Cyclosporin A does not modify Langerhans' cell number and distribution in normal human skin.

We used the model of human skin graft on nude mouse to investigate a possible influence of systemically administered cyclosporin A (CsA) on epidermal Langerhans' cells (LC). This experimental model has the advantage of being independent of the systemic humoral and cellular influences of a human host. No change in the human LC distribution or number could be observed after 3 weeks of CsA therapy as revealed by anti-CD1 and anti-HLA-DR immunohistochemical stainings and the cell counting, despite the evidence of the drug effect on the keratinocyte proliferation. However, our findings do not rule out the possibility that CsA influences the LC functional capacities responsible for the local cell-mediated immunity responses.