Evaluation of Elecsys Syphilis Assay for Routine and Blood Screening and Detection of Early Infection.

Treponema pallidum infections can have severe complications if not diagnosed and treated at an early stage. Screening and diagnosis of syphilis require assays with high specificity and sensitivity. The Elecsys Syphilis assay is an automated treponemal immunoassay for the detection of antibodies against T. pallidum The performance of this assay was investigated previously in a multicenter study. The current study expands on that evaluation in a variety of diagnostic settings and patient populations, at seven independent laboratories. The samples included routine diagnostic samples, blood donation samples, samples from patients with confirmed HIV infections, samples from living organ or bone marrow donors, and banked samples, including samples previously confirmed as syphilis positive. This study also investigated the seroconversion sensitivity of the assay. With a total of 1,965 syphilis-negative routine diagnostic samples and 5,792 syphilis-negative samples collected from blood donations, the Elecsys Syphilis assay had specificity values of 99.85% and 99.86%, respectively. With 333 samples previously identified as syphilis positive, the sensitivity was 100% regardless of disease stage. The assay also showed 100% sensitivity and specificity with samples from 69 patients coinfected with HIV. The Elecsys Syphilis assay detected infection in the same bleed or earlier, compared with comparator assays, in a set of sequential samples from a patient with primary syphilis. In archived serial blood samples collected from 14 patients with direct diagnoses of primary syphilis, the Elecsys Syphilis assay detected T. pallidum antibodies for 3 patients for whom antibodies were not detected with the Architect Syphilis TP assay, indicating a trend for earlier detection of infection, which may have the potential to shorten the time between infection and reactive screening test results.

Increased Maternal Serum Interleukin-6 Concentrations at 11 to 14 Weeks of Gestation in Low Risk Pregnancies Complicated with Gestational Diabetes Mellitus: Development of a Prediction Model.

The aim of the study was to examine interleukin-6 (IL-6) maternal serum concentration at 11 to 14 gestational weeks in normal pregnancies and pregnancies complicated by gestational diabetes mellitus (GDM) and to create first trimester prediction models for GDM. Case-control study conducted in a Fetal Medicine Unit. Study population included 40 GDM cases and 94 controls. Maternal characteristics, first trimester ultrasound markers, biochemical indices, and IL-6 levels were used for our analysis. IL-6 was related to maternal weight among the maternal characteristics, (R(2)=0.0679, p=0.01). IL-6 was increased (p=0.001) in the GDM group (median=2 pg/ml) compared to the control group (median=1.5 pg/ml) even after adjustment for maternal weight. IL-6 was inversely related to birth weight adjusted for gestational age at delivery (r=-0.3382, p<0.001) and glucose levels at oral glucose test. Maternal weight and age were the only predictors of GDM among the maternal characteristics [Detection Rate (DR)=59.4%; for 25% False Positive Rate (FPR); Area Under the Curve (AUC)=0.7291; Model R(2)=0.1096, p<0.001]. IL-6 alone was a significant predictor of GDM (DR=51.3%; for 25% FPR; AUC=0.6731; Model R(2)=0.0616, p<0.001). Combination of maternal characteristics with IL-6 yielded an improved prediction (DR=67.5%; for 25% FPR; AUC=0.7586; Model R(2)=0.1521, p<0.001). IL-6 concentrations are increased at 11-14 weeks in pregnancies with GDM. Combination of maternal characteristics and maternal serum IL-6 levels may provide effective first trimester screening for GDM.