Induction of interleukin 10 by sublingual immunotherapy for house dust mites: a preliminary report.

BACKGROUND

Subcutaneous specific immunotherapy has been demonstrated to be capable of inducing T-cell regulatory response. Interleukin 10 (IL-10) plays a crucial role in inducing allergen-specific tolerance; however, no previous studies have examined IL-10 production after sublingual immunotherapy (SLIT).

OBJECTIVE

To evaluate T-cell proliferation and IL-10 production in patients successfully treated with SLIT for house dust mites (HDMs).

METHODS

Peripheral blood mononuclear cells were isolated from patients after at least 3 years of successful HDM SLIT and from matched untreated allergic patients and healthy control subjects. After 3 and 6 days of in vitro stimulation with phytohemagglutinin (PHA), Candida albicans, and Dermatophagoides farinae, proliferation and production of IL-10 were measured.

RESULTS

Patients treated with SLIT showed a significant reduction of proliferation induced by C albicans compared with untreated atopic patients (P < .001), but a significant reduction was also demonstrated in healthy controls compared with untreated atopic patients (P < .001). Patients treated with SLIT also showed a significant increase of IL-10 production after Candida and PHA stimuli compared with patients with untreated rhinitis (P < .001 for both). Patients with untreated rhinitis did not produce IL-10.

CONCLUSION

This preliminary study confirms reduced T-cell proliferation and preliminarily provides the first evidence, to our knowledge, of peripheral IL-10 production in allergic patients successfully treated with HDM SLIT.