Beyond Symptoms: Radiologic identification of asymptomatic Mycobacterium avium complex pulmonary infections

Keiji Fujiwara; Fumiya Watanabe; Fumiko Uesugi; Koji Furuuchi; Masashi Ito; Tatsuya Kodama; Yoshiaki Tanaka; Takashi Yoshiyama; Satoshi Mitarai; Atsuyuki Kurashima; Ken Ohta; Kozo Morimoto

doi:10.1016/j.rmed.2024.107627

Beyond Symptoms: Radiologic identification of asymptomatic Mycobacterium avium complex pulmonary infections

Respir Med. 2024 May:226:107627. doi: 10.1016/j.rmed.2024.107627. Epub 2024 Apr 9.

Authors

Affiliations

¹ Respiratory Disease Center, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan; Department of Mycobacterium Reference and Research, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan; Department of Basic Mycobacteriosis, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
² Department of Pharmacometrics and Pharmacokinetics, Meiji Pharmaceutical University, Tokyo, Japan.
³ Respiratory Disease Center, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan.
⁴ Department of Mycobacterium Reference and Research, The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Tokyo, Japan; Department of Basic Mycobacteriosis, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
⁵ Respiratory Disease Center, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan; Department of Clinical Mycobacteriosis, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan; Division of Clinical Research, Fukujuji Hospital, Japan Anti-Tuberculosis Association, Tokyo, Japan. Electronic address: morimotok@fukujuji.org.

PMID: 38604553
DOI: 10.1016/j.rmed.2024.107627

Abstract

Background: Although international nontuberculous mycobacterial pulmonary disease (NTM-PD) guidelines highlight symptom presence at diagnosis, the clinical characteristics of asymptomatic Mycobacterium avium complex pulmonary infection (MAC-PI) patients remain understudied. We clarified the clinical characteristics and course of asymptomatic MAC-PI patients.

Methods: We retrospectively analyzed 200 consecutive patients with MAC-PIs and adequate available data who newly met the microbiological and radiological criteria for NTM-PD at Fukujuji Hospital from January 2018 to June 2020. We compared the clinical characteristics and course of asymptomatic patients with symptomatic patients and evaluated factors influencing treatment initiation through multivariate analysis.

Results: 111 patients were symptomatic and 89 were asymptomatic at diagnosis. While the proportion was significantly lower than that in the symptomatic group (28.8 %), 15.7 % of asymptomatic group patients had cavitary lesions (P = 0.042). In the asymptomatic group, treatments were initiated in 38 (42.7 %) patients, and cavitary lesions, a positive acid-fast bacilli smear, and younger age were independent risk factors for treatment initiation. Among 22 (57.9 %) patients who experienced disease progression necessitating treatment during follow-up, 13 (34.2 %) displayed radiological progression without any worsening of symptoms. Agents used for treatment were consistent across the groups, with no significant differences in culture conversion, microbiological recurrence rates, or spontaneous culture conversion rates.

Conclusion: Routine health checkups and radiological examinations can detect clinically important MAC-PIs even in the absence of symptoms. Considering that the clinical course of asymptomatic MAC-PI patients is largely similar to that of symptomatic patients, timely and appropriate management and intervention are essential for all MAC-PI patients.

Keywords: Health checkup; Mycobacterium avium; Nontuberculous mycobacteria; Symptom.

MeSH terms

Age Factors
Aged
Aged, 80 and over
Asymptomatic Infections
Disease Progression
Female
Humans
Male
Middle Aged
Mycobacterium avium Complex* / isolation & purification
Mycobacterium avium-intracellulare Infection* / diagnosis
Mycobacterium avium-intracellulare Infection* / diagnostic imaging
Mycobacterium avium-intracellulare Infection* / drug therapy
Mycobacterium avium-intracellulare Infection* / microbiology
Retrospective Studies
Risk Factors
Tomography, X-Ray Computed / methods