Funding sources The research is supported by the Deutsche Forschungsgemeinschaft.
Bimodal immune activation in psoriasis
Article first published online: 13 JAN 2014
© 2013 British Association of Dermatologists
British Journal of Dermatology
Volume 170, Issue 1, pages 59–65, January 2014
How to Cite
Christophers, E., Metzler, G. and Röcken, M. (2014), Bimodal immune activation in psoriasis. British Journal of Dermatology, 170: 59–65. doi: 10.1111/bjd.12631
Conflicts of interest None declared.
- Issue published online: 13 JAN 2014
- Article first published online: 13 JAN 2014
- Accepted manuscript online: 30 SEP 2013 10:55AM EST
- Manuscript Accepted: 11 SEP 2013
- Deutsche Forschungsgemeinschaft
Psoriasis is an immune-regulated skin disease with various clinical subtypes and disease activities. The majority of patients present with predominantly stable plaques. At the onset of new lesions, plaque-type psoriasis frequently demonstrates pin-sized and highly inflammatory papules sometimes with an inflammatory border. The histopathology of initial psoriasis differs from stable plaque-type psoriasis. Early lesions demonstrate innate immune cells with neutrophils, degranulating mast cells and macrophages. These are followed by interleukin (IL)-1-dependent T helper (Th)17 cells, finally resulting in the Th1-dominated immunopathology of stable plaque-type psoriasis, where mononuclear cells predominate with interspersed neutrophilic (Munro) microabscesses. These features suggest a bimodal immune pathway where alternate activation of either innate (autoinflammatory) or adaptive (autoimmune) immunity predominates. Neutrophilic infiltrations appear during early psoriasis with Munro abscesses. They are time limited and occur periodically, clinically best seen in linear nail pitting. These features strongly suggest a critical role for an IL-1–Th17-dominated autoinflammation in the initiation of psoriasis, followed by a Th1-dominated late-phase reaction. The concept of bimodal immune activation helps to explain results from therapeutic interventions that are variable and previously only partly understood.