Background:
The aim of this study was to examine the olfactory function of patients with hereditary
angioedema (HAE) and to investigate whether genetic mutations, pre-existing conditions,
quality of life, drug intake or specific laboratory values affect the sense of smell.
Methods:
Olfactory function of 31 patients with HAE and a sex- and age-matched control group
was examined using the 3-stage “sniffin' sticks”-test (TDI: threshold, discrimination,
identification). All study participants had to fill in an ENT-specific questionnaire
(RSOM-31) and one for quality of life (SF-36). Furthermore nasal endoscopies were
performed. Blood samples of 30 patients clinically diagnosed with HAE were collected
and genetic analysis (PCR and MLPA) were performed to detect mutations in the SERPING
1 gene. An array-based gene expression analysis of olfactory receptor genes on chromosome
11 was carried out in these patients.
Results:
Patients with HAE suffered significantly more often from hyposmia than healthy controls
(p < 0.01). The disease duration correlated negatively with the overall TDI-result
and the olfactory threshold. Subjects with hyposmia had significantly lower levels
of C1-inhibitor-concentration (p = 0.026), C1-inhibitor-activity (p < 0.01) and C4
(p < 0.01). Comorbidities, quality of life, drug intake and clinical findings in ENT
examinations did not significantly differ between HAE patients and healthy controls
and had no influence on the TDI-results. The genetic analysis showed no mutations
of olfactory receptor genes on chromosome 11.
Conclusion:
This study corroborated previous evidence suggesting a decreased sense of smell in
patients with HAE. Neither ENT-specific diseases, nor genetic alterations seem to
be the cause of an impaired sense of smell in patients with HAE.
