The aim of our study was to perform verification of serum indices on three clinical chemistry platforms.
This study was done on three analyzers: Abbott Architect c8000, Beckman Coulter AU5800 (BC) ...and Roche Cobas 6000 c501. The following analytical specifications were verified: precision (two patient samples), accuracy (sample with the highest concentration of interferent was serially diluted and measured values compared to theoretical values), comparability (120 patients samples) and cross reactivity (samples with increasing concentrations of interferent were divided in two aliquots and remaining interferents were added in each aliquot. Measurements were done before and after adding interferents).
Best results for precision were obtained for the H index (0.72%-2.08%). Accuracy for the H index was acceptable for Cobas and BC, while on Architect, deviations in the high concentration range were observed (y=0.02 0.01-0.07+1.07 1.06-1.08x). All three analyzers showed acceptable results in evaluating accuracy of L index and unacceptable results for I index. The H index was comparable between BC and both, Architect (Cohen's κ 95% CI=0.795 0.692-0.898) and Roche (Cohen's κ 95% CI=0.825 0.729-0.922), while Roche and Architect were not comparable. The I index was not comparable between all analyzer combinations, while the L index was only comparable between Abbott and BC. Cross reactivity analysis mostly showed that serum indices measurement is affected when a combination of interferences is present.
There is heterogeneity between analyzers in the hemolysis, icteria, lipemia (HIL) quality performance. Verification of serum indices in routine work is necessary to establish analytical specifications.
IntroductionLaboratory plays important part in screening, diagnosis, and management of thyroid disorders. The aim of this study was to estimate current laboratory preanalytical, analytical and ...postanalytical practices and policies in Croatia.
Materials and methodsWorking Group for Laboratory Endocrinology of the Croatian Society of Medical Biochemistry and Laboratory Medicine designed a questionnaire with 27 questions and statements regarding practices and protocols in measuring thyroid function tests. The survey was sent to 111 medical biochemistry laboratories participating in external quality assurance scheme for thyroid hormones organized by Croatian Centre for Quality Assessment in Laboratory Medicine. Data is presented as absolute numbers and proportions.
ResultsFifty-three participants returned the questionnaire. Response rate varied depending on question, yielding a total survey response rate of 46-48%. All respondents perform thyroid stimulating hormone (TSH). From all other thyroid tests, most performed is free thyroxine (37/53) and least TSH-stimulating immunoglobulin (1/53). Laboratories are using nine different immunoassay methods. One tenth of laboratories is verifying manufacturer’s declared limit of quantification for TSH and one third is verifying implemented reference intervals for all performed tests. Most of laboratories (91%) adopt the manufacturer’s reference interval for adult population. Reference intervals for TSH are reported with different percentiles (90, 95 or 99 percentiles).
ConclusionThis survey showed current practices and policies in Croatian laboratories regarding thyroid testing. The results identified some critical spots and will serve as a foundation in creating national guidelines in order to harmonize laboratory procedures in thyroid testing in Croatia.
Blood-Gas Analyzers (BGAs) are commonly used in parallel with central laboratory analyzers (CLAs). Given the often-divergent results between BGAs and CLAs this study aims to: 1. Determine whether the ...measurements of potassium (K), sodium (Na), glucose (Glu), lactate (Lact) and total hemoglobin (ctHb) on BGAs and CLAs are interchangeable; 2. Establish reference intervals (RIs) for both analyzer systems using an indirect statistical approach.
During a one-year study period K, Na, Glu, Lact and ctHb measurements from 500 arterial blood samples, measured on ABL 90 FLEX BGAs were compared with corresponding venous samples measured on Roche c8000 and Sysmex XN-9000 analyzers. Interchangeability of methods was tested based on the Acceptable Change Limit, Total Change Limit and the guidelines published by the German Medical Association for quality assurance in medical laboratories criteria. Indirect RIs were estimated based on all routine analysis data using the software Reference Limit Estimator (RLE).
With the exception of Na, the BGAs differed significantly from the CLAs for the tested analytes (P < 0.001) but, with the exception of ctHb, did meet the interchangeability criteria. For K, Na, Gluc and ctHb the reference intervals obtained with RLE did not differ statistically between the analyzer systems.
The interchangeability criteria were met for Na, K and Gluc and Lact. The indirect RIs obtained with RLE, are comparable between two systems for Na, K, Gluc an ctHb. Lact differed significantly in the lower reference limit between the BGAs and CLAs. The simultaneous use of both analyzing systems is thus only advisable for Na, K and Gluc.
POCT; Blood-Gas Analyzers; Central-Laboratory analyzers; Interchangeability; Reference intervals.
Nucleocapsid gene-positive, envelope gene-negative (N2+/E-) SARS-CoV-2 PCR results obtained with the Cepheid Xpert Xpress SARS-CoV-2 assay are an infrequent phenomenon. We assessed the validity of ...the N2+/E- cases with an indirect approach by analyzing their occurrence in relation to overall positive PCR rates and absolute number of PCR tests (24,909 samples, collected June 2021 to July 2022). Additionally, 3022 samples were analyzed with the Xpert Xpress CoV-2-plus assay in August/September 2022. The incidence of monthly N2+/E- cases closely followed the overall frequency of positive tests (p < 0.001), while there was no correlation with the monthly number of PCR test. The observed distribution of N2+/E- cases implicates, that they are not merely artefacts, but rather represent samples with a very low viral load. This phenomenon will persist with the Xpert Xpress SARS-CoV-2 plus assay, which also produced more than 10% results where only one target gene replicated with a very high Ct value.
The aim of this study was to screen practices used in verification procedures for methods/analysers among medical biochemistry laboratories (MBLs) in Croatia. We hypothesized that these procedures ...differ widely from laboratory to laboratory and wanted to gather specific data on steps used in the verification workflow.
In order to obtain data, an online survey was conducted. The survey, divided in two sections, contained 29 questions and statements addressing general characteristics and specific steps of the verification workflow of each individual MBL. The survey was disseminated among managers of all MBLs in Croatia.
A total of 108/196 (55%) laboratories participated in the survey. Forty nine MBLs were excluded from the second part of the survey: 14 have not implemented verification procedures, and 35 MBLs due to the absence of answers. The most relevant results of the second part of the survey showed that: 18/59 (0.31) of the responding MBLs have difficulties when defining acceptance criteria, 27/59 (0.46) used the Clinical and Laboratory Standards Institute protocol for precision estimation; the majority of MBLs used a median of 20 samples for method/analyser comparisons and estimated bias using internal quality control samples; reference intervals provided by external sources are mainly adopted; 60% of MBLs do not include linearity verification in their protocol and do not use the national document for the estimation of measurement uncertainty.
Heterogeneous verification protocols are routinely utilized across Croatian MBLs which clearly confirms that a national document might help in the harmonization of verification procedures.
The measurement of β-hydroxybutyrate (βOHB) concentrations is a corner stone of the diagnosis of diabetic ketoacidosis and other ketonic states. The aim of this study was to perform a validation of a ...peripheral blood βOHB assay (Randox) on a Roche cobas c502 analyser and to establish a βOHB reference range for the validated assay.
Precision, linearity and limit of detection and blank (LoD, LoB) were determined according to Clinical and Laboratory Standards Institute (CLSI) EP05-A3, EP 06-A and EP17-A2 guidelines, using commercial control material and residual patient sample pools. As method comparison, for 190 semi-quantitative measurements of urine ketones we determined the corresponding βOHB blood concentration. The reference range was based on the CLSI C28-A3 guideline, using 304 randomly selected serum samples from population based German National Cohort (GNC) study.
Coefficients of variation for the validated assay ranged from 1.5% for high concentrations (3.1 mmol/L) to 6.5% for low concentrations (0.1 mmol/L). Detection capacity was LoB = 0.011 mmol/L and LoD = 0.037 mmol/L. Linearity of the assay ranged from 0.10 to 3.95 mmol/L. The agreement between the semi-quantitative urine ketone test and the βOHB blood test was moderate (Kappa = 0.66). The obtained 95% serum reference range was estimated as 0.02 to 0.28 mmol/l βOHB.
The Ranbut βOHB assay showed good precision and analytical performance. Our results confirm that βOHB measurement in peripheral blood is indeed a preferable alternative to the semi-quantitative measurement of urine ketones.
Highlights • Serum omentin-1 levels were significantly lower in diabetic HD patients. • The risk of one-and-half- year was 3.68 times higher in patients with diabetes. • Omentin-1 is independent ...factor that predict mortality in patients with diabetes.
Provider: - Institution: - Data provided by Europeana Collections- Kardiovaskularne bolesti uzrokovane aterosklerozom predstavljaju značajan uzrok smrtnosti u hemodijaliziranih
(HD) bolesnika. ...Bolesnici koji se liječe HD imaju i do 30 puta veću stopu smrtnosti uzrokovanu kardiovaskularnim
bolestima. Rizični čimbenici uključeni u patogenezu ateroskleroze u HD bolesnika pacijenata uključuju dijabetes,
hipertenziju, dislipidemiju, pušenje, oksidativni stres, upalu te endotelnu disfunkciju. Budući da ateroskleroza ima
dugačku subkliničku fazu veoma je važno da patološki procesi budu otkriveni čim ranije, dok je bolest još u
asimptomatskoj fazi. Povećana debljina intime-medije (IMT) prepoznata je kao rani indikator subkliničke
ateroskleroze, kako u općoj populaciji tako i u HD-ih bolesnika te je povezana s tradicionalnim i novijim
kardiovaskularnim čimbenicima rizika. Nekoliko je studija dokazalo da je karotidna ateroskleroza povezana s
adhezijskim molekulama te omentin-1 proteinom. Ciljevi ovog rada bili su sljedeći: a) istražiti povezanost sICAM-1,
sVCAM-1, omentin-1 proteina te ostalih netradicionalnih rizičnih čimbenika sa subkliničkom aterosklerozom; b)
ispitati dijagnostičku vrijednost ovih specifičnih markera u otkrivanju subkliničke ateroskleroze i c) ispitati njihovu
ulogu kao prediktora smrtnosti u asimptomatskih bolesnika.
Počevši od studenog 2011. godine, kohorta od 210 HD-ih bolesnika sudjelovala je u trogodišnjem istraživanju.
Ispitanici su bili podijeljeni u tri skupine ovisno o prisutnosti ateroskleroze. Ateroskleroza je dijagnosticirana na
temelju mjerenja debljine intima-medija karotidne arterije. Uzorkovanje krvi izvršeno je na početku studije te svakih
12 mjeseci iza toga sve do kraja istraživanja. Ehokardiografska mjerenja učinjena su na početku i na kraju studije.
Dokazana je slaba korelacije između IMT i sICAM-1 (r=0,39, P=0,001), sVCAM-1 (r=0,27, P=0,015) i omentin-1
proteina (r=-0,25, P=0,020). Omentin-1 protein je pokazao dobru korelaciju s parametrima sistoličke i dijastoličke
funkcije lijeve klijetke (r=0,52, P=0,001 i r=0,51, P=0,001). Multivarijantna analiza je pokazala kako su koncentracije
sICAM-1 i omentin-1 proteina snažni neovisni pretkazatelji IMT (P=0,031 i P=0,010). Coxova analiza
proporcionalnih rizika pokazala je da su koncentracija sICAM-1 i omentin-1 proteina snažni pretkazatelji
kardiovaskularne smrti (HR=1,85, CI=1,18-2,32, P=0,021 i HR=4,14, CI=1,38-12,1, P=0,004,) te da uzastopno
mjerenje koncentracija sICAM-1 i omentin-1 proteina predstavlja jake prediktore IMT progresije (HR=1,98, 95%
CI=1,21-2,38, P<0,002 i HR=2,91, 95% CI=1,57-4,72, P<0,001).
Naša studija je pokazala kako su koncentracije ICAM-1 I omentin-1 proteina jaki pretkazatelji kardiovaskularne
smrti u asimptomatskih HD bolesnika. Porast koncentracije ICAM-1 te pad koncentracije omentin-1 proteina imaju
ključnu ulogu u ranoj progresiji ateroskleroze.- Atherosclerotic cardiovascular complications represent significant cause of mortality in hemodialysis (HD)
patients. Patients undergoing HD have up to 30 times higher incidence of cardiovascular disease mortality. Risk
factors involved in pathogenesis of atherosclerosis in patients undergoing HD include diabetes, hypertension,
dyslipidemia, smoking, oxidative stress, inflammation and endothelial dysfunction. Since atherosclerosis has a long
subclinical phase it is important that pathogenic processes are identified while disease is still asymptomatic. Increased
carotid intima-media thickness (cIMT) is well recognized as an early indicator of subclinical atherosclerosis both in
the general population and in HD patients and it is associated with traditional and emerging CV risk factors. Several
studies have shown that carotid atherosclerosis is associated with circulating concentrations of soluble adhesion
molecules (CAMs) and omentin-1 protein. The aims of this study were to: a) investigate association of sICAM-1,
sVCAM-1, omentin-1 and other non-traditional risk factors with subclinical atherosclerosis; b) examine the diagnostic
value of these specific markers in the early detection of subclinical atherosclerosis and c) examine their role as
predictors of mortality in group of patients with subclinical atherosclerosis on regular HD.
Starting from November 2011, a cohort of 210 HD patients participated in this three-year follow-up study. The
subjects were divided into three groups according to the presence of atherosclerosis. Atherosclerotic disease was
assessed by measuring carotid intima-media thickness (IMT). Samplings were withdrawn at baseline and thereafter
every 12 months until the end of follow-up. Echocardiography was performed at baseline and at the end of follow-up.
IMT showed weak correlation with sICAM-1 (r=0.39, P=0.001), sVCAM-1 (r=0.27, P=0.015), and omentin-1 (r=-
0.25, P=0.020), also omentin-1 showed good correlation with parameters of systolic and diastolic function (r=0.52,
P=0.001 and r=0.51, P=0.001). Multivariate analysis showed that sICAM-1 and sVCAM-1 concentrations were a
strong independent correlate of IMT (P=0.031 and P=0.010, respectively). The Cox proportional analysis showed that
sICAM-1 and omentin-1 concentrations were strong predictors of cardiovascular death (HR=1.85, CI=1.18-2.32,
P=0.021 and HR=4.14, CI=1.38-12.1, P=0.004, respectively) and that serial measurements of these markers predict
IMT progression (HR=1.98, 95% CI=1.21-2.38, P<0.002 and HR=2.91, 95% CI=1.57-4.72, P<0.001, respectively).
Our study demonstrated that sICAM-1 and omentin-1 levels are strong predictors of cardiovascular death in HD
patients with subclinical atherosclerosis. . We believe that an increase in sICAM-1 and decrease in omentin-1 levels
could play an important role in the early progression of atherosclerosis.- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Purpose
Atherosclerotic cardiovascular complications represent significant cause of mortality in hemodialysis (HD) patients. The aims of this study were to: (a) investigate association of sICAM-1, ...sVCAM-1, omentin-1 and other non-traditional risk factors with subclinical atherosclerosis; (b) examine the diagnostic value of these specific markers in the early detection of subclinical atherosclerosis; and (c) examine their role as predictors of mortality in group of patients with subclinical atherosclerosis on regular HD.
Materials and methods
Starting from November 2011, a cohort of 210 HD patients participated in this 3-year follow-up study. The subjects were divided into three groups according to the presence of atherosclerosis. Atherosclerotic disease was assessed by measuring carotid intima-media thickness (IMT). Samplings were withdrawn at baseline and thereafter every 12 months until the end of follow-up.
Results
IMT showed weak correlation with sICAM-1 (
r
= 0.39,
P
= 0.001), sVCAM-1 (
r
= 0.27,
P
= 0.015) and omentin-1 (
r
= −0.25,
P
= 0.020), and also omentin-1 showed good correlation with parameters of systolic and diastolic function (
r
= 0.52,
P
= 0.001 and
r
= 0.51,
P
= 0.001). Multivariate analysis showed that sICAM-1 and sVCAM-1 concentrations were a strong independent correlate of IMT (
P
= 0.031 and
P
= 0.010, respectively). The Cox proportional analysis showed that sICAM-1 and omentin-1 concentrations were strong predictors of cardiovascular death (HR 1.85, CI 1.18–2.32,
P
= 0.021 and HR 4.14, CI 1.38–12.1,
P
= 0.004, respectively) and that serial measurements of these markers predict IMT progression (HR 1.98, 95 % CI 1.21–2.38,
P
< 0.002 and HR 2.91, 95 % CI 1.57–4.72,
P
< 0.001, respectively).
Conclusions
Our study demonstrated that sICAM-1 and omentin-1 levels are strong predictors of cardiovascular death in HD patients with subclinical atherosclerosis.
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