Immunoblot and Witmer's Coefficient Comparison in Ocular Toxoplasmosis

Abstract

Abstract: : Purpose: To compare the immunoblot technique of local antibody production in the aqueous humor in suspected toxoplasmosis with the Witmer coefficient and describe the interest of performing both methods in difficult cases. Methods: A prospective study from June 2001 to August 2004 included 40 eyes of 40 patients with recent chorio–retinal lesions was performed. The aqueous tap was taken at least two weeks after the symptoms began to appear and each sample was divided into two and processed separately. One sample underwent the immunoblot technique and the other underwent calculation of the Witmer coefficient (by agglutination HS). Results: Sensitivity of the immunoblot technique was 63.6% and that of the Withmer coefficient 45.5%. Combined sensitivity of both techniques together was 77.3%. Conclusions: This type of examination appears to be indicated in atypical cases of ocular toxoplasmosis when diagnosis is not made after two weeks of evolution.

Keywords: chorioretinitis • microbial pathogenesis: experimental studies • toxoplasmosis