Extracorporeal Photopheresis and Its Use in Clinical Dermatology in Canada

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy that has been used for over 35 years to treat numerous conditions. ECP was initially approved by the US FDA in 1988 for the treatment of Sézary syndrome, a leukemic form of cutaneous T-cell lymphoma (CTCL). Although CTCL remains the only FDA-approved indication, ECP has since been used off-label for numerous other conditions, including graft-versus-host disease (GvHD), systemic sclerosis, autoimmune bullous dermatoses, Crohn's disease, and prevention of solid organ transplant rejection. In Canada, ECP is mainly used to treat CTCL, acute and chronic GvHD, and in some instances systemic sclerosis. Herein, we review the current concepts regarding ECP mechanism of action, treatment considerations and protocols, and efficacy.

Optical coherence tomography angiography of normal skin and inflammatory dermatologic conditions

BACKGROUND

In clinical dermatology, the identification of subsurface vascular and structural features known to be associated with numerous cutaneous pathologies remains challenging without the use of invasive diagnostic tools.

OBJECTIVE

To present an advanced optical coherence tomography angiography (OCTA) method to directly visualize capillary-level vascular and structural features within skin in vivo.

METHODS

An advanced OCTA system with a 1310 nm wavelength was used to image the microvascular and structural features of various skin conditions. Subjects were enrolled and OCTA imaging was performed with a field of view of approximately 10 × 10 mm. Skin blood flow was identified using an optical microangiography (OMAG) algorithm. Depth-resolved microvascular networks and structural features were derived from segmented volume scans, representing tissue slabs of 0-132, 132-330, and 330-924 μm, measured from the surface of the skin.

RESULTS

Subjects with both healthy and pathological conditions, such as benign skin lesions, psoriasis, chronic graft-versus-host-disease (cGvHD), and scleroderma, were OCTA scanned. Our OCTA results detailed variations in vascularization and local anatomical characteristics, for example, depth-dependent vascular, and structural alterations in psoriatic skin, alongside their resolve over time; vascular density changes and distribution irregularities, together with corresponding structural depositions in the skin of cGvHD patients; and vascular abnormalities in the nail folds of a patient with scleroderma.

CONCLUSION

OCTA can image capillary blood flow and structural features within skin in vivo, which has the potential to provide new insights into the pathophysiology, as well as dynamic changes of skin diseases, valuable for diagnoses, and non-invasive monitoring of disease progression and treatment. Lasers Surg. Med. 50:183-193, 2018. © 2018 Wiley Periodicals, Inc.