Oral Presentation ASPCR-ASDR Conference 2013

A quantitative approach to histopathological dissection of elastin-related disorders using multiphoton microscopy (#71)

Philip L Tong 1 2 3 , Jim Qin 3 , Caroline L Cooper 4 5 , Patricia M Lowe 1 2 , Dedee F Murrell 6 7 , Steven Kossard 8 , Lai Guan Ng 9 , Ben Roediger 3 , Wolfgang Weninger 1 2 3 , Nikolas K Haass 1 2 3 10
  1. Discipline of Dermatology, University of Sydney, Camperdown, NSW, Australia
  2. Department of Dermatology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia
  3. Centenary Institute, Newtown, NSW, Australia
  4. Sydney Medical School, University of Sydney, Camperdown, NSW, Australia
  5. Tissue Pathology and Diagnostic Oncology , Royal Prince Alfred Hospital, Camperdown, NSW, Australia
  6. Faculty of Medicine, University of New South Wales, Randwick, NSW, Australia
  7. Department of Dermatology, St. George Hospital, Kogarah, NSW, Australia
  8. Skin and Cancer Foundation, Darlinghurst, NSW, Australia
  9. Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore
  10. University of Queensland Diamantina Institute, Woolloongabba, QLD, Australia

Background: Multiphoton microscopy (MPM) is a novel imaging technology that has recently become applicable for diagnostic purposes. The use of (near) infrared light in MPM allows for deep tissue imaging. In addition, this modality exploits the autofluorescent nature of extracellular matrix fibres within the skin.

Objective: The aim of this study was to quantitate the structure and abundance of elastic fibres in human dermis in three dimensions utilizing autofluorescent signals generated by MPM for the objective examination of elastin-related skin disorders.

Methods: Cross-sections of skin samples from elastin-related disorders were analysed by MPM and correlated to histopathological examination. In situ visualisation of elastic fibres by MPM was conducted by en face imaging of ex vivo skin samples through the intact epidermis. Image analysis software was used to quantify elastic fibres in three dimensions.

Results: Based on the MPM-detected autofluorescence specific for elastin, we developed the Dermal Elastin Morphology Index (DEMI), calculated as the ratio of elastic fibre surface area and volume. This enabled objective three-dimensional quantification of elastic fibres. Quantitative scoring of sun-damaged skin using the DEMI correlated with qualitative histopathological grading of the severity of solar elastosis. Furthermore, this approach was applied to changes in elastin in other elastin-related skin disorders, such as pseudoxanthoma elasticum (PXE), PXE-like syndrome, elastofibroma, focal dermal elastosis, anetoderma, mid-dermal elastolysis and striae distensae. We also imaged elastic fibres in intact ex vivo skin imaged en face through the epidermis, indicating that this approach could be used in patients in vivo.

Conclusions: MPM has the potential for non-invasive in vivo visualisation of elastic fibres in the dermis with near histological resolution. The DEMI is a novel approach to enable objective assessment of elastic fibres to support diagnosis as well as monitoring of disease progress or therapy of elastin-related skin disorders.