A PCR-Based Approach for Early Diagnosis of Head and Neck Aspergillosis: A Pilot Study.

BACKGROUND

Aspergillosis is a fungal disease caused by the inhalation of fungal spores of the genus Aspergillus spp. This fungus mainly affects the lungs but can spread and infect the maxillofacial region through the bloodstream or inoculation of the fungus after extraction or endodontic treatment, especially in the upper posterior teeth. The disease has nonspecific clinical manifestations that hinder its early diagnosis. Although the Polymerase Chain Reaction (PCR) technique holds promise as a diagnostic tool for aspergillosis, anatomopathological analysis services do not routinely adopt this method.

OBJECTIVES

Therefore, the present study aimed to evaluate the applicability of PCR and standardise the techniques of preparation of biological samples for the detection of the three species: Aspergillus niger, Aspergillus fumigatus and Aspergillus flavus.

Methods

Six samples of formalin-fixed, paraffin-embedded tissue (FFPE) with a histopathological diagnosis suggestive of aspergillosis were investigated using PCR. As a positive control for the PCR reaction, morphologically and genetically characterized cultures were used, with their sequences deposited at NCBI under accession codes MW837777 (A. fumigatus) and MW837779 (A. niger). The A. flavus culture used is reference RC 2053.

RESULTS

Four of the six samples evaluated were positive for Aspergillus spp., of which one was co-infected with A. fumigatus and A. flavus species, while two others were positive only for A. flavus, and one sample was positive only for A. fumigatus.

CONCLUSIONS

These findings suggest that PCR can be used as an auxiliary method for diagnosing aspergillosis. However, this was a pilot study, and expansion of the sample size and the evaluation of PCR in comparison with other diagnostic tests for aspergillosis are essential to determine the accuracy of the method.