Elevated 8-Isoprostane Levels in Basal Cell Carcinoma and in Uva Irradiated Skin

Isoprostanes are prostaglandin isomers produced from the peroxidation of polyunsaturated fatty acids from the cellular membrane. They have been used as a specific index of cellular lipoperoxidation and as an indirect measure of oxidative stress. However, these molecules also present several biological activities. An oxidative environment measured as the presence of other indirect measurements of reactive oxygen species lipoperoxidation has recently been described in basal cell carcinoma, the most frequent type of non-melanoma skin cancer. This study aims to measure the levels of 8-isoprostaglandin F2α, an isoprostane widely studied in other models as a by-product of ROS-induced lipid peroxidation, in basal cell carcinoma and in UVA irradiated healthy skin. We found that 8-iso-PGF2α is present in higher levels in BCC specimens compared to healthy non sun-exposed skin, confirming previous studies on the production of lipoperoxidation in this tumor. Moreover, we demonstrated that topical pre-treatment with a compound containing vitamin E is capable of reducing 8-iso-PGF2α formation in UV irradiated skin suggesting a role for isoprostanes in UV induced inflammation and eventually carcinogenesis and confirming the function of vitamin E as an antioxidant in this model.

IL-1α, IL-6 and TNF-α in Cutaneous Lesions of Lupus Erythematosus are Inhibited by Topical Application of Calcipotriol

Lupus Erythematosus (LE) is an autoimmune disorder with an unknown etiology and pathogenesis. Skin lesions of LE express several cytokines which correlate to histological findings such as IL-1 and IL-6 which are mediators of epidermal growth and proliferation. Skin lesions of LE are generally treated with immunosuppressive agents such as oral or topically applied corticosteroids. Recently a new drug, calcipotriol, a vitamin D3 analogue has been useful in treatment of psoriasis with no ad verse effect on calcium metabolism. This drug shares immunomodulatory effects with vit. D3 by inhibiting several cytokines produced by keratinocytes.

In order to test the clinical effectiveness of calcipotriol in cutaneous lesions of LE we have investigated several proinflammatory cytokines such as: IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-8, MCP-1, TNF-α. Using an avidin-biotin immunoperoxidase system we have found IL-1 in both forms, IL-6 and TNF-α in basal keratinocytes in patients affected with LE, after treatment they were reverted to normal. This inhibition is induced at a molecular level as demostrated by reduced IL-1, IL-6 and TNFα mRNA expression. This is the first report showing that calcipotriol is effective in cutaneous lesions of LE and suggesting that this action is due to an inhibition of protein synthesis and mRNA expression for IL-1α, IL-6 and TNFα.

Role of Th2 cytokines, RANTES and eotaxin in AIDS-associated eosinophilic folliculitis

The pathogenesis of AIDS-associated eosinophilic folliculitis is still unknown. The expression of chemokines and Th2-type cytokines is increased in other conditions associated with tissue eosinophilia and in allergic reactions. We evaluated the mRNA expression by reverse transcriptase polymerase chain reaction of two Th2 cytokines (interleukin-4 and interleukin-5) and of two chemokines (RANTES and eotaxin) in the skin of 6 patients with AIDS-associated eosinophilic folliculitis; the tissue localization of eotaxin was shown by immunohistochemistry. We demonstrated the increased expression of interleukin-4, interleukin-5, RANTES and eotaxin in lesional skin of the patients compared to normal skin of HIV+ individuals. We concluded that a Th2 pattern is present in AIDS-associated eosinophilic folliculitis. The cytokine milieu in this disease may favour a Th2 immune response to an unknown antigen, whereby RANTES and eotaxin act in synergy with interleukin-4 and interleukin-5 to mediate tissue inflammation.

Expression of eotaxin, interleukin 13 and tumour necrosis factor-alpha in dermatitis herpetiformis

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.

'Suction split' as a routine method to differentiate epidermolysis bullosa acquisita from bullous pemphigoid

BACKGROUND AND DESIGN

Epidermolysis bullosa acquisita (EBA) and bullous pemphigoid (BP) are diseases with similar clinical, histological, and immunofluorescent findings. Diagnosis requires the use of immunoelectron microscopy, immunoprecipitation or immunoblotting, but in recent years the differential diagnosis has been based on a cheaper technique named salt split skin. This study demonstrates that with a suction blister the fracture is at the same level as that obtained with the sodium split method and that it is also faster and cheaper. Suction blisters on normal skin and autoimmune perilesional bullous lesions, obtained with a hand vacuum pump, were studied by direct immunofluorescence and electron microscopy to evaluate the level of the split on normal suction split skin. Normal human split skin was also used as a substrate for an indirect immunofluorescent study using sera of patients with BP (68 sera), EBA (10 sera) and cicatricial pemphigoid (CP) (16 sera). Direct immunofluorescent examination was also done on perilesional skin after artificial separation obtained with a hand-vacuum pump in patients with the same diseases listed above (32 BP, 11 CP, 6 EBA).

RESULTS

On normal human skin split by suction or sodium chloride (NaCl; 1 mol/l) direct immunofluorescence and electron microscopy demonstrated that the split is at the lamina lucida level. Indirect immunofluorescent study of both normal human skin and perilesional skin split using suction as a substrate showed IgG deposits localized on the floor of the suction blister in all cases of EBA, whereas in over 88% of cases of BP and in over 62% of CP the IgG were localized on the roof. Similar results were obtained with direct immunofluorescence in perilesional skin.

CONCLUSIONS

'Suction split' represents a simple technique to differentiate EBA from BP. This method provides final response in a few hours compared to at least 1-2 days with the sodium split method. Furthermore, the suction split method is cheaper and the tissue can be re-utilized for molecular biology and immunohistochemical studies.

Th2-like cytokine activity in dermatitis herpetiformis

Dermatitis herpetiformis (DH) is a chronic subepidermal blistering disease, in which a perivascular cellular infiltrate, composed mainly of CD4+ T lymphocytes together with a varying number of neutrophils and eosinophils, is thought to be important in the pathogenesis of blister formation. The aim of this study was to investigate the potential role of cytokines such as the interleukins IL-4 and IL-5 and to quantify the distribution of T cells as well as their state of activation using alkaline phosphatase-antialkaline phosphatase and reverse transcriptase-polymerase chain reaction (RT-PCR) procedures in seven patients with typical clinical and histological features of DH. A strong extracellular staining with anti-IL-4 monoclonal antibody was detected in the upper dermis with a prevalent perivascular pattern in perilesional areas, whereas in the dermal-epidermal separation sites there was an intense, scattered distribution. IL-5 was intensely expressed, mainly at the intracellular level, by eosinophils and lymphocytes. Concerning RT-PCR, five DH patients showed a strong positive signal for both IL-4 and IL-5 cytokines while two patients showed a faint signal for both IL-4 and IL-5; these last two cases were histologically poor in inflammatory cells. In view of these results, it can be hypothesized that the recruitment of eosinophils and neutrophils in DH may be induced not only by granulocyte macrophage colony-stimulating factor and IL-8 as previously demonstrated, but also by Th2 cytokines as well.