A Brazilian report using serological and molecular diagnosis to monitoring acute ocular toxoplasmosis

Abstract

Toxoplasmosis was recently included as a neglected disease by the CDC. Ocular toxoplasmosis (OT) is one clinical presentation of congenital or acquired infection. The laboratory diagnosis is being used worldwide to support the clinical diagnosis and imaging. The aim of this study was to evaluate the use of images, serology and molecular methods to monitor acute OT in immunocompetent patients during treatment. Five immunocompetent patients were clinically diagnosed with acute OT. The clinical evaluation was performed by ophthalmologic examination using the Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), slit lamp biomicroscopy, fundoscopic examination with indirect binocular ophthalmoscopy (Binocular ophthalmoscope ID 10, Topcon Corporation, USA) color fundus photography, fluorescein angiography and spectral optical coherence tomography (OCT). Serology were performed by ELISA (IgA, IgM, IgG Diasorin, Italy) and confirmed by ELFA (IgG, IgM Biomerieux, France). Molecular diagnoses were performed in peripheral blood by cPCR using the Toxoplasma gondii B1 gene as the marker. Follow-up exams were performed on Day +15 and Day +45. All patients were male. The mean age was 41.2 ± 11.3 years (median: 35; range: 31-54 years). All were positive for IgG antibodies but with different profiles for IgM and IgA, as well as PCR. For all patients the OCT exam showed active lesions with the inner retinal layers being abnormally hyper-reflective with full-thickness disorganization of the retinal reflective layers, which assumed a blurred reflective appearance and the retina was thickened. The presence of IgA and IgM confirmed the acute infection and thus was in agreement with the clinical evaluation. Our results show the adopted treatment modified the serological profile of IgM antibodies and the PCR results, but not the IgG and IgA antibodies and that imaging is good tool to follow-up patients. (AU)