Diagnostic Value of Positive Findings of Toxoplasma gondii-Specific Immunoglobulin M Serum Antibody in Uveitis Patients to Confirm Ocular Toxoplasmosis.

Purpose: To assess the value of positive immunoglobulin (Ig) M serum antibody (Ab) findings in uveitis patients. Methods: We reviewed medical records of patients who had a positive serological test for Toxoplasma gondii-specific IgM Ab. Their clinical data, including history, demographic characteristics, laboratory findings, clinical findings, treatment outcomes, and recurrences, were reviewed retrospectively. Results: Of 2919 uveitis patients who underwent a serological test for suspected ocular toxoplasmosis (OT), 18 presented with positive Ig M results. All 18 patients (100.0% specificity) were clinically diagnosed with OT. None had any retinochoroidal scar at the initial visit, indicating the OT was a recent and primary infection. However, 15 patients (83.3%) had no history suspected to account for the Toxoplasma transmission. Conclusions: The T. gondii IgM serum Ab is a specific biomarker for diagnosis of primary OT. Epidemiological studies are warranted to investigate the non-classic transmission routes of T. gondii in OT.