Clinical classification of chronic obstructive pulmonary disease with invasive pulmonary aspergillosis: a retrospective study

Background: Patients with chronic obstructive pulmonary disease (COPD) complicated by invasive pulmonary aspergillosis (IPA) have high mortality and significant clinical heterogeneity. However, systematic classification criteria are currently lacking. To address this, our study proposes a clinical classification system specifically for COPD-IPA, based on its distinct clinical manifestations and pulmonary imaging features. Methods: We performed a retrospective analysis of clinical and radiological features in patients diagnosed with COPD-IPA during hospitalization from 2008 to 2024 to develop a novel clinical classification system. Demographic characteristics, laboratory parameters, radiologic manifestations, and prognosis were compared across the identified subtypes. Results: The study cohort comprised 63 COPD-IPA patients, who were predominantly elderly males (mean age: 70.9±8.7 years; 95.2% male). A novel classification system defined five distinct subtypes: (I) the fulminant type (3/63, 4.8%), which progressed rapidly to respiratory failure [partial pressure of arterial oxygen (PaO2)/fraction of inspired oxygen (FiO2): 204.0±36.2 mmHg], was associated with hemodynamic instability (2/3, 66.7%), and had a high mortality rate (2/3, 66.7%); (II) the pneumonic type (35/63, 55.5%), presenting primarily as lobar or segmental consolidation (26/35, 74.3%) and frequently misdiagnosed as bacterial pneumonia; (III) the tuberculosis-like type (14/63, 22.2%), typically exhibiting upper-lobe fibro-proliferative lesions (13/14, 92.9%); (IV) the asthma-like type (7/63, 11.1%), characterized by mucoid impaction (5/7, 71.4%) and steroid-refractory trait; (V) the tumor-like type (3/63, 4.8%), manifesting in all cases as solitary ground-glass opacity (GGO) nodules or mixed solid lesions. Additionally, one patient (1/63, 1.6%) presented with diuretic-unresponsive, diffuse GGOs in both lower lungs, suggesting a potential heart failure-like type. Critical differences emerged between the subtypes: the fulminant subtype had the most severe oxygenation impairment (lowest PaO2/FiO2, P