Evaluation of the functional characteristics of the set of reagents called VDRL Plus

[摘要] Introduction: the VDRL test (venereal disease research laboratories) is a no-treponemal slide microaglutination test for the qualitative and semi-quantitative detection of plasma reagins in human serum. The VDRL Plus contains non alcoholic stabilized antigen suspension based in cardiolipin, lecithin and cholesterol in phosphate buffer. Objective: to determine a group of functional parameters in the diagnostic or clinical performance of the VDRL Plus set of reagents produced by the Center of Isotopes (CENTIS). Methods: several parameters, such as, sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios were evaluated. Likewised, Youden and Kappa indexes were calculated. Two references methods were employed, that is, TPHA (Treponema pallidum hemagglutination) and RPR-Carbon (rapid plasma reagin)-carbon, both from CENTIS. Serum samples were collected from several health centers in Havana city. Two different product batches were evaluated.Results: the sensitivity value for both evaluated batches was 100 % and the specificity was 81 and 84 %. The positives predictive values were 71 and 75 % and negative predictive value was 100 %. The positive likelihood ration were 5.3 and 6,3 % respectively and negative likelihood ration was 0 % for both batches. The Youden indexes obtained (0.84 and 0.81) and Kappa's indexes showed that there was an adequate correlation between the results obtained and the evaluation and reference methods. Conclusions: the evaluated functional characteristics showed that they are consistent among studied batches and that the VDRL Plus assay is suitable for the intended use.

[学科分类] 传染病学

[关键词] VDRL;RPR-carbon;syphilis;non-treponemal test