Comparison of immunoblotting, Goldmann-Witmer coefficient and real-time PCR on aqueous humor for diagnosis of ocular toxoplasmosis

J Clin Microbiol. 2008 Apr 9 [Epub ahead of print]

Comparison of immunoblotting, Goldmann-Witmer coefficient and real-time PCR on aqueous humor for diagnosis of ocular toxoplasmosis

Fekkar A, Bodaghi B, Touafek F, Le Hoang P, Mazier D, Paris L.

AP-HP, Groupe hospitalier Pitié-Salpêtrière, Service Parasitologie Mycologie, Paris, F-75013 France; Université Pierre et Marie Curie-Paris 6, UMR S511 Paris, F-75013 France; INSERM, U511, Paris, F-75013 France; AP-HP, Groupe hospitalier Pitié-Salpêtrière, Service Ophtalmologie Paris, F-75013 France.

We compared three biological methods for the diagnosis of ocular toxoplasmosis (OT). Paired aqueous humor and serum samples from 34 patients with OT and from 76 patients with other ocular disorders were analysed with three methods: immunoblotting or western blot (WB), calculation of the Goldmann-Witmer coefficient (GWC), and polymerase chain reaction (PCR). WB and GWC each revealed intraocular production of specific anti-Toxoplasma immunoglobulin G (IgG) in 81% of samples (30 of 37). PCR detected toxoplasmic DNA in 38% of samples (13 of 34). Nine of the 13 PCR-positive patients were immunocompetent. Combining the techniques significantly improved the diagnostic sensitivity, to 92% with the GWC-WB combination, 90% with the WB-PCR combination, and 93% with the GWC-PCR combination. Combination of all three techniques improved the sensitivity to 97%.

PMID: 18400917 [PubMed - as supplied by publisher]