Standardized tape stripping prior to patch testing induces upregulation of Hsp90, Hsp70, IL-33, TNF-ALPHA; and IL-8/CXCL8 mRNA: new insights into the involvement of 'alarmins'

Objectives: To investigate epidermal mRNA expression of mediators implicated in the regulation of inflammation induced by tape stripping according to our standardized protocol in human skin. Patients/Methods: Thirty-one healthy volunteers (median age 26 years, range 18-62 years) participated in the study. We measured epidermal mRNAs coding for cytokines [tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin (IL)-1 alpha, IL-1 beta, IL-33, IL-10, IL-8/CXCL8, chemokine (C-C motif) ligand 2 (CCL2)/MCP-1 (monocyte chemotactic protein-1), chemokine (C-C motif) ligand 5 (CCL5)/RANTES (regulated upon activation normal T-cell expressed, and presumably secreted), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF)], an adhesion molecule [intercellular adhesion molecule type 1 (ICAM-1)], heat shock proteins (Hsp27, Hsp70 and Hsp90), and the inflammasome complex [NACHT-LRR-PYD-containing protein-3 (NALP3), apoptosis-associated speck-like protein containing a CARD (ASC)/CARD5 (caspase recruitment domain-containing protein-5) and caspase-1] in tape-stripped skin of the upper back relative to untreated skin of the upper back, using quantitative real-time reverse transcription polymerase chain reaction technology. Results: Epidermal mRNA expression levels of TNF-alpha, Hsp90, Hsp70, IL-33, and IL-8/CXCL8 were significantly upregulated, whereas CCL5/RANTES expression was significantly downregulated 6 hr after standardized tape stripping. Conclusions: Tape stripping the skin according to our standardized protocol shows immunostimulatory effects, with induction of keratinocyte-derived 'alarmins' and cytokines mounting an immune response, which may contribute to the increased sensitivity of the strip patch test versus the patch test.