Investigation of the genetic regulation in allergic rhinitis

Association between polymorphisms of the angiotensin-converting enzyme and angiotensinogen genes and allergic rhinitis in a Korean population

Angiotensin-converting enzyme (ACE) inactivates bradykinin, substance P, and neurokinin A, which are thought to play important roles in the pathogenesis of inflammatory diseases. Expression of angiotensinogen, a precursor of angiotensin, is enhanced by augmented secretion of proinflammatory cytokines (eg, interleukin-1) in the site of inflammation. Insertion or deletion (I/D) ACE and M235T angiotensinogen gene polymorphisms were reported to be associated with atopy in a Czech population. Using polymerase chain reaction restriction fragment length polymorphism and SNaPshot typing analysis, we investigated the frequencies of the genotypes and alleles of the ACE gene in 137 patients with allergic rhinitis, of the M235T angiotensinogen gene in 186 patients with allergic rhinitis, and of both in 219 healthy control subjects. There was no difference in the frequency of the DD genotype of the ACE gene in the controls and patients (odds ratio, 1.32 [0.66-2.60]; p > .05). The D allele was more frequent in patients, but the difference was not statistically significant (odds ratio, 1.21 [0.89-1.64]; p > .05). There was no difference in the frequency of the TT genotype of the angiotensinogen gene in the controls and patients (odds ratio, 1.01 [0.38-2.69]; p > .05). The T allele was more frequent in patients, but the difference was not statistically significant (odds ratio, 1.10 [0.78-1.55]; p > .05). Our results indicate that polymorphisms in the genes for ACE and angiotensinogen may not be related to the development of allergic rhinitis in the Korean population.

High contribution contrast between the genes of eosinophil peroxidase and IL-4 receptor α-chain in Japanese cedar pollinosis

BACKGROUND

Japanese cedar pollinosis is the most common form of hayfever in Japan in spring and has remarkably increased since 1960.

OBJECTIVE

We sought to clarify the candidate genes for cedar pollinosis using a case-control study.

METHODS

After diagnosing 351 subjects on the basis of an intradermal test, nasal provocation test, and questionnaire regarding nasal and conjunctival symptoms, we determined the blood-specific IgE values and genotypes of eosinophil peroxidase (EPO) and interleukin-4 receptor alpha-chain (IL4RA) in 145 patients with pollinosis and 206 healthy subjects, including 75 healthy subjects with higher specific IgE values.

RESULTS

We found significant differences in the frequencies of Pro358Leu in EPO and of Ile50Val and Glu375Ala in IL4RA between patients and healthy subjects. There was a significantly higher frequency of 358Leu in EPO in patients than in healthy subjects showing a higher specific IgE value. In contrast, we recognized significant changes in the prevalence of Ile50Val and Glu375Ala in IL4RA in healthy subjects with a normal IgE value compared with those in healthy subjects with a higher specific IgE value. The relationship between EPO polymorphisms and the onset of symptoms was exactly opposite that for IL4RA.

CONCLUSIONS

These results suggest that Pro358Leu in EPO is strongly involved in the development of cedar pollinosis. Ile50Val and Glu375Ala in IL4RA seem to be related to cedar pollen sensitization. Subjects with Ile50 or Glu375 might develop cedar pollinosis with increased exposure to cedar pollen.

A genome-wide linkage analysis of orchard grass-sensitive childhood seasonal allergic rhinitis in Japanese families

Seasonal allergic rhinitis (SAR) is an inflammatory disease of the nose and eyes that follows sensitization to air-born pollens. We conducted a genome-wide linkage screening of 48 Japanese families (188 members) with orchard grass (OG)-sensitive SAR children (67 affected sib-pairs) in a farming community in central Japan where OG was planted for apple farming and OG pollen is a major cause of SAR. We used the GENEHUNTER program to performed nonparametric multipoint linkage analysis for OG-sensitive SAR as a qualitative trait and for log total serum IgE levels and OG-RAST IgE levels as quantitative traits. Genotyping data of 400 microsatellite markers suggested linkage of SAR to chromosomes 1p36.2, 4q13.3, and 9q34.3 (P < 0.001), linkage of serum total IgE levels to 3p24.1, 5q33.1, 12p13.1, and 12q24.2 (P < 0.001), and linkage of OG-RAST IgE levels to 4p16.1, 11q14.3, and 16p12.3 (P < 0.001). Weak evidence for linkage of SAR to 5q33.1 was also observed (P = 0.01). All these regions, with the exception of 9q34.3, have been previously reported to be linked to asthma and/or atopy. These data suggest that, although loci linked to SAR are likely to be common to asthma, a strong contribution by specific gene(s) to OG-sensitive SAR is unlikely.