Background: Psoriasis is a chronic, relapsing, inflammatory skin disease, in which regulatory T cells (Tregs) play an important role. Recently, human Treg ectoenzymes (CD39/CD73) have been reported to mediate the suppressive activity of Tregs.
Aim: To investigate the proportions of CD39/CD73 expressing Foxp3(+) regulatory T cells in different types of psoriatic lesions.
Methods: Immunohistochemical staining was used to analyse expression of Foxp3, CD39 and CD73 in biopsy tissue from healthy controls and from patients with different types of psoriasis.
Results: In normal control biopsies, CD39(+) cells were scattered throughout the epidermis and dermis, while CD73(+) cells were localized predominantly in the dermis. The proportion of cells that were both CD39(+) and Foxp3(+) was significantly lower in pustular psoriasis (PP) and erythrodermic psoriasis (EP) than in psoriasis vulgaris (PV) (25.0 ± 2.6%, 26.5 ± 2.0% and 45.1 ± 3.5%, respectively; P < 0.001). Likewise, CD73(+) Foxp3(+) cells were lower in PP and EP than in PV (6.2 ± 1.9%, 11.6 ± 2.8% and 17.7 ± 2.3% respectively, P < 0.001). There were no significant differences in the population size of double-staining cells in EP compared with PP.
Conclusion: The relative reduced expressions of CD39 and CD73 within Foxp3(+) Tregs may imply a different immunopathogenesis for different psoriatic lesions.
© 2014 British Association of Dermatologists.