Low-dose cyclosporin A microemulsion in children with severe atopic dermatitis: Clinical and immunological effects

Cyclosporin A (CsA) is an effective and well-tolerated treatment for severe childhood atopic dermatitis (AD). By starting at a low dose, the therapeut ic safety should be further increased. The aim of this study was to evaluat e low-dose CsA in childhood AD with respect to clinical outcome and modulat ion of T-cell dysregulation. In an open prospective study, 10 children (age : 22-106 months) with severe AD (mean objective SCORAD score > 40 on two ba seline measurements at a minimum interval of 2 weeks) were treated with CsA solution for 8 weeks. All patients received a starting dose of 2.5 mg/kg/d ay, which was increased stepwise in non-responders to a maximum of dose of 5 mg/kg/day. Disease activity was monitored using the SCORAD index. The fre quency of cytokine-producing peripheral blood T lymphocytes was analyzed by intracellular cytokine staining, and T-cell numbers were measured by fluor escence-activated cell sorter (FACS) analysis. Twenty healthy age-matched c hildren were included as controls for the immunological data. Nine of the 1 0 patients had a SCORAD reduction of at least 35%. In seven patients this w as achieved with low-dose CsA at 2.5 mg/kg/dav (n = 4) and 3.5 mg kg/day (n = 3). Seven of the nine responders experienced no relapse within the 4-wee k follow-up period. At baseline the percentage of interleukin-4 (IL-4), IL- 13, and human leucocyte antigen (HLA)-DR-positive CD3(+) cells was higher i n the patient group than in the controls. After CsA treatment there was a s ignificant reduction in interferon-gamma (IFN-gamma), IL-2, IL-4, IL-13. an d HLA-DR-positive CD3(+) cells. Hence, in severe pediatric AD, CsA microemu lsion. when started at a low dose (2.5 mg/kg/day), improves clinical measur es of disease, reduces T-lymphocyte cytokine production, and regulates T-ce ll activation.