The LYT EIA and LYM/LYG EIAs were used as first-tier tests within a two-EIA algorithm that used the C6 EIA as the second-tier test (14, 15). assess the performance of these EIAs as first-tier tests and when used in two-tiered algorithms, including a modified two-tiered testing (MTTT) approach where the second-tier test was a C6 EIA. Similar sensitivities and specificities were obtained for the two testing strategies (LYT versus LYM/LYG) when used as first-tier tests (sensitivity, 83 to 85%; specificity, 85 to 88%) with an observed agreement of 80%. ELR510444 Sensitivities of 68 to 69% and 76 to 77% and specificities of 97% and 98 to 99% resulted when the two EIA strategies were followed by Western immunoblotting and ELR510444 when used in an MTTT, respectively. The MTTT approach resulted in significantly higher sensitivities than did STTT. Overall, the LYM/LYG EIAs performed equivalently to the LYT EIA in test-to-test comparisons or as first-tier assays in STTT or MTTT with few exceptions. whole-cell sonicate (WCS), whole proteins, or a single peptide (2, 3). Among these EIAs is bioMrieux’s polyvalent Vidas LYT, which detects IgM and IgG antibodies to in human serum. This assay uses a WCS preparation from strain B31 and has been used extensively in clinical laboratories that test for Lyme disease. Additionally, this assay is fully automated and has been shown to produce a higher sensitivity than other commercially available EIAs (4, 5). However, the LYT assay yields a lower specificity than some of the other commercially available EIAs and does not differentiate between IgM and IgG antibody reactivity (6). More recently, bioMrieux developed a strategy for first-tier Lyme Mouse monoclonal to CD23. The CD23 antigen is the low affinity IgE Fc receptor, which is a 49 kDa protein with 38 and 28 kDa fragments. It is expressed on most mature, conventional B cells and can also be found on the surface of T cells, macrophages, platelets and EBV transformed B lymphoblasts. Expression of CD23 has been detected in neoplastic cells from cases of B cell chronic Lymphocytic leukemia. CD23 is expressed by B cells in the follicular mantle but not by proliferating germinal centre cells. CD23 is also expressed by eosinophils. disease testing that separately detects IgM antibodies (LYM assay) to recombinant antigens DbpA and OspC and IgG antibodies (LYG assay) to recombinant antigens VlsE, DbpA, and OspC. Both assays contain recombinant antigens from (101)9 (9)14 (14)3 (3)17 (17)17 (17)1 (1)????????Nonendemic(102)5 (5)9 (9)1 (1)10 (10)10 (10)4 (4)????????All healthy controls14 (7)23 (11)4 (2)27 (13)27 (13)5 (2)????All negative controls53 (15)44 (13)9 (3)53 (15)40 (12)12 (3) Open in a separate window aThese data have been reported previously (4, 14). bPositive LYM results were reported regardless of duration of illness prior to specimen collection. cEndemic, samples from controls in areas where Lyme disease is endemic. dNonendemic, samples from controls in areas where Lyme disease is not endemic. Pairwise comparisons of the two testing strategies (LYM/LYG versus LYT) showed that when all samples were tested, there was no significant difference between the two first-tier testing ELR510444 strategies (see Table S1 in the supplemental material). However, when samples were broken out into subgroups (Lyme disease, other diseases, and healthy controls), significant differences were observed for other diseases ( 0.01) and healthy controls (= 0.04). Specifically, the LYM/LYG EIAs (with duration of illness considered for LYM testing) resulted in an 18% decrease in false-positive results for other diseases compared to the LYT EIA. This increased specificity was largely due to more correct calls for syphilis and infectious mononucleosis samples and resulted in test agreements of only 25% and 53%, respectively (Table 2). For healthy controls, the LYM/LYG EIAs resulted in a 6% increase in false-positive results over the LYT EIA. The percentages of agreement between the two EIA testing strategies for healthy controls from areas ELR510444 where Lyme disease is endemic and areas where it is not endemic were 80% and 87%, respectively. TABLE 2 Agreement between the combined LYT ELR510444 and dissociated LYM and LYG EIAs(101)800.12 (0.08, 0.31)????????Nonendemic(102)870.06 (?0.13, 0.26)All samples tested (471)800.55 (0.46, 0.64) Open in a separate window aA 30-day duration-of-illness cutoff was considered for LYM testing. bThe 95% confidence intervals are indicated in parentheses. cNaN, not a number; the kappa value cannot be computed because the two EIA strategies were in complete agreement. dEndemic and nonendemic are as defined in the footnotes to Table 1. Similar comparisons were performed between the two bioMrieux EIA strategies and the C6 EIA (Table 1; see also Table S1 in the supplemental material). When all samples were compared, there was a significant difference ( 0.01) between the LYM/LYG EIAs (with duration of illness considered) and the C6 EIA due to the number of healthy controls that were called positive by the LYM/LYG EIAs (11% increase). When the LYT EIA was compared to the C6 EIA, there was only a significant ( 0.01) increase (22%) in positive assay results for other diseases when using the LYT EIA. This also resulted in a significant difference ( 0.01) between these two assays when all samples were tested but not when samples from Lyme disease patients or healthy controls were tested. The difference between the proportion of samples called positive by the combined LYM/LYG EIAs and that by the LYT EIA was calculated to be ?3.4% (95% confidence interval [CI] of ?7.6% to 0.8%) with a value of.