2024 Guidelines of the Polish Society of Laboratory Diagnostics and the Polish Lipid Association on laboratory diagnostics of lipid metabolism disorders.

Lipid disorders are the most common (even 70%) and worst monitored cardiovascular risk factor (only 1/4 of patients in Poland and in CEE countries are on the low-density lipoprotein cholesterol (LDL-C) goal). To improve this, clear and simple diagnostic criteria should be introduced for all components of the lipid profile. These are the updated guidelines of the two main scientific societies in Poland in the area - the Polish Society of Laboratory Diagnostics (PSLD) and the Polish Lipid Association (PoLA), which, in comparison to those from 2020, introduce few important changes in recommendations (two main lipid targets, new recommendations on LDL-C measurements, calculations new goals for triglycerides, new recommendations on remnants and small dense LDL) that should help the practitioners to be early with the diagnosis of lipid disorders and in the effective monitoring (after therapy initiation), and in the consequence to avoid the first and recurrent cardiovascular events.

Validation of Becton Dickinson Barricor™ tubes for use with Abbott Alinity™ and Siemens Atellica® highly sensitive cardiac troponin I measuring systems.

BACKGROUND: BD Barricor™ tubes have been proposed to decrease laboratory turnaround time (TAT). We analytically validated and then clinically verified these tubes for use with Abbott Alinity™ and Siemens Atellica® highly sensitive cardiac troponin I (hs-cTnI) assays. METHODS: hs-cTnI measurements were undertaken in paired Barricor™ and in-use PSTII™ tubes on both systems. 359 matched samples with hs-cTnI levels between 3 and 15,000 ng/L (Atellica® values) were used to assess the hemolysis rate and make method comparisons. 599 paired patient samples were collected on emergency department (ED) admission to compare the performance of the rapid acute myocardial infarction (AMI) rule-out strategy based on hs-cTnI concentrations lower than recommended thresholds (<4 ng/L Alinity™; <5 ng/L Atellica®) when different tubes and systems were employed. RESULTS: No between-tube differences in hemolysis rate were seen when free hemoglobin concentrations in plasma samples were ≥0.25 g/L, even if PSTII™ showed a significant increase of hemolysis rate vs. Barricor™ (31% vs. 22%, p=0.007) when a lower cut-off for hemolysis (≥0.11 g/L) was employed on the Atellica® detection system. The alternate use of these tubes did not influence the hs-cTnI results obtained from either of the two assays, which remained markedly biased (~40%) irrespective of the tube used. The expected optimal ability of very low hs-cTnI values on ED admission for ruling out AMI was confirmed by using both systems regardless of the tube type. CONCLUSIONS: Barricor™ and PSTII™ tubes can provide analytically equivalent hs-cTnI results when used on either Alinity™ or Atellica® hs-cTnI assays.

Reference values and biological determinants for cardiac myosin-binding protein C concentrations assessed with an enzyme-linked immunosorbent assay.

Background: Cardiac myosin-binding protein C (cMyC) is a novel cardio-specific biomarker of potential diagnostic and prognostic value for cardiovascular events. This study aims to determine reference values for cMyC and identify biological determinants of its concentration. Methods: A population of 488 presumably healthy adults were enrolled to define biological determinants which affect cMyC concentrations in serum. Concentrations of cMyC were assessed using enzyme-linked immunosorbent assays from commercially available kits. Eligibility for inclusion in this study evaluated all subjects' anthropometric, demographic and laboratory measurements. After applying strict inclusion criteria, a reference population (n=150) was defined and used to determine reference values. Reference values were derived using a robust method.

Diagnostic Performance of Biomarker-Based Scores as Predictors of Metabolic Dysfunction-Associated Fatty Liver Disease Risk in Healthy Children.

INTRODUCTION: Metabolic dysfunction-associated fatty liver disease (MAFLD)-a new definition for non-alcoholic fatty liver disease-reflects the impact of metabolic abnormalities on liver function. We assessed the diagnostic accuracy of biomarker-based scores for prediction of MAFLD in apparently healthy children. METHODS: This study included 144 children aged 9-11. MAFLD was recognized in 14 girls and 29 boys. Anthropometric indices, glycemia, insulin resistance, lipid profile, enzymes (ALT, AST, GGT, ALP), CRP, N-terminal propeptide of type I procollagen (P1NP) and collagen type I C-telopeptide (CTX-1) levels were measured. Fatty liver and hepatic steatosis index (FLI, HSI) and potential indicators of liver fibrogenesis: P1NP/ALP, P1NP/ALPxALT, P1NP/ALPxCRP were calculated. RESULTS: P1NP/ALPxALT and P1NP/ALPxCRP were significantly higher in subjects with MAFLD. FLI was a good, significant predictor of MAFLD occurrence, regardless of sex. In boys, P1NP/ALPxCRP was a comparable predictor as CRP (OR 1.14 vs. 1.17; p < 0.001). P1NP/ALPxCRP had better discrimination capability in boys (AUC = 0.79; p < 0.001). However, the use of this algorithm did not improve discriminatory power in comparison to CRP (AUC = 0.81; p < 0.001), but gave a better sensitivity for MAFLD prediction (86% vs. 59%). CONCLUSIONS: We suggest that P1NP/ALPXCRP is a reliable tool for MAFLD prediction in routine pediatric practice.

Discordance between lipoprotein (a) and LDL-cholesterol levels in cardiovascular risk assessment in apparently healthy subjects.

BACKGROUND AND AIMS: Lipoprotein(a) is a recognized independent cardiovascular risk factor and apolipoprotein B (apoB) level better reflects the risk than LDL-cholesterol. Despite this cardiovascular prediction mostly relies on traditional risk factors. We evaluated the association between Lp(a) and lipid biomarkers of cardiovascular risk in relation to age and sex in apparently healthy individuals. METHODS AND RESULTS: 422 presumably healthy subjects aged 19-84 were included. Lipid profile, Lp(a), apoB and small dense low-density lipoprotein cholesterol (sdLDL-C) were assayed. Subjects were divided at desirable cut-points of apoB and LDL-C. A group with elevated apoB (≥100 mg/dL) at low LDL-C (≤115 mg/dL) was appointed as high-risk and a group with low apoB but elevated LDL-C as low-risk. Significantly elevated triglycerides, TG/HDL-C and sdLDL-C were found in high risk group, but Lp(a) levels were comparable. TG/HDL-C was the best predictor of high risk with a very good diagnostic accuracy (AUC = 0.85), whereas Lp(a) had no discriminatory power. Women aged ≤40 with low LDL-C ≤ 100 mg/dL and elevated Lp(a) ≥ 40 mg/dL had higher levels of apoB and sdLDL-C (p = 0.002; p = 0.07) than those with Lp(a) < 40 mg/dL, which was not observed in men. In young females increase of LDL-C and apoB significantly raised the risk of elevated Lp(a). CONCLUSIONS: Women younger than 40 with low LDL-C may be at increased cardiovascular risk associated with elevated Lp(a) and apolipoprotein B levels. Inclusion of Lp(a) and apoB in the routine lipid testing providing information on an individual level may improve the prediction of cardiovascular risk in primary prevention.

Association between Fasting and Postprandial Levels of Liver Enzymes with Metabolic Syndrome and Suspected Prediabetes in Prepubertal Children.

Elevated liver enzyme activity may be associated with metabolic syndrome (MetS); however, it is not included in the MetS definition for children. Postprandial changes in the levels of biochemistry tests are related to manifestations of metabolic abnormalities. We assessed the association between fasting and postprandial liver enzymes levels with MetS and elevated hemoglobin A1c (HbA1c) in children aged 9-11. The study included 51 girls and 48 boys, all presumably healthy. In all participants' anthropometric indices, fasting glucose, insulin, lipid profile and HbA1c were measured. Enzymes, including alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), were assayed in fasting and postprandial states. Individuals were divided into subgroups: with (MetS(+): n = 26); without MetS (MetS(-): n = 73); with HbA1c levels ≤ 5.3% (n = 39); and ≥5.7% (n = 11). Elevated fasting GGT levels were found in 23% of MetS(+) children and rarely in MetS(-) children; increased postprandial GGT was noted in 35% of MetS(+) individuals. Postprandial GGT changes tend to predict MetS (OR = 1.16; p = 0.092). Increased fasting ALT was found rarely in MetS(+) children, but did not occur in MetS(-) children. HbA1c ≥ 5.7% occurred rarely and neither fasting ALT nor GGT were related to elevated HbA1c. However, postprandial change of ALT was a good positive predictor of increased HbA1c (OR = 1.33; p = 0.021). Postprandial GGT performs better as an indicator of metabolic syndrome occurrence, and instead postprandial ALT may predict prediabetes in prepubertal children.

The Kynurenine Pathway in Obese Middle-Aged Women with Normoglycemia and Type 2 Diabetes.

We examined the relationships of tryptophan (Trp) and the metabolites of the kynurenine pathway (KP) to the occurrence of type 2 diabetes (T2D) and metabolic risk factors in obese middle-aged women. The study included 128 obese women divided into two subgroups: a normoglycemic group (NG, n = 65) and a T2D group (n = 63). The concentrations of serum tryptophan (Trp), kynurenine (Kyn), 3-hydroxykynurenine (3HKyn), quinolinic acid (QA), and kynurenic acid (Kyna) were analyzed using ultra-high-performance liquid chromatography coupled with electrospray ionization/triple quadrupole mass spectrometry. Blood biochemical parameters and anthropometric parameters were measured. The women with T2D had significantly higher Trp, Kyna, Kyna/QA ratio, and Kyna/3HKyn ratio values than the NG women. Logistic regression analysis showed that the concentrations of Trp and Kyna and the values of the Kyna/3HKyn ratio were most strongly associated with T2D occurrence, even after controlling for confounding factors. The model with Trp level and Kyna/3HKyn ratio accounted for 20% of the variation in the presence of T2D. We also showed a different pattern of correlations between kynurenines and metabolic factors in the NG and T2D women, which was mostly reflected in the stronger relationship between BMI and KP metabolites in the NG obese women. An increase in Trp and Kyna levels with an accompanying increase in Kyna/3HKyn ratio value is associated with the occurrence of T2D in obese middle-aged women.

Serum ANGPTL8 and ANGPTL3 as Predictors of Triglyceride Elevation in Adult Women.

Angiopoietin-like proteins ANGPTL3 and ANGPTL8 have been shown to inhibit lipoprotein lipase, and thus regulate triglyceride level in the circulation. Whether the regulation of lipid metabolism by ANGPTLs is affected by the menopausal status remains unclear. We aimed to assess the relationships between serum ANGPTL3 and ANGPTL8 and atherogenic biomarkers in presumably healthy women during ageing. The study group included 94 women of whom 31 were premenopausal (PRE ≤ 40 years) and 37 were postmenopausal (POST ≥ 52 years). Atherogenic lipid and non-lipid biomarkers and ANGPTLs (ANGPTL3, ANGPTL8) were assayed in serum samples. TG/HDL-C index, non-HDL-cholesterol, remnant cholesterol concentrations, and BMI were calculated. Median levels of ANGPTL3 and concentrations of lipid biomarkers were significantly higher in POST comparing to PRE but ANGPTL8 levels were not different. In PRE, ANGPTL8 levels correlated significantly with TG and TG/HDL-C index while there were no correlations between ANGPTL3 and these biomarkers. In POST both ANGPTLs correlated with TG, sdLDL-C, and TG/HDL-C. ANGPTL8 and sd-LDL-C were the most significant predictors of early triglyceride elevation > 100 mg/dL (1.13 mmol/L) in the whole group and POST whereas the prediction power of ANGPTL3 was negligible in the whole group and non-significant in the subgroups. We demonstrated a significant positive correlation of ANGPTL3 with age category which predisposes to postmenopause. Despite the increase in ANGPTL3 level with ageing the ANGPTL3/ANGPL8 ratio was maintained. In conclusion, ANGPTL8 predicts the early triglyceride elevation better than ANGPTL3, especially in postmenopausal women. The association of ANGPTL3 with triglyceride levels is weaker than ANGPTL8 and depends on menopausal status. We suggest that the choice for the best efficient treatment of dyslipidemia with new inhibitors of angiopoietin-like proteins may depend on the menopausal status.

Relationships between Bone Turnover Markers and Factors Associated with Metabolic Syndrome in Prepubertal Girls and Boys.

The associations between individual components of metabolic syndrome (MetS) and bone health in children are complex, and data on this topic are sparse and inconsistent. We assessed the relationship between bone turnover markers and markers of the processes underlying MetS (insulin resistance and inflammation) in a group of presumably healthy children aged 9-11 years: 89 (51 girls, 38 boys) presenting without any features of MetS and 26 (10 girls, 16 boys) with central obesity and two features of MetS. Concentrations of glucose, triglycerides (TG), HDL cholesterol (HDL-C), C-reactive protein (CRP), HbA1c, total 25-hydroxyvitamin D (25(OH)D), intact-P1NP (N-terminal propeptide of type I procollagen), CTX-1 (C-terminal telopeptide of type I collagen) were assayed and insulin resistance was assessed (HOMA-IR). BMI centile, waist circumference (WC) and blood pressure were measured. The presence of MetS in girls resulted in significantly lower concentrations of CTX-1 and a trend to lower CTX-1 in boys. The concentrations of bone formation marker i-P1NP were not affected. Among the features associated with MetS, HOMA-IR appeared as the best positive predictor of MetS in girls, whereas CRP was the best positive predictor in boys. A significant influence of HOMA-IR on the decrease in CTX-1 in girls was independent of BMI centile and WC, and the OR of having CTX-1 below the median was 2.8-fold higher/1SD increased in HOMA-IR (p = 0.003). A weak relationship between CTX-1 and CRP was demonstrated in girls (r = -0.233; p = 0.070). Although TG, as a MetS component, was the best significant predictor of MetS in both sexes, there were no correlations between bone markers and TG. We suggest that dyslipidemia is not associated with the levels of bone markers in prepubertal children whereas CRP is weakly related to bone resorption in girls. In prepubertal girls, insulin resistance exerts a dominant negative impact on bone resorption, independent of BMI centile and waist circumference.

Analysis of profibrogenic microRNAs (miRNAs) expression in urine and serum of chronic kidney disease (CKD) stage 1-4 patients and their relationship with proteinuria and kidney function.

PURPOSE: Besides conventional kidney diseases diagnostics, micro RNAs (miRNAs) assessment in urine and serum is considered to be a promising non-invasive method of diagnostics of renal parenchymal diseases and valuable therapeutic target also. The purpose of the study was to investigate the role of several miRNAs as a markers of kidney damage. METHODS: Assessment of 45 chronic kidney disease (CKD) patients stage 1-4 and 17 healthy control. Sample of urine and blood was taken from each participant for molecular analysis using Real Time PCR method to identify such micro-RNAs as: hsa-miR-155-5p, hsa-miR-214-3p, hsa-miR-200a-5p, hsa-miR-29a-5p, hsa-miR-21-5p, hsa-miR-93-5p, and hsa-miR-196a-5p. Basic biochemical test was done. Analysis was performed in CKD patients group and subgroup with chronic glomerulonephritis (CGN) confirmed by kidney biopsy. Moreover, analysis was performed in subgroup with different estimated glomerular filtration rate (eGFR) (according to CKD-EPI equation: eGFR < 60 ml/min, eGFR > 60 ml/min) and different daily protein excretion (DPE): (DPE < 3.5 g; DPE > 3.5 g). RESULTS: Increased relative expression of hsa-miR-29-5p, hsa-miR-21-5p, and hsa-miR-196a-5p and decreased expression of hsa-miR-155-5p, hsa-miR-214-5p, hsa-miR-200a-5p, and hsa-miR-93-5p was demonstrated in urine of analyzed CKD patients. In subpopulation of chronic glomerulonephritis (CGN) patients, there was higher level of expression in urine of hsa-miR-155-5p, hsa-miR 214-3p, hsa-miR-93-5p, and hsa-miR-196a-5p in CGN with DPE < 3.5 g. CGN patients with eGFR < 60 ml/min showed higher expression level of miRNAs such as hsa-miR-214-3p, hsa-miR-29-5p, hsa-miR-93-5p, and hsa-miR-196-5p in urine. There was increase in hsa-miR 155-5p, hsa-miR-214-3p, and hsa-miR-200a-5p serum expression level in CKD population and reduction of hsa-miR-29a-5p, hsa-miR-21-5p, and hsa-miR-93-5p expression. Increased level of expression of hsa-miR-155-5p; hsa-miR-214-3p, hsa-miR-200a-5p, and hsa-miR-29-5p was found in CGN patients with eGFR > 60 ml/min. CONCLUSION: Increased relative expression of profibrogenic miRNAs in urine or serum of CKD patients with eGFR > 60 ml/min and DPE < 3.5 g may indicate higher degree of fibrosis at early CKD stages.

Relationship between Serum Angiopoietin-like Proteins 3 and 8 and Atherogenic Lipid Biomarkers in Non-Diabetic Adults Depends on Gender and Obesity.

Hypertriglyceridemia is an independent risk factor for coronary artery disease. Lipoprotein lipase (LPL) plays an essential role in the metabolism of triglyceride-rich lipoproteins (TRLs). Angiopoietin-like proteins ANGPTL3 and ANGPTL8 are shown to be important regulators of LPL activity. Increased concentrations of these proteins may reflect cardiovascular risk, and the treatment of patients with dyslipidemia with ANGPTLs inhibitors may decrease this risk. We assessed the gender-specific relationships of serum ANGPTL3 and ANGPTL8 with atherogenic lipid biomarkers and obesity in non-diabetic adults. The study comprised 238 participants aged 25-74 [122 with triglycerides (TG) <150 mg/dL (<1.7 mmol/L) and 116 with hypertriglyceridemia]. Total cholesterol, HDL-cholesterol, LDL-cholesterol, TG, C-reactive protein (CRP), glycated hemoglobin, apolipoprotein B, small dense LDL-C (sd-LDL-C), ANGPTL3, and ANGPTL8 were measured. Non-HDL-cholesterol, remnant cholesterol (remnant-C) concentrations, and body mass index (BMI) were calculated. Results: Women and men did not differ in terms of age, CRP levels, the percentage of obese subjects, and concentrations of atherogenic lipid biomarkers, except higher TG in males and higher ANGPTL3 concentrations in females. Positive correlations of both ANGPTLs with TG, remnant-C, and sdLDL-C levels were found in females. In males, only ANGPTL3 correlated positively with atherogenic biomarkers, but there were no correlations with ANGPTL8. Concentrations of ANGPTL3 were higher in obese men, whereas ANGPTL8 levels were higher in obese women. In women alone, ANGPTL8 showed very good discrimination power to identify subjects with hypertriglyceridemia (AUC = 0.83). Contrary to this, ANGPTL3 was a better discriminator of hypertriglyceridemia (AUC = 0.78) in male subjects. Regression models, adjusted for age, sex, and BMI showed a weak but significant effect of ANGPTL8 to increase the risk of hypertriglyceridemia. Conclusions: In females, ANGPTL8 is more strongly associated with TRLs metabolism, whereas in males, ANGPTL3 plays a more important role. We suggest sex differences be taken into consideration when applying new therapies with angiopoietin-like proteins inhibitors in the treatment of dyslipidemia.

The Association between Branched-Chain Amino Acids (BCAAs) and Cardiometabolic Risk Factors in Middle-Aged Caucasian Women Stratified According to Glycemic Status.

We examined the glycemic status-stratified relationships between total serum branched-chain amino acid (BCAA) concentrations and cardiometabolic risk factors in middle-aged Caucasian women. The study included 349 women divided into 2 subgroups: a normoglycemic group (NG, n = 184) and a dysglycemic group (DG, n = 165). Blood samples, anthropometric parameters, and blood pressure were measured. HOMA-IR, albumin-corrected calcium (CCa), and fatty liver index (FLI) were calculated. BCAA concentrations were higher in the women with dysglycemia. BCAAs moderately correlated with BMI and FLI in the NG group and with BMI, FLI, total calcium (TCa), CCa, HbA1c, TG/HDL-C, and HDL-C in the DG group. After adjusting for age and BMI, correlations for TCa, CCa, HbA1c, HDL-C, and TG/HDL-C remained significant. The coexistence of increased BCAAs with dysglycemic status was associated with markedly higher concentrations of TCa, CCa, HbA1c, and TG, which were not observed in the DG women with low level of BCAAs. Multiple regression showed that TCa or CCa, age and BCAAs were significantly associated with HbA1c independently of BMI only in the DG group. We conclude that dysglycemia in particular predisposes women to a significant relationship between total BCAAs and circulating calcium and HbA1c, and that these relationships are independent of BMI and may reflect the pathophysiological calcium-dependent mechanisms connecting BCAAs with metabolic disturbances.

Low Serum 25-hydroxyvitamin D Level Does Not Adversely Affect Bone Turnover in Prepubertal Children.

Both vitamin D and insulin-like growth factor 1 (IGF-1) play essential roles in bone metabolism and may interact during prepubertal bone accrual. We investigated the association of low serum 25-hydroxyvitamin D (25(OH)D) (<20 ng/mL) with the circulating bone turnover markers, when compared to their interaction with IGF-1. SUBJECTS AND METHODS: Serum 25(OH)D, IGF-I, P1NP (N-terminal propeptide of type I procollagen), and CTX-1 (C-terminal telopeptide of type I collagen) were measured, and the bone turnover index (BTI) was calculated in 128 healthy children, aged 9-11 years. RESULTS: Mean 25(OH)D concentration was 21.9 ± 4.9 ng/mL, but in 30.5% of participants it was <20 ng/mL (<50 nmol/L). We observed a trend for higher P1NP (p < 0.05) and IGF-1 (p = 0.08), towards lower 25(OH)D in tertiles. Levels of P1NP in the lowest 25(OH)D tertile (<20 ng/mL) were the highest, while CTX and BTI remained unchanged. Additionally, 25(OH)D negatively correlated with IGF-1, while the correlation with P1NP was not significant. A strong positive correlation of IGF-1 with P1NP and BTI but weak with CTX was observed. Low 25(OH)D (<20 ng/mL) explained 15% of the IGF-1 variance and 6% of the P1NP variance. CONCLUSIONS: Low levels of 25(OH)D do not unfavorably alter bone turnover. It seems that serum 25(OH)D level may not be an adequate predictor of bone turnover in children.

Cardioprotective Effects of Nutraceuticals: Focus on Omega-3 Polyunsaturated Fatty Acids.

Cardiovascular diseases are the leading cause of mortality worldwide [...].

Effect of fasting hyperglycemia and insulin resistance on bone turnover markers in children aged 9-11 years.

AIM: Impaired regulation of glucose metabolism in childhood adversely affects bone health. We assessed the effect of fasting hyperglycemia and insulin resistance on bone turnover markers in prepubertal children with normal glycemia (<100 mg/dL) and fasting hyperglycemia (100-125 mg/dL). METHODS: Glucose, hemoglobin A1c, IGF-I (insulin-like growth factor I), iP1NP (N-terminal propeptide of type I procollagen), CTX-1 (C-terminal telopeptide of type I collagen) and insulin were measured. Bone turnover index (BTI) and HOMA-IR (homeostasis model assessment) were calculated. RESULTS: Bone resorption marker (CTX) levels were decreased by 26.5% in boys with hyperglycemia, though only 7% in girls. Hyperglycemia had no effect on the bone formation marker iP1NP. IGF-1, the best predictor of bone marker variance accounted for 25% of iP1NP and 5% of CTX variance. Girls presented significantly higher BTI indicating the predominance of bone formation over resorption. Insulin resistance significantly decreased CTX. In girls, HOMA-IR and IGF-1 predicted 15% of CTX variance. CONSLUSIONS: Fasting hyperglycemia and insulin resistance in children impact bone turnover suppressing bone resorption. Hyperglycemia decreased resorption, particularly in boys, while suppression of resorption by insulin resistance was more pronounced in girls. We suggest that the progression of disturbances accompanying prediabetes, may interfere with bone modelling and be deleterious to bone quality in later life.

Bone health and hyperglycemia in pediatric populations.

The impact of prediabetes and diabetes on skeletal health in the context of increased risk of fragility fractures in adults has been studied recently. However, the prevalence of diabetes, overweight, and obesity have also increased in younger subjects. Current data concerning bone metabolism based on assessment of markers for bone turnover and of bone quality in diabetes patients in diverse age groups appears to be inconsistent. This review synthesizes the current data on the assessment of bone turnover based on the use of circulating bone markers recommended by international organizations; the effects of age, gender, and other factors on the interpretation of the data; and the effects of type 1 and type 2 diabetes as well as hyperglycemia on bone quality and turnover with particular emphasis on the pediatric population. Early intervention in the pediatric population is necessary to prevent the progression of metabolic disturbances that accompany prediabetes and diabetes in the context of common low vitamin D status that may interfere with bone growth.

Traceability validation of six enzyme measurements on the Abbott Alinity c analytical system.

Background Laboratory professionals should independently verify the correct implementation of metrological traceability of commercial measuring systems and determine if their performance is fit for purpose. We evaluated the trueness, uncertainty of measurements, and transferability of six clinically important enzyme measurements (alanine aminotransferase [ALT], alkaline phosphatase [ALP], aspartate aminotransferase [AST], creatine kinase [CK], γ-glutamyltransferase [γGT], and lactate dehydrogenase [LDH]) performed on the Abbott Alinity c analytical system. Methods Target values and associated uncertainties were assigned to three pools for each enzyme by using the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference measurement procedures (RMPs) and the pools were then measured on the Alinity system. Bias estimation and regression studies were performed, and the uncertainty associated with Alinity measurements was also estimated, using analytical performance specifications (APS) derived from biological variability of measurands as goals. Finally, to validate the transferability of the obtained results, a comparison study between two Alinity systems located in Milan, Italy, and Bydgoszcz, Poland, was carried out. Results Correct implementation of traceability to the IFCC RMPs and acceptable measurement uncertainty fulfilling desirable (ALP, AST, LDH) or optimal APS (ALT, CK, γGT) was verified for all evaluated enzymes. An optimal alignment between the two Alinity systems located in Milan and Bydgoszcz was also found for all enzyme measurements. Conclusions We confirmed that measurements of ALT, ALP, AST, CK, γGT, and LDH performed on the Alinity c analytical system are correctly standardized to the IFCC reference measurement systems and the system alignment is consistent between different platforms.

Quantifying atherogenic lipoproteins for lipid-lowering strategies: Consensus-based recommendations from EAS and EFLM.

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol (=total - HDL cholesterol) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDL cholesterol is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDL cholesterol shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a)-cholesterol is part of measured or calculated LDL cholesterol and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDL cholesterol decline poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDL cholesterol or apolipoprotein B, especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDL cholesterol includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apolipoprotein B measurement can detect elevated LDL particle numbers often unidentified on the basis of LDL cholesterol alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.