Teresa Adamek-Guzik

Persistent skin colonization with Staphylococcus aureus in atopic dermatitis: relationship to clinical and immunological parameters

Background Staphylococcus aureus has important implications for the pathogenesis of atopic dermatitis (AD). In some patients S. aureus can be eradicated from the skin during anti‐inflammatory treatment, while in others bacterial colonization is persistent. Potential mechanisms and features of these two distinct groups of patients are not known.

Urinary leukotriene levels are increased during exacerbation of atopic eczema/dermatitis syndrome. Relation to clinical status

Background:  Leukotrienes are potent mediators of allergic inflammation and their role in the pathogenesis of allergic disorders, particularly asthma, is well established. Their importance in the pathogenesis of atopic eczema/dermatitis syndrome (AEDS) is still unclear. We aimed to compare urinary cysteinyl leukotriene (Cys‐LT) levels during exacerbation and remission of AEDS in relation to clinical status, IgE levels, and eosinophil counts.

Nitric oxide metabolite levels in children and adult patients with atopic eczema/dermatitis syndrome.

We read with great interest the recent study by Taniuchi et al. (1) showing increased nitric oxide (NO) metabolite levels in sera of children with atopic eczema/dermatitis syndrome (AEDS). Taniuchi et al. have also shown a correlation between NO3 levels and skin lesion severity. As the authors conclude these results could indicate an important role of NO in the pathogenesis of erythema (2) as well as in the modulation of the Th1–Th2 cell balance in AEDS. The problem of altered NO metabolism in AEDS is also very important from the therapeutic point of view, as NO synthase (NOS) inhibitors could be used topically to alleviate skin symptoms (3). We have undertaken a similar study in adults with AEDS and could not confirm the observations of Taniuchi et al. from childhood AEDS. We aimed to study whether plasma levels of nitrite/nitrate (NOx) reflect local skin NO generation during allergic inflammation in AEDS. Additionally we studied cNOS and iNOS mRNA expression (by RT-PCR) in peripheral blood leukocytes during exacerbation and remission of the disease. Seventeen adult male (age 18–47 years) patients with persistent AEDS and 17 healthy subjects were included in the study. Plasma NOx concentrations, measured by the modified Griess reaction (4), as well as total serum IgE levels and clinical status (SCORAD scale), were compared during exacerbation and remission of the disease and with the control group. No significant difference in the mean NOx levels or eNOS/ iNOS expression was observed during exacerbation of AEDS compared with either remission or the control group. We postulate that the difference between our observations and findings by Taniuchi et al. (1) could be explained by the fact that the area of affected skin, relative to total skin surface and body weight, is smaller in adults than in children with AEDS. However, we also observed that in a subgroup of 40% of patients NOx levels were significantly higher during remission than during exacerbation. Interestingly in this group SCORAD score during remission was significantly higher than in the remaining group, suggesting an incomplete remission in these patients. Similarly the weak induction of iNOS in the peripheral mononuclear cell fraction was observed only in this group. The increase in plasma NOx during remission may lead to the latency of skin inflammation, in the chronic phase of AEDS. This phenomenon may be related to findings that Th1 type cytokines (interferon IFN-c) are up-regulated in the chronic phase of AEDS (5). In mouse models, activation of iNOS in peripheral blood leukocytes and in antigen presenting cells, is triggered by Th1 cell-derived IFN-c (6). Alternatively, Th1 cells, dominating in the chronic subacute phase of AEDS, may be potentially an additional source of NO (7). These observations require further studies. Summarising, in contrast to the findings of Taniuchi et al. (1), we found that in adult patients without generalized skin lesions, plasma NOx concentrations do not reflect local AEDS exacerbation. However, an increase in the NOx serum concentrations may be related to the more chronic course of adult AEDS.