Asthma Phenotypes in Japanese Adults - Their Associations with the CCL5 ADRB2 Genotypes.

Abstract

BACKGROUND:

Cluster analyses were previously performed to identify asthma phenotypes underlying asthma syndrome. Although a large number of patients with asthma develop the disease later in life, these previous cluster analyses focused mainly patients with younger-onset asthma.

METHODS:

Cluster analysis examined the existence of distinct phenotypes of late-onset asthma in Japanese patients with adult asthma. We then associated genotypes at the CCL5, TSLP, IL4, and ADRB2 genes with the clusters of asthma identified.

RESULTS:

Using the 8 variables of age, sex, age at onset of the disease, smoking status, total serum IgE, %FEV1, FEV1/FVC, and specific IgE responsiveness to common inhaled allergens, two-step cluster analysis of 880 Japanese adult asthma patients identified 6 phenotypes: cluster A (n = 155): older age at onset, no airflow obstruction; cluster B (n = 170): childhood onset, normal-to-mild airflow obstruction; cluster C (n = 119): childhood onset, the longest disease duration, and moderate-to-severe airflow obstruction; cluster D (n = 108): older age at onset, severe airflow obstruction; cluster E (n = 130): middle-age at onset, no airflow obstruction; and cluster F (n = 198): older age at onset, mild-to-moderate airflow obstruction. The CCL5-28C>G genotype was significantly associated with clusters A, B and D (OR 1.65, p = 0.0021; 1.67, 0.018; and 1.74, 0.011, respectively). The ADRB2 Arg16Gly genotype was also associated with clusters B and D (OR 0.47, p = 0.0004; and 0.63, 0.034, respectively).

CONCLUSIONS:

The current cluster analysis identified meaningful adult asthma phenotypes linked to the functional CCL5 and ADRB2 genotypes. Genetic and phenotypic data have the potential to elucidate the pheno- typic heterogeneity and pathophysiology of asthma.

• Authors: Yoshiko Kaneko, Hironori Masuko, Tohru Sakamoto, Hiroaki Iijima, Takashi Naito, Yohei Yatagai, Hideyasu Yamada, Satoshi Konno, Masaharu Nishimura, Emiko Noguchi, Nobuyuki Hizawa
• Journal: Allergology international : official journal of the Japanese Society of Allergology (Allergol Int) Vol. 62 Issue 1 Pg. 113-121 ( 2013) ISSN: 1440-1592 [Electronic] England
• PMID: 28942984 (Publication Type: Journal Article)
• Copyright: © 2013 Japanese Society of Allergology.