"Eczemas" and leptin.

BACKGROUND: Leptin belongs to the helical cytokine family and has structural similarity to interleukin (IL)-6, IL-12, IL-15, prolactin, and growth hormone. It is mainly secreted by adipocytes but (at lower levels) also by stomach, skeletal muscle, and placenta. Initially, leptin was considered an antiobesity hormone, but experimental evidence has also shown pleiotropic effects on hematopoiesis, angiogenesis, lymphoid organ homeostasis, and T-lymphocyte functions. Recent evidence indicates that leptin modifies T-cell immunity by promoting T helper 1 proinflammatory immune response and production of cytokines. OBJECTIVE: The aim of the present study was to evaluate leptin serum levels in patients with allergic contact dermatitis (ACD) and atopic dermatitis and to evaluate the correlation of these levels with different patterns of lymphocyte subpopulations. METHODS: Serum leptin was assayed by enzyme-linked immunosorbent assay. Immunophenotypic analysis of peripheral blood was performed by flow cytometry. RESULTS: We found that serum leptin levels were higher in ACD patients than in healthy controls (p = .02). In these patients, an inverse correlation between serum leptin and the percentage of CD4CD25 T lymphocytes was observed (p = .002). CONCLUSION: These data seem to suggest that leptin might play a role in the pathogenesis of ACD and thus have implications for the therapy for ACD.