Background:
The dermal and perivascular infiltrate in dermatitis herpetiformis (dh), which is mainly composed of cd4+ lymphocytes, neutrophils and eosinophils, is believed to play an important part in the pathogenesis of the disease. previous studies suggest that cytokines such as interleukin (il) -8, granulocyte-macrophage colony-stimulating factor, il-4 and il-5 could be involved in the pathogenesis of dh. these cytokines appear to drive tissue infiltration and maturation of eosinophils. part of the effect of t-helper (th) 2-type cytokines (il-4, il-5) on eosinophils could be mediated by eotaxin, which is a highly specific chemotactic protein induced by various cytokines [il-4, il-13, tumour necrosis factor (tnf) -alpha and interferon-gamma].
Objectives:
To evaluate the expression of eotaxin and its inducers, il-13 and tnf-alpha, in dh. methods we examined lesions collected from 10 dh patients with active disease. sections from each specimen were incubated with anti-il-13, anti-tnf-alpha and anti-eotaxin antibodies. chloroacetyl esterase reaction was performed to show mast cell infiltration.
Results:
Eotaxin was mainly expressed at the tips of the dermal papillae, within the microabscesses. positivity was also found in the lymphomonocytic infiltrate in the dermis. il-13 was expressed in the dermal infiltrate and tnf-alpha was found in the inflammatory infiltrate and in dermal vascular cells.
Conclusions:
These findings confirm the importance of the lymphomonocytic infiltrate and of th2 cytokines in the pathogenesis of this disease, suggesting that tissue infiltration in dh is mediated by cell-specific chemokines such as eotaxin and not only by non-specific chemokines such as il-8.