Li Xiuting, Yew Yik Weng, Vinod Ram Keertana, Oon Hazel H, Thng Steven Tien Guan, Dinish U S, Olivo Malini
A⁎STAR Skin Research Labs (A⁎SRL), Agency for Science, Technology and Research (A⁎STAR), 31 Biopolis Way, #07-01 Nanos, Singapore 138669, Republic of Singapore.
National Skin Centre, Singapore.
Photoacoustics. 2024 Apr 23;38:100611. doi: 10.1016/j.pacs.2024.100611. eCollection 2024 Aug.
Psoriasis is a chronic inflammatory skin disease, characterized by thick scaly plaques. It imposes a notable disease burden with varying levels of severity affecting the quality of life significantly. Current disease severity assessment relies on semi-objective visual inspection based on the Psoriasis Area and Severity index (PASI) score that might not be sensitive to sub-clinical changes. Histology of psoriasis skin lesions necessitate invasive skin biopsies. This indicates an unmet need for a non-invasive, objective and quantitative approach to assess disease severity serially. Herein, we employ multispectral Raster-Scanning Optoacoustic Mesoscopy (ms-RSOM) derived structural and microvascular functional imaging metrics to examine the lesional and non-lesional skin in psoriasis subjects across different severities and also evaluate the treatment outcome in a subject with topical steroids and biologics, such as adalimumab. ms-RSOM derived structural metrics like epidermal thickness and total blood volume (TBV) and microvascular functional information such as oxygen saturation (sO) are evaluated by spectrally resolving the endogenous chromophores like melanin, oxy-, and deoxy-hemoglobin. Initial findings reveal an elevated sO and TBV with severity in lesional and non-lesional psoriasis skin, thus representing increasing inflammation. An increase in epidermal thickness is also noted with the degree of severity, corresponding to the inflammation and increased abnormal cell growth. As a marker to evaluate the treatment response, we observed a decrease in epidermal thickness, sO and TBV in a psoriasis patient post-treatment, which is consistent with the decrease in the PASI score from 4.1 to 1.9. We envision that ms-RSOM has a huge potential to be translated into routine clinical setting for the diagnosis of severity and assessment of treatment monitoring in psoriasis subjects.
银屑病是一种慢性炎症性皮肤病，其特征为有厚鳞屑斑块。它造成显著的疾病负担，严重程度各异，对生活质量有重大影响。目前的疾病严重程度评估依赖于基于银屑病面积和严重程度指数（PASI）评分的半客观视觉检查，该评分可能对亚临床变化不敏感。银屑病皮肤病变的组织学检查需要进行侵入性皮肤活检。这表明迫切需要一种非侵入性、客观且定量的方法来连续评估疾病严重程度。在此，我们采用多光谱光栅扫描光声显微镜（ms-RSOM）得出的结构和微血管功能成像指标，来检查不同严重程度的银屑病患者的皮损和非皮损皮肤，并评估一名使用局部类固醇和生物制剂（如阿达木单抗）治疗的患者的治疗效果。通过对黑色素、氧合血红蛋白和脱氧血红蛋白等内源性发色团进行光谱解析，评估ms-RSOM得出的结构指标，如表皮厚度和总血容量（TBV），以及微血管功能信息，如氧饱和度（sO）。初步研究结果显示，在皮损和非皮损的银屑病皮肤中，sO和TBV随严重程度升高，从而表明炎症加剧。还注意到表皮厚度随严重程度增加，这与炎症及异常细胞生长增加相对应。作为评估治疗反应的指标，我们观察到一名银屑病患者治疗后表皮厚度、sO和TBV下降，这与PASI评分从4.1降至1.9一致。我们设想，ms-RSOM在转化为常规临床应用以诊断银屑病严重程度和评估治疗监测方面具有巨大潜力。
