EVALUATION OF SENSITIVITY AND SPECIFICITY OF 6 D-DIMER LATEX ASSAYS

The results of six commercially available D-Dimer latex assays were co mpared with those obtained by two D-Dimer enzyme-linked immunosorbent assays; this comparison was done by assessing the sensitivity and spec ificity of the assays. Results indicated that five of the six latex as says were unable to detect consistently D-Dimer levels tie, equal to t he claims stated in the manufacturers' package inserts). performance, in order of decreasing sensitivity ([true positive/(true positive+fals e negative)] as compared with the enzyme-linked immunosorbent assay re sults), was as follows: ACCUCLOT D-Dimer (Sigma Diagnostics, St Louis, Mo) (93.8%) greater than Fibrinosticon (Organon Teknika Corp, Durham, NC) (81.3%) greater than D-Di Test (Diagnostica Stago, Asnieres, Fran ce) (68.8%) greater than Dade Dimer-test Latex Assay (Baxter Diagnosti cs Inc, Miami, Fla) (59.4%) greater than Dimertest Latex Kit (American Diagnostics Inc, Greenwich, Conn) and DimerKlone (Ortho Diagnostic Sy stems Inc, Raritan, NJ) (56.3%). The estimated sensitivity for the low est sensitivity assays (group 1) (American Diagnostica Inc, Ortho Diag nostic Systems, and Dade Diagnostics) was approximately 1.5 mg/L; the estimated sensitivity for the moderate sensitivity assays (group 2) (O rganon Teknika Corp and Diagnostica Stage) was approximately 1.0 mg/L; and the estimated sensitivity for the highest sensitivity assay (grou p 3) (Sigma Chemical Co) approached a detection limit in the 0.25- to 0.50-mg/L range.