopy. Skin biopsies for histological and immunohistochemical investigations were taken from 5 patients and 2 healthy controls. At RCM observation, the diameter, perimeter and area of cutaneous capillaries were significantly increased in comparison to healthy controls, as histologically confirmed, whereas blood flow speed was significantly slower. Videocapillaroscopy showed a pathologic pattern of disease activity in 8 SSc patients and was non-specific in the remaining 2. In addition, RCM showed epidermal atrophy, flattening of rete ridges and dermal fibrosis in 7 SSc patients with long-standing disease but not in 3 patients with a recent onset. RCM provides measurable morphological and functional findings of microcirculation in patients suffering from diffuse-type SSc. These findings can integrate with, but not substitute, those provided by standard videocapillaroscopy. In addition, unlike videocapillaroscopy, RCM allows the investigation of epidermal and dermal changes.