High levels of interleukin-8, soluble CD4 and soluble CD8 in bullous pemphigoid blister fluid. The relationship between local cytokine production and lesional T-cell activities.

Background Bullous pemphigoid (BP) is an inflammatory subepidermal blistering disease associated with autoantibodies that recognize hemidesmosomal proteins. In addition to autoantibodies, the cell-mediated immune reaction is considered to play an important part in blister formation. Objectives To investigate some T-cell activation markers and inflammatory cytokines in the blister fluid and sera of patients with BP. Methods We measured soluble CD4 (sCD4) and soluble CD8 (sCD8), which have been, respectively, associated with CD4 and CD8 T-cell activation. Enzyme-linked immunosorbent assays were also used to quantify the production of the leucocyte chemoattractant interleukin (IL) -8 and of the cytokines IL-1α, IL-1β, IL-6, IL-10 and tumour necrosis factor-α in the blister fluid and sera of 11 patients with BP. Results The mean ± SD level of sCD4 in patients’ blisters (42·4 ± 25·0 units mL-1) was significantly elevated (P < 0·005) compared with that in their sera (11·2 ± 8·9) and that in the suction blisters of 10 healthy people (11·4 ± 5·4; P < 0·005). Mean ± SD IL-8 concentrations in BP blisters (4683·6 ± 3878·1 pg mL-1) were much higher than those in their sera (17·1 ± 18·9; P < 0·001), and were very significantly elevated (P < 0·005) in comparison with those in suction blisters of healthy persons (512 ± 292). sCD4 levels in BP blisters were inversely related to IL-10 levels (P = 0·03, r2 = 0·85), IL-8 levels were positively related to sCD8 levels (P = 0·01, r2 = 0·54), and IL-1β levels were positively related to sCD8 concentrations (P < 0·005, r2 = 0·65). Conclusions The correlations suggest that there is a delicately orchestrated network of cytokines and cell-mediated immunity operating in BP blisters. [ABSTRACT FROM AUTHOR]