Upregulated levels of human β-defensins in patients with seasonal allergic rhinitis after allergen-specific immunotherapy treatment.

BACKGROUND

Antimicrobial peptides (AMPs) are important actors in the innate immune system. One class of AMPs is the human β-defensins (HBDs), a group of small peptides with a broad spectrum of antimicrobial activities. Expression of HBDs is downregulated in different manifestations of allergic disease. In this study, we examine whether allergen-specific immunotherapy (ASIT) affects the nasal levels of HBDs in patients with seasonal allergic rhinitis (SAR).

METHODS

Nasal biopsies were examined for the occurrence of HBD1-3 with real-time reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. Nasal lavage (NAL) fluids from healthy individuals, untreated SAR patients and SAR patients before and after ASIT were analyzed for levels of HBD1-3 using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Examination of nasal biopsies revealed HBD1-3 expression at gene level as well as at protein level in all samples tested. HBD1 and HBD3 messenger RNA (mRNA) levels were downregulated in SAR patients compared to healthy individuals. All HBDs were found in NAL fluids. SAR patients having completed 3 years of ASIT displayed higher levels of HBD1 and HBD2 than before treatment, whereas levels of HBD3 were unaffected.

CONCLUSION

The present study demonstrates an upregulation of HBD1 and HBD2 in SAR patients after completion of ASIT. This may reflect the importance of an intact innate immune response as part of our defense against infections among allergic individuals.