Immunoassay Research Articles

BackgroundPepsinogen (PG) and gastrin-17 (G-17) are widely used in the screening of gastric diseases. Our cross-sectional clinical study investigates the relationship between Helicobacter pylori (HP) infection, sex, and age on serum levels of PG and G-17 in asymptomatic subjects in Rizhao, China.MethodsA total of 12,746 asymptomatic subjects were enrolled in the study between August 2023 and January 2024. Serum levels of pepsinogen I (PGI), pepsinogen II (PGII), and G-17 were measured using the chemiluminescent microparticle immunoassay method, and the PGI/PGII ratio (PGR) was calculated. HP infection was detected using the Colloidal Gold Method, and the relationship between age, sex, HP infection, and serum PG and G-17 levels was analyzed.ResultsHP prevalence was 19.33% in this study. The serum PGI, PGII, and G-17 levels were significantly higher in the HP-positive group compared to the HP-negative group (P < 0.001), whereas the PGR was notably lower in the HP-positive group (P < 0.001). Spearman correlation tests analysis indicated a positive correlation between HP infection and PGI, PGII, and G-17 (r = 0.144, P < 0.001; r = 0.418, P < 0.001; r = 0.268, P < 0.001), and a negative correlation with PGR (r = −0.438, P < 0.001). ROC curve shows that the AUC of the combination of PGI, PGII, PGR, and G-17 in diagnosing HP positive were 0.605 (95% CI: 0.592–0.618), 0.805 (95% CI: 0.795–0.816), 0.820 (95% CI: 0.811–0.830), and 0.709 (95% CI: 0.698–0.720), respectively. The detection rates of abnormal PG and G-17 levels were significantly higher in the HP-positive group than in the HP-negative group (P < 0.01). Males exhibited significantly higher levels of both PGI and PGII than females (P < 0.001). The G-17 levels were higher in males than females in the 50–59 age group (P < 0.05). Spearman correlation analysis revealed that serum levels of both PGI and PGII exhibited an increase with age. Serum PGI, PGII, and G-17 levels were positively correlated with age, although the relationship was weak (r = 0.228, P < 0.001; r = 0.246, P < 0.001; r = 0.042, P < 0.001). Following adjustment for sex and Helicobacter pylori infection covariates using a restricted cubic spline (RCS), the analysis revealed a significant overall association between PGI, PGII, PGR, and G-17 serum levels and age (P for overall < 0.001, P for overall < 0.001, P for overall = 0.003, and P for overall < 0.001, respectively). Furthermore, a nonlinear relationship was found between PGI, PGR, and G-17 levels and age (nonlinear P = 0.004, nonlinear P = 0.001, and nonlinear P = 0.008, respectively), whereas PGII exhibited a linear correlation (nonlinear P = 0.841).ConclusionSerum levels of PG and G-17 are associated with HP infection, sex, and age. These findings provide region-specific insights into the relationships between these biomarkers and HP infection, highlighting the importance of considering HP infection status, sex, and age in future research.

Given its narrow therapeutic index and risk of nephrotoxicity, vancomycin requires accurate concentration monitoring. While immunoassays such as the Kinetic Interaction of Microparticles in Solution (KIMS) are widely used for their speed and simplicity, they are susceptible to interference by paraproteins such as monoclonal immunoglobulins. Here, we present the first case of falsely elevated vancomycin concentrations measured by KIMS due to monoclonal IgM interference, indicated by a ‘kinetic flag’ error, and evaluated pre-analytical approaches to mitigate this interference. We applied three pre-analytical techniques to overcome this issue: dithiothreitol (DTT) treatment to reduce disulfide bonds in IgM, ultrafiltration with a 100-kDa cutoff to physically remove IgM molecules, and heterophilic blocking tubes (HBT) to neutralize nonspecific binding by heterophilic antibodies. Vancomycin concentrations were measured using both KIMS (Cobas c702, Roche Diagnostics) and Chemiluminescent Microparticle Immunoassay (CMIA, Architect i2000SR, Abbott Laboratories). In pre-vancomycin-dose samples, both DTT treatment and ultrafiltration resolved the ‘kinetic flag’ error and corrected vancomycin concentrations to below the lower limit of quantification (LLOQ). In post-vancomycin-dose samples, DTT reduced vancomycin concentration to 16.82 μg/mL (93.8% of the naïve concentration), while ultrafiltration reduced it to 9.22 μg/mL (51.4%). HBT treatment did not resolve the error, and falsely elevated results persisted. This study reports the first case of IgM paraprotein interfering with vancomycin measurement by KIMS, underlining the importance of recognizing monoclonal IgM as a potential source of interference. DTT treatment effectively corrected the interference, while ultrafiltration reduced vancomycin concentration, highlighting the need for careful interpretation.

BackgroundThis study aimed to investigate serum CXC motif chemokine ligand 8 (CXCL-8) as a potential biomarker for diagnosing esophageal cancer (EC).MethodsPatients diagnosed with EC (n = 141) were enrolled at the Department of Thoracic Surgery, Fujian Medical University Union Hospital, from July through December 2023. Sixty cases were early esophageal cancer (EEC), whereas 81 were advanced (AEC) based on diagnostic criteria. Healthy volunteers (n = 75) were recruited as controls. Serum CXCL-8 levels were quantified using an enzyme-linked immunosorbent assay. Levels of carcinoembryonic antigen (CEA), cytokeratin 19 fragment (Cyfra211), and squamous cell carcinoma antigen (SCC) were assessed using a chemiluminescent microparticle immunoassay. Clinical and pathological attributes of patients with EC were documented and analyzed. Diagnostic efficacies of CXCL-8, CEA, Cyfra211, and SCC for EC were evaluated using receiver operating characteristic (ROC) curves.ResultsSerum concentrations of CXCL-8, CEA, Cyfra211, and SCC were significantly higher in patients with EC than in controls (P < 0.05). In the EC group, areas under the curves (AUCs) for CXCL-8, CEA, Cyfra211, and SCC were 0.906, 0.707, 0.705, and 0.797, respectively. The combined application of CXCL-8+CEA, CXCL-8+Cyfra211, and CXCL-8+SCC yielded AUCs of 0.931, 0.940, and 0.950, respectively, and was significantly higher than that of the combination of CEA+Cyfra211+SCC (0.854). In EEC, the diagnostic performance of CXCL-8 was similar to that in the EC group. The sensitivity of CXCL-8 was greater than that of CEA, Cyfra211, and SCC alone, and the combination of the three markers (P < 0.05).ConclusionsCXCL-8 could be used to distinguish patients with EC from healthy controls, including EEC.

Disclosure: A.J. Newman: None. S. Mahrokhian: None. J. Chan: None. I. Hanna: None. A. Ferrebus: None. J.M. Brown: None. R.J. Auchus: None. A. Vaidya: None.Background: Accurate and specific assays for serum cortisol are essential to the clinical endocrinologist. However, the availability of cortisol assays varies across laboratories. We evaluated the correlation of serum cortisol measurements by liquid chromatography tandem mass spectroscopy (LC-MS/MS) with a modern cortisol immunoassay (IA) across the physiologic range of cortisol production in healthy participants. Methods: Healthy adults (n=97), without known or suspected cortisol excess or insufficiency, and who were not taking glucocorticoid medications, were prospectively recruited to undergo measurement of morning serum cortisol, post-overnight dexamethasone (1 mg) suppression testing (DST), and a 250 mcg cosyntropin stimulation (CST). Serum cortisol was measured by LC-MS/MS and with the Beckman-Coulter Access cortisol polyclonal IA. Inter-assay cortisol concentrations were evaluated using correlation analyses and Bland-Altman plots. Results: Median random morning cortisol by IA was 8.5 mcg/dL (IQR 6.8-11.5) and by LC-MS/MS was 8.7 mcg/dL (7.0-11.7). After 1 mg DST, median cortisol by IA was 0.8 mcg/dL (0.6-1.1) and by LC-MS/MS was 0.8 mcg/dL (0.6-1.2). Following CST, median cortisol by IA was 19.8 mcg/dL (17.4 - 22.1) and by LC-MS/MS was 20.9 mcg/dL (17.8-24.0). The correlation between LC-MS/MS and IA serum cortisol concentrations across the entire range was strong (r = 0.95, P < 0.001). In the range relevant to the evaluation for adrenal insufficiency, where cortisol < 5 mcg/dL, measured values were highly correlated (r = 0.77, P < 0.001). Similarly, in the range of values typically used to adjudicate a normal hypothalamic-pituitary-adrenal axis (10 - 20 mcg/dL), values were again highly correlated (r = 0.76, P < 0.001). CONCLUSIONS: Cortisol measured by the widely used Access immunoassay was highly correlated with the gold standard of LC-MS/MS across the physiologic range of cortisol production, including morning values, post-dexamethasone suppressed values, and post-cosyntropin stimulated values. These findings provide reassurance that the use of this specific Access IA serves as a reliable surrogate for the gold standard LC-MS/MS when evaluating cortisol across the spectrum of adrenal function.Presentation: Monday, July 14, 2025

Disclosure: O. Sergeyev: None. V. Bezuglov: None. N. Soloveva: None. V. Shtratnikova: None. N. Vavilov: None. A. Zubritskiy: None. M.M. Lee: None. V. Ashapkin: None. V. Zgoda: None. J. Pilsner: None. A. Suvorov: None.Objectives. Recently, we reported the intra-individual variability of molecular markers in repeated ejaculates among healthy young men (Sergeyev et al, 2024). We now comprehensively investigate the association of reproductive hormones in seminal plasma (SP) with semen quality, proteome and small non-coding RNA (sncRNA) profiles in the different components of the same set of ejaculates. Methods. Subsets of 85 ejaculate samples were randomly selected from 443 collected ejaculates by 18-19-year-old participants of the Russian Children’s Study (RCS) prospective cohort for basic semen analysis and reproductive hormone measurements (testosterone (T), estradiol (E2), LH, FSH, DHEAS, prolactin (P)) in SP (Architect i1000SR and chemiluminescent microparticle immunoassay). Intra-assay coefficient of variation for all 6 hormones ranged 0.75-4.9%. In a subset of 10 samples, label-free quantitation (LFQ) and targeted isotope labeling-based quantitation (TILBQ) of 10 proteins in SP and seminal extracellular vesicles (EV), and RNA-seq of sncRNA in EVs and sperm were performed. Data was analyzed by univariate and multivariate linear regression. Results. Median (25-75%) values for total motile sperm were 80.5 (36.9-614) 106/ejaculate and for hormones were T 0.95 (0.68-1.29) nmol/L; E2 118 (97.5-136) pg/mL; LH 0.06 (0.05-0.09) iu/L; FSH 0.25 (0.16-0.51) iu/L; DHEAS 100.7 (52.5-147.2) ug/dL; and P 7.3 (5.5-9.0) ng/mL. Using strict quantification criteria, we identified 420 and 979 proteins by LFQ in SP and EV, respectively; 256 microRNA (miRNA), 62 piwi-interacting RNA (piRNA), 159 mature tRNA, and 77 tRNA-derived small RNA (tsRNA) by RNA-seq in EV and 104 miRNA, 230 piRNA, 136 mature tRNA, and 13 tsRNA in sperm samples. The following significant (p<0.05) positive associations were identified using TILBQ data: E2 with LAMP2, LAMA5, ALDOA, KLK3, RL7 and FAS, and DHEAS with LAMP2 in EV; P and DHEAS with PPAP, P with LAMA5, and DHEAS with LAMP2 in SP. Based on LFQ in SP, T was positively and E2 was negatively associated with 47 and 7 proteins, respectively (p<0.001). Based on LFQ in EV, T, E2 and DHEAS were associated with 15, 9 and 12 proteins, respectively (p<0.001). P was also positively associated with 25 sncRNA in EV (p<0.001). In multivariate models adjusted for BMI and abstinence time, higher P, T and DHEAS in SP were associated with higher total motile sperm, b-estimate (p-value) 10.5 (0.0008), 28.2 (0.04) and 0.34 (0.049), respectively. Conclusions. Our study establishes associations with seminal plasma reproductive hormones, semen quality and molecular biomarkers that might have diagnostic utility in the evaluation of male fertility. Funding. Russian Foundation for Basic Research (RFBR) #20-015-00458 - proteome; Russian Science Foundation (RSF), #18-15-00202 - sncRNA; and the National Institute of Environmental Health Sciences (NIEHS), USA, #R01 ES014370 - parent RCS.Presentation: Saturday, July 12, 2025

BackgroundFrontline healthcare workers (HCWs) faced a high risk of SARS-CoV-2 infection during the early stages of the COVID-19 pandemic. This study aims to determine the prevalence and incidence of SARS-CoV-2 infection in HCWs using various serological methods and to evaluate diagnostic reliability.MethodsA prospective study was conducted on 240 frontline and 120 non-frontline HCWs at Siriraj Hospital in Bangkok, Thailand, from May 2020 to March 2021. Blood samples were collected at enrollment and at 4, 12 and 48 weeks. Three serological methods were utilized: electrochemiluminescence immunoassay (ECLIA) for qualitative anti-nucleocapsid protein antibodies, enzyme-linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA) for quantitative anti-spike receptor-binding domain (RBD) antibodies. ELISA-positive samples were further analyzed with microneutralization and flow cytometry-based assays.ResultsOne non-frontline HCW had initial positive ECLIA result but tested negative by both ELISA and CMIA. Two frontline HCWs consistently tested positive by ELISA over these 48 weeks, resulting in a seroprevalence of 0.83% (2/240) among frontline HCWs. Ten frontline and six non-frontline HCWs had borderline or positive level of anti-RBD IgG by ELISA but were negative for microneutralization. A flow cytometry-based assay suggested that these positive ELISA results were likely due to cross-reactivity from pre-existing antibodies against other human coronaviruses (HCoVs), particularly HCoV-HKU1.ConclusionsAn extremely low prevalence of SARS-CoV-2 infection among HCWs in Thailand at the pandemic’s outset, likely due to effective transmission control. Pre-existing antibodies against other human coronaviruses could lead to false positive serological testing for SARS-CoV-2.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12985-025-02960-y.

Background: Despite the widespread implementation of Hepatitis B vaccination, some children fail to develop protective immunity. Thus, identifying markers for vaccine unresponsiveness is crucial for optimizing current strategies. As interleukin-12 (IL-12), a central cytokine in Th 1 immune activation, has shown potential as a predictive biomarker, the aim of this study was to determine its role in the Hepatitis B vaccine response, highlighting novel findings regarding the threshold level of IL-12 in the pediatric population in doing so. Methods: A cross-sectional study was conducted on a community in Bandung City. The subjects were 7–12-month-old babies who had completed primary Hepatitis B vaccination (0, 2, 3, and 4 months of age). Blood tests for anti-HB examination were performed with a Chemiluminescent Microparticle Immunoassay (CMIA) to determine the response and non-response groups, and an Enzyme Immunosorbent Assay (ELISA) was used for IL-12 detection. Data were analyzed using the Kruskal–Wallis test, Chi-square test, Spearman Correlation, and Receiver Operating Characteristics. Statistical analysis was conducted with SPSS version 18.0. Results: The results of this study indicate that 4.5% of the subjects were unresponsive to the Hepatitis B vaccine. The most important finding was a significant correlation between IL-12 and the presence of anti-HB titers in the responsive and non-responsive groups (p = 0.016). The Receiver Operating Characteristics (ROC) curve for IL-12 identified a cut-off point of ≥10.65 pg/mL (>100 mIU/mL in anti-HBs), with a sensitivity of 64.23%, specificity of 68.75%, and accuracy of 65.2%. Conclusions: Interleukin-12 can be considered as an early candidate biomarker for responsiveness to the Hepatitis B vaccine in children.

Understanding the reproductive biology of giant pandas is crucial for their breeding success and conservation. Pregnancy monitoring, however, is challenging due to delayed implantation and obligatory pseudopregnancy, which limits the effectiveness of traditional immunoassays (IA). To remedy this, we combined polar metabolomics and steroidomics to enable a comprehensive view of the urinary molecular composition across six different reproductive phases spanning six pregnant and seven pseudopregnant cycles. Statistical comparisons revealed 696 discriminative features, including 174 features in the early luteal stages, well before the current pregnancy diagnostic window. Pregnant and pseudopregnant cycles showed differences in amino acid, energy, and steroid metabolism before and after CL reactivation, with androgen levels being significantly elevated in pregnant females specifically, suggesting a role in embryo implantation. Interestingly, we detected only one existing IA target metabolite, but identified other discriminative metabolites that may underlie IA signal detection. Finally, we demonstrated that classification models comprising biomarker panels may improve (early) pregnancy diagnosis with accuracies ranging from 0.763 to 1.000 across reproductive phases. These findings offer possibilities for assigning new biomarkers and optimizing IA target selection, thereby enhancing pregnancy monitoring sensitivity and reliability while improving our understanding of giant panda reproductive biology to support conservation efforts.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19067-7.

Abstract Background Hemoglobin A1c is used to assess glycemic control to both diagnose and monitor diabetes mellitus. Several different methodologies are available including high performance liquid chromatography (HPLC), capillary electrophoresis (CE), and immunoassay (IA). These methods are standardized and traceable to the Diabetes Control and Complications Trial (DCCT). The aim of this study was to evaluate the difference in HbA1c results between methods and percent of reportable results in variant samples. Methods The HPLC (Bio-Rad Laboratories, Inc; D-100), the CE(Sebia Inc; Capillarys 3), and IA(Roche Diagnostics Inc; Tina-quant Generation 3) were compared using two sets of residual patient samples left after physician ordered testing was complete: 1) samples with an absence of abnormal hemoglobin peaks (i.e. non-variant) detected by HPLC; 2) samples with abnormal hemoglobin peaks (i.e. variant) characterized by hemoglobin electrophoresis performed clinically or lacking an A1c peak by HPLC/CE. The samples were tested within manufacturers stability claims. 317 non-variant samples were compared between the HPLC and CE methods. The absolute difference was calculated for each method using this equation (HbA1c%avg – HbA1c%X) where HbA1c%avg is the average of the methods that produced reportable results and X is the result from each method evaluated. Differences less than or equal to +/-0.3% were considered acceptable. 28 of the 317 non-variant and 47 variant samples were tested by all 3 methodologies. The 47 variant samples grouped into 3 cohorts: common heterozygous variants (HbC, HbD, HbE, HbS and HbF, n=10), uncommon heterozygous variants (n=29) and homozygous variants lacking HbA (n=8). The absolute differences in variant sample results were calculated for samples that did not surpass manufacturer’s claims for producing an accurate result. The frequency of producing a numeric result in variant samples was calculated for each method. Results The HPLC/CE non-variant sample comparison (N=317) had results spanning the measuring range (3.8% - 14.0%) with average(range) of absolute difference=0.1(-0.4to0.6%) with 293/317(92.4%) samples within +/-0.3%. The HPLC/CE/IA non-variant sample comparison (N=28) had a result range=4.0%-9.4%, the average(range) of difference=0.1(-0.2to0.5%) with 25/28 (89.2%) of samples within +/-0.3%. Common heterozygous variant samples gave numeric results with no disqualifying flags in 9 of 10(HPLC), 8 of 10(CE), and 9 of 10(IA) samples tested. The average(range) difference from average=0.0(-0.3,0.5%) for HPLC, 0.0(-0.2,0.3%) for CE, and -0.1(-0.6,0.2%) for IA. Uncommon variant samples gave results in 4 of 29 (HPLC), 20 of 29 (CE), and 26 of 29 (IA) of samples tested. The average(range) difference from average=-0.1(-0.3,0.1%) for HPLC, 0.0(-1.0,1.1%) for CE, and 0.0(-1.1,1.0%) for IA. The homozygous variant (no HbA) samples gave results in 0 of 8 (HPLC), 0 of 8 (CE), and 4 of 8 (IA) of those tested. Conclusion All three methods meet their claims for accurately measuring hemoglobin A1c from non-variant and common hemoglobin variants. The advantage of HPLC and CE is the ability to identify hemoglobin variants that may impact HbA1c quantitation. The IA method provides the most numeric results. IA gave results even when HbA was absent. The lab should understand the capabilities and limitations of their HbA1c method on the population served.

Abstract Background Early screening potential sepsis is the key points for clinician to implement the promptly medical treatment. In this study, we aimed to evaluate the diagnostic and prognostic value of Presepsin, HE4, OI (Oxygenation index, PaO2/FiO2), and combined indicator (Presepsin+HE4+OI, PHO) in patients with sepsis in the ICU. Methods A total of 411 patients were enrolled (165 Non-sepsis and 246 sepsis) in the ICU of the First Affiliated Hospital of Sun Yat-Sen University (Guangzhou, China) from May 2021 to May 2022. Clinical data, laboratory indicators, and blood samples were collected at admission of hospitalization. Presepsin and HE4 were measured by chemiluminescent microparticle immunoassay. ROC curve analysis and Spearman*s correlation were used to evaluate the value of Presepsin, HE4, OI and PHO in the diagnosis and prognosis of sepsis. Results The levels of Presepsin, HE4 and OI in sepsis group were significantly higher than those in non-sepsis group (all P&amp;lt;0.05), and the levels of Presepsin, HE4 and OI were positively correlated with 30-day mortality in sepsis patients. For the diagnosis of sepsis, the AUCs of Presepsin, HE4 and combined indicator PHO were higher than that of other laboratory infection indicators, and the AUC of combined indicator PHO was higher than that of Presepsin, HE4, OI alone. For the prognosis of sepsis, ROC curve analysis showed that the AUC of Presepsin, HE4, OI and combined indicator PHO were 0.652 (95% CI: 0.586-0.725), 0.657 (95% CI: 0.587-0.726), 0.649 (95% CI: 0.583-0.720), and 0.706 (95% CI: 0.641-0.772), respectively. Conclusion For sepsis patients, Presepsin, HE4 and OI all have high diagnostic and prognostic value, and the combined indicator PHO outperforms the single index in diagnostic and prognostic performance.

Abstract Background CMV or cytomegalovirus infections are very common in most countries worldwide. The danger arises in pregnancy if mothers do not have pre-existing IgG antibodies for the virus, as acute infections or re-activation of the virus are harmful to the fetus. Depending on clinical symptoms, pregnant mothers may be screened for the presence of anti-CMV IgG. Methods The Alinity i CMV IgG assay is a chemiluminescent microparticle immunoassay (CMIA) and awas compared to the FDA-cleared Liason CMV IgG assay on a cohort of 153 specimens. Discrepancies between the assays were further tested for Avidity and CMV IgM. Results Correlation between the Alinity and the Liason CMV IgG methods showed an r of 0.91, Concordance as measured was excellent with a Kappa of 0.96 (0.92 to 1.00). Of the 153 specimens tested, 74 were positives, 76 negatives by both methods. 3 specimens were discrepant between the methods: 1 Liason low positive and Alinity non-reactive, 1 Liason negative and Alinity Grayzone, and 1 Liason negative and Alinity reactive. The discrepant reflex testing indicated that the specimen showing grayzone /negative results was also IgM positive (therefore and acute infection) and the specimen showing positive Alinity/ negative Liaison results was negative for IgM and a high avidity specimen. Conclusion The Alinity I and the Liaison CMV IgG assays demonstrated excellent concordance and correlation.

Abstract Background It is known that Immunoassays (IA) used in diagnostic laboratories are prone to interfere with antibodies of any classes present in the serum of the patients (IgA, IgG, IgM or IgE). Interferences can give either false positive or false negative results depending on the interaction with the IA. In Multiple Myeloma Disease patients (MMP), Vitamin D (VitD) measurement is recommended in phosphocalcium metabolism alterations. High concentrations of paraproteins in the serum of these patients could analytically affect the results. Objectives 1)To Evaluate the presence of interference in VitD Measurement in MMP compared to a control group. 2)To look for an association between Ig concentration, type of this and percentage (%) of post-treatment decrease VitD levels. Methods Cross-sectional and prospective study. VitD levels were measured by Chemiluminescence (Alinity-Abbott) in 48 samples: 26 MMP without VitD supplementation but positive Igs processed by Nephelometry (Beckman), 22 controls without MMP or any other autoimmune disease. VitD concentration was measured directly (DC) and after precipitation samples with PEG 25%(EC) in equal proportions to investigate the presence of interferences. A decrease % was calculated between DC and EC. Results In 11/26 (42%) samples from MMP a decrease in EC compared to DC of more than 30% was observed, maximum % value obtained in control patients (Graph). No association was observed between Ig concentration (G;M or A), type of paraproteins (?,?,?/?) and the % decrease. Conclusion Samples from MMP showed a decrease % in VitD measurement, signalling that presence of Igs could interfere for its dosage. Control patients did not exceed 30% decrease. According to our results, we suggest in MMP the systematic search of interference in VitD dosages using this methodology. in order to provide an evaluation compatible with the clinic from the laboratory.

Abstract Background Sepsis and its complications are one of the leading causes of mortality. Timely diagnosis and treatment are highly important in reducing morbidity and mortality. Serum biomarkers may aid in the early diagnosis of sepsis and therapeutic intervention. Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin, and its primary trigger is infection. Increased serum PCT is associated with bacterial endotoxin and inflammatory cytokines. Therefore, PCT is widely used as a biomarker for bacterial infection and sepsis. Clinically, PCT greater than 2 ng/mL is associated with high risk of sepsis, and PCT less than 0.5 ng/mL is associated with low risk. We aimed to investigate the correlation between PCT and blood culture in the early diagnosis of sepsis in an unselected population with suspected bloodstream infections and evaluated the interpretative criteria helpful in diagnosis of systemic bacterial infection or sepsis. Methods We retrospectively analyzed medical records of 127 patients (72 (56.7%) males and 55 (43.3%) females) aged (X±SD(69.2±20.4) range (4-100 years) from different hospital departments who visited Dr. Sulaiman Alhabib Group of Hospitals (HMG) in Riyadh from January 2021 to December 2022. with suspected bloodstream infections who had PCT data and blood culture results. PCT was quantitatively determined by the BRAHMS PCT assay on the Abbott Allinity I System, which is a two-step chemiluminescent microparticle immunoassay (CMIA). Blood culture was done using BactAlert system (bioMérieux). Results Among study group blood culture was positive in 75 cases (59.1%) and negative in 52 cases (40.9), PCT was positive in 107 cases (84.3%) and negative in 20 cases (15.7%). Both tests were correlated (either positive or negative) in 71 cases (56%). PCT results were correlated to culture results (applying cutoff value 0.1 ng/ml) using Pearson Chi-Square test and results were insignificant (P value &amp;gt; 0.5). PCT found to have sensitivity of 84% (73.7% to 91.5%, 95% CI) and specificity of 15.4% (6.9 to 28.1%, 95% CI) To assess the significance of interpretative criteria, PCT results were classified into 3 groups (moderate risk for progression to sever sepsis (0.5-1.99 ng/ml), sever systematic response (2-9.99 ng/ml) and high likelihood of sever sepsis or septic shock (= 10ng/ml). One way ANOVA studies show Significant difference among the 3 subgroups of culture negative cases (F value =3.48, P= 0.38) and among culture positive cases (F value= 4.56, P= 0.14). However, the student T test shows insignificant results when each risk category was compared among culture positive and negative cases (p value of 0.73, 0.83, 0.75 respectively). Conclusion PCT elevated levels in study population may indicate sepsis (good screening assay with accepted sensitivity) but should be interpreted cautiously alongside with blood culture results. Further research is needed to establish the specificity of PCT. Test interpretative criteria may work as good predictor of inflammatory status rather than septic status

Obesity is a risk factor for vitamin D deficiency (VDD) with limited data on their association with Bangladeshi children. The aim of this study was to compare vitamin D levels and the status among obese, overweight and normal-weight children. This cross-sectional study was performed in the Obesity Clinic, Department of Endocrinology, Bangladesh Medical University hospital, Bangladesh from May 2020 to August 2021 and included 100 children of 10-17 years [age-matched 50 children with normal BMI, 22 with overweight and 28 with obesity: 14.0 (12.0-17.0) vs. 12.50 (10.0-16.25) vs. 12.50 (11.0-14.0), years, median (IQR), p=0.114] of both sexes (boys/girls: 49/51). Height and weight were measured to calculate body mass index (BMI) and plotted in the Centre for Disease Control chart to classify normal, overweight and obese with cut-offs of 85th and 95th BMI-percentile. Serum 25-hydroxy vitamin D[25(OH)D] was measured by chemiluminescent microparticle immunoassay. VDD (<20 ng/mL) and insufficiency (20-29.9ng/mL) were found in 92 and eight patients respectively with none having sufficiency (≥30 ng/ml). Among 92 patients with VDD, 61 (66.30%) had mild VDD (10-19.9 ng/mL) and 31 (33.70%) had moderate to severe VDD (<10 ng/mL). Vitamin D level and status were statistically similar across BMI-spectrum (NS for all). Vitamin D level did not significantly correlate with BMI (r=-0.026, p=0.798). Children with moderate to severe VDD had significantly higher percent of girls (67.7% vs. 44.3%, p=0.047), living in urban area (100.0% vs. 85.2%, p=0.026) with higher socio-economic status (61.3% vs. 32.8%, p=0.023) than those with mild VDD. In conclusion, despite high percentages of VDD, vitamin D had no association with BMI in children.

Retrospective analysis of Hepatitis B seroprevalence and vaccination coverage in South India: Bridging laboratory evidence with literature trends.

To evaluate trends in voluntary non-remunerated blood donors (VNRBD) versus replacement donors, and to investigate the prevalence of transfusion-transmitted infections (TTIs) among healthy blood donors in Malakand Division, Pakistan. Retrospective study. Place and Duration of the Study: Department of Health, Regional Blood Centre, Central Hospital Saidu Sharif, Swat, Pakistan, from 2021 to 2024. This study analysed trends in VNRBD and replacement donors, along with the seroprevalence of TTIs (HCV, HBV, HIV, and Syphilis) using automated chemiluminescent microparticle immunoassay (CMIA). The Chi-square test in R-Studio was conducted to analyse trends in blood donor categories and TTIs over the four years. A total of 94,716 healthy blood donors were screened during the study period. Male donors dominated both categories, with 80,105 (84.57%) in replacement and 14,526 (15.34%) in voluntary donations. Female participation remained minimal, with only 27 (0.03%) in replacement and 58 (0.06%) in voluntary donations. Most donors were in the age range of 18-33 years, totalling 71,107 (75.1%). Statistically significant changes (p <0.001) in voluntary and replacement donation trends were confirmed by the Chi-square test. A total of 2,292 (2.42%) TTIs were detected, including 873 (0.92%) cases of HCV, 637 (0.67%) cases of HBV, 220 (0.23%) cases of HIV, and 562 (0.59%) cases of syphilis. The study revealed a 2.42% TTIs prevalence among 94,716 donors, with male dominance (84.57%) and low female participation (0.03%). Syphilis and HIV cases increased in 2024 (p <0.001), highlighting the need for targeted blood donation campaigns and improved screening to reduce TTIs in Pakistan. Voluntary non-remunerated blood donation, Replacement blood donation, Transfusion-transmitted infections, HCV, HBV, HIV, Syphilis.

Background/Objectives: Hepatitis B virus (HBV) remains a persistent challenge for transfusion safety. Although testing for hepatitis B surface antigen (HBsAg) and nucleic acid testing (NAT) reduces transmission risk, antibodies to hepatitis B core antigen (anti-HBc) and antibodies to hepatitis B surface antigen (anti-HBs) provide additional insight into past infection and vaccine-induced immunity. We aimed to determine their seroprevalence among blood donors in southern Croatia and assess associations with age, occupation, and time since vaccination. Methods: This cross-sectional study was conducted between February and November 2024 at two regional transfusion centers in southern Croatia. A total of 1008 voluntary blood donors, all HBsAg- and NAT-negative, were tested for anti-HBc and anti-HBs using chemiluminescent microparticle immunoassay. Demographic and vaccination data were collected through verified medical records. Results: Anti-HBc was detected in 0.5% of donors, exclusively among the unvaccinated. Protective anti-HBs levels were found in 38.1% overall and 70.6% of vaccinated donors, with significant declines by age and more than 15 years post-vaccination (p = 0.024). Healthcare workers showed higher seroprotection than non-healthcare donors (67.0% vs. 35.1%; p < 0.001), although one-third still lacked protective levels. Conclusions: HBV exposure was rare, but waning vaccine-induced immunity was evident, with protective anti-HBs levels in 70.6% of vaccinated donors, declining with age and time since vaccination. These findings highlight the need for periodic monitoring of anti-HBs and targeted booster strategies, especially in older and occupationally exposed groups. HBsAg and NAT provide a high level of transfusion safety, while the role of routine anti-HBc testing in this low-endemic context should be carefully evaluated in view of its potential benefits and drawbacks. Donor-based surveillance is a valuable tool for evaluating long-term vaccine effectiveness and guiding public health policy.

Several assays have been used to monitor tacrolimus levels. Automated immunoassay systems are preferred routinely because of their simplicity and rapid turnaround times. However, variations in the measured results for the same sample by different assays necessitate the evaluation of various immunoassay systems for consistency. This study aimed to compare whole-blood tacrolimus concentrations measured using 2 different chemiluminescence analytical methods: chemiluminescent microparticle immunoassay (CMIA; Abbott Diagnostics) and chemiluminescent immunoassay (CLIA; Snibe Diagnostics). A total of 257 patients who had undergone kidney transplantation were included in this study. Whole-blood tacrolimus concentrations were measured using the MAGLUMI 800 analyzer and compared with the ARCHITECT i1000SR analyzer using correlation analysis and Bland-Altman plots. There was a strong correlation between tacrolimus concentrations measured using MAGLUMI and those measured using ARCHITECT (R = 0.916, P < .001). An intraclass correlation coefficient (ICC) value of 0.934 (CI = 0.915-0.949) indicated excellent reliability of the measurements. Comparison of samples with a routine ARCHITECT assay for tacrolimus showed a minimal bias of 0.385 ng/mL (95% CI = 4.46%-3.69%), but scattering analysis indicated that the method agreed when the tacrolimus levels were low but disagreed at high levels. Overall, the measured tacrolimus level in patient samples was higher by MAGLUMI than by ARCHITECT with a median difference of 0.17 ng/mL and a median percentage difference of 3.4% respectively. Snibe MAGLUMI is a reliable assay with excellent correlation, but a small positive bias against Abbott ARCHITECT in measuring whole-blood tacrolimus levels. This bias is most likely due to the cross-reactivity of the metabolites in the Snibe MAGLUMI platform.

Objective: To establish an optimal confirmation zone for initial hepatitis B surface antigen (HBsAg) results obtained via Chemiluminescence Microparticle Immunoassay (CMIA) on the Architect i1000SR platform, aiming to enhance diagnostic accuracy and reduce unnecessary confirmatory testing and associated costs. Methods: A retrospective-prospective mixed study was conducted on 231 serum samples analysed at the Centre Pasteur of Cameroon between April 2018 and December 2019. Initial results obtained using the Architect HBsAg Qualitative II assay were confirmed through the Architect HBsAg Confirmatory test. Samples encompassed a broad range of signal-to-cutoff (S/CO) ratios (0.9 –&gt; 500). Confirmation rates were analysed across intervals. Fisher’s exact test with Bonferroni correction was applied to assess statistical differences. Results: Of the 231 samples meeting inclusion criteria, 172 (74.5%; 95% CI: 68.3–79.9) were confirmed reactive, representing 74.8% of initially reactive samples (172/230). Confirmation rates were lowest in the 1.00–1.10 interval (9.1%) and the 1.10–10.00 interval (48.8%), both significantly lower than for samples above 200 S/CO (p &lt; 0.0001). All samples above 200 S/CO were confirmed positive. The highest unconfirmed S/CO value observed was 170.01, supporting the effectiveness of the defined confirmation range (S/CO 0.90–200). Conclusion: The optimal confirmation zone was defined as 0.90–200 S/CO. Confirmatory testing below this threshold is essential, while values &gt;200 can be considered definitively positive. Implementing this strategy can reduce costs, streamline workflow and turnaround times especially in resource-limited settings without compromising accuracy.

BackgroundThis study aims to assess the diagnostic value of the Epstein-Barr virus (EBV) BNLF2b antibody(P85-Ab), alone or in combination with VCA-IgA, Rta-IgG, and Zta-IgA antibodies, in the context of nasopharyngeal carcinoma (NPC).MethodsThe study included 100 NPC patients and 100 healthy controls. Chemiluminescent microparticle immunoassay was utilized to measure P85-Ab levels in the serum samples of both NPC patients and healthy controls. Additionally, the ELISA method was employed to detect serum levels of VCA-IgA, Rta-IgG, and Zta-IgA antibodies. The study analyzed the roles of serum P85-Ab in conjunction with VCA-IgA, Rta-IgG, and Zta-IgA antibodies in the diagnosis of NPC.ResultsSerum levels of P85-Ab, VCA-IgA, Rta-IgG, and Zta-IgA antibodies in NPC patients were significantly higher than those in the normal control group (P < 0.05). The area under the receiver operating characteristic curve (AUC) for individual diagnosis of NPC using serum P85-Ab, VCA-IgA, Rta-IgG, and Zta-IgA antibodies were 0.964, 0.916, 0.838, and 0.840, respectively. The AUC for the combined detection of the four markers in diagnosing NPC was 0.996, indicating the optimal diagnostic value of the combined detection.ConclusionThe combined detection of P85-Ab with VCA-IgA, Rta-IgG, and Zta-IgA antibodies demonstrates high diagnostic value for nasopharyngeal carcinoma. Serum P85-Ab may serve as a potential marker for the diagnosis of NPC.