Serum neurofilament levels in patients with multiple sclerosis: A comparison of SIMOA and high sensitivity ELISA assays and contributing factors to ELISA levels.

BACKGROUND: Serum neurofilaments (sNfs), especially the most investigated serum neurofilament light chain (sNfL), are promising biomarkers in multiple sclerosis (MS). However, their clinical utility is still limited, given the availability and costs of accessible analytical methods. The gold standard for the detection of sNfs is represented by the single molecule arrays (SIMOA). Recently, a high sensitivity enzyme-linked immunosorbent assay (hsELISA) has also been introduced. The objective of the study was to compare both assays for the determination of sNfL and neurofilament heavy chain (sNfH) concentrations in a defined MS cohort. The second objective was to identify contributing factors to sNfs concentrations determined by hsELISA. METHODS: Serum samples were collected from MS patients attending the MS Centre, University Hospital Ostrava, Czech Republic. The levels of sNfs were detected using SIMOA and hsELISA assays. RESULTS: The Spearman's rank correlation coefficient between the sNfL SIMOA and sNfL hsELISA and between the sNfH SIMOA and sNfH hsELISA was moderate rs= 0.543 (p = 0.001) and rs= 0.583 (p = 0.001), respectively. The Passing-Bablok regression analysis demonstrated bias between both methods. Equally significant bias between the methods was confirmed by the Bland-Altman plots. Furthermore, confounding factors affecting the sNfL levels were glomerular filtration rate (eGFR; 95% CI -2.34 to -0.04) and sex (95% CI -2.38 to -0.10). The sNfH levels were affected by age (95% CI 0.01 to 0.07), eGFR (95% CI -2.45 to -0.02), body mass index (BMI; 95% CI -0.31 to -0.05), and blood volume (95% CI 0.69 to 3.35). CONCLUSION: This analytical study showed significant differences between hsELISA and SIMOA methods, especially for the sNfH concentrations. We identified confounding factors for sNfs levels determined by hsELISA. The sNfs levels were influenced by renal function and sex, whilst sNfH levels were affected by age, BMI, and total blood volume.

Contribution of miRNAs and Other Inflammatory Biomarkers to the Differentiation of Inflammatory and Non-Inflammatory Joint Effusions.

PURPOSE OF THE STUDY The aim of the study was to determine miR-146a-5p, miR-223-3p and miR-23a-3p by an enzyme immunoassay in patients with inflammatory and non-inflammatory joint effusion and to verify the usefulness of these miRNAs as biomarkers of joint inflammation. MATERIAL AND METHODS Synovial fluid (SF) samples were collected from 82 patients. The group consisted of 60 non-inflammatory, 11 inflammatory-non-pyogenic, 11 inflammatory-pyogenic SF. SF miRNA was isolated by RNA Isolation Kit Plasma/Serum. The concentrations of miRNA were determined by enzyme-linked immunosorbent assays (ELISA), C-reactive protein, interleukin-6 and procalcitonin on automatic analyser, presepsin on POCT system, interleukin-1 and human neutrofil defensins 1-3 by ELISA. RESULTS A statistically significant negative correlation was found between miR-146-5p and miR-223-3p, WBC, IL-1ß, IL-6 and CRP (P < 0.05) in all groups; a statistically significant positive correlation was found between miR-223-3p and miR-23a-3p, WBC, PMN, IL-1beta, IL-6 and HNP1-3, as well as a positive correlation of miR-23a-3p with IL-1ß, IL-6 and HNP1-3. A statistically significant difference was found between miR-146a-5p, miR-223-3p and miR-23a-3p and individual SF groups, P = 0.006, P < 0.001, respectively. PMN, WBC, Il-1ß, IL-6, HNP 1-3 predicted the inflammatory processes with excellent diagnostic power (AUC > 0.9). The clinical relevance expressed by effect size was the strongest in miR-223-3p, PMN, IL-1 , HNP 1-3 between non-inflammatory and inflammatory-pyogenic group. CONCLUSIONS Our study quantified the SF miRNA by ELISA. We have shown that miR-146a-5p, miR-223-3p and miR-23a-3p can be an important group of biomarkers for the detection and monitoring of various pathophysiological conditions in synovial fluid, including inflammatory conditions. Key words: miRNA, synovial fluid, inflammatory joint disease, enzyme-linked immunosorbent assay.

Gamma-heavy chain disease.

BACKGROUND: Gamma-heavy chain disease is a rare disease, described so far in approximately 150 cases. The aim of this work was laboratory dia-gnostics of immunoglobulin heavy chain disease. MATERIALS AND METHODS: A 60-year-old patient was referred to the University Hospital in Ostrava for suspected marginal zone lymphoma from gastric bio-psy. Staging examinations including bone marrow trepanobio-psy and PET/CT were added; special examinations required serum protein electrophoresis, immunofixation electrophoresis, determination of polyclonal immunoglobulins, free light chains, and immunoglobulin heavy/light chain pairs. Isoelectric focusing in agarose gel followed by affinity immunoblotting and SDS electrophoresis was added due to unclear findings. RESULTS: 0.1 % of plasma cells were found in the bone marrow, of which 87 % were clonal (pathological) plasma cells, followed by the cyt cytotype LAMBDA + CD38 + CD138 + CD45 + CD19 + CD56- CD27 + CD81- CD117-. Monoclonal heavy chains were found in the patients serum. No monoclonal immunoglobulin heavy or light chains were detected in urine. The PET/CT examination showed generalized lymphadenopathy, splenomegaly and inhomogeneous accumulation of fluorodeoxyglucose in axillary and appendicular skeleton, but without the presence of typical osteolytic lesions. CONCLUSION: Monoclonal heavy chains of immunoglobulins are a rare disease. In contrast to the detection of a complete paraprotein molecule, additional methods must be used to confirm them. The finding of monoclonal heavy chain gamma in the serum of the study patient is related to the presence of marginal zone lymphoma, which was proven from a gastric bio-psy. The study was supported by the project of MH CZ - DRO - FNOs /2017 (Biobank in Teaching Hospital Ostrava) The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.

The rs1803274 polymorphism of the BCHE gene is associated with an increased risk of coronary in-stent restenosis.

BACKGROUND: We sought to identify gene polymorphisms that confer susceptibility to in-stent restenosis after coronary artery bare-metal stenting in a Central European population. METHODS: 160 controls without post-percutaneous coronary intervention in-stent restenosis were matched for age, sex, vessel diameter, and diabetes to 160 consecutive cases involving in-stent restenosis of the target lesion within 12 months. Using real time polymerase chain reaction and melting-curve analysis, we detected 13 single-nucleotide polymorphisms in 11 candidate genes - rs1803274 (BCHE gene), rs529038 (ROS1), rs1050450 (GPX1), rs1800849 (UCP3), rs17216473 (ALOX5AP), rs7412, rs429358 (ApoE), rs2228570 (VDR), rs7041, rs4588 (GC), rs1799986 (LRP1) and rs2228671 (LDLR). Multivariable logistic regression was used to test for associations. RESULTS: The rs1803274 polymorphism of BCHE was significantly associated with in-stent restenosis (OR 1.934; 95 % CI: 1.181-3.166; p = 0.009). No association was found with the other studied SNPs. CONCLUSIONS: The A allele of rs1803274 represents a risk factor for in-stent restenosis in Central European patients after percutaneous coronary intervention with bare-metal stent implantation.

Angiopoietin-like protein 4: development, analytical characterization, and clinical testing of a new ELISA.

The aim of our work was to develop an assay for the determination of angiopoietin-like protein 4 (Angplt4) in human blood, and to investigate its levels in healthy volunteers and donors suffer from metabolic syndrome. We developed and evaluated the sandwich ELISA method for the quantitative determination of human Angplt4 in serum samples. We conducted also the pilot study on individuals with metabolic syndrome or familiar hypercholesterolemia and healthy probands and measured blood pressure, waist circumference, Angplt4 serum levels, serum cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, insulin, glucose, A-FABP and calculate BMI and QUICKI insulin sensitivity index. In the study on 30 healthy volunteers we demonstrated that sex or age is not the determinant for Angplt4 serum values. Furthermore, we tested 115 individuals with metabolic syndrome and found that probands with metabolic syndrome did not differ in Angplt4 values than healthy individuals from the first study (medians 8.7 vs. 8.1 ng/ml, p = 0.6). Individuals with metabolic syndrome did not differ in sex or age from healthy. Angplt4 values correlated with the HDL-cholesterol (r = -0.25; p < 0.01), FGF-21 (r = 0.23, p < 0.01), glucose (r = 0.17; p = 0.03), uric acid (r = 0.17; p = 0.49), lipocalin-2 (r = 0.23, p < 0.01), triacylglycerols (r = 0.25; p < 0.01) and number or characters of metabolic syndrome (r = 0.21; p < 0.01). No significant correlation was found between serum Angplt4 and BMI, WC or QUICKI. However, we performed stepwise regression and we found that Angplt4 was not an independent marker for metabolic syndrome. The patients from the metabolic syndrome group suffering diabetes mellitus (n = 83) did not differ in serum Angplt4 from the group of healthy patients, too. The pilot study supports the hypothesis about the role of Angplt4 as a new class of lipid metabolism modulator. Their values could be a new key predictors of metabolic syndrome. Further research is necessary to confirm our findings in individuals with dyslipidemia, obesity, coronary artery diseases and different medication in order to assess Angplt4 value as a risk predictor of accelerated atherosclerosis.

Lipocalin-2: development, analytical characterization, and clinical testing of a new ELISA.

Lipocalin-2 (also known as neutrophil gelatinase-associated lipocalin [NGAL]) has been described as a promising marker of metabolic syndrome associated with inflammation. The aim of our work was to develop an assay for the determination of lipocalin-2 in human serum and to investigate its levels in healthy volunteers and donors suffering from metabolic syndrome. We also conducted a pilot study on individuals with metabolic syndrome and on healthy probands and measured lipocalin-2 in these individuals. We developed and evaluated the sandwich ELISA method for the quantitative determination of human lipocalin-2 in serum samples. We measured blood pressure, waist circumference, serum cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, insulin, glucose, creatinine, hs-CRP, and adiponectin and calculated the BMI and Quicki insulin sensitivity index. In the study on 153 healthy volunteers, we showed that sex and age are not determinative for lipocalin-2 serum values. Furthermore, we tested 45 individuals with metabolic syndrome; values of lipocalin-2 did not differ (78.8 vs. 80.0 microg/l, p =0.56) from the data of healthy individuals from the first study. Neither group differed with regard to sex or age. Lipocalin-2 correlated with alanine aminotransferase (ALT) (r=-0.3, p<0.01) aspartate aminotransferase (AST) (r=-0.3, p<0.01), cholesterol (r=-0.21, p=0.047), creatinine (r=0.19, p=0.05), and high-sensitivity C-reactive protein (hs-CRP) (r=0.22, p=0.036). No significant correlation was found between serum lipocalin-2 and BMI, waist circumference, blood pressure, triglycerides, HDL, Quicki, or the number of metabolic syndrome components. When study patients with metabolic syndrome were further stratified according to the number of components of metabolic syndrome, serum concentrations of lipocalin-2 did not differ. The results presented demonstrate the analytical competence of the lipocalin-2 assay. However, we assumed that lipocalin-2 is not a routinely usable marker of metabolic syndrome or obesity. The association between serum lipocalin-2 and obesity or metabolic syndrome was not validated in our study.