Elafin is induced in epidermis in skin disorders with dermal neutrophilic infiltration: interleukin-1 beta and tumour necrosis factor-alpha stimulate its secretion in vitro.
BACKGROUND
Elafin, an elastase inhibitor produced by keratinocytes, is overexpressed in the subcorneal region of skin affected by psoriasis, a major feature of which is epidermal infiltration by neutrophil leucocytes.


OBJECTIVE
We studied the expression of elafin in the epidermis in other skin disorders characterized by dermal neutrophil infiltration and in skin disorders with dermal lymphocyte infiltration.


METHODS
We examined biopsies from the lesional skin of patients with Behçet's syndrome, Sweet's syndrome, pyoderma gangrenosum, cutaneous allergic vasculitis and acute bacterial infection (cellulitis), and from the skin of patients with chronic prurigo, discoid lupus erythematosus and psoriasis. We performed in vitro experiments using cultured keratinocytes treated with mediators such as interleukin (IL)-1 beta, tumour necrosis factor (TNF)-alpha, IL-6, neutrophil elastase and interferon (IFN)-gamma.


RESULTS
Anti-elafin antibody showed a strong reaction with the subcorneal region of the epidermis in patients with Behçet's syndrome, Sweet's syndrome, pyoderma gangrenosum, cutaneous allergic vasculitis and acute bacterial infection (cellulitis), but showed no reaction in skin from patients with dermal lymphocyte infiltration such as is seen in chronic prurigo and discoid lupus erythematosus. The in vitro experiments demonstrated that treatment with IL-1 beta and TNF-alpha resulted in 2.6-fold and 4-fold stimulation of elafin secretion, respectively, whereas IL-6, neutrophil elastase and IFN-gamma caused no significant changes in elafin release.


CONCLUSIONS
These results suggest that inflammatory mediators such as IL-1 beta or TNF-alpha secreted by dermal neutrophils may be involved in overexpression of elafin in keratinocytes; this could protect the epidermis from degradation by dermal neutrophil infiltration.
Tanaka
N
N
Department of Dermatology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan.
Fujioka
A
A
Tajima
S
S
Ishibashi
A
A
Hirose
S
S
D018929:Cell Culture Techniques; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015603:Keratinocytes / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D012871:Skin Diseases / Q000378:metabolism* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D007375:Interleukin-1; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha