Establishment of Aspergillus fumigatus-specific IgG cut-off level for diagnosis of chronic pulmonary aspergillosis in the Iranian population

Asadi Shahi Sarae, Sabrieh; Aliyali, Masoud; Mortezaee, Vida; Jamaati, Hamidreza; Asgarian Omran, Hossein; Abedi, Siavash; Mehravaran, Hossein; Yazdani Charati, Jamshid; Mirenayat, Maryam Sadat; Pourabdollah, Mihan; Lookzadeh, Somayeh; Moazeni, Maryam; Mayahi, Sabah; Ghazanfari, Mona; Haghani, Iman; Abastabar, Mahdi; Hedayati, Mohammad T

doi:10.22034/cmm.2026.345514.1741

Establishment of Aspergillus fumigatus-specific IgG cut-off level for diagnosis of chronic pulmonary aspergillosis in the Iranian population

Document Type : Original Articles

Authors

Sabrieh Asadi Shahi sarae ¹

Masoud Aliyali ²

Vida Mortezaee ³

Hamidreza Jamaati ³

Hossein Asgarian Omran ⁴

Siavash Abedi ²

Hossein Mehravaran ²

Jamshid Yazdani Charati ⁵

Maryam Sadat Mirenayat ⁶

Mihan Pourabdollah ³

Somayeh Lookzadeh ³

Maryam Moazeni ¹

Sabah Mayahi ¹

Mona Ghazanfari ⁷

Iman Haghani ⁷

Mahdi Abastabar ¹

Mohammad T Hedayati ¹

¹ Department of Medical Mycology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran

² Pulmonary and Critical Care Division, Imam Khomeini Hospital, Mazandaran University of Medical Sciences, Sari, Iran

³ Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran

⁴ Department of Immunology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran

⁵ Department of Biostatistics, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran

⁶ Pulmonary Rehabilitation Research Center (PRRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran

⁷ Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran

10.22034/cmm.2026.345514.1741

Abstract

Background and Purpose: The optimal cut-off level for serum Aspergillus-specific IgG (SAfIgG) in the diagnosis of chronic pulmonary aspergillosis (CPA) remains to be established for different countries. This study aimed to establish a cut-off level for SAfIgG in CPA diagnosis and validate its diagnostic accuracy in the Iranian population.
Materials and Methods: Diagnostic performance of SAfIgG was evaluated in patients with chronic obstructive pulmonary disease (COPD) suspected of having CPA who had referred to the two reference centers for pulmonary diseases in Iran, during 2021-2023. Levels of SAfIgG were measured using an enzyme-linked immunosorbent assay. Optimal cut-off point for SAfIgG was determined using the receiver operating characteristics (ROC) curve and Youden's index and was subsequently validated.
Results: In total, 30 (15.3%) out of 196 COPD patients were diagnosed with CPA. The ROC curve analysis yielded an area under the curve of 0.632 (95% CI: 0.421-0.843; p=0.114), with an optimal cut-off value of 23.5 U (sensitivity: 71.4%; specificity: 61.4%). The SAfIgG levels were significantly higher in CPA patients (median [IQR], 39 [31-55] U) compared with non-CPA patients (20 [15-24] U; p<0.001).
Conclusion: The findings indicated that SAfIgG, with a cut-off value of 23.5 U, provided moderate sensitivity and specificity for screening and may be used in combination with the culture method to confirm the diagnosis of CPA in COPD patients. However, the variability in cut-off values across different populations highlights the need for standardized guidelines to improve diagnostic consistency and reliability.

Keywords

Aspergillus fumigatus, Chronic obstructive pulmonary disease, IgG

Subjects