Upregulation of IL IL ‐36 cytokines in folliculitis and eosinophilic pustular folliculitis

摘要

Abstract Background Members of the interleukin ( IL )‐36 family, IL ‐36α, IL ‐36β and IL ‐36γ, are potent chemoattractive cytokines for neutrophils and eosinophils. IL ‐36 receptor antagonist ( IL ‐36Ra) inhibits IL ‐36α, IL ‐36β and IL ‐36γ activity. However, the immunohistological expression of IL ‐36α, IL ‐36β, IL ‐36γ and IL ‐36Ra has never been addressed in normal follicles, folliculitis or eosinophilic pustular folliculitis ( EPF ). Methods We performed immunohistochemical staining for IL ‐36α, IL ‐36β, IL ‐36γ and IL ‐36Ra using 10 cases of EPF , nine of non‐specific folliculitis, 10 normal skin samples and 10 samples of normal follicles adjacent to a sebaceous naevus as a control. Two dermatologists, who were blind to the patient records, evaluated all of the slides. Results The immunoreactive IL ‐36α was hardly detected in the follicular epithelium and epidermis in the normal skin, folliculitis or EPF . The expression of IL ‐36β, IL ‐36γ and IL ‐36Ra was augmented in both folliculitis and EPF compared with that in normal follicles. Negative correlations were detected between IL ‐36β and IL ‐36Ra and between IL ‐36γ and IL ‐36Ra in normal follicles; however, these were absent in folliculitis. In contrast to normal follicles and folliculitis, a significant positive correlation between IL ‐36β/γ and IL ‐36Ra was shown in EPF . Conclusions The overexpression of IL ‐36β, IL ‐36γ and IL ‐36Ra is an integral part of the inflammatory response of folliculitis and EPF . The coordinated expression of IL ‐36γ and IL ‐36Ra may be related to the pathomechanism of EPF .