Sputum microbiota and inflammatory subtypes in asthma, COPD, and its overlap

Chie Morimoto, MD, PhD; Hisako Matsumoto, MD, PhD; Natsuko Nomura, MD, PhD; Hironobu Sunadome, MD, PhD; Tadao Nagasaki, MD, PhD; Susumu Sato, MD, PhD; Atsuyasu Sato, MD, PhD; Tsuyoshi Oguma, MD, PhD; Isao Ito, MD, PhD; Mariko Kogo, MD, PhD; Keisuke Tomii, MD, PhD; Tomoko Tajiri, MD, PhD; Kai Ohashi, MSc; Takamitsu Tsukahara, PhD; Toyohiro Hirai, MD, PhD

Journal of Allergy and Clinical Immunology: Global (Feb 2024)

Sputum microbiota and inflammatory subtypes in asthma, COPD, and its overlap

Chie Morimoto, MD, PhD,
Hisako Matsumoto, MD, PhD,
Natsuko Nomura, MD, PhD,
Hironobu Sunadome, MD, PhD,
Tadao Nagasaki, MD, PhD,
Susumu Sato, MD, PhD,
Atsuyasu Sato, MD, PhD,
Tsuyoshi Oguma, MD, PhD,
Isao Ito, MD, PhD,
Mariko Kogo, MD, PhD,
Keisuke Tomii, MD, PhD,
Tomoko Tajiri, MD, PhD,
Kai Ohashi, MSc,
Takamitsu Tsukahara, PhD,
Toyohiro Hirai, MD, PhD

Affiliations

Chie Morimoto, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
Hisako Matsumoto, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kindai University, Osaka, Japan; Corresponding author: Hisako Matsumoto, MD, PhD, Department of Respiratory Medicine and Allergology, Faculty of Medicine, Kindai University, 377-2, Osaka Sayama City, Osaka 589-8511, Japan.
Natsuko Nomura, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
Hironobu Sunadome, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
Tadao Nagasaki, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
Susumu Sato, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Care and Sleep Control Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
Atsuyasu Sato, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
Tsuyoshi Oguma, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
Isao Ito, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan
Mariko Kogo, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Respiratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
Keisuke Tomii, MD, PhD: Department of Respiratory Medicine, Kobe City Medical Center General Hospital, Kobe, Japan
Tomoko Tajiri, MD, PhD: Department of Respiratory Medicine, Japanese Red Cross Wakayama Medical Center, Wakayama, Japan; Department of Respiratory Medicine, Allergy and Clinical Immunology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
Kai Ohashi, MSc: Kyoto Institute of Nutrition & Pathology, Inc, Kyoto, Japan
Takamitsu Tsukahara, PhD: Kyoto Institute of Nutrition & Pathology, Inc, Kyoto, Japan
Toyohiro Hirai, MD, PhD: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan

Journal volume & issue: Vol. 3, no. 1
p. 100194

Abstract

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Background: Airway microbiota in asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) remains unknown. Objective: This study with ACO-enriched population aimed to clarify airway microbiota in ACO and in mixed granulocytic inflammation, often detected in ACO and chronic airway diseases. Methods: This is an observational cross-sectional study. Patients with asthma with airflow limitation, ACO, and COPD were enrolled. Blood tests, pulmonary function, exhaled nitric oxide, and sputum tests were conducted. Sputum microbiota was evaluated using the 16S rRNA gene sequencing technique. Results: A total of 112 patients (13 asthma, 67 ACO, and 32 COPD) were examined. There were no significant differences in α-diversity among the 3 diseases. The relative abundances of phylum Bacteroidetes, class Bacteroidia, and genus Porphyromonas were associated with decreased eosinophilic inflammation, and were significantly lower in ACO than in COPD. In a comparison of sputum inflammatory subtypes, the proportion of Haemophilus was numerically highest in the mixed granulocytic subtype, followed by the neutrophilic subtype. Likewise, the proportion of Haemophilus was the highest in the intermediate-high (2%-8%) sputum eosinophil group and lowest in the severe (≥8%) eosinophil group. Clinically, Haemophilus proportion was associated with sputum symptoms. Finally, the proportion of Streptococcus was associated with higher blood eosinophil counts and most severe airflow limitation. Conclusions: Bacteroidia and Porphyromonas abundances in sputum are associated with the eosinophil-low phenotype, and ACO may be characterized by a decrease in these taxa. A mild elevation in sputum eosinophil does not preclude the presence of Haemophilus, which should be noted in the management of obstructive airway diseases.

Published in Journal of Allergy and Clinical Immunology: Global

ISSN: 2772-8293 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Specialties of internal medicine: Immunologic diseases. Allergy
Website: https://www.sciencedirect.com/journal/journal-of-allergy-and-clinical-immunology-global

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