These results demonstrate that while the qualitative performance of HBV detection has considerably improved compared to that of a previously published HBV proficiency study, the detection levels of many commercial quantitative assays are still too high to allow adequate quantitation of all relevant clinical samples.Direct detection and quantitation of hepatitis B virus (HBV) DNA in plasma or serum are now used routinely to evaluate viremia in HBV-infected persons, to identify infectious chronic carriers, and to predict and monitor the efficacy of antiviral therapy (2,8,11). Since the early 1980s, a variety of molecular detection and quantitation methods have been developed, including dot and slot blot hybridization with radioactive and nonradioactive DNA probes (19-21), chemiluminescent detection of HBV DNA-RNA hybrids (14), PCR amplification of HBV DNA followed by hybridization to probes bound to a microwell plate (10, 12, 22) or magnetic beads (13), branched DNA (bDNA) signal amplification of an HBV DNA-DNA hybrid (7), transcription-mediated amplification (9), and fluorescent real-time detection of amplified HBV DNA (1). Each method, calibrated uniquely, exhibits its own sensitivity, specificity, and dynamic range. Standardization is ongoing (5, 6).To assess the relative value of these methods in detecting and quantitating HBV DNA, international proficiency studies with well-characterized, simulated clinical samples would be required. In the first and only such study published to date (17), 39 laboratories analyzed 22 samples, including 12 undiluted samples with and without HBV DNA. (The lowest positive sample contained 3.5 pg/ml, or approximately 980,000 copies/ml.) Only 27.9% of the data sets had all 12 samples correct, and 34.9% showed false-positive results. Clearly, a majority of the participating laboratories had problems with both sensitivity and specificity.The present report describes two recent HBV proficiency panels (lowest viral load of 1,000 copies/ml) designed by the European Union Concerted Action on Quality Control (EU QCCA) of Nucleic Acid Amplification in Diagnostic Virology and prepared by Boston Biomedica, Inc. (BBI; West Bridgewater, Mass.). The results obtained with these panels demonstrate that while the qualitative detection of HBV DNA has significantly improved, the detection levels of many commercial quantitative assays are still too high to allow adequate quantitation of the clinical samples seen in routine diagnostic laboratories. MATERIALS AND METHODSPanels. (i) Preparation. Panels were prepared by BBI from human plasma containing HBV DNA of subtype ad or ay by appropriate dilution in sterile filtered defibrinated plasma (Basematrix) with 0.09% sodium azide as preservative in accordance with the ISO 9001 Quality System Standards and the 21CFR 820 "Good Manufacturing Practice for Medical Devices: General." Plasma units were obtained from Food and Drug Administration-licensed facilities that comply with the applicable federal regulations (21CFR, part 600).The pilot dilutions made for...

Environmental pollutants may affect the immune system of marine mammals in many areas of the industrialized world. This study provides the first evidence for metal-induced hypersensitivity in harbor seals and demonstrates a relationship between this immunopathy and the level of metals in blood. The concentrations of 20 essential and nonessential elements were analyzed in the blood of 13 harbor seals from the North Sea. In addition, their T-lymphocyte response to metals in terms of hypersensitivity was investigated using a lymphocyte transformation test (LTT) according to the MELISA (memory lymphocyte immuno-stimulation assay) modification. The results showed metal hypersensitivities in 7 of 11 seals investigated in MELISA (data from two seals could not be assessed), reflecting a positive or possible positive reaction in 13 of 154 total single tests. Four animals responded to one metal and three animals to multiple metals. The sensitizing metals were molybdenum (Mo), titanium (Ti), nickel (Ni), chromium (Cr), aluminum (Al), lead (Pb), and tin (Sn). Furthermore, the seals with a Ni-, Al-,.and Cr-sensibilization showed the highest concentrations of these metals in blood. In 8 of the 13 positive cases, elevated blood metal concentrations correlated with the hypersensitivity reaction. Summarizing, we demonstrate in this first pilot study the potential immunological impact of metals in seals, a topic rarely investigated previously. Our results show the value of a combined biological and effect-monitoring tool to investigate pollution-induced immunopathies in live animals.

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The Elbe is one of the major rivers releasing pollutants into the coastal areas of the German North Sea. Its estuary represents the habitat of a small population of harbor seals (Phoca vitulina). Only little is known about the health status and contamination levels of these seals. Therefore, a first-ever seal catch was organized next to the islands of Neuwerk and Scharhörn in the region of the Hamburg Wadden Sea National Park. The investigations included a broad set of health parameters and the analysis of metals and organic pollutants in blood samples. Compared to animals of other Wadden Sea areas, the seals showed higher γ-globulin levels, suggesting higher concentrations of pathogens in this near-urban area, elevated concentrations for several metals in particular for V, Sn, Pb, and Sr, and comparable ranges for chlorinated organic contaminants, except for elevated levels of hexachlorobenzene, which indicates characteristic inputs from the Elbe.