Alpha-defensin overexpression in patients with Bell's palsy and Ramsay Hunt syndrome.

OBJECTIVES

To investigate the biological factors related to the onset of Bell's palsy, we sought to identify differentially expressed genes in peripheral blood mononuclear cells (PBMCs) and plasma of patients with Bell's palsy and Ramsay Hunt syndrome (RHS).

METHODS

We carried out DNA microarray analyses using PBMCs taken from patients with Bell's palsy at their initial visit and 2 to 4 weeks later. To validate these analyses, we measured the relative messenger RNA levels of alpha-defensin in paired PBMCs by reverse transcription-polymerase chain reaction. The plasma concentrations of alpha-defensin in patients and healthy volunteers were quantified by enzyme-linked immunosorbent assay.

RESULTS

The DNA microarray analysis identified alpha-defensin as a candidate gene related to the onset of Bell's palsy. Reverse transcription-polymerase chain reaction analysis showed that the relative alpha-defensin messenger RNA levels in PBMCs from the later visit were increased at least twofold in 9 of 13 patients (69%) with Bell's palsy and in 4 of 6 patients (67%) with RHS. The plasma alpha-defensin concentrations in the patients with RHS were significantly higher than those in healthy volunteers (p = 0.0013) and in the patients with Bell's palsy (p = 0.0306). Elevations of plasma alpha-defensin were observed in 5 of the 9 patients with Bell's palsy who demonstrated alpha-defensin overexpression in PBMCs.

CONCLUSIONS

alpha-Defensin may be one of the biological factors related to the onset of Bell's palsy and RHS.