Elevated levels of eotaxin and interleukin-5 in blister fluid of bullous pemphigoid: correlation with tissue eosinophilia

Background Bullous pemphigoid (BP) often provokes blood and tissue eosinoph ilia, which suggests that some chemoattractants modulate the eosinophil inf iltration in BP. Eotaxin, a CC chemokine, strongly attracts eosinophils, an d interleukin (IL)-5 induces eosinophil differentiation, proliferation and colony formation in vitro. Objectives To examine the correlation between le vels of eotaxin and IL-5 and the number of lesional eosinophils, and the ex pression of eotaxin in BP lesions. Patients/methods In this study we measur ed eotaxin and IL-5 levels in blister fluid of BP by enzyme-linked immunoso rbent assay. We also examined the expression of eotaxin in BP lesions by im munohistochemistry. Results Both eotaxin and IL-5 were detected at high lev els in BP blister fluid. Blister fluid eotaxin, but not IL-5 levels, correl ated significantly with the number of dermal infiltrating eosinophils. By i mmunohistochemistry, eotaxin was strongly expressed in epidermal keratinocy tes around BP blisters. Conclusions These findings suggest that eotaxin and IL-5 are strongly associated with the tissue eosinophilia of BP. Therapies which aim to inhibit production of eotaxin and IL-5 may improve the inflam mation and blister formation in BP.