$130 Abstracts J ALLERGY CLIN IMMUNOL FEBRUARY 2003 241 Brain-Derived Neurotrophic Factor (BDNF)and Neerotrophin-3 (NT-3) Inhibit Eosinophil Apoptosis in Atopic Dermatitis U. Ranp ~, N. Deneka ~, H. Renz 2, A. Kapp t, B. WedP; lDepartment of Dermatology and Allergology, Medical University of Hannover, Han- nover, GERMANY, 2Department of Clinical Chemistry and Molecular Diagnostics, University of Marburg, Marburg, GERMANY. RATIONALE: Neurotrophic factors increase nerve excitability, neurotrans- mitter synthesis and are produced by immunocompetent cells. Recently, it was described that neurotrophins also play a pivotal role in allergic asthma and rhinitis, diseases with increased levels of BDNF and NT-3. Therefore, the aim of this study was to investigate the possible role of BDNF and NT-3 on peripheral blood eosinophils especially in atopic dermatitis tAD). METHODS: AD Patients were defined according to the criteria of Hani- fin and Rajika. Peripheral blood eosinophils were purified by CD16 neg- ative selection (purity >98%) and stimulated each with BDNF or NT-3 (10, 50 and 100 ng/ml) with incubation for 24 up to 120 hours. Eosinophil viability and apoptosis were assessed by trypan dye exclusion, FACS analysis using a modification of the Nicoletti protocol and Annexin V, respectively. Chemotactic index was assessed in a modified Boyden chamber assay. RESULTS: Programmed cell death of AD eosinophils was significantly delayed (p<0.05-0.01) after stimulation with BDNF and NT-3 for 24 hours up to 120 hours in culture, at each time point. Moreover, chemotac- tic index was significantly increased in AD eosinophils after stimulation with BDNF and NT-3 (p<0.05-0.01). CONCLUSIONS: These data clearly show that BDNF and NT-3 modu- late the programmed cell death of AD eosinophils. Together with the evi- dence of increased chemotactic index these results suggest a functional role of BDNF and NT-3 in supporting the inflammatory response espe- cially in atopic dermatitis. Further experiments will have to elucidate neu- rotrophin receptor expression on peripheral blood eosinophils especially in atopic dermatitis. Funding: Medical Universi~' of Hannover #~Af~ T Helper (Th) 2 Predominance in Atopy Is Due to Preferential L Thl Memory/Effector Cell Apoptosis M. Akdis z , A. Trautmann I , S. K]unker I , 1. Daig]e L , U. C. Kucuksezer 2, W. Deglmann 3, R. Disch 3, K. Blaser ], C. A. Akdis~; tSwiss Institute of Aller- gy and Asthma Research (SIAF), Davos, SWITZERLAND, 2Institute for Experimental Medical Research, Istanbul, TURKEY, 3Clinic for Derma- tology and Allergy, Davos, SWITZERLAND. T cells constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated, Th2-biased peripheral immune response appears to be an important pathogenetic factor. In atopic dermatitis, cir- culating cutaneous lymphocyte-associated antigen-bearing (CLA+) CD45RO+ T cells with skin-specific homing property represent an acti- vated memory/effector T cell subset. They express high levels of Fas and Fas-ligand and undergo activation-induced apoptosis. The freshly purified CLA+ CD45RO+ T cells of atopic individuals display distinct features of in vivo triggered apoptosis such as pro-caspase degradation and active caspase-8 formation. Particularly, the Th 1 compartment of activated mem- ory/effector T cells selectively undergoes activation-induced cell death, skewing the immune response towards surviving Th2 cells in atopic indi- viduals. The apoptosis of circulating memory/effector T cells was con- fined to atopic individuals, whereas non-atopic patients such as psoriasis, intrinsic-type asthma, contact dermatitis, intrinsic-type atopic dermatitis, bee venom allergic patients and healthy controls did not show any evi- dence for enhanced T cell apoptosis in vivo. These results define a novel mechanism for peripheral Th2 response in atopy. Funding: Swiss National Foundation 43 Variation of Gene Expression in PBMC After Stimulation with Staphylococcal Enterotoxin B (SEB) Among Dexametbasone and FKS06 A. Akasawa; National Research Institute for Child Health and Develop- ment, Tokyo, JAPAN. RATIONALE: In the pathogenesis of atopic dermatitis, SEB plays important roles not only as an allergen but also as a superantigen. In order to identify a SEB-inducible gene cluster, mRNA expression in human PBMC after stimulation with SEB or inhibition by dexamethasone or FK506 was investigated. METHODS: PBMC was obtained from non-atopic donors and cultured with 100 ng/ml SEB in the presence or absence of 1 mM dexamethasone or 100 ng/ml FK506 for 6 hours. The mRNA expression profile was com- prehensively evaluated using a high density oligonucleotide probe array system (GeneChip, Affymetrix). RESULTS: Using hierarchical clustering-analysis, out of a total of 10,000 genes we identified a cluster containing 660 genes as having been up-regulated by SEB. This cluster was further sub-divided into the fol- lowing sub-clusters (contained genes). (1) Genes up-regulated by dexam- ethasone (IL-1R antagonist), (2) Genes down-regulated by dexametha- sone (MCP-3, GATA-2 and Flt-3 ligand), (3) Genes down-regulated by FK506 but not dexamethasone (IL-2, IL-3, IL-4, IL-5, IL-13, GM-CSF, IL-2R and GM-CSFR b chain). CONCLUSIONS: SEB may participate in the inflammatory reactions in atopic dermatitis through up-regulating multiple genes expression. The fact that corticosteroids and FL506 distinctively inhibited genes expression in PBMC suggests that the use of these drugs should be selected after consid- eration of the involvement of SEB in the pathogenesis of atopic dermatitis. Funding: Organization for Pharmaceutical Safety and Research and the 44 Tacrolimns Ointment Monotherapy Is Safe and Effective for the Long-TermTreatment (More Than 3 Years) of Atopic Der- matitis in Pediatric Patients J. M. Hanifin ], D. Y. Leung -~, A. Paller 3, J. Rico4; ]Department of Der- matology, Oregon Health Sciences University, Portland, OR, 2National Jewish Medical and Research Center, Denver, CO, 3Children's Memorial Hospital, Chicago, IL, 4Fujisawa Healthcare. lnc, Deerfield, IL. RATIONALE: To evaluate the long-term safety and efficacy of 0.1% tacrolimus ointment monotherapy in pediatric atopic dermatitis tAD) patients. METHODS: In this open-label, non-comparative, multicenter extension study, tacrolimus ointment 0.1% was applied twice daily to affected areas. Patients were evaluated for safety and efficacy at baseline, week 1 and every 3 months thereafter. RESULTS: A total of 391 patients (2 to 15 years of age) were evaluable for safety and efficacy. Half (51%) were female; 21% were African Amer- ican. At baseline, 38% of patients had severe AD. Almost half (46%) were treated with tacrolimus ointment intermittently up to a maximum of 49 months. Nineteen percent of children received a topical steroid at some point during this 3-year study. Patients rarely discontinued the study due to an adverse event (2%) or lack of efficacy (6%). Improvement was observed within 1 week and continued with intermittent tacrolimus oint- ment monotherapy. The mean %BSA affected at baseline was 32% and fell to 11% at month 36. There was no indication of an increased risk lor any adverse event and hazard rate analyses demonstrated no increased risk of cutaneous or systemic infection or other adverse events with long-term use of 0.1% tacrolimus ointment. The incidence of skin infections, includ- ing herpes simplex and warts, was comparable to or lower than that pre- viously reported in patients with AD. CONCLUSIONS: Tacrolimus ointment monotherapy is rapidly effective and is a safe and effective non-steroidal topical treatment in the long-term management of AD in pediatric patients. Funding: Fujisawa Healthcare, hw