Scandinavian Journal of Clinical & Laboratory Investigation最新文献

Serum antinuclear antibodies (ANAs) facilitate the diagnosis and evaluation of patients with many systemic autoimmune conditions. However, there are no systematic reports concerning differences in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Therefore, we assessed the differences in serum ANAs in GBS and CIDP patients and control subjects in a Chinese cohort. A retrospective enrollment of 417 patients was conducted for this study, consisting of 158 clinically confirmed GBS patients, 115 CIDP patients, and 144 non-GBS and CIDP inpatients as a control group. The measurement of serum ANAs, including autoantibodies against the Ro52 protein (anti-Ro52 antibody), anti-Sjogren's-syndrome-related antigen A antibodies (anti-SSA), anti-mitochondrial antibody M2 (AMA-M2), etc., was performed on all enrolled patients. Additionally, erythrocyte sedimentation rate (ESR), anti-streptolysin O (ASO), and C-reactive protein (CRP) values were also assessed. The results revealed significantly higher positive rates of Anti-Ro52 antibody, AMA-M2, and Anti-SSA antibody in the GBS group compared to the CIDP and control groups (adjusted p < 0.001). In the GBS group, Anti-Ro52 and AMA-M2 antibody positivity was moderate to severe, while anti-SSA antibody positivity was mild. In the GBS group, the most common finding for a serum ANAs burden score was 3 (58, 36.71%), which was higher than the CIDP group where a score of 1 was the most common finding (14, 12.17%). Anti-Ro52 antibodies, anti-SSA antibodies, and AMA-M2 were closely associated with GBS. Differential positivity of serum ANAs in GBS and CIDP patients was proposed to provide a reference for clinical diagnosis and treatment methods.

This study aims to propose and evaluate a modified version of the One-Sample Kolmogorov-Smirnov (K-S) test that addresses its current limitations in large sample groups, with the goal of improving its accuracy and reliability in assessing normality assumptions in medical research data. In addition to the classical K-S test, a logarithmic modification was applied to reduce the impact of sample size. This modification replaces the sample size in the test calculation with a logarithmic formula (ln n²) to prevent z-values from becoming excessively small in large samples. Statistical analyses were conducted using Microsoft 365/Excel, SPSS 21.0 and STATA/MP18 with a geometric approach employed to assess data normality using the Geometric Approach to Normality Testing. The study analyzed real-world laboratory data obtained from the complete blood count (CBC) results of 122,310 adult patients (aged ≥18 years) who were treated at Cerrahpaşa Medical Faculty Hospital throughout 2022. The modified K-S test with the proposed logarithmic modification (ln n²) reduced the tendency to reject normality solely due to large sample size. The modified test was able to confirm that some hematological parameters did indeed fit normal distribution models, while discriminating those that did not. In particular, analysis of the data set trimmed by 0.5% showed further improvement in test performance. Consequently, the proposed modification is shown to provide a more sensitive method for assessing the assumption of normal distribution in large data sets. The method can be easily integrated into existing statistical software, making it accessible for routine use in large-scale data analysis.

Familial hypocalciuric hypercalcemia (FHH) is a genetically heterogeneous autosomal dominant disorder of calcium homeostasis, which is usually asymptomatic and characterized by low or normal phosphorus, inappropriately normal or elevated PTH, and low fractional excretion of calcium (FECa) in addition to hypercalcemia. Loss-of-function mutations in the G protein subunit alpha 11 (GNA11) gene, an important downstream signaling partner of the Calcium-sensing receptor (CaSR), cause FHH type 2. We reviewed the GNA11 gene-associated FHH type 2. A 14-year-old male was referred due to hypercalcemia (2.89 mmol/L). Slightly elevated PTH (7.95 pmol/L), but normal phosphorus (1.19 mmol/L), alkaline phosphatase (271 U/L), magnesium (0.95 mmol/L), and albumin (43 g/L) levels were detected. The FECa was found to be low when serum calcium was high (FECa was <0.01%, and <0.01% on two separate tests). A homozygous c.301T > C, p.Y101H variant was detected in the GNA11 gene. The same variant was detected heterozygous for both parents. While the calcium levels of the mother and father were normal, their spot urinary FECa was found low (Ca: 2.47 mmol/L, FECa: <0.01%, and Ca: 2.45 mmol/L, FECa: 0.01%, respectively). Hypocalciuria without hypercalcemia can be detected in cases heterozygous for the GNA11 gene mutation. Severe hypercalcemia may not occur in homozygous cases.

Home sampling of saliva is noninvasive, easy, and convenient, especially for multiple sampling. Such samples are therefore appropriate for the measurement of melatonin, a biomarker for circadian dysregulation. However, home sampling is restricted by access to appropriate storage conditions. This study, therefore, evaluated the effect of common storage conditions on the stability of melatonin in synthetic fiber swabs employed for home sampling. Saliva was provided by healthy volunteers during daytime, pooled and subsequently divided into fractions, each spiked with different amounts of melatonin. Synthetic fiber swabs were allowed to accumulate saliva from these fractions followed by storage at room temperature, 4 °C or -20 °C for 24, 48 or 72 h. The melatonin levels were analyzed employing a commercial ELISA assay. Differences in concentrations at each storage condition were evaluated with a two-way repeated measures ANOVA followed by a Tukey multiple comparison test. Samples were significantly more stable at -20 °C compared to room temperature and 4 °C, irrespective of the storage duration. However, no significant decrease from baseline was observed for samples stored at either 4 °C or -20 °C after 72 h. In comparison, a significant decrease was observed at room temperature after just 24 h. In conclusion, storage at -20 °C may be considered the gold standard for synthetic fiber swabs for quantification of salivary melatonin. However, storage at 4 °C ensures stability for 72 h while also ensuring convenience for home sampling. It is therefore our recommendation that such home samples are refrigerated, transported cold and centrifuged within 72 h of collection.

This study aimed to investigate the effect of obesity on angiogenesis and its relationship with liver steatosis in obese children and adolescents. The study ıncluded 81 obese ın chıldren and 30 healthy controls. Obese subjects were subdıvıded by ultrasound ınto three groups: no steatosıs, grade 1 lıver steatosıs (NAFL), and grade 2 NAFL. Obese individuals, regardless of the presence of NAFL, exhibited significant insulin resistance (p < .01) compared to their lean counterparts. All obese subjects showed elevated serum ALT, wıth a sıgnıfıcantly greater ın those wıth NAFL. Marked dyslipidemia by decreased high-density lipoprotein (HDL) levels and elevated triglycerides, was observed in obese individuals with NAFL. The serum levels of angiopoietin-1 (Ang-1) and vascular endothelial growth factor-165b (VEGF165b) were measured as anti-angiogenic markers, while vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2) and P-selectin were assessed as pro-angiogenic factors. Compared to normal-weight children (5558 ± 674 pg/mL), Ang-1 levels were significantly elevated in all obese subgroups (8861 ± 1026; 8105 ± 615; 7388 ± 924, respectıvely). However, no significant differences in Ang-1 levels were observed among the obese subgroups. Ang-1 and VEGF165b levels were significantly higher in insulin-resistant individuals (7575 ± 747 pg/mL and 293 ± 44.4 pg/mL, respectively) compared to insulin-sensitive subjects (6143 ± 557 pg/mL and 179 ± 31.4 pg/mL, respectively). These findings suggest that insulin resistance in obese children is associated with altered angiogenic signaling. However, no significant differences in the serum levels of angiogenic factors were observed between obese groups with and without NAFL.

The aim of this study was to validate the blood glucose point-of-care system, cobas^® pulse (Roche Diagnostics GmbH), which is the successor to the Accu-Chek^® Inform II system (Roche Diagnostics GmbH). Since the cobas^® pulse device is intended to replace an existing device from the same manufacturer, we found it highly relevant to perform an industry-independent validation regarding accuracy and comparability with existing glucose measurement systems. From 40 randomly selected, non-fasting adults capillary and venous blood was drawn simultaneously. Correlation and agreement was evaluated by comparing capillary blood glucose on cobas^® pulse to plasma glucose on cobas^® 8000 (Roche Diagnostics GmbH) and capillary blood glucose on ABL800 Flex (Radiometer, Denmark), respectively. The cobas^® pulse generally showed good agreement with both comparison methods, although the agreement between cobas^® pulse and ABL800 Flex was better (bias -0.01 mmol/L) than between cobas^® pulse and cobas^® 8000 (bias 0.61 mmol/L). Differences between measurements of low blood glucose levels (range 0.5 to 4.8 mmol/L) and higher blood glucose levels (range 9.7 to 15.3 mmol/L) when comparing cobas^® pulse to ABL800 Flex was also within allowable limits. Altogether, the validation study demonstrated a clinically satisfactory performance of the cobas^® pulse point-of-care device.

The aim was to assess and compare the analytical performance of the FUS-200 and its new upgrade, the MUS-3600 urine autoanalyzers, and to compare performance with manual microscopy. First morning, void urine samples were randomly collected, and suitable samples were analyzed on both autoanalyzers. In addition, concurrent manual microscopic examinations were performed for all suitable urine samples. Carry-over, linearity and imprecision analysis were performed to assess analytical and diagnostic performance of both urine autoanalyzers according to Clinical and Laboratory Standards Institute (CLSI) EP15-A2, and the study was conducted in accordance with CLSI GP16-A3 Urinalysis; Approved Guideline. A total of 518 samples were collected, and of these, 494 (95.4%) were suitable for analysis and were included in the study. Sensitivity and positive likelihood ratio (LR+) values for WBC and squamous epithelium (SqEC) counts for both autoanalyzers were >90% and >10%, respectively. Specificity and LR+ values obtained from MUS-3600 were better compared to the FUS-200 (respectively 92.8 vs. 84.7; 5.5 vs. 10.1). One group agreement between the MUS-3600 and manual microscopy was >90%. Both analyzers displayed comparable performance for RBC and WBC counts, which were moderately correlated with each other. These results show the diagnostic performance of the MUS-3600 and FUS-200 was satisfactory for urine sediment analysis and was compatible with manual microscopy findings. However, random urine samples are sub-optimal for evaluating diagnostic performance, particularly for bacterial, cast, crystal and yeast analysis. Thus, we recommend using more appropriate urine samples for this comparison, such as from patients with suspected urinary tract infections.

Elevated triglyceride (TG) levels, common in hypertriglyceridemia, can significantly interfere with electrolyte analysis, particularly by the indirect ion-selective electrode (ISE) method. However, comprehensive data on the concentration-dependent measurement differences for potassium, sodium and chloride, along with validated corrective algorithms, are lacking. This study assessed the discrepancies in these electrolytes between direct and indirect ISE methods in serum samples with high TGs, while developing correction formulas for the indirect ISE. A total of 154 serum samples with high TGs and 50 control serum samples were analyzed in this retrospective cross-sectional study. Triglycerides were measured using colorimetric methods on the Roche Cobas 8000 analyzer (Roche Laboratories, Basel, Switzerland). Sodium, potassium and chloride were measured with direct ISE (Vitros 5600 Integrated System; Ortho-Clinical Diagnostics, Inc., Raritan, NJ) and indirect ISE (Roche Cobas 8000 analyzer). Our results revealed significant negative biases in the indirect ISE, particularly in samples with TG >20.00 mmol/L. For TG levels between 20.01 and 30.00 mmol/L, the negative biases for sodium, potassium and chloride were -2.31%, -3.86% and -4.58%, respectively. Notably, in the subgroup with TG >60.00 mmol/L, the negative biases reached their maximum values: -12.05% for potassium, -6.88% for sodium, and -10.59% for chloride. Additionally, linear correction formulas that aligned indirect results with direct measurements were developed and validated. Post-correction, differences fell within clinical thresholds (Diff_Na of |4| mmol/L, Diff_Cl of |4| mmol/L, Diff_K of |0.5| mmol/L). Collectively, high TGs impact electrolyte measurements by indirect ISE, but the correction formulas might mitigate the discrepancies. These correction formulas were platform-specific, and their generalizability to other analytical systems requires further investigation.

As neuroblastoma is a highly heterogeneous pediatric solid tumor, it is essential to select appropriate reference genes to compare the concentration of circulating free DNA (cfDNA) between patients with neuroblastoma and healthy individuals. cfDNA was extracted from peripheral blood and quantified using quantitative Polymerase Chain Reaction (qPCR). The stability of candidate reference genes (RGs) was analyzed using the ΔCt method, geNorm, NormFinder, and BestKeeper. The results from these four algorithms were integrated using the RefFinder tool to generate a comprehensive stability ranking and assess the stability of these candidate RGs across different sample groups. Alpha hemoglobin stabilizing protein (AHSP) and Hypoxanthine-Guanine Phosphoribosyltransferase 1 (HPRT1) exhibited the highest stability, whereas Beta-2-microglobulin(B2M) and HBS1-like protein(HBS1L) demonstrated the lowest stability. qPCR of cfDNA from patients with neuroblastoma revealed differences in the stability of various reference genes. Prioritizing reference genes with better stability may facilitate more accurate detection of intergroup differences in the samples.

Objectives: To develop and present simple visual and descriptive summary measures of agreement in method comparison studies with replicated measurements and to discuss detection of drift in method comparison studies. Summary measures may serve as an exploratory data analysis guiding further agreement and decision analysis of two methods using the Bland and Altman method and mixed-effects modeling. Materials and methods: The methodological approach is illustrated using freely available clinical datasets from two published method comparison studies with repeated measurements on each subject. Results: With the use of ellipses and a numerical ideality index as summary measures for each subject with paired measurements from two clinical methods, it is possible to quickly decode a dataset's intra- and interindividual variation, differential and proportional bias, possible drift, and the number of measured subjects in clinically relevant areas for the two methods. Conclusion: Simple and intuitive exploratory method comparison analysis can be performed and interpreted even for relatively large datasets prior to more advanced statistical analysis of method comparisons using data with replicated measurements.