Fukushima H, Hirano T, Shibayama N, et al. Int Arch Allergy Immunol. 2006;141:281–289
PURPOSE OF THE STUDY. To examine the prevalence and role of Staphylococcus aureus superantigens on the pathophysiology and immunosuppressive drug sensitivity in patients with atopic dermatitis (AD).
STUDY POPULATION. Twenty-nine patients with AD and 13 healthy control patients were included in the study.
METHODS. Twenty-nine patients with AD were classified into 2 groups on the basis of their clinical AD scores: a low-score group (n = 14), corresponding to patients with mild-to-moderate AD, and a high-score group (n = 15), corresponding to patients with severe AD. Plasma antistaphylococcal enterotoxin B or toxic-shock syndrome toxin-1 (TSST-1) immunoglobulin E (IgE) levels were measured for the patients and healthy subjects by enzyme-linked immunosorbent assay. Also, individual drug sensitivity was estimated by determining the drug concentrations that would provide 50% inhibition (IC50) of peripheral blood mononuclear cell (PBMC) proliferation in vitro.
RESULTS. The levels of plasma anti-staphylococcal enterotoxin B or TSST-1 IgE in the patients with severe AD were significantly higher than those in the patients with mild-to-moderate AD (P < .05 and P < .01, respectively). When stimulated with concanavalin A in vitro, PBMCs in the patients with severe AD exhibited low sensitivity to the suppressive efficacy of tacrolimus (FK506) as compared with the patients with mild-to-moderate AD (P < .01). Furthermore, there was a significant correlation between the IC50 values of FK506 and plasma anti–TSST-1 IgE levels (P < .01).
CONCLUSIONS. PBMCs in patients with severe AD exhibited lower sensitivity to FK506 and had higher plasma levels of anti–TSST-1 IgE as compared with the patients with mild AD. S aureus superantigens seem to be one of the causes of decreased PBMC sensitivity to FK506; therefore, an alternative treatment would be useful on the basis of individual drug-sensitivity data and anti–TSST-1 IgE levels.
REVIEWER COMMENTS. Patients with AD commonly develop superinfections that require antimicrobial treatment. This study suggests that untreated superinfection may contribute to the ineffectiveness of topical medications that are commonly used as routine skin care for patients with AD. Attentiveness to the presence of concomitant skin infection is necessary for comprehensive skin care for patients with AD.
- Copyright © 2007 by the American Academy of Pediatrics