Phenotypes of Allergic Bronchopulmonary Aspergillosis Identified by Cluster Analysis

T. Oguma, J. Tanaka, K. Harada, K. Tomomatsu, K. Asano, Japan ABPM research program;

Author address: 

Division of Pulmonary Medicine, Tokai University School of Medicine, Kanagawa, Japan.

Abstract: 

Introduction: Allergic bronchopulmonary aspergillosis (ABPA) is known as type I and III allergic disease for Aspergillus. Clinical presentation of ABPA ranges from asymptomatic mucus plugs to severe asthmatic symptoms or destructive and fibrotic lung disease. Our nationwide survey in Japan also demonstrated several unique clinical characteristics of ABPA in Japan compared to those previously reported, such as late-onset, relatively lower serum IgE levels, and frequent recurrences/flares (Oguma T et al. Allergol Int, Epub ahead of print). These heterogeneities may reflect not only the different clinical stages of the disease, but also different phenotypes. We herein attempt to identify phenotypes in ABPA using cluster analysis.
Methods: Non-hierarchical cluster analysis was performed for 349 patients with possible ABPA-central bronchiectasis (ABPA-CB) of the retrospective national-wide cohort study in Japan executed in 2013. Definition of possible ABPA-CB were, (1) presence of specific serum immunoglobulin E (IgE) antibodies or a positive skin reaction to Aspergillus, and (2) presence of bronchiectasis or mucoid impaction in the central bronchi on the thoracic CT scan. Decision tree analysis was also conducted to create the tree algorism and 68 patients in another multi-center cohort were assigned to the appropriate clusters.
Results: Three clusters were identified. Cluster 1 (n=95) was characterized with early-onset (median ages, 39 years), male-dominance, and frequent recurrences (65%). The patients in cluster 2 (n=115) were middle age at onset (56 years), female-dominant, and showed lower values of total serum IgE (median, 505 IU/mL). Cluster 3 (n=139) included the patients with later age at onset (68 years), female-dominant disease accompanied by asthma less frequently (71%). Decision tree analysis suggested a classification algorism of the phenotypes based on age of onset (> or ≤ 52 years) and total serum IgE levels (> or ≤ 890 IU/mL). The subtypes of ABPA in the second cohort classified based on the algorism, showed similar clinical characteristics to those in the first cohort.
Conclusions: There are 3 distinct clinical phenotypes characterized by different age of onset, gender, asthma prevalence, total serum IgE levels, and frequency of recurrences.

2018

abstract No: 

A1278 / P1019

Full conference title: 

The American Thoracic Society Conference 2018
    • ATS 2018