PMC9551172_01
PMC9551172_02
PMC9551172_03
PMC9551172_04
Selection of target lesions and control sites for optical coherence tomography (OCT). Patient 3 was a 45-year-old male patient with plaque psoriasis showing PASI = 10.8 and BSA = 10% at baseline. A representative target lesion (blue) on his trunk was selected for 52 weeks monitoring. A perilesional location was selected as the control site (gray). The scans were performed repetitively at the same lesional and non-lesional location.
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F1
The thickened ETL decreased during the observation period under therapy (Figure 4, row 1). In good agreement with the OCT measurements, the clinical severity was reduced in the target lesion (TSS) and in the global assessment (PASI or EASI) (Supplementary Figure 1).
Optical coherence tomography (OCT) imaging parameters for objective quantification of skin inflammation. Epidermal thickness (ET), vascular density rho, plexus depth theta, vessel diameter delta, and vessel count N were calculated in unaffected skin (control) and in target lesions (psoriasis and atopic dermatitis) at baseline. Lesional inflammatory skin exhibited increased epidermal thickness denoted by green lines and alterations in vasculature in comparison to control sites. The vascular density is exemplarily shown at 400 mum depth and the vessel diameter is shown at 600 mum depth. The plexus depth is indicated by white arrows. The vessel count was performed at 200 mum depth.
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F2
Characteristic vascular patterns and shapes were visible in the en-face mode at about 200 mum depth (Supplementary Figure 2).
Optical coherence tomography (OCT) guided monitoring of biologic therapy in psoriasis and atopic dermatitis. Patient 3 with psoriasis (P3) was treated with certolizumab (top) and patient 4 with atopic dermatitis (A4) was treated with dupilumab (bottom) for t = 52 weeks. The vertical B-scans and the corresponding en-face scans at 400 mum depth were collected in the course of therapy. Hyperkeratotic psoriatic plaques led to a signal reduction at baseline. Under therapy a decrease of the epidermal thickening (arrows) and a normalization of the vascularization (red signal) were observed in psoriasis and atopic dermatitis. No significant changes were detected in the control sites (C3 and C4).
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F3
In line with clinical and histopathological findings, at baseline we measured a thicker ETL in psoriasis due to hyperkeratosis (Figure 3, top). A similar observation was made in atopic dermatitis where the increased ETL was due to spongiosis and/or lichenification (Figure 3, bottom). The higher rhoL from baseline decreased after therapy start as a result of reduction in vessel diameter and/or vessel count (Supplementary Figure 3).
Monitoring therapy response using optical coherence tomography (OCT). In psoriasis (P1-P3) and atopic dermatitis (A4), the epidermal thickness (ET) was fitted to calculate the exponential decay rate or response rate lambda. The vessel count N was calculated using ImageJ (U.S. National Institutes of Health, Bethesda, MD, USA). After 52 weeks of treatment, we observed a full normalization of the increased epidermal thickness and the vessel count. The vascular parameters such as vascular density rho, vessel diameter delta, and plexus depth theta were calculated by using the proprietary VivoSight vessel analysis software (Michelson Diagnostics, Maidstone, Kent, UK). Prior to treatment, the vascular density in inflamed skin was higher than in the control areas. Interestingly, we observed an upward shift of the plexus depth and smaller vessel diameters in psoriatic skin in comparison to the control at baseline. Eczematous skin showed larger vessel diameters. As a potential sign of therapy response, the vascular parameters normalized during therapy course. For correlation, the total sign score (TSS) was used to clinically assess the target lesions and their control sites. For psoriasis, erythema E, induration I, and desquamation D were assessed using a 5-point scale (0-12). For atopic dermatitis, six clinical signs including erythema E, papulation I, excoriation Ex, lichenification Li, crusting C, and dryness Dr were graded using a 4-point scale (0-18).
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F4
The thickened ETL decreased during the observation period under therapy (Figure 4, row 1). After 52 weeks, we observed a full normalization of the vessel count (Figure 4, row 5).