We investigated serum concentrations of specific inflammatory parameters in patients with significant carotid artery stenosis (CAS) of 50-99%, with an additional focus on patients with moderate stenosis (50-69%), in terms of both symptomatic status and plaque morphology, to determine whether there are certain parameters that can be associated with plaque instability before the progression of CAS to a high degree. The study included 119 CAS patients, 29 of whom had moderate stenosis, and 46 controls. Ultrasonography of the carotid arteries was performed using color flow Doppler and B-mode duplex ultrasound, and serum inflammatory parameters were measured using commercially available enzyme immunoassays. When comparing patients with 50-99% stenosis, only serum amyloid A (SAA) was higher in symptomatic patients, while in the group of patients with 50-69% stenosis, myeloperoxidase (MPO) was higher and pentraxin-3 (PTX-3) was lower in symptomatic compared to asymptomatic patients, and soluble urokinase plasminogen activator receptor (suPAR) was higher in patients with carotid plaque of unstable compared to stable morphology. Our results suggest that the importance of different inflammatory parameters in patients with moderate CAS is not the same as in CAS patients in general, and therefore their separate investigation in patients with high and moderate stenosis may be beneficial. SAA has the potential to be further considered in research to predict CAS symptom risk. There is a possibility that MPO and PTX-3 play a role in the development of CAS symptoms originating from less stenotic plaques and that suPAR is involved in the destabilisation of such plaques.

To overcome the challenges of a manual leukocyte differential count, we have developed FlowDiff, an 8-colour, single tube flow cytometry panel, and investigated whether it could potentially replace the manual differential in our laboratory. The instrument was set up in accordance with the EuroFlow settings, and the protocol comprised a stain-lyse no wash process, taking approximately 30 min of working time, without the addition of a toxic lysis reagent. We found a very good correlation for all leukocyte populations between FlowDiff and the Sysmex XN analyzer in 80 normal, non-flagged samples. In addition, FlowDiff showed a very good correlation with manual differential in 168 abnormal samples, as well as a high diagnostic accuracy. FlowDiff correctly identified all samples with acute leukemia ( = 13) and differentiated all B-lymphomas ( = 49) in samples with lymphocytosis. Moreover, FlowDiff detected an additional five samples with B-lymphocytosis without any prior hematological malignancy, which turned out to be a B-lymphoma. Our data suggest that FlowDiff, our 8-colour flow cytometry-based differential, is comparable to, and can successfully substitute the manual differential.

Measuring plasma albumin is a common and important laboratory test. We compared the results obtained with the bromocresol green (BCG) colorimetric, immunoturbidimetric (IT), and capillary electrophoresis (CE) methods and evaluated the clinical reliability of the colorimetric test. Samples from 320 patients including 227 patients with hypoalbuminemia (albumin levels <35 g/L) were analyzed. Results were compared between different patient groups. The BCG method indicated significantly higher plasma albumin levels than the CE and IT methods, especially in patients with elevated C-reactive protein, alpha-1 globulin (a1G), and alpha-2 globulin (a2G) values. A significant proportion of patients with mild hypoalbuminemia tested using the BCG method (alb) and were classified as severely hypoalbuminemic (albumin <20 g/L) when switching to the CE or IT method (alb and alb). These patients had elevated a1G and/or a2G levels. This change of result implied an additional indication for albumin replacement therapy. The BCG method significantly overestimates albumin levels in patients with inflammation and hypoalbuminemia, which may lead to inappropriate therapeutic decisions.

The erythrocyte sedimentation rate (ESR) is a widely used diagnostic test, influenced by all physiological and pathological conditions that can bias blood rheology by interfering factors. This study aimed to evaluate the performance of the CUBE 30 touch ESR analyzer in samples with preanalytical variables, as lipemia, hemolysis, and icterus or in presence of fibrinogen., Moreover we focused to define the maximum time limits to ensure a reliable ESR measure. Accuracy, intra-run and inter-run precision, and stability studies were performed. Moreover, hemolytic, jaundiced, lipemic samples and fibrinogen sensitivity were analyzed for interference study. Statistical analyses were performed. CUBE 30 touch and Westergren method comparison showed no statistical differences (Spearman Coefficient, R=0,95). In the intra-run precision, the CV% mean obtained on samples with normal ESR level was 8,9%; with middle ESR level was 5,9% and with high ESR level the CV% was 4,3%. Inter-run precision test showed CV% of for single samples and overall samples in the range (12,3% for normal level and 4,8% for abnormal level). The samples stored at 4 °C showed good stability up to 3 h from collecting time. ESR samples showing lipemia, hemolysis or jaundice showed good correlations with the gold standard method (R 0,901, 0,940, 0,911;  < 0,0001), however, Westergren tests were more sensitive than CUBE 30 touch to fibrinogen additions. The high comparability with the Westergren method, both in normal and interfering samples, and the good precision, support the usefulness of CUBE 30 touch in the clinical routine laboratory.

Isolated hypogammaglobulinemia (IH) is an electrophoretic pattern that can be encountered on serum protein electrophoresis (SPEP) and is defined as a decreased but morphologically normal γ-globulin fraction with normal α- and β-globulin fractions. SPEP is mainly used to detect monoclonal proteins which are usually observed as additional peaks in the electropherogram. However, they may also be more discretely present in a significant proportion of patients presenting with IH. Therefore, we aimed to evaluate i) via both retrospective and prospective analysis to what extent paraproteins as identified by immunofixation are present in patients demonstrating IH on SPEP and ii) whether other parameters may predict their presence in IH-patients. For this purpose, we first reviewed historic SPEP- and immunofixation results in our tertiary hospital and determined paraprotein prevalence in this retrospective cohort. This analysis showed immunofixation was requested in only 519/3938 (13.2%) historic IH-results with 52/519 (10%) patients demonstrating paraproteins. Next, various laboratory parameters were compared between paraprotein-positive and -negative patients and subjected to logistic regression models but regrettably, no parameter could be retained as promising predictor of paraproteins. Lastly, to confirm paraprotein prevalence seen in the historical query, we conducted a six-month prospective analysis during which immunofixation was requested more frequently in IH-cases during routine diagnostics and which showed paraproteins to be present in 20/83 (24.1%) of IH-patients. Hence, as up to 24% of patients with IH may harbour paraproteins, one should consider performing follow-up analyses (e.g. immunofixation, urine electrophoresis and/or free light chain analysis) for all IH-cases identified via SPEP.

The concentration of many biochemical parameters changes significantly during pregnancy and the postpartum period, causing a need for specific reference values for biochemical parameters in these life periods. We have collected blood samples in pregnancy week 18, 28 and 36 and six weeks, four months and six months postpartum from 139 healthy women. Blood samples from 59 healthy never-pregnant women were included as controls. Serum samples were analyzed for 23 common biochemical parameters and reference intervals for pregnancy and postpartum periods were computed with the non-parametric method in accordance with recommendations from IFCC and CLSI. The dynamics of different biochemical parameters during and after pregnancy vary considerably between parameters. Some analytes like serum amylase and HDL cholesterol do not differ from never-pregnant values. Of the 23 parameters, serum alkaline phosphatase, chloride, gamma-glutamyl transferase and sodium and urea which were still significantly changed at six months postpartum compared to never-pregnant women. The physiological changes related to pregnancy and lactation have profound effects on biochemical parameters, denoting the use of specific reference intervals for both pregnancy and the postpartum period.

Monoclonal gammopathy has been reported to interfere with several laboratory measurement results. We investigated potential interference in monoclonal gammopathy on immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) concentrations using three different routine chemistry instruments: Alinity (Abbott Laboratories), Cobas 8000 (Roche Diagnostics) and Optilite (Binding Site) at the Department of Clinical Biochemistry, Aalborg University Hospital, Denmark. Blood samples collected from 216 patients with known monoclonal gammopathy were analyzed on Alinity, Cobas and Optilite. Diagnoses were ascertained from clinical records. Scatter plots with Passing-Bablok regression were used to investigate associations between concentrations of IgA, IgG and IgM measured with each of the different instruments. Furthermore, comparison of IgG analyses on Alinity, Optilite and Cobas according to monoclonal IgM concentration was explored with Bland-Altman plots. A total of 81 patients were identified with IgM type monoclonal gammopathy and 8 of these patients (10%) had analytical interference as reflected by more than 25% decrease in the level of IgG measured on Alinity as compared to Optilite and Cobas. All blood samples with interference on IgG measurement using Alinity were from patients with lymphoplasmacytic lymphoma/Waldenströms macroglobulinemia and all of them had monoclonal IgM concentrations above 10 g/L. This study identified a source of interference from IgM monoclonal gammopathy on IgG measurement performed using Alinity. The interferences caused falsely low results of IgG which is important to recognize to ensure proper patient management.

To establish age- and sex-specific reference intervals (RIs) for serum tumor markers (AFP, CEA, CA125, CA199, CA153, HE4, CA724, CYFRA21-1, PSA, and NSE) among a cohort of healthy individuals in South China, a retrospective analysis was conducted on 51,353 samples collected from 2015 to 2020, during health assessments at Guangdong Provincial People's Hospital. The influence of age and gender on serum tumor markers was investigated. New RIs were determined using non-parametric rank-based methods per CLSI EP28-A3C guidelines. Significant differences were detected across age groups for AFP, CEA, CA125, CA199, HE4, CYFRA21-1, PSA, and NSE ( < 0.05). The upper reference limits (URLs) for CA153 and HE4 are significantly lower compared to our current laboratory standards. The URL for CA125 exceeds these limits in individuals under 50 but decreases in those aged 50 and above. For CA199, CEA, and PSA, the URLs are below current standards in individuals younger than 60 but exceed them in those aged 60 and older. Noteworthy elevations were observed in CA724, CYFRA21-1, and NSE levels. Our study establishes age- and sex-specific RIs for ten serum tumor markers among healthy individuals from South China, providing a fundamental resource for the prevention, early detection, and management of tumor-related disorders.

Particle-enhanced turbidimetric immunoassay (PETIA) is a new measurement procedure for detecting fecal calprotectin (FC). We aimed to investigate the accuracy and clinical performance of PETIA for FC. We assessed the accuracy of PETIA for FC measurements through concordance analysis, Passing-Bablok regression and Bland-Altman analysis, using enzyme-linked immunosorbent assay (ELISA) as the reference. To evaluate the clinical performance of PETIA, the FC levels of individuals with significant and non-significant bowel diseases were compared. The receiver operating characteristic (ROC) analysis was performed to determine the appropriate cut-off value of FC detected by PETIA for discriminating subjects with significant and non-significant colorectal lesions. Of the 413 cases analyzed, 340 (82.3%) were concordant between PETIA and ELISA. No significant discordance was observed. There was a good agreement (y = -7.710+0.957x) between PETIA and ELISA for detecting FC. The FC level detected by PETIA in patients with significant bowel diseases (159.1 [31.3, 821.0] µg/g) was significantly higher than that of subjects with non-significant bowel diseases (10.3 [4.2, 38.5] µg/g) ( < 0.001). The AUC of FC for identifying significant bowel diseases detected by PETIA was 0.82 ( < 0.001). With a cut-off value of 77.6µg/g, the specificity and positive predictive value were 92.2% and 97.1%, respectively. The PETIA for FC measurement showed good clinical performance for detecting bowel diseases.

Preeclampsia (PE) pathogenesis is strongly related to diminished nitric oxide (NO) bioavailability and enhanced oxidative stress. Emerging evidence suggests that red blood cells (RBCs) eNOS enzyme contributes to systemic NO bioavailability by its ability of both NO and ROS generation. We aimed to investigate RBC eNOS enzyme activity, NO and ROS generation capacity, eryptosis index and aggregation levels in preeclamptic and uncomplicated pregnant women. Fifty-eight PE patients and 36 healthy pregnant women were included to the investigation. RBC eNOS enzyme activity, intracellular NO, calcium and ROS concentrations and eryptosis levels were determined flow cytometric methods. RBC deformability and aggregation were measured LORRCA. Intracellular NO and phosphorylated RBC eNOS levels decreased in PE group compared to healthy pregnant group ( < 0.05,  < 0.001 respectively). Intracellular ROS and calcium levels, eryptosis values and aggregation indexes in the PE group were significantly higher than healthy pregnant group ( < 0.05,  < 0.01,  < 0.05,  < 0.05 respectively). Our results demonstrate for the first time that RBC produce lower NO and higher ROS under PE conditions. Further, RBC of PE patients were more prone to eryptosis and aggregation compared to control group. Our results suggest that, in addition to endothelial cells, RBC also contribute to decreased plasma NO bioavailability producing less NO and high ROS in PE. Considering increased tendency to eryptosis and aggregation, RBC seem to play role in haemodynamic changes of PE pathogenesis.

The association between the MCM6-13910-C/T polymorphism and lactose intolerance in individuals of European descent is well known. However, the notion that having a single versus a double allelic mutation might influence one's phenotype has been hypothesized. This study investigated whether patients with the three genotypes C/C, C/T, T/T differed in response to a lactose tolerance test (LTT) in a Danish setting. Anonymized data on 603 individuals with results for both genetic test and LTT were investigated. Mean delta glucose values were plotted for the time points of the LTT (0, 15, 30, 45 and 60 min) for the C/C, C/T and T/T genotype, respectively. Further, the agreement between the three genotypes and the diagnostic interpretation of the LTT were examined using a cut-off of > 1.4 mmol/L rise in glucose. In subjects with the C/C genotype, mean glucose delta levels were markedly lower compared to both the C/T and T/T genotypes at all time points. Overall, a difference between mean glucose delta values among the C/T and T/T genotype could not be shown. Using a LTT cut-off of > 1.4 mmol/L, the proportions of lactose intolerant LTT results for each genotype were as follows: 58% among C/C, 5% among C/T, and 7% among T/T. In a Danish healthcare setting, the C/C genotype was on average associated with a smaller glucose response during a LTT when compared to the C/T and T/T genotypes. A marked difference in the LTT response among the C/T and T/T genotype was not observed.

ABTRACTThis study retrospectively reviews individuals diagnosed with biotinidase deficiency in Eastern Anatolia to analyze the genetic variants and their relationship with biotinidase activity levels. The research focuses on determining the percentage impact of different variants on enzyme activity. The study included 357 patients who presented to Erzurum City Hospital with symptoms of biotinidase deficiency between 2018 and 2023 and were referred to the medical genetics department. Biotinidase enzyme levels were determined using spectrophotometric and colorimetric techniques, while Sanger sequencing analyzed the four exons and intron boundaries of the BTD gene. In the analysis of 357 patients (181 boys, 176 girls), the most frequent variant was c.1270G > C | p.Asp424His. Biotinidase enzyme activity was above 30% in 97.3% of patients with a homozygous p.D424His mutation. The mutations that caused the most significant decrease in enzyme activity were c.410G > A p.Arg137His, c.38_delinsTCC p.Cys13phefs*36, and c.1535C > T p.Thr512Met. Hearing loss (4 patients) and optic atrophy (1 patient) were mainly observed in patients with the c.38_delinsTCC mutation (homozygous or heterozygous). Most patients were asymptomatic, and mild symptoms were effectively prevented with biotin treatment. This study provides a detailed analysis of genetic diversity and clinical presentation in biotinidase deficiency cases in Eastern Anatolia, demonstrating the efficacy of biotin treatment. It highlights the significant role of genetic variants in phenotypic diversity and the need for personalized treatment, calling for further genetic research to enhance understanding of variant diversity and its impact on enzyme activity.

Hemoglobin Tacoma is known to potentially interfere HbA1c assays. The variant is common in Finland with prevalence of up to 2% regionally and cases are also reported in areas that have attracted Finnish immigrants, especially in Sweden and North America. Here, we investigated the effect of Hb Tacoma on seven HbA1c methods. 20 non-variant and 20 Hb Tacoma samples were measured with Tina-quant Gen. 3 (immunoassay, considered as reference) and the following point of care instruments: Afinion 2, HbA1c 501 (both utilizing boronate affinity), QuikRead go, cobas b 101, DCA Atellica, and Standard F (all immunoassays). Repeatability was also assessed by measuring both non-variant and Hb Tacoma samples five times each at two different levels. For non-variant samples, the mean relative bias with all methods was < ±4%, whereas for Hb Tacoma samples Standard F had 38% mean relative bias. In absolute bias, the difference was 17 mmol/mol on average and constant through the measured range. For other methods the mean relative bias for Hb Tacoma samples was < ±6%. The repeatability with all methods was similar for non-variant and Hb Tacoma samples and at highest 4.1% (mean CV% of two levels). The observed interference by Standard F is likely due to two-antibody assay design as Hb Tacoma has been shown to result in conformational change. This interference is clinically significant and highlight the need for better controlling and better understanding hemoglobin variants in HbA1c testing.

Frozen saliva samples are often used for later determination of salivary glucocorticoids in research studies on stress and endocrine disorders. We studied the stability of cortisol and cortisone in saliva after six years of storage at -80 °C by repeated analysis of 153 stored aliquots, collected with Salivette, using liquid chromatography tandem mass spectrometry. We found a very high agreement between the first and the repeated measurement after six years at -80 °C, for both cortisol and cortisone concentrations (= 0.96 and = 0.98, respectively). Passing-Bablok regression equations were  = 0.02 + 1.00 and  = 0.02 + 1.14 for cortisol and cortisone, respectively. We conclude that salivary cortisol and cortisone concentrations remain essentially unaltered after six years of storage at -80 °C.

It is common practice in laboratories to store biological samples in ultra-low temperature (ULT) freezers. There is growing interest in raising the temperature of ULT freezers in order to save energy and reduce expenses, as energy conservation becomes increasingly important and sustainable laboratory practices gain popularity. In our laboratory, plasma samples are stored for three months for diagnostic purposes. We therefore took the opportunity to investigate the effect of two different storage temperatures (-70 °C vs -80 °C), on activated partial thromboplastin time (APTT), factor VIII (FVIII), international normalized ratio (INR) and factor VII (FVII) measurements on paired plasma samples collected from 26 individuals after three months of storage. Automated coagulation analysers CS-5100 and ACL TOP were used to perform the tests. We found no consistent difference between the two storage temperatures for any of the four coagulation parameters (all -values > 0.05). We conclude that the temperature of ULT freezers used to store plasma samples for APTT, FVIII, INR, and FVII measurements can be safely increased from -80 to -70 °C without affecting the stability of the samples.

A low eGFR/eGFR-ratio is characteristic of a group of serious kidney disorders called 'Selective Glomerular Hypofiltration Syndromes'. This study examines if such a low ratio can also be used to evaluate the risk for women with hypertensive disorders in pregnancy to develop severe maternal morbidity. All women discharged from the perinatal ward at the Skåne University Hospital in Lund during the period of 1-9-2016 to 31-8-2017 under one of the diagnoses within hypertensive disorders in pregnancy were considered for inclusion in the study. After delivery and discharge from the hospital, records from included patients were reviewed and all registered measures of renal function were analysed. An eGFR/eGFR-ratio ≤0.60 in a sample drawn not earlier than three days before delivery was considered as defining a high risk for severe maternal morbidity. A strong association (p-value: 0.035) between severe maternal morbidity and an eGFR/eGFR-ratio ≤0.60 was found in a subgroup of 32 women diagnosed with 'preeclampsia with severe features'. A total of 69 women were included in the study. Fifty were defined as high-risk and seventeen of them (34%) developed severe maternal morbidity. Among the nineteen women defined as low-risk only two (10.5%) developed severe maternal morbidity (p-value: 0.051). A low eGFR/eGFR-ratio seems promising as a predictive marker for maternal morbidity in hypertension in pregnancy. Its performance as a tool in the monitoring of progressing disease should be evaluated further in larger cohorts. Delivery before the eGFR/eGFR-ratio decreases to, or below, 0.60 might help avoid maternal complications.

Cobalamin C is the most common inborn error of intracellular cobalamin metabolism caused by biallelic pathogenic variants in the MMACHC gene, leading to impaired conversion of dietary vitamin B12 into its two metabolically active forms, methylcobalamin and adenosylcobalamin. Biochemical hallmarks are elevated plasma total homocysteine (HCYs) and low methionine accompanied by methylmalonic aciduria. This study aimed to evaluate the clinical, biochemical, and molecular analysis of Pakistani patients with CblC defect.

In this dual-center study, we assessed the BioHermes A1C EXP M13 system for point-of-care (POC) HbA1c testing against two NGSP-certified HPLC instruments, the Bio-Rad D100 and Tosoh G8. Analyzing 605 samples, we evaluated the A1C EXP's reproducibility, sensitivity, specificity and impact of anemia on HbA1c measurements. The device showed excellent reproducibility with CVs under 2.4% and high sensitivity and specificity for diabetes diagnosis-98.1% and 96.8% against D100, and 97.1% and 96.7% against G8. Passing-Bablok regression confirmed a close correlation between A1C EXP and the HPLC instruments, with equations  = 0.10625 + 0.9688x (D100) and  = 0.0000 + 0.1000x (G8), and Bland-Altman plots indicated mean relative differences of -1.4% (D100) and -0.4% (G8). However, in anemic samples, A1C EXP showed a negative bias compared to HPLC devices, suggesting that anemia may affect the accuracy of HbA1c results. The study indicates that A1C EXP is a reliable POC alternative to laboratory assays, albeit with considerations for anemic patients.

Breast cancer (BC) is among the most commonly diagnosed cancers. Besides mammography, breast ultrasonography and the routinely monitored protein markers, the variations of small molecular metabolites in blood may be of great diagnostic value. This study aimed to quantify specific metabolite markers with potential application in BC detection. The study enrolled 50 participants, 25 BC patients and 25 healthy controls (CTRL). Dried blood spots (DBS) were utilized as biological media and were quantified a simplified liquid chromatography tandem mass spectrometry (LC-MS/MS) method, used in expanded newborn screening. The targeted metabolomic analysis included 12 amino acids and 32 acylcarnitines. Statistical analysis revealed a significant variation of metabolic profiles between BC patients and CTRL. Among the 44 metabolites, 18 acylcarnitines and 10 amino acids remained significant after Bonferroni correction, showing increase or decrease and enabled classification of BC patients and CTRL. The well-established LC-MS/MS protocol could provide results within few minutes. Therefore, the combination of an easy-to-handle material-DBS and LC-MS/MS protocol could facilitate BC screening/diagnosis and in the next step applied to other cancer patients, as well.