Diagnosis of invasive aspergillosis: Application of Polymerase Chain Reaction Techniques (PCR) and Enzyme-Linked Immunosorbent Assay for Detection of Galactomannan (EIA-GM^®)

Abstract

Introduction: invasive aspergillosis (AI) is a serious fungal infection caused by species of the genus Aspergillus that primarily affects leukemic and diabetic patients and those recipients of stem cell transplants, which have neutropenia. The fungi spores that colonize the lung epithelium may invade the endothelial cell lining and vascular access and thus, spread to other organs through the blood. The high mortality of the disease is related to severe immunosuppression, rapid infection progression, and especially lack of an early and efficient diagnosis. Therefore, the diagnosis in the initial infection phase is beneficial, providing a more effective therapy that can reduce the disease's mortality rate. Objective: this study aimed at evaluating the applicability of the polymerase chain reaction (PCR) in assisting the diagnosis of AI compared to the results generated by galactomannan enzyme immunoassay (EIA-GM®) that is already commercially validated. Methods: 245 samples from patients treated in the Santa Casa de Belo Horizonte hospital were analyzed. Among these samples, 16% (N = 39) were positive in EIA-GM® tests. Subsequently, these 39 positive samples were analyzed by PCR. Results: According to the results, the PCR technique showed 97.44% sensitivity, 97.96% accuracy, and 100% specificity compared to EIA-GM®. Conclusion: the PCR technique may aid in the diagnosis of AI, always associating the results to the patient's clinical and immunoassay tests.