Atopic dermatitis (AD) is a chronic, inflammatory skin disease in which a pathogenetic role of Th2 cells has been supposed. This study investigated the presence of soluble CD30 (sCD30), an activation marker of T-cell clones able to produce Th2-type cytokines, in sera from pediatric patients affected by AD (n = 25) with no symptoms of asthma or rhinitis. The severity of the disease was graded by both the SCORAD and Costa et al. clinical scoring systems. Serum levels of sCD30 were significantly higher in patients with AD in respect to both normal donors (n = 20) and urticaria patients (n = 10), and a positive correlation between serum sCD30 and clinical score was found (r = 0.508; P = 0.01) when AD patients were evaluated by Costa et al.'s method. Furthermore, a significant association (r = 0.443; P = 0.027) between sCD30 and serum levels of the soluble interleukin (IL)-2 receptor (sIL-2R) was observed in AD. The presence of high amounts of sCD30 in atopic patients seems to confirm the role of this molecule as an activation marker useful for in vivo evaluation of a Th2 immune response, and the correlation observed with both clinical score and sIL-2R levels indicates the role of sCD30 as an additional marker of disease activity in pediatric patients with AD.

Mycosis fungoides and Sézary syndrome represent the most frequent forms of cutaneous T cell lymphoma. Both are characterized by skin infiltrating and/or circulating malignant cells displaying a CD4+CD7- phenotype in the majority of cases. Because an expansion of CD4+CD7- cells may also be found in inflammatory dermatoses or in the aging process, we evaluated, by flow cytometry, the relationship between CD7 expression and the distribution of differentiation/activation or homing antigens on peripheral blood lymphocytes from 36 cutaneous T cell lymphoma patients and from healthy donors. CD4+CD7- cells were increased in all patients with cutaneous T cell lymphoma. As a consequence, the CD7+/- ratio was reduced in stage I-II mycosis fungoides (3.96 vs 6.55 in healthy donors), and inverted in stage III-IV MF and Sézary syndrome (0.28 and 0.12 respectively). In the late stage of disease, the CD7+/- inverted ratio was strictly related to the expression of CD15s, CD60, and CD45R0, and the lack of expression of CD26 and CD49d. Interestingly, in leukemic patients, this phenotype was also associated with peculiar morphologic (large size) or phenotypical (CD3dim expression) characteristics. Furthermore, a progressive reduction of circulating CD8+ cells was also seen throughout all stages of disease. The presence of these populations in cutaneous T cell lymphoma at late phases of disease and Sézary syndrome suggests that all of these molecules may play an important part in the activation pathway and skin homing of circulating T cells in lymphoproliferative disorders. Therefore, this may constitute a distinctive feature in cutaneous T cell lymphoma patients with more aggressive characteristics.

We suggest that IL-16 could serve as a useful marker of disease activity in childhood pAEDS.

SUMMARY Cutaneous infiltration of activated CD4+ T cells and eosinophils is an early event in blister formation during bullous pemphigoid (BP), suggesting that the trafficking of circulating leucocytes through the sites of inflammation, their activation and cytokine release is crucial in the pathogenesis of the disease. IL-16 is a major chemotactic factor able to recruit CD4 + cells in the skin during inflammation and to induce the expression of functional high-affinity interleukin (IL)-2 receptors, thus contributing to cellular activation and proliferation. We performed a study in order to evaluate the presence of IL-16 in skin samples and sera and blister fluids of patients affected with BP in active phase of the disease ( n = 39), compared with healthy donors studied as control group. Ten patients were also evaluated before and after steroid therapy. Our results demonstrated that IL-16 was expressed strongly by keratinocytes and by dermal infiltrating CD4 + T lymphocytes in lesional skin of BP patients. High levels of IL-16 were detected in sera and blisters of BP, significantly higher in respect to healthy donors. When patients were investigated for the presence of eosinophil cationic protein (ECP) and soluble CD30 (sCD30) to reveal signs of eosinophils and Th2-cells activation, we found a positive correlation between IL-16 serum levels and both ECP and sCD30, suggesting that IL-16 is involved in Th2 lymphocytes and eosinophils recruitment during BP.

BAT can be considered a reliable new in vitro method to evaluate A. simplex hypersensitivity in patients with CU, supplementing standardized procedures in both diagnosis and follow-up.