The Studies On The Relationship Between Th1/Th2-type Cytokine And Alopecia Areata

Objective:Alopecia areata(AA) is a common hair loss disease withunknown etiology and undetermined pathogenesis and without effectivetreatment methods,which is often associated with severe psychologicalproblems,especially in girls and young women.so it is important to explorethe pathogenesis of AA and to look for the effective therapeuticapproaches.Recently,there is strong evidence indicating AA is atissue-specific autoimmune disease. Hair loss caused by AA is associatedwith a perifollicular lymphocytic infiltrate made up primarily of CD4+cells, associated with a CD8+ intrafollicular infiltrate. In addition,Evidenceof immune activation still includes expression of human leukocyteantigen (HLA-DR), HLA-A,B,C, and intercellular adhesion molecule(ICAM-1) on the follicular epithelium.It is likely that the follicularexpression of HLA-DR and ICAM-1 is induced by interferon(IFN)-[gamma] produced by T cells. this evidence indicate that AA is amediated by a Th1 T-lymphocyte response. Among the Th2-typecytokines,Interleukin (IL)-10 is widely accepted to exert animmunosuppressive action on T helper( Th1) cell-mediated skin diseasessuch as psoriasis vulgaris or allergic contact dermatitis, and is involved inthe induction of tolerance in T cell mediated autoimmune diseases. So weexplore the relationship between Th1/Th2-type cytokine and AA, tounderstand the role of Th1/Th2-type cytokine in AA pathogenesis.furthermore, IL-10 may be a candidate for novel treatment modalities in Tcell mediated diseases where current therapeutic approaches are insufficientor unsuccessful. Methods: Serum levels of IFN-γ and IL-10 were determined inpretreatment and posttreatment respectively by enzyme linkedimmunoabsorbent assays(ELISA) in 30 patients with alopecia areata,andcompared with 20 normal controls.the duration of 30 patients with AAwhich were treated by topical minoxidol four months successfully is withinone month,we also analysed the correlation between serum IFN-γ andIL-10 before and after treatment. Results: (1)Serum levels of IFN-γwere significantly higher in thepatients with AA before treatment than the control group(P<0.01),whereasserum levels of IL-10 have no significant difference compared with thenormal controls(P>0.05);(2) Serum IFN-γ levels were significantlyreduced in the patients with AA after treatment compared with those in thepatients with AA before treatment(P<0.01),and have no significantdifference compared with the normal controls(P>0.05); while serum levelsof IL-10 after treatment were significantly elevated compared with thosebefore treatment(P<0.01),and also significantly elevated compared withthe normal controls(P<0.01);(3)there were significant negative correlationbetween serum levels of IFN-γ and IL-10 before and after treatment(r1=-0.61, P1<0.01;r2=-0.57, P2<0.01)。 Conclusions: IFN-γinduced by activated T lymphocyte play animportant role in the pathogenesis of alopecia areata,further indicatingalopecia areata is an T lymphocyte-mediated tissue-specific autoimmunedisease.there are the condition of Th1 predominance in the initiation phaseof AA;there are decreased Th1-type cytokines and increased Th2-typecytokines after treatment,indicating the condition of Th2 predominance;itneed to confirmed that whether IL-10 is a novel immunotherapeuticapproach or not.