Paracoccidioidomycosis disease seven years after positive serology: serological reactivity analysis in the period before and after disease onset

Paracoccidioidomycosis (PCM) is one of the most important systemic mycoses in Latin America. Several cases of positive serology in healthy individuals without clinical manifestation have been detected, particularly in rural areas. However, there are no reports of serologic investigation pre- and post-manifestation of PCM. In this study, serological reactivity in the period before and after disease onset was evaluated in a patient who presented clinical manifestations of PCM disease seven years after a positive serology test. In 2003, the patient did not show any oral lesions and was apparently healthy but had a positive ELISA (enzyme-linked immunosorbent assay) result. In 2010, the patient presented disease manifestations: lesions on the labial and jugal mucosa. A biopsy was obtained from the area for histopathological exam and fungal culture analysis, and a fungus with Paracoccidioides brasiliensis characteristics was detected. The Serological analysis in the pre- and post-disease onset periods revealed ELISA reactivity (?1/800) in both samples; immunodiffusion reaction was negative prior to disease onset and positive (1/16) during the PCM disease phase. Immunoblotting results showed recognition of antigens of high molecular mass and gp43 in both phases, with gp70 also observed during the disease phase. This case highlights the importance of periodic medical supervision and the need for further investigation when serology tests are positive for PCM. Additionally, the findings of serum reactivity with P. brasiliensis high molecular mass and gp43 antigens are noteworthy.