A Non-invasive Tape Absorption Method for Recovery of Inflammatory Mediators to Differentiate Normal from Compromised Scalp Conditions

Background/aims: A simple non-invasive tape (Sebutape) adsorption method was used to recover inflammatory proteins from normal and compromised human scalp (i.e. dandruff and seborrheic dermatitis) in order to assess the inflammatory and immunologic changes relevant to these clinical conditions.

Methods: The scalps of subjects identified by a dermatologist as having either dandruff (n = 18), seborrheic dermatitis (n = 19) or normal scalp (n = 16) were visually graded to obtain total adherent scalp flaking scores (TASFS). Sebutape samples were then collected from both the high and low TASFS scalp sites using a one-minute tape application. To recover inflammatory molecules, tapes were extracted in buffered saline with sonication and the tape extracts analysed using commercial immunoassay methods for pro-inflammatory cytokines [i.e. interleukin-1alpha (IL-1alpha), IL-1beta, IL-1 receptor antagonist (IL-1ra), IL-8 and tumor necrosis factor-alpha (TNF-alpha)] and the immunologic cytokines [i.e. IL-2, IL-4, IL-10, IL-12, IL-15 and interferon gamma (IFN-gamma)]. Nitric oxide (NO) was also assayed on tape extracts using the Greiss reaction. To account for differences in protein loading on the tapes all cytokine and NO results were normalized using the total protein (TP) amounts recovered in tape extracts.

Results: The IL-1alpha/TP levels recovered from dandruff and seborrheic scalps were significantly decreased (P = 0.03) compared to normal appearing scalp levels. The scalp levels of IL-1ra/TP and the ratio of IL-ra to IL-1alpha were significantly (P = 0.002) or directionally (P = 0.07) higher in seborrheic dermatitis scalps and dandruff scalps, respectively, compared to normal scalps. The IL-1ra and the IL-1ra/IL-1alpha ratio values correlated well with the TASFS. The TNF-alpha/TP levels recovered from dandruff scalps were significantly higher (P = 0.02) than levels recovered from seborrheic dermatitis and normal scalp subjects. IL-2/TP was significantly increased (P = 0.01) and IFN-gamma and NO significantly decreased (P = 0.05) in the seborrheic dermatitis scalp samples compared to normal controls.

Conclusion: The Sebutape method has proven useful for distinguishing normal from diseased scalp conditions. The cytokines recovered from the scalp tape samples showed distinct patterns that differentiated dandruff, seborrheic dermatitis and normal scalp populations. These methods may also prove useful for monitoring the clinical efficacy of therapeutic actives for treating dandruff and seborrhea.