Chemiluminescent Immunoassay Method Research Articles

Comparative Analysis of Nucleocapsid Antibody Levels, Neutralizing Antibodies, and Spike receptor-binding Domain in Severe Acute Respiratory Syndrome Coronavirus-2 Patients

ABSTRACT Introduction: Serological testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is crucial for detecting antibodies generated in response to infection. Neutralizing antibodies (NAbs) target the receptor-binding domain (RBD) of the spike protein (S-RBD) and can exist in the forms of immunoglobulin G (IgG), IgM, and IgA. This study aimed to assess specific antibody responses to the nucleocapsid protein (N), S-RBD, and NAbs and correlate them with the clinical spectrum of coronavirus disease 2019 (COVID-19). Methods: A cross-sectional design was conducted at the Dr. Soetomo General Academic Hospital, Indonesia. We examined 48 patients with confirmed COVID-19 of varying severity (mild, moderate, severe, and critical) on treatment days 0, 3, and 6. We measured nucleocapsid antibodies, S-RBD, and neutralization using the chemiluminescence immunoassay method. The comparative analysis of IgM, IgG, NAB, and S-RBD levels is adjudicated using the independent t-test. Results: Specific antibody levels on treatment days 0, 3, and 6 showed significant differences (P < 0.05). Notably, significant differences were observed in comparisons such as severe recovery versus severe death groups on day 0 in IgG, mild versus severe recovery on day 3 in IgM, moderate versus severe recovery, severe recovery versus severe death, and mild versus severe recovery on day 3, as well as on day 6 in anti-S-RBD, and mild versus severe recovery on day 3 and day 6 in neutralization of SARS-CoV-2 (P < 0.05). Conclusions: These findings highlight the dynamic antibody responses during COVID-19 treatment and their relevance for clinical outcomes.

Screening of Syphilis Using the Reverse Algorithm and its Trends Among Healthy/Asymptomatic Blood Donors: A Regional Transfusion Centre Study from Northern Pakistan

Objective: To determine the syphilis trends by using the reverse algorithm in healthy/asymptomatic blood donors from Northern Pakistan. Study Design: Perspective longitudinal study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Transfusion (AFIT), Rawalpindi Pakistan, from Jan to Sep 2022. Methodology: After taking a complete history from potential donors, an appointed blood bank doctor performed a general physical examination. Potential donors’ blood samples were tested for syphilis by the Chemiluminescent Microparticle Immunoassay (CMIA) method followed by reflexively testing of CMIA reactive blood samples with Rapid Plasma Reagin (RPR), and results were interpreted as positive or negative. Results: A total of 56122 donors donated blood over nine months, including 55742(99.3%) males and 380(0.7%) females. Blood donors ranging from 18-65 years with a mean age of 28.82±7.1 were included in the study. Out of 56122 blood donor samples submitted, 487(0.87%) turned out to be syphilis positive by CMIA method, comprising 485(99.59%) males and 02(0.41%) females. Of 487 CMIA-positive serum samples, 216(44.3%) were RPR-positive, all male donors. Conclusion: A higher latent syphilis trend was observed in replacement non-voluntary young male donors between 18 and 40 years of age. The majority of the syphilis positives donors were male, while females made up a negligible percentage.

Vitamin D Deficiency Is Associated with Advanced Liver Fibrosis and Impaired Fasting Glucose in Alcohol Use Disorder.

Vitamin D deficiency is a risk factor for liver disease, insulin resistance, and beta cell dysfunction. Individuals with alcohol use disorder (AUD) have many comorbidities, with a heavy burden of liver disease and metabolic complications, including type 2 diabetes mellitus (T2DM). We aimed to analyze the prevalence and associations of vitamin D deficiency in patients admitted for in-hospital treatment of AUD. A cross-sectional study was conducted in patients consecutively admitted for the treatment of AUD between January 2017 and October 2023. Sociodemographic data, substance use characteristics, and blood parameters were available at admission. Vitamin D status was assessed through the serum concentrations of 25-hydroxyvitamin D [25(OH)D] levels using a direct competitive chemiluminescent immunoassay method. Deficiency of vitamin D was defined as a concentration less than 20 ng/mL; impaired fasting glucose (IFG) was defined by fasting blood glucose >100 mg/dL (5.6 mmol/L), and advanced liver fibrosis by an FIB-4 index >3.25. Two hundred and forty-three patients were included (75% male) with a mean age of 49 ± 10 years, mean BMI of 26.4 ± 7.3, mean alcohol consumption of 163 ± 81 g/day, and a mean duration of AUD of 18.1 ± 11.2 years. Mean 25(OH)D, fasting blood glucose, AST, ALT, and platelets were 14.4 ± 10.2 ng/mL, 103.4 ± 40.9 mg/dL, 55.1 ± 75.8 U/L, 44.8 ± 76.6 U/L, and 206.3 ± 84.8 × 109/L, respectively. The prevalence of vitamin D deficiency was 80.6%, and 41.1% of patients had levels less than 10 ng/mL. IFG was present in 32.3% of patients, and 20.5% had FIB-4 values >3.25. In the multivariable analysis, IFG (OR, 2.51; 95% CI: 1.02-6.17, p = 0.04) and advanced liver fibrosis (OR, 4.27; 95% CI: 1.21-15.0, p = 0.02) were the only factors associated with vitamin D deficiency. Vitamin D deficiency was very prevalent in this series of patients with AUD and was associated with impaired fasting glucose and advanced liver fibrosis.

Investigating the cut-off values of captopril challenge test for primary aldosteronism using the novel chemiluminescent enzyme immunoassay method: a retrospective cohort study

The measurement evolution enabled more accurate evaluation of aldosterone production in hypertensive patients. However, the cut-off values for novel assays have been not sufficiently validated. The present study was undertaken to validate the novel chemiluminescent enzyme immunoassay for aldosterone in conjunction with other methods. Moreover, we also aimed to establish a new cut-off value for primary aldosteronism in the captopril challenge test using the novel assay. First, we collected 390 plasma samples, in which aldosterone levels measured using liquid chromatography-mass spectrometry ranged between 0.18 and 1346 ng/dL. The novel chemiluminescent enzyme immunoassay showed identical correlation of plasma aldosterone with liquid chromatography-mass spectrometry, in contrast to conventional radioimmunoassay. Further, we enrolled 299 and 39 patients with primary aldosteronism and essential hypertension, respectively. Plasma aldosterone concentrations measured using the novel assay were lower than those measured by radioimmunoassay, which resulted in decreased aldosterone-to-renin ratios. Subsequently, positive results of the captopril challenge test based on radioimmunoassay turned into “negative” based on the novel assay in 45% patients with primary aldosteronism, using the conventional cut-off value (aldosterone-to-renin activity ratio > 20 ng/dL per ng/mL/h). Receiver operating characteristic curve analysis demonstrated that aldosterone-to-renin activity ratios > 8.2 ng/dL per ng/mL/h in the novel assay was compatible with the conventional diagnosis (sensitivity, 0.874; specificity, 0.980). Our study indicates the great measurement accuracy of the novel chemiluminescent enzyme immunoassay for aldosterone, and the importance of measurement-adjusted cut-offs in the diagnosis of primary aldosteronism.

HormoneBayes: A novel Bayesian framework for the analysis of pulsatile hormone dynamics.

The hypothalamus is the central regulator of reproductive hormone secretion. Pulsatile secretion of gonadotropin releasing hormone (GnRH) is fundamental to physiological stimulation of the pituitary gland to release luteinizing hormone (LH) and follicle stimulating hormone (FSH). Furthermore, GnRH pulsatility is altered in common reproductive disorders such as polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA). LH is measured routinely in clinical practice using an automated chemiluminescent immunoassay method and is the gold standard surrogate marker of GnRH. LH can be measured at frequent intervals (e.g., 10 minutely) to assess GnRH/LH pulsatility. However, this is rarely done in clinical practice because it is resource intensive, and there is no open-access, graphical interface software for computational analysis of the LH data available to clinicians. Here we present hormoneBayes, a novel open-access Bayesian framework that can be easily applied to reliably analyze serial LH measurements to assess LH pulsatility. The framework utilizes parsimonious models to simulate hypothalamic signals that drive LH dynamics, together with state-of-the-art (sequential) Monte-Carlo methods to infer key parameters and latent hypothalamic dynamics. We show that this method provides estimates for key pulse parameters including inter-pulse interval, secretion and clearance rates and identifies LH pulses in line with the widely used deconvolution method. We show that these parameters can distinguish LH pulsatility in different clinical contexts including in reproductive health and disease in men and women (e.g., healthy men, healthy women before and after menopause, women with HA or PCOS). A further advantage of hormoneBayes is that our mathematical approach provides a quantified estimation of uncertainty. Our framework will complement methods enabling real-time in-vivo hormone monitoring and therefore has the potential to assist translation of personalized, data-driven, clinical care of patients presenting with conditions of reproductive hormone dysfunction.

Hydroxyapatite-Gold Modified Screen-Printed Carbon Electrode for Selective SARS-CoV-2 Antibody Immunosensor.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or coronavirus disease 2019 (COVID-19), is still spreading worldwide; therefore, the need for rapid and accurate detection methods remains relevant to maintain the spread of this infectious disease. Electrochemical immunosensors are an alternative method for the rapid detection of the SARS-CoV-2 virus. Herein, we report the development of a screen-printed carbon electrode immunosensor using a hydroxyapatite-gold nanocomposite (SPCE/HA-Au) directly spray-coated with the immobilization receptor binding domain (RBD) Spike to increase the conductivity and surface electrode area. The HA-Au composite synthesis was optimized using the Box-Behnken method, and the resulting composite was characterized by UV-vis spectrophotometry, TEM-EDX, and XRD analysis. The specific interaction of RBD Spike with immunoglobulin G (IgG) antibodies was evaluated by differential pulse voltammetry and electrochemical impedance spectroscopy methods in a [Fe(CN)6]4-/3- solution redox system. The IgG was detected with a detection limit of 0.0561 pg mL-1, and the immunosensor had selectivity and stability of 103-122% and was stable until week 7 with the influence of storage conditions. Also, the immunosensor was tested using real samples from human serum, where the results were confirmed using the chemiluminescent microparticle immunoassay (CMIA) method and showed satisfactory results. Therefore, the developed electrochemical immunosensor can rapidly and accurately detect SARS-CoV-2 antibodies.

Serum 25-Hydroxyvitamin D, Vitamin D Receptor, and Vitamin-D-Binding Protein Gene Polymorphisms and Risk of Dementia Among Older Adults With Prediabetes.

The association between vitamin D and dementia risk in those with prediabetes remains uncertain. We aimed to evaluate the association of serum 25-hydroxyvitamin D (25OHD) with incident dementia among older adults with prediabetes, and examine whether apolipoprotein E (APOE) genotypes, vitamin D receptor (VDR), and vitamin-D-binding protein (VDBP) gene polymorphisms may modify this association. A total of 34237 participants aged ≥60 with prediabetes (HbA1c <6.5% and ≥5.7%) and without dementia at baseline were included from the UK Biobank. Serum 25-hydroxyvitamin D (25OHD) was measured using chemiluminescent immunoassay method. The primary outcome was incident all-cause dementia. Secondary outcomes included incident Alzheimer's disease (AD) and vascular dementia, respectively. The VDR and VDBP gene polymorphisms included single nucleotide polymorphisms of rs7975232, rs1544410, rs2228570, rs731236, and rs7041, rs4588, respectively. During a median follow-up of 11.8 years, 941 (2.7%) participants developed incident all-cause dementia. Overall, serum 25OHD was inversely associated with all-cause dementia (per standard deviation increment, adjusted hazard ratio: 0.82; 95% confidence interval: 0.75, 0.89). Similar trends were found for incident AD and vascular dementia. Furthermore, there was a stronger inverse relationship between serum 25OHD and all-cause dementia among VDR rs7975232 C allele noncarriers (p-interaction < 0.05). However, APOE Ɛ4, other VDR, and VDBP gene polymorphisms did not significantly modify the relation of serum 25OHD with incident all-cause dementia (all p-interactions >.05). There was an inverse association between serum 25OHD and incident dementia among older adults with prediabetes, especially in VDR rs7975232 AA allele carriers.

Antibody Response to Sars-CoV-2 in Adults After 18 Months of Second Dose Vaccination of Astra Zeneca

Vaccination is one of the methods of preventing SARS-Cov-2 infection. Although the efficacy of several vaccines has been observed, it is unknown how long the antibodies remain in the body. The purpose of this study was to examine the antibody titers in adults, 18 months after receiving two doses of the Astra Zeneca vaccine. This is a cross-sectional study with adult subjects who received two doses of the Astra Zeneca vaccine in the Bogor area, conducted in 2023. To evaluate antibody titers (IgG) in serum specimens, the Chemiluminescent Microparticle Immunoassay (CMIA) method was utilized. The antibody titer ≥ 50.0 AU/mL was considered positive. The characteristics 122 subjects were mostly: female (63,1%), 36-45 years old, senior high school graduate (45.9%), unemployed (62,3%), had hypertension history (44.7%), and had no COVID-19 infection during the last six months. The results demonstrate that all the subjects had a positive SARS Cov-2 antibody titer, with a range titer of 87 - 80260 AU/mL and a geometric mean titer of 3246.4 AU/mL. In conclusion, this study found that the two doses of the Astra Zeneca vaccine made a significant contribution to the acquisition of anti-SARS-CoV-2S antibodies in adults.

CHARACTERISTICS OF CIRCADIAN BLOOD PRESSURE PROFILE IN PATIENTS WITH ACUTE CORONARY SYNDROME AND THEIR ASSOCIATION WITH THYROID FUNCTION

The paper presents the results of a study of circadian arterial blood pressure (ABP) profile in patients with Acute Coronary Syndrome (ACS) and their association with thyroid-stimulating hormone (TSH) levels.&#x0D; Aim. To conduct a comparative analysis of circadian BP monitoring (CBPM) indicators in patients with ACS and their association with the TSH level.&#x0D; Materials and Methods. The study includes 125 patients with ACS aged 36 to 81 (mean age - 60.98± 0.81 years old). The patients were divided into two groups according to thyroid function. Group one (I) included 51 individuals (40.8%) - hypothyroid patients (TSH level&gt;4mIU/ml), mean age - 62.51±1.18 years old; Group II included 74 individuals (59.2%) - euthyroid patients (TSH level 0.4-4mIU/ml), mean age - 59.93±1.08 years old. The serum-free thyroxine (FT4) levels were within the normal range in both groups. In the general group, the proportion of individuals with unstable angina (UA) was 28.8%, and with myocardial infarction (MI) - 71.2%. In particular, in Group I, the proportion of individuals with UA was 23.53%, and with MI - 76.47%; in Group II, the proportion of individuals with UA was 32.43%, and with MI - 67.57%, p&gt;0,05 between Groups I and II. The circadian BP monitoring was carried out using the Biomed ВАТ41-2 device after stabilization of the patient's condition (on the second day of hospital admission). The following indicators have been determined: systolic BP (SBP) - daytime, nighttime, and average daily (24 hours) (SBPd, SBPn, and SBPav); diastolic BP (DBPd, DBPn, and DBPav); pulse BP (PBPd, PBPn, and PBPav); time index (TI) for SBPd, SBPn, and SBPav (SBPd TI, SBPn TI, and SBPav TI) and DBP (DBPd TI, DBPn TI, and DBPav TI); variability of SBPd, SBPn, and SBPav (SBPd var, SBPn var, and SBPav var) and DBP (DBPd var, DBPn var, and DBPav var); average daily index for SBP (SBP AvDI) and DBP (DBP AvDI); average daily heart rate (HRav). To study thyroid function in patients enrolled, TSH and FT4 levels were determined by chemiluminescent immunoassay method on the ARCHITECT iSystem analyzer using reagent kits for the quantitative determination of TSH (ARCHITECT TSH) and FT4 (ARCHITECT Free T4).&#x0D; Results and Discussion. The comparison of the CBPM results in both groups of patients with ACS shows significantly higher mean nighttime (SBPn and DBPn) levels in Group I patients compared to Group II patients: SBPn - by 6.27% (125.44±2.98 mm Hg (I) versus 117.58±2.26 (II), p&lt;0,05), DBPn - by 6.15% (73.65±1.91 mm Hg (I) versus 69.12±1.62 (II), p&lt;0,05), in the absence of a significant between-group difference between the mean levels of respective daytime and average daily indicators. Mean DBPn TI value also turned out to be significantly higher in Group I patients compared to Group II patients - by 33.69% (42.47±4.60% (I) versus 28.16±3.60% (II), p&lt;0.01). Significant difference was detected between mean SBP AvDI and DBP AvDI indicators in hypothyroid patients (I) versus respective indicators in euthyroid patients (II): SBP AvDI (I) 2.52±1.25% versus SBP AvDI (II) 5.99±0.98, p&lt;0.05; and DBP AvDI (I) 4.69±1.38% versus DBP AvDI (II) 8.88±1.32, p&lt;0.05.&#x0D; Conclusions. 1. Mean nighttime BP indicator (SBPn, DBPn, and DBPn TI) levels were significantly higher in the Group of hypothyroid patients with ACS, compared to euthyroid patients. In addition, the proportion of patients whose mean nighttime SBP and DBP levels exceeded the permissible values (SBPn&lt;120, DBPn&lt;70 mm Hg) was significantly higher in the Group of hypothyroid patients (I) compared to the Group of euthyroid patients (II). 2. Every third hypothyroid patient (I) (SBP AvDI: 37.25% and DBP AvDI: 31.37%) had a night-peaker circadian BP profile, characterized by nighttime BP increase instead of reduction, which suggests an extremely unfavorable prognosis. The findings may signal an additional adverse effect of thyroid dysfunction on arterial tone and, accordingly, BP regulation, which brings about a high risk of complications of ACS.

Exploring the Predictive Value of Inflammatory Biomarkers in COVID-19 Patients: A Prospective Cohort Study in Malang, Indonesia

The objective of this study was to assess the predictive value of inflammatory biomarkers in COVID-19 patients, namely the CRP/albumin ratio (CAR), interleukin 6 (IL-6), IL-6/lymphocyte ratio (IL-6/LY), and neutrophil/lymphocyte ratio (NLR). A prospective cohort study was conducted between January to June 2021 at Dr. Saiful Anwar General Hospital, Malang, East Java, Indonesia. CRP and albumin levels were measured using COBAS C6000. IL-6 was measured using the enzymatic chemiluminescence immunoassay (ECLIA) method and NLR was calculated based on flow cytometry evaluation of neutrophil and lymphocyte. Patient outcomes were obtained from medical records. Out of the 102 COVID-19 patients, 60 were non-survivors. The findings revealed that the area under the receiver (AUC) for CAR, IL-6, IL-6/LY, and NLR were 0.71, 0.77, 0.75, and 0.65, respectively. Kaplan-Meier curve analysis demonstrated significant differences between the groups stratified by these cut-off values. Notably, CAR and IL-6 exhibited the most accurate predictive values for mortality in COVID-19 patients. These findings suggest that CAR and IL-6 may serve as valuable biomarkers for predicting mortality in COVID-19 patients. Importantly, CAR offers an advantage over IL-6 as it is relatively more affordable, making it a viable option even if COVID-19 becomes endemic.

Relationship among serum 25-hydroxyvitamin D, fibrosis stage, genetic susceptibility, and risk of severe liver disease

ObjectivesThe prospective association between vitamin D and new-onset severe liver disease is still uncertain. The aim of this study was to assess the association of serum 25-hydroxyvitamin D (25(OH)D) with new-onset severe liver disease and to evaluate whether fibrosis stage, as assessed by the fibrosis- 4 (FIB-4) scores and genetic risk for liver cirrhosis may modify this association. MethodsThe study included 439 807 participants without liver diseases at baseline from the UK Biobank. Serum 25(OH)D concentrations were measured using the chemiluminescent immunoassay method. The primary outcome was new-onset severe liver disease, a composite definition of compensated or decompensated liver cirrhosis, liver failure, hepatocellular carcinoma, and liver-related death. ResultsDuring a median follow-up of 12 y, 4510 participants developed new-onset severe liver disease. Overall, there was an inverse association of serum 25(OH)D with new-onset severe liver disease (per SD increment, adjusted hazard ratio [HR], 0.87; 95% confidence interval, 0.84–0.91). Similarly, serum 25(OH)D (per SD increment) was significantly and inversely associated with new-onset compensated cirrhosis, decompensated cirrhosis, liver failure, and liver-related death, respectively, with HRs ranging from 0.75 to 0.87. No significant association was found for hepatocellular carcinoma. Furthermore, there was a stronger inverse association between serum 25(OH)D and severe liver disease among those with a higher FIB-4 score (≥2.67, 1.3 to <2.67, and <1.3; Pinteraction < 0.001). However, the genetic risks for liver cirrhosis, calculated using 12 related single nucleotide polymorphisms, did not significantly modify the association between serum 25(OH)D and severe liver disease (Pinteraction = 0.216). ConclusionsLower serum 25(OH)D concentrations were significantly associated with a greater risk for new-onset severe liver disease, especially in participants with higher FIB-4 scores.

Cytological study of different thyroid lesions and its correlation with thyroid function test

The research relevance of the combined use of fine needle aspiration cytology, sonography, and thyroid function tests is determined by accurate diagnostics of thyroid enlargement in both adults and children. The study aimed to analyse thyroid lesions through cytological analysis and their correlation with thyroid function test results. This cross-sectional study enrolled 100 patients with suspected thyroid disorders and nodules. Comprehensive assessments included clinic demographics, fine needle aspiration cytology procedures, and thyroid hormone profiles. Based on the Bethesda system, cytological diagnoses were correlated with thyroid function test results using the chemiluminescent microparticle immunoassay method. Non-tumour thyroid lesions were found to be the most common (95%), with colloidal goitre being the most common. Neoplastic cases mainly included papillary and follicular carcinoma. Most thyroid lesions occurred among the 21-30 age group, non-neoplastic cases were more frequent among the 10-20 age group, and neoplastic cases were more common in those aged 21-40. All patients had neck swelling. Most cases were euthyroid (76%), predominantly classified as Category 2. A strong correlation between cytological diagnoses and thyroid hormone levels (p=0.04) was observed. Fine needle aspiration cytology demonstrated good sensitivity (80%) and high specificity (98.46%), with an 80% positive predictive value and 98.46% negative predictive value, resulting in a diagnostic accuracy of 97.14%. The study highlights the valuable role of fine needle aspiration cytology, when coupled with thyroid function tests, in effectively guiding the management of patients with thyroid lesions, owing to its impressive accuracy, sensitivity, and specificity

Significance of the rs754635 variant of the cholecystokinin gene in the development of obesity in children

So far, the possible influence of single nucleotide variants (SNV) of the cholecystokinin (CCK) gene on the likelihood of developing obesity and metabolic disorders in children has not been demonstrated. The aim of the study SNV associations of the CSK gene to predict the probability of obesity and personalize the development trajectory of various metabolic disorders associated with obesity in children. Materials and methods. 252 obese children aged 6-18 years were examined. The main group (n=152) was represented by children with metabolically unhealthy obesity (MUO). The control group (n=100) consolidated of children with metabolically healthy obesity (MHO). Whole genome sequencing (CeGat, Germany) was performed in 31 children of the main and 21 children of the control group. Serum levels of interleukin-1β were measured using a chemiluminescent immunoassay (CLIA) method, interleukin-6 - by enzyme-linked immunosorbent assay (ELISA), Synevo, Ukraine. Results. The G allele of SNV rs754635 of the CCK gene was significantly more frequent among children with both MHO (t=10.93; p&lt;0.05) and MUO (t=12.96; p&lt;0.05) compared to healthy individuals. The G allele of SNV rs754635 of the CCK gene was associated with basal hyperglycemia (r=0.44) and impaired carbohydrate tolerance (r=0.33) in the MHO phenotype and with the atherogenicity index of the lipid spectrum (r=0.40) and was inversely correlated with the level of high-density lipoproteins (HDL) (r=-0.58) in children with MUO phenotype, p&lt;0.05. Conclusions. The G allele SNV rs754635 of the CCK gene is associated with obesity and the development of metabolic disorders. The research was carried out in accordance with the principles of the Declaration of Helsinki. The research protocol was approved by the Local Ethics Committee of the institution mentioned in the work. Informed consent of parents or their guardians was obtained for conducting research. No conflict of interests was declared by the author.

B-023 Optimizing Measurement of Homocysteine in an Emergency Care Pathway

Abstract Background/Context New indications for homocysteine measurement have emerged in recent years, and homocysteine is now being used as a marker of nutritional deficiency as well as a marker of nitrous oxide intoxication and there is a need to return quickly results to adapt the treatment and orientate diagnosis. Current rapid methods are not adapted to extremely high values encountered which are frequently greater than 50 µmol/L that need use of mass spectrometry that is unfortunately not adapt to emergency. Hence, we evaluated here a new immunological method that allows for the reliable and rapid rendering of homocysteine results in order to integrate it into our care pathways. Method We prospectively measured plasma homocysteine using both liquid chromatography-mass spectrometry (UPCL—Sciex AP 3200) and the Chemiluminescence Immunoassay (CLIA) method (Maglumi-Snibe). To limit the bias for each assay, the analyses were performed on the same EDTA plasma sample with the same pre-analytical treatment. Bland-Altman plots and Deming regression were used to assess agreement between the homocysteine LC-MS/MS method and homocysteine CLIA method. Results Our study included 169 paired samples. The intra- and inter-assay imprecision was comprised between 0.73–2.21% and between 2.75–3.73%, respectively. Linearity, without sample dilution, was acceptable in the range of 5–70 mol/L. This CLIA assay correlated with the HCY LC-MS/MS assay with a slope of 0.9334, intercept of 1.750, R2 = 0.9637 and average bias of −0.6867 μmol/L. Discussion The CLIA method produces results comparable to mass spectrometry while significantly reducing analysis time and result delay. This method is thus more appropriate when homocysteine is used not only for emergency diagnosis but also for nutritional monitoring of the patient. This method also allows for the measurement of extremely high concentrations, which are becoming more common in laboratories.

The Role of Matrix Metalloproteinase 13 and Vitamin D in Osteoarthritis: A Hospital-Based Observational Study.

Introduction Osteoarthritis (OA) is the most common form of degenerative joint disease characterized by the progressive degeneration of articular cartilage, osteophyte formation, and joint space narrowing. Matrix metalloproteinases (MMPs) are potential biomarkers for osteoarthritis. Aims and objective The study's aim is the estimation of serum and synovial fluid matrix metalloproteinase (MMP) 13 and serum vitamin D levels in the grade 3 and grade 4 stages of osteoarthritis according to the Kellgren and Lawrence (KL) system of classification. Materials and methods A total of 100 subjects were included; of them, 25 patients with grade 3 and 25 patients with grade 4 knee osteoarthritis diagnosed clinically and radiologically according to the Kellgren and Lawrence criteria have been enrolled in the study, and 50 patients with knee pain having a diagnosis other than degenerative OA of the knee were taken as controls. Venous blood and synovial fluid have been collected from all of them for the estimation of MMP-13 and vitamin D. The enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) methods were used for the estimation of MMP-13 and vitamin D, respectively. Results The mean value of synovial fluid MMP-13 was found to be elevated in grade 4 as compared to grade 3 and the control group, whereas the mean value of serum MMP-13 was found to be elevated in grade 3 as compared to grade 4 and control. The level of serum vitamin D was found deficient in OA patients as compared to control. The Kruskal-Wallis test was performed to compare these groups, and there was a significant difference between these groups(p-value of <0.05). Summary and conclusion High synovial and serum MMP-13 is associated with knee structural abnormalities in patients with knee OA as compared to the control groupsuggesting that MMP-13 can be a biomarker in knee OA, whereas the decreased level of vitamin D may be associated with an increased risk for the progression of OA; hence, serum vitamin D may be a good indicator for the prediction of the initiation of OA.

Impact of anti-squamous cell carcinoma antigen antibodies on serum squamous cell carcinoma antigen levels measured by chemiluminescent immunoassay and chemiluminescent enzyme immunoassay.

The serum squamous cell carcinoma antigen (SCCA) level is a well-known tumor marker for squamous cell carcinoma. In this study, we examined the impact of immunoglobulin (Ig)-bound macromolecular SCCA on serum SCCA levels measured by 2 different methods. Seventy-five serum samples with an SCCA level >5.0 ng/mL as determined by a chemiluminescent immunoassay (CLIA) were also analyzed using a chemiluminescent enzyme immunoassay (CLEIA). The levels of IgG- and IgA-type anti-SCCA antibodies, which form immunoglobulins and macromolecules, respectively, were determined using an enzyme-linked immunosorbent assay. An absorption test was performed to confirm the presence of anti-SCCA antibodies. The correlation coefficient between the values measured by CLEIA and CLIA was 0.768. The ratio of SCCA levels measured by CLEIA to those measured by CLIA in 14 samples with IgG-type anti-SCCA antibodies was significantly lower than that in samples without these antibodies (P < .031). Absorption tests showed that SCCA levels measured by CLIA might be falsely high in samples with IgG-type anti-SCCA antibodies, probably due to reactions with SCCA1. The level of SCCA as measured by CLIA and CLEIA methods correlate well, but the presence of SCCA antibodies can affect the results of the CLIA method.

Analytical Performance of a Novel Latex Turbidimetric Immunoassay, "Nanopia TARC", for TARC/CCL17 Measurement: A Retrospective Observational Study.

Thymus- and activation-regulated chemokine (TARC, also known as CCL17) is used as a biomarker for atopic dermatitis. The methods currently used for its measurement are complex, time-consuming, and require large machinery, warranting the need for a method that is simple, has a quick turnaround time, and requires less complex machinery. We evaluated the analytical performance of a novel latex turbidimetric immunoassay method, "Nanopia TARC", on 174 residual serum samples from patients with skin or allergic diseases. This evaluation included the assessment of the limit of blank/detection/quantification (LOB/D/Q), precision, accuracy, linearity, interference, and commutability between Nanopia TARC and "HISCL TARC", based on the chemiluminescent enzyme immunoassay (CLEIA) method. The LOB/D/Q values were 13, 57, and 141 pg/mL, respectively. The coefficient of variation of the repeatability was 0.9-3.8%, and that of the intermediate precision was 2.1-5.4%. The total error of the accuracy was 1.9-13.4%. The linearity was 141 and 19,804 pg/mL for TARC. The correlation coefficient between Nanopia TARC and HISCL TARC determined using the Passing-Bablok regression analysis was 0.999. Furthermore, the concordance of diagnostic criteria with AD was 92%. Nanopia TARC was confirmed to have the same analytical performance for TARC measurement as the existing CLEIA method.

Determination of 25 hydroxyvitamin D reference ranges in Hatay region by indirect method

Objective: The aim of this study is to determine the reference ranges of 25 hydroxyvitamin D (25(OH)D) levels from the serum 25(OH)D results of the patients and to investigate variations across age and gender groups.&#x0D; &#x0D; Methods: The patients (n=26829) who applied to Hatay Mustafa Kemal University Hospital between January 2018 and December 2019 and whose 25(OH)D levels were studied were included in this retrospective study. Serum 25(OH)D levels were studied by the chemiluminescence immunoassay method. The hospital information management system was used to obtain the test results and patient data. The indirect method was used to determine the reference ranges.&#x0D; &#x0D; Results: The prevalence of 25(OH)D deficiency in the patients participating in this study was 60.9% in the general population, 54.9% in men, and 67.5% in women. It has been observed that 25(OH)D deficiency is more common in women than in men. The reference ranges determined in this study were lower than the reference ranges provided by the manufacturer.&#x0D; &#x0D; Conclusion: In this study, 25(OH)D levels and reference ranges of Hatay Region were determined in a very large population. It can be said that the results of our region will contribute to the studies to be carried out on the determination of 25(OH)D levels and reference ranges throughout the country.

Impact of frequency and duration of freeze-dried inactivated tissue culture hepatitis A vaccine (Aimmugen®) vaccination on antibody titers; a japanese cross-sectional study

BackgroundThe effect of the timing of additional doses and the long-term persistence of lyophilized inactivated tissue culture hepatitis A (HA) vaccine (Aimmugen®) on antibodies is unknown. MethodsA single-center, cross-sectional, observational study was conducted in collaboration with the Japan Air Self-Defense Force, whose personnel were immunized with Aimmugen® when deployed to endemic areas. Patients who consented to this study after a medical examination with blood sampling between June 2022 and February 2023 were included; HA-IgG level in the residual serum was measured using the chemiluminescent immunoassay method. The exact vaccination history was investigated based on immunization records maintained by the Ministry of Defense, and a questionnaire was used to collect confounding factors. ResultsOf the 181 participants observed, 49 were in the unvaccinated group, and 132 were in the vaccinated group. Out of the vaccinated group, 6.8 % received either one or two doses, 40.9 % received three doses, and 52.3 % received more than four doses. IgG antibody titers (S/CO value) in each group (0, 1 or 2, 3, and over 4) increased in a frequency-dependent manner, with those vaccinated over four times showing significantly higher IgG antibody titers than all other groups (0.19 ± 0.10 vs 3.66 ± 3.00 vs 7.63 ± 3.57 vs 10.57 ± 1.86, respectively). When the number of months elapsed from the last vaccination to the date of blood collection in each group was plotted against IgG antibody titer, the slope of the regression line flattened out from a decreasing trend in the order 1 or 2, 3, over 4. ConclusionsThree doses of Aimmugen® are efficacious, but four or more doses induce more robust and sustained antibody production. Additionally, four or more doses may be effective when there is a need to ensure long-term immunity or risk of prolonged exposure.

Higher pro-inflammatory cytokines IL-6 and IFN-γ are associated with anti-SARS-CoV-2 spike protein-specific seroconversion in renal allograft recipients.

Maintenance immunosuppressive regimensare speculated to hamper immunogenic response against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) in renal transplant recipients (RTRs) compared to the healthy population. Healthy people with SARS-CoV-2 infection often develop neutralizing antibodies and secret copious quantities of cytokines, leading to virus clearance and sometimes more severe immune-related complications. RTRs, either acquired SARS-CoV-2 infection (infection group, n=132) or were vaccinated with two vaccine doses (vaccination group, n=78) against SARS-CoV-2, were recruited in the study. Thirty-five unvaccinated RTRs, without anti-SARS-CoV-2 spike protein-specific antibodies, were also included as control. Cytokines interleukine-6 (IL-6), interferon-γ (IFN-γ), TGF-β, and IL-10 were measured using ELISA. The SARS-CoV-2 spike protein-specific IgG-titer was measured by chemiluminescent microparticle immunoassay methods. The seroconversion rate in the infection group was 115/132 (87.12%), with a median antibody titer 706.40au/mL (IQR, 215.45-1844.42), and in the vaccination group was 63/78 (80.76%) with antibody titer 1454.20au/mL (IQR, 80.52-3838.75). The IL-6, IFN-γ, TGF-β, and IL-10 levels were significantly higher in both the infection and vaccination group compared to healthy control. In the infection group, pro-inflammatory cytokines IL-6 (55.41±24.30 vs. 31.64±16.98pg/mL, p<.001) and IFN-γ (91.21±33.09 vs. 61.69±33.28pg/mL, p=.001) were significantly higher in the seroconverter group as compared to non-seroconverter. Similarly, in the vaccination group, pro-inflammatory cytokines IL-6 (50.31±25.67 vs. 30.00±11.19pg/mL; p=.002) and IFN-γ (65.70±39.78 vs. 32.14±17.48pg/mL; p=.001) were significantly higher in the seroconverter group compared to non-seroconverter. In contrast, TGF-β (820.96±415.78 vs. 1045.57±204.66; p=.046) was higher in non-seroconverter. Pro-inflammatory cytokines IL-6 and IFN-γ were significantly associated with seroconversion after SARS-CoV-2 infection and vaccination in RTRs.