This multicenter bidirectional cohort study aims to investigate the clinical characteristics and prognostic outcomes of patients with allergic bronchopulmonary aspergillosis (ABPA) stratified by fungal microbiological status in sputum or bronchoalveolar lavage fluid (BALF).

Patients diagnosed with ABPA according to the ISHAM 2024 criteria will be classified into fungal-positive and fungal-negative groups based on results from fungal culture, galactomannan (GM) testing, and metagenomic next-generation sequencing (mNGS) of sputum or BALF samples.

The study will compare baseline clinical features, laboratory findings, radiological characteristics, treatment response, and long-term outcomes, including acute exacerbation rate and time to first exacerbation, between the two groups.

All participants will be followed for up to 12 months with serial clinical and laboratory assessments.

Inclusion Criteria:

• 1.Adult patients (≥18 years old) diagnosed with allergic bronchopulmonary aspergillosis (ABPA) according to the 2024 International Society for Human and Animal Mycology (ISHAM) diagnostic criteria.

  2.Patients hospitalized during the study period in participating centers with sputum or bronchoalveolar lavage fluid (BALF) collection performed.

  3.At least one mycological test performed on sputum or BALF, including fungal culture, galactomannan (GM) assay, metagenomic next-generation sequencing (mNGS), or targeted next-generation sequencing (tNGS), with clearly interpretable results (positive or negative).

  4.Availability of complete and traceable clinical data, including medical history, imaging, laboratory tests, treatment records, and follow-up information, with no critical missing data.

  5.Willingness to participate in follow-up and signed informed consent (for prospective participants), with good compliance for follow-up.

  6.No systemic antifungal therapy or other interventions that may significantly affect mycological test results within 1 month prior to enrollment.

Exclusion Criteria:

• 1.Coexisting pulmonary fungal infections (e.g., invasive pulmonary aspergillosis) or other confirmed non-fungal pulmonary infections.

  2.Presence of other structural lung diseases, such as pulmonary tuberculosis, lung cancer, or lung abscess.

  3.Severe immunodeficiency or other significant allergic pulmonary diseases that may confound the diagnosis of ABPA.

  4.Absence of sputum or BALF samples, or lack of valid mycological test results. 5.Incomplete key clinical data (e.g., total IgE, Aspergillus-specific IgE/IgG, imaging, or pulmonary function data) or inability to complete at least 3 months of follow-up.

  6.Systemic antifungal treatment within 1 month prior to enrollment or participation in another interventional clinical trial.

  7.Contraindications to bronchoscopy/BAL procedures or known severe allergy to relevant reagents used in testing.

This study will include adult patients (≥18 years old) diagnosed with allergic bronchopulmonary aspergillosis (ABPA) according to the 2024 ISHAM diagnostic criteria. The study population consists of retrospectively identified cases from participating hospitals' electronic medical records and prospectively enrolled patients during the study period. Eligible patients must have undergone sputum or bronchoalveolar lavage fluid (BALF) sampling with at least one mycological test (culture, GM assay, mNGS, or tNGS) and have complete clinical, imaging, laboratory, treatment, and follow-up data. Participants will be stratified into BALF/sputum mycological positive and negative groups. Patients with coexisting pulmonary fungal infections, missing key data, or inability to complete follow-up will be excluded.