Scandinavian journal of clinical and laboratory investigation
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Figures of allowable bias are used to make rational choices of quality control rules, to judge the validity of published reference values, and to determine the stability of sample materials. Usually, allowable bias is parametrically defined as 0.25 times the total biological standard deviation, because that is half the width of the 90% confidence interval of parametrically estimated reference limits from 120 reference values. The published figures are mostly derived from very small populations, less than 120. ⋯ Clearly larger allowable bias was derived from the resampling method than from the percentile difference method, showing that non-parametric estimation of reference limits from 120 reference values implies a larger allowable bias than 0.25 times the normal biological standard deviation. With some exceptions, the figures of allowable bias using the percentile difference method were in the same order of magnitude as parametrically derived figures in other studies, and lend some support to the results from those smaller studies. Whether such bias specifications, if met, guarantee measurements of sufficient clinical quality is unknown.
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Scand. J. Clin. Lab. Invest. · Feb 2019
Comparative Study Observational StudyComparison of thromboelastometry by ROTEM® Delta and ROTEM® Sigma in women with postpartum haemorrhage.
Haemostatic treatment in women experiencing postpartum haemorrhage is increasingly based on point-of-care devices such as ROTEM® thromboelastometry. Recently, a fully automated successor of the ROTEM® Delta device, the ROTEM® Sigma was introduced. To determine whether these devices provide similar results, we compared ROTEM® parameters using the ROTEM® Delta and Sigma devices in women experiencing postpartum haemorrhage. ⋯ Substantial variation was found between FIBTEM assays of the devices. Consequently, results of FIBTEM assays should always be interpreted in the context of device-specific reference values. Correlation with Clauss fibrinogen was better in the ROTEM® Sigma device.
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Scand. J. Clin. Lab. Invest. · Feb 2019
Increased antibody levels to stage-specific Epstein-Barr virus antigens in systemic autoimmune diseases reveal a common pathology.
The immune responses to antigens from different stages of the Epstein-Barr virus (EBV) life cycle were investigated in systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren's syndrome (SS), and systemic sclerosis (SSc) to gain knowledge of EBV's involvement in the etiology of systemic autoimmune diseases (SADs) and for an overview of the humoral immune responses against EBV. Investigations were performed by the use of ELISA. IgM, IgA, and IgG antibody binding to 11 EBV antigens: EBNA1, EBNA2, BALF5, EAD, BALF2, EA/R, VCA p18, VCA p23, gB, gp350, and gp42 were examined in serum pools from SAD patients and healthy controls (HCs). ⋯ Specifically, SLE was characterized by strongly increased IgA to EAD both compared to HCs and other SADs, and RA was characterized by increased IgM levels to several EBV antigens. The SADs may be partly distinguished by their differential immune responses to various antigens in the EBV life cycle. All together, these findings support an association between EBV infection and SADs.
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Scand. J. Clin. Lab. Invest. · Feb 2019
Age- and sex-specific reference values for non-HDL cholesterol and remnant cholesterol derived from the Nordic Reference Interval Project (NORIP).
Non-HDL-cholesterol (non-HDL-C) has been reported to be a better marker of cardiovascular risk than LDL-cholesterol (LDL-C) especially in individuals with high triglyceride values. Further, levels of remnant cholesterol have been suggested to in part explain residual risk not captured with LDL-C. The aim of the present study was to define reference values for non-HDL-C and remnant cholesterol based on data from the Nordic Reference Interval Project (NORIP). ⋯ Age- and sex-specific reference intervals should be used for the triglyceride rich lipid variables non-HDL-C and remnant cholesterol. Since these markers may add information on risk burden beyond LDL-C, our hope is that these reference intervals will aid the introduction of automatic reporting of non-HDL-C by hospital laboratories.
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Scand. J. Clin. Lab. Invest. · Nov 2018
Comparative StudyComparison of allergen-specific IgE levels between Immulite 2000 and ImmunoCAP systems against six inhalant allergens and ten food allergens.
In vitro allergen-specific immunoglobulin E (sIgE) measurement has been used as an important diagnostic tool for allergic diseases. Currently, quantitative sIgE levels are detected mainly by using ImmunoCAP and Immulite 2000 assay system. These two systems have the same calibration scale at 0-100 kUA/L, but they differ in used allergens, detection methods and automation systems. ⋯ The class results from these two assays showed good agreements for all allergens. For quantitative sIgE results, these two assays showed moderate positive correlations for Dog dander (r = 0.683) and Mackerel (r = 0.573) but high to very high correlations for the other 14 allergens (r = 0.734-0.972). Immulite 2000 and ImmunoCAP assays demonstrated good concordance and correlation for 16 common allergens, but international standards against each specific allergen for calibration and harmonization of sIgE tests are still needed.