(1-3)-β-D-Glucan Antigen Detection and PCR for Diagnosis of Invasive Fungal Lung Infections

Abstract

Background: Invasive fungal lung infection (IFLI) is a collective term used to describe a range of opportunistic infections, caused by one or more endemic or opportunistic fungi, the most isolated microbes in these infections are Candida species, Aspergillus species and Cryptococcus species. Clinical symptoms typically manifest as fever, cough, dyspnea, chest pain, and hemoptysis, Radiologic examination showed various presentations, few had typical features, such as denseness, cavitation, a halo sign some even showed negative results. For diagnosis; microscopy, fungal culture, galactomannan antigen, and PCR are useful tests. Other tools include imaging facilities and blood serum biomarkers. Antigen detection methods include (1-3)-β-D-Glucan lacks higher sensitivity, PCR hasn’t been standardized, in this study, we evaluated serum (1-3)-β-D- Glucan antigen in comparison with PCR for diagnosis accuracy. Objective: This study aimed to evaluate serum (1-3)-β-D-Glucan antigen detection and PCR methods for diagnosis of invasive fungal lung infections . Methodology: The study conducted a cross-sectional comparative study on suspected IFLI patients and a healthy control group. Clinical and radiological criteria were used for patient selection. Blood and bronchoalveolar lavage (BAL) samples were collected for biomarker assessment. PCR and BDG antigen detection were evaluated. Results: Male patients accounted for 78.1%, with no significant gender difference. Hypertension (40%), followed by diabetes (22%), were identified as the most common risk factors. BDG antigen levels were significantly associated with fungal infections. Sensitivity was 92%, specificity 80%, with an AUC of 0.879. BDG levels correlated with treatment outcomes. Conclusion: Elevated BDG levels were associated with cancer and COPD patients. While BDG provides supportive evidence for fungal infection, a multifaceted approach is crucial. Implementing new diagnostic tools and centralizing laboratories of fungal identification in clinical setting are essential as the diagnostic landscape evolves.