Falsely elevated thyroid hormone levels caused by anti-ruthenium interference in the Elecsys assay resembling the syndrome of inappropriate secretion of thyrotropin.

The syndrome of inappropriate secretion of thyrotropin (SITSH) is defined as the inappropriate non-suppression of serum TSH in the presence of elevated free thyroid hormone; TSH-secreting pituitary adenomas and the syndrome of resistance to thyroid hormone are the main etiologies of SITSH. In addition, erroneous thyroid function testing may result in the diagnosis of this syndrome. A 63-year-old woman was referred because of suspected SITSH. Laboratory tests showed a normal TSH (0.52 µIU/L; normal range: 0.5-5.0) measured by sandwich Elecsys, and elevated FT4 (3.8 ng/dL; normal range: 0.9-1.6) and FT3 (7.6 pg/mL; normal range: 2.3-4.0), determined by competitive Elecsys. To exclude possible assay interference, aliquots of the original samples were retested using a different method (ADVIA Centaur), which showed normal FT4 and FT3 levels. Eight hormone levels, other than thyroid function tests measured by competitive or sandwich Elecsys, were higher or lower than levels determined by an alternative analysis. Subsequent examinations, including gel filtration chromatography, suggested interference by substances against ruthenium, which reduced the excitation of ruthenium, and resulted in erroneous results. The frequency of similar cases, where the FT4 was higher than 3.2 ng/dL, in spite of a non-suppressed TSH, was examined; none of 10 such subjects appeared to have method-specific interference. Here, a patient with anti-ruthenium interference, whose initial thyroid function tests were consistent with SITSH, is presented. This type of interference should be considered when thyroid function is measured using the Elecsys technique, although the frequency of such findings is likely very low.

Screening for hepatitis B virus infection in pregnancy: U.S. Preventive Services Task Force reaffirmation recommendation statement.

DESCRIPTION: Reaffirmation of the 2004 U.S. Preventive Services Task Force (USPSTF) recommendation on screening for hepatitis B virus hepatitis B virus infection in pregnancy. METHODS: The USPSTF performed a brief literature update, including a search for new and substantial evidence on the benefits and harms of screening pregnant women for hepatitis B virus infection. FINDING: The net benefit of screening continues to be well established. RECOMMENDATION: Screen for hepatitis B virus infection in pregnant women at their first prenatal visit. (Grade A recommendation.).

Screening for hepatitis B virus infection in pregnant women: evidence for the U.S. Preventive Services Task Force reaffirmation recommendation statement.

BACKGROUND: Screening for hepatitis B virus (HBV) infection in pregnant women to identify newborns who will require prophylaxis against perinatal infection is a well-established, evidence-based standard of current medical practice. In 2004, the U.S. Preventive Services Task Force (USPSTF) recommended universal screening of pregnant women for HBV infection at the first prenatal visit. PURPOSE: To search for large, high-quality studies related to hepatitis B screening in pregnancy that have been published since the 2004 USPSTF recommendation. DATA SOURCES: English-language studies indexed in PubMed and the Cochrane Database of Systematic Reviews and published between 1 January 2001 and 5 March 2008. STUDY SELECTION: For benefits of screening and newborn prophylaxis, we included systematic reviews; meta-analyses; and randomized, controlled trials. For harms of screening, we included systematic reviews; meta-analyses; randomized, controlled trials; cohort studies; case-control studies; and case series of large, multisite databases. Abstracts and full articles were independently reviewed for inclusion by both reviewers. DATA EXTRACTION: Data on the benefits of screening, including benefits of hepatitis B immune globulin and hepatitis B vaccine prophylaxis of newborns of hepatitis B surface antigen-positive mothers, were extracted by 1 reviewer. DATA SYNTHESIS: No new studies met inclusion criteria. A 2006 systematic review of randomized, controlled trials found that newborn prophylaxis reduced perinatal transmission of HBV infection; all relevant trials were published in 1996 or earlier. LIMITATION: The focused search strategy, which was restricted to English-language articles, may have missed some smaller studies or new research published in languages other than English. CONCLUSION: No new evidence was found on the benefits or harms of screening for HBV infection in pregnant women. Previously published randomized trials support the 2004 USPSTF recommendation for screening.

[Risks of drug screening using immunoassays]. / Risiken beim Drogenscreening mit Immunoassays.

Now-a-days immunoassays are world wide used for the rapid screening of drugs. Despite the fact that they are a highly valuable tool for the test of legal and illicit drugs, there is a non-negligible risk of false positive and false negative findings and many pitfalls must be taken into account when using these tests in an uncritical manner and without valid confirmation procedures.