IgM interference in the Abbott iVanco immunoassay: a case report

Vancomycin; Interference; IgM paraprotein; Immunoassay; SERU

Neonatal thyroid-stimulating hormone concentrations in Belgium: a useful indicator for detecting mild iodine deficiency?

It has been proposed that neonatal thyroid-stimulating hormone (TSH) concentrations are a good indicator of iodine deficiency in the population. A frequency of neonatal TSH concentrations above 5 mU/L below 3% has been proposed as the threshold indicating iodine sufficiency. The objective of the present study was to evaluate feasibility and usefulness of nation-wide neonatal TSH concentration screening results to assess iodine status in Belgium. All newborns born in Belgium during the period 2009-2011 (n = 377713) were included in the study, except those suffering from congenital hypothyroidism and premature neonates. The frequency of neonatal TSH concentrations above 5 mU/L from 2009 to 2011 in Belgium fluctuated between 2.6 and 3.3% in the centres using the same TSH assay. There was a significant inverse association between neonatal TSH level and birth weight. The longer the duration between birth and screening, the lower the TSH level. Neonatal TSH levels were significantly lower in winter than in spring or autumn and significantly lower in spring and summer than in autumn while significantly higher in spring compared to summer. In conclusion, despite that pregnant women in Belgium are mildly iodine deficient, the frequency of neonatal TSH concentrations above 5 mU/L was very low, suggesting that the neonatal TSH threshold proposed for detecting iodine deficiency needs to be re-evaluated. Although neonatal TSH is useful to detect severe iodine deficiency, it should not be recommended presently for the evaluation of iodine status in mildly iodine deficient regions.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Bland Altman plot of comparison of Method 1 (Autodelphia) used by centre 1,2,3,4 versus Method 2 (ELISA commercial Biorad) used by centre 5.

<p>Mean difference: −3.854 mU/L (CI −4.291 to −3.417 mU/L) (left) and method 1 (Autodelphia) used by centre 1,2,3,4 versus method 3 (ELISA) used by centre 6; mean difference: −1.470 mU/L (CI −1.692 to −1.249 mU/L) (right).</p

Least square means of difference in TSH among years and seasons, linear mixed model regression.

*<p>transformed values.</p

Distribution of TSH values (between 0 and 15 mU/L) over the three different years by the six different scenarios.

***<p>P<0.05 for all Tukey tests comparing differences in TSH levels over the years 2009, 2010, 2011. TSH1: TSH values of centre 5 and 6 converted to Autodelphia method using point estimators for intercept and slope. TSH2: TSH values of centre 5 and 6 converted to Audodelphia method using lower limit of CI for intercept and slope. TSH3: TSH values of centre 5 and 6 converted to Autodelphia method using higher limit of CI for intercept and slope. TSH4: TSH values of centre 5 and 6 converted to Autodelphia method using lower limit of CI for intercept and higher limit of CI for slope. TSH5: TSH values of centre 5 and 6 converted to Autodelphia method using lower limit of CI for slope and higher limit of CI for intercept. TSH6: Only TSH values of 4 centres using Autodelphia method.</p

Regression equations and 95% CI to convert TSH levels of centre 5 and 6 to Autodelphia method.

<p>Centre 5: Liège; Centre 6: Louvain en Woluwé. CI confidence interval.</p