Langerhans cells that express matrix metalloproteinase 9 increase in human dermis during sensitization to diphenylcyclopropenone in patients with alopecia areata
✍ Scribed by L.C. Heffler; A-L. Kastman; G. Jacobsson Ekman; A. Scheynius; J. Fransson
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 284 KB
- Volume
- 147
- Category
- Article
- ISSN
- 0007-0963
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✦ Synopsis
Background:
We know little of the initial events during the sensitization phase of contact allergy in humans. alopecia areata (aa), a disease of unknown pathogenesis characterized by patchy hair loss, may be treated by inducing contact allergy to diphenylcyclopropenone (dpc), later followed by its topical application.
Objectives:
To learn more about the initial events during sensitization in human skin, we studied the early events during induction of contact allergy to dpc in patients with aa.
Methods:
Dpc 2% and sodium lauryl sulphate (sls) 4% were applied on the backs of eight patients with aa. punch biopsies were taken 6 and 24 h after application. the biopsies were snap-frozen and cryostat sections were evaluated with immunohistochemistry using antibodies against cd1a, hla-dr, cd3, cd54 and matrix metalloproteinase 9 (mmp-9).
Results:
After 24 h all subjects exhibited erythema on the dpc-treated areas. histological evaluation of biopsies from these areas showed hydropic degeneration and a significantly increased number of mmp-9+ cells in the dermis (p < 0.0005). the mmp-9+ cells were identified with double immunofluorescence staining as cd1a + langerhans cells. the expression of the other markers studied remained unaltered irrespective of treatment, including treatment with sls.
Conclusions:
Our findings show that dpc induces an irritant reaction leading to an increased number of mmp-9+ cd1a+ cells in the dermis during the initial phase of sensitization.