Comparison between a new thyroglobulin assay with the well-established Beckman Access immunoassay: A preliminary report.

OBJECTIVES: Measurement of serum thyroglobulin (Tg) plays a key role in the post-thyroidectomy management of differentiated thyroid carcinoma (DTC). In this context, the performance of new-generation thyroglobulin assay has clinical implications in the follow-up of DTC patients. Aim of this study was to compare the new highly sensitive Liaison Tg II (Tg-L) with the well-established Tg Access assay (Tg-A). MATERIALS AND METHODS: A total of 91 residual serum samples (23 positive and 68 negatives for Tg auto-antibodies) were tested by the Beckman Access and Diasorin Liaison assays. Study samples were from 21 patients with pathologically proven DTC and control samples from 70 (16 patients with benign thyroid disease and 54 apparently healthy subjects). RESULTS: Our results showed that Tg-L was highly correlated with Tg-A for both values ranging between 0.2 and 50 ng/mL (Pearson's r = 0.933 [95%CI 0.894-0.958], P < .001) and higher than 50 ng/mL (Pearson's r = 0.849 [95%CI 0.609-0.946], P < .001). For Tg values lower than 0.2 ng/mL, the overall concordance rate was 92%. Moreover, we tested 7 fine-needle aspiration washout fluids (FNA), showing an overall concordance rate in discriminating negative and positive of 100%. Finally, we found no interference by Tg auto-antibodies (TgAbs) for both Tg-L and Tg-A. Conversely, rheumatoid factor (RF) interferes with Tg-A, but not with Tg-L in one patient with no relapsing thyroid carcinoma. CONCLUSIONS: Liaison Tg II demonstrated a good correlation with Access Tg assay both for sera and FNAs. Further studies on larger population are needed to evaluate Tg-L clinical impact on DTC patient's follow-up.

Clinico-pathological significance of hepatitis C virus core antigen levels in chronic infection.

Hepatitis C virus core antigen (HCVcoreAg) may be measured in serum with a sensitive, recently validated assay. Beyond its value as a marker of viral infection, there are little data on its relation with clinical, histological, and virological parameters. In this study, the significance of HCVcoreAg levels was studied in a prospective cohort of 114 patients with chronic hepatitis C. HCVcoreAg was measured by a commercial chemiluminescent microparticle immunoassay. Clinical and virological data included quantitative HCV-RNA, HCV genotype, ALT, GGT, IL28B rs12979860 polymorphism as well as liver histology parameters. HCVcoreAg levels were correlated significantly with HCV-RNA (r=0.56; P<0.0001) but also with ALT levels (r=0.258; P<0.01) and liver necroinflammatory activity (r=0.205; P<0.04). Patients harbouring HCV genotype 3 showed lower levels of HCVcoreAg than both genotype 1 and two patients. In genotype 3, a direct correlation between steatosis and HCVcoreAg was found. Levels of HCVcoreAg also varied according to the IL28B genotype. These data suggest that the evaluation of HCVcoreAg serum levels may provide relevant data for the baseline clinical evaluation of chronic hepatitis C patients. HCVcoreAg serum levels may be a useful tool to further the understanding of chronic hepatitis C pathobiology.

Comparison of anti-hepatitis D virus (HDV) ETI-AB-DELTAK-2 assay and the novel LIAISON® XL MUREX anti-HDV assay in the diagnosis of HDV infection.

Hepatitis B/D virus infection leads to severe liver disease. HDV infection is not routinely investigated since the diagnosis is based on enzyme immunoassays (EIAs), which are not available in all laboratories. This study investigates the performance of new automated assay for anti HDV Ab detection: LIAISON® XL Murex anti-HDV. HBsAg-positive samples were evaluated for HDV serology using the ETI-AB-DELTAK-2 and the new LIAISON® XL Murex with a concordance of 97.5% and 2.42% discordant results. The discordant specimens reacted negatively with EIA and positively with the new test. Dilutions of HDV-purified antibodies and HDV-positive samples were tested with both assays, showing a lower detection limit for the new assay. In conclusion, LIAISON® XL Murex showed a good concordance with the reference method and allowed a more rapid HDV detection. This new diagnostic tool may be useful for a more efficient approach to the HDV diagnosis and evaluation of HDV epidemiology.