Intravital Monitoring of Psoriasis Treatment Response and Drug Delivery Using Multiphoton Fluorescence Lifetime Imaging.

backgroundMultiphoton tomography equipped with fluorescence lifetime imaging (MPT-FLIM) is a novel noninvasive imaging technique for analyzing morphological and metabolic states of skin diseases at a subcellular resolution. The present study is the first to establish MPT-FLIM as an imaging modality to monitor treatment response in psoriasis during topical anti-inflammatory therapy. MATERIALS AND

methodsPatients with psoriasis treated with topical calcipotriol/ betamethasone dipropionate (C/B) or a calcipotriol derivative (C/-) formulation were recruited and monitored using MPT-FLIM. Imaging was performed at baseline on day 0, and during treatment on days 3 and 28.

resultsA total of six patients prescribed C/B, six patients prescribed C/- and four healthy controls were recruited. Characteristic histological features were visualized, including acanthosis, parakeratosis, papillomatosis, and thinning of the granular layer. There was a strong correlation between clinical, multiphoton tomographic, and pathophysiological improvement during treatment. Assessment of subclinical metabolic changes was a predictive parameter for treatment outcome. Detection of fluorescence signals from drug components allowed for tracking of drug distribution in intra- and intercellular spaces.

conclusionMPT-FLIM proved to be a suitable tool for monitoring treatment response in psoriasis patients and tracking drug delivery. It could be a potential method for monitoring other inflammatory skin diseases during treatment to adjust therapy on an individual level.