Reactogenicity and Peak Anti-RBD-S1 IgG Concentrations in Individuals with No Prior COVID-19 Infection Vaccinated with Different SARS-CoV-2 Vaccines

OBJECTIVE

To investigate the association of immune response with vaccination adverse effects at peak anti-receptor-binding domain spike subunit 1 (anti-RBDS1) IgG after full vaccination with Comirnaty, Spikevax, or Vaxzevria.

METHODS

Anti-RBDS1 IgG concentrations after vaccination were determined in healthy adults vaccinated with the Comirnaty, Spikevax, and Vaxzevria vaccines. The association of reactogenicity and peak antibody response after vaccination was tested.

RESULTS

Anti-RBDS1 IgG values were significantly higher in the Comirnaty and Spikevax group, compared with the Vaxzevria group (P < .001). Fever and muscle pain were found to be significant independent predictors of peak anti-RBDS1 IgG in the Comirnaty and Spikevax groups (P = .03 and P = .02, respectively). The multivariate model, adjusted for covariates, showed that no association between reactogenicity and peak antibody concentrations was found in the Comirnaty, Spikevax, and Vaxzevria groups.

CONCLUSIONS

No association between reactogenicity and peak anti-RBDS1 IgG after vaccination with the Comirnaty, Spikevax, and Vaxzevria vaccine was found.

Comparison of three different protocols for obtaining hemolysis

OBJECTIVES

Hemolysis is associated with erroneous or delayed results. Objectives of the study were to compare four different methods for obtaining hemolysis in vitro on three different analyzers.

METHODS

Hemolysis was prepared with addition of pure hemoglobin into serum pool, osmotic shock, aspiration through blood collection needle, freezing/thawing of whole blood. Biochemistry parameters were measured in duplicate at Architect c8000 (Abbott, Abbott Park, USA), Beckman Coulter AU680 (Beckman Coulter, Brea, USA) and Cobas 6000 c501 (Roche, Mannheim, Germany), according to manufacturers' declarations. Cut-off value was defined as the highest value of H index with corresponding bias lower than acceptance criteria.

RESULTS

We were not able to obtain results with freezing protocol. On all three platforms, lowest number of analytes were sensitive to hemolysis at H=0.5 using method of adding free hemoglobin. When osmotic shock was used, cut-off values for the most analytes were generally met at lower values. Hemolysis significantly interfered with measurement of potassium and lactate dehydrogenase (LD) at H=0.5 on all platforms. The most of the tested analytes had the lowest acceptable H index when aspiration method was used. At the low level of hemolysis (H=0.8) glucose, sodium, potassium, chloride, phosphate, and LD were affected on all analyzers, with some additional analytes depending on the manufacturer.

CONCLUSIONS

Hemolysis interference differs on different analyzers and according to protocol for obtaining hemolysis. Aspiration method was generally the most sensitive to hemolysis interference, while addition of free Hb was the most resistant.

Impact of Preanalytical and Analytical Methods on Cell-Free DNA Diagnostics

While tissue biopsy has for the longest time been the gold-standard in biomedicine, precision/personalized medicine is making the shift toward liquid biopsies. Cell-free DNA (cfDNA) based genetic and epigenetic biomarkers reflect the molecular status of its tissue-of-origin allowing for early and non-invasive diagnostics of different pathologies. However, selection of preanalytical procedures (including cfDNA isolation) as well as analytical methods are known to impact the downstream results. Calls for greater standardization are made continuously, yet comprehensive assessments of the impact on diagnostic parameters are lacking. This study aims to evaluate the preanalytic and analytic factors that influence cfDNA diagnostic parameters in blood and semen. Text mining analysis has been performed to assess cfDNA research trends, and identify studies on isolation methods, preanalytical and analytical impact. Seminal and blood plasma were tested as liquid biopsy sources. Traditional methods of cfDNA isolation, commercial kits (CKs), and an in-house developed protocol were tested, as well as the impact of dithiothreitol (DTT) on cfDNA isolation performance. Fluorimetry, qPCR, digital droplet PCR (ddPCR), and bioanalyzer were compared as cfDNA quantification methods. Fragment analysis was performed by qPCR and bioanalyzer while the downstream application (cfDNA methylation) was analyzed by pyrosequencing. In contrast to blood, semen as a liquid biopsy source has only recently begun to be reported as a liquid biopsy source, with almost half of all publications on it being review articles. Experimental data revealed that cfDNA isolation protocols give a wide range of cfDNA yields, both from blood and seminal plasma. The addition of DTT to CKs has improved yields in seminal plasma and had a neutral/negative impact in blood plasma. Capillary electrophoresis and fluorometry reported much higher yields than PCR methods. While cfDNA yield and integrity were highly impacted, cfDNA methylation was not affected by isolation methodology or DTT. In conclusion, NucleoSnap was recognized as the kit with the best overall performance. DTT improved CK yields in seminal plasma. The in-house developed protocol has shown near-kit isolation performance. ddPCR LINE-1 assay for absolute detection of minute amounts of cfDNA was established and allowed for quantification of samples inhibited in qPCR. cfDNA methylation was recognized as a stable biomarker unimpacted by cfDNA isolation method. Finally, semen was found to be an abundant source of cfDNA offering potential research opportunities and benefits for cfDNA based biomarkers development related to male reproductive health.

MiR-182-5p and miR-375-3p Have Higher Performance Than PSA in Discriminating Prostate Cancer from Benign Prostate Hyperplasia

Simple Summary

Prostate cancer (PCa) is the most prevalent neoplasia among men worldwide but is commonly “mimicked” by benign prostate hyperplasia (BPH). Their discrimination by the prostate-specific antigen (PSA) is often uncertain, resulting in lengthy diagnostic protocols and recurrent tissue biopsies. The development of more appropriate biomarkers, possibly present in liquid biopsy, would significantly improve PCa and BPH patient management. To address this challenge, in this study miR-375-3p, miR-182-5p, miR-21-5p, and miR-148a-3p were analyzed by ddPCR in blood plasma and seminal plasma of patients with PCa and BPH prior to tissue biopsy. Among other findings, miR-182-5p and miR-375-3p were found to have statistically significantly higher expression in PCa patients compared to BPH in blood, with a combined specificity of 90.2% to predict positive or negative biopsy results. The data presented emphasize the great potential of miRNAs as liquid biopsy biomarkers for PCa.

Abstract

Prostate cancer (PCa) is the most commonly diagnosed neoplasm among men. Since it often resembles benign prostate hyperplasia (BPH), biomarkers with a higher differential value than PSA are required. Epigenetic biomarkers in liquid biopsies, especially miRNA, could address this challenge. The absolute expression of miR-375-3p, miR-182-5p, miR-21-5p, and miR-148a-3p were quantified in blood plasma and seminal plasma of 65 PCa and 58 BPH patients by digital droplet PCR. The sensitivity and specificity of these microRNAs were determined using ROC curve analysis. The higher expression of miR-182-5p and miR-375-3p in the blood plasma of PCa patients was statistically significant as compared to BPH (p = 0.0363 and 0.0226, respectively). Their combination achieved a specificity of 90.2% for predicting positive or negative biopsy results, while PSA cut-off of 4 µg/L performed with only 1.7% specificity. In seminal plasma, miR-375-3p, miR-182-5p, and miR-21-5p showed a statistically significantly higher expression in PCa patients with PSA >10 µg/L compared to ones with PSA ≤10 µg/L. MiR-182-5p and miR-375-3p in blood plasma show higher performance than PSA in discriminating PCa from BPH. Seminal plasma requires further investigation as it represents an obvious source for PCa biomarker identification.

In sickness and in health: pivotal role of vitamin D

Within the last several years, frequency of vitamin D testing has multiplied substantially all over the world, since it has been shown to have an important role in many diseases and conditions. Even though liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been identified as "gold standard" method for vitamin D measurement, most laboratories still use immunochemistry methods. Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D₂ and 25(OH)D₃ in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams. Vitamin D is mostly measured in serum or plasma, but new studies are showing importance of measuring vitamin D in pleural effusions, breast milk, urine, synovial fluid and saliva. Besides the main role in calcium homeostasis and bone metabolism, many studies linked vitamin D deficiency with cancer, cardiovascular diseases, diabetes, fertility and many other conditions. However, even though initial observational studies indicated that supplementation with vitamin D might be beneficial in disease development and progression; first results of well-designed randomized controlled prospective studies did not find differences in frequency of cardiovascular events or invasive cancer between patients taking vitamin D supplementation compared to placebo. In the light of these recent findings, validity of excessive vitamin D testing remains an open question.

Long-term stability of clinically relevant chemistry analytes in pleural and peritoneal fluid

Introduction

Our aim was to investigate the stability of clinically relevant analytes in pleural and peritoneal fluids stored in variable time periods and variable storage temperatures prior to analysis.

Materials and methods

Baseline total proteins (TP), albumin (ALB), lactate dehydrogenase (LD), cholesterol (CHOL), triglycerides (TRIG), creatinine (CREA), urea, glucose and amylase (AMY) were measured using standard methods in residual samples from 29 pleural and 12 peritoneal fluids referred to our laboratory. Aliquots were stored for 6 hours at room temperature (RT); 3, 7, 14 and 30 days at - 20°C. At the end of each storage period, all analytes were re-measured. Deviations were calculated and compared to stability limits (SL).

Results

Pleural fluid TP and CHOL did not differ in the observed storage periods (P = 0.265 and P = 0.170, respectively). Statistically significant differences were found for ALB, LD, TRIG, CREA, urea, glucose and AMY. Peritoneal fluid TP, ALB, TRIG, urea and AMY were not statistically different after storage, contrary to LD, CHOL, CREA and glucose. Deviations for TP, ALB, CHOL, TRIG, CREA, urea and AMY in all storage periods tested for both serous fluids were within the SL. Deviations exceeding SL were observed for LD and glucose when stored for 3 and 7 days at - 20°C, respectively.

Conclusions

TP, ALB, CHOL, TRIG, CREA, urea and AMY are stable in serous samples stored up to 6 hours at RT and/or 30 days at - 20°C. Glucose is stable up to 6 hours at RT and 3 days at - 20°C. The stability of LD in is limited to 6 hours at RT.

Integrity of serum samples is changed by modified centrifugation conditions

Background Serum samples should be centrifuged for at least 10 min at 1300-2500 × g. Changed centrifugation conditions could compromise sample quality. The objective of this study was to compare the serum quality and turnaround time (TAT) using different centrifugation conditions. Methods The study was done in four different periods (A, B, C and D) at different conditions: for 10, 5 and 7 (A, B and C, respectively) at 2876 × g, and 7 (D) min at 4141 × g. Sample quality was assessed as the proportion of samples with: (a) aspiration errors, (b) H index >0.5 g/L and (c) suppressed reports of potassium (K) due to hemolysis. TAT was calculated for emergency samples. The proportions of samples (a), (b) and (c) were compared according to period A. Results The number of aspiration errors was significantly higher in samples centrifuged at 2876 × g for 5 min (p = 0.021) and remained unchanged when centrifuged for 7 min (p = 0.066 and 0.177, for periods C and D, respectively). In periods B, C and D, the proportion of samples with hemolysis was higher than that in period A (p-values 0.039, 0.009 and 0.042, respectively). TAT differed between all periods (p < 0.001), with the lowest TAT observed for B and D. The lowest number of samples exceeding 60-min TAT was observed in period D (p = 0.011). Conclusions The integrity of serum samples is changed with different centrifugation conditions than those recommended. Our study showed that shorter centrifugation at higher force (7 min at 4141 × g) significantly decreases TAT, with unchanged proportion of samples with aspiration errors.

Patient's knowledge and awareness about the effect of the over-the-counter (OTC) drugs and dietary supplements on laboratory test results: a survey in 18 European countries

Background Nowadays over-the-counter (OTC) drugs and dietary supplements are widely used. Their use can have a significant impact on the validity of laboratory results. The aim of this multicenter European study was to determine the frequency of consumption of various dietary products and OTC drugs among patients and explore their level of knowledge and awareness about the potential impact of various products on laboratory test results. Methods Eighteen European countries participated in this study. The survey was carried out anonymously on a subsequent series of outpatients (n=200) in each participating country. Included were patients who were referred to the laboratory for blood sampling and who voluntarily agreed to participate in the study. The survey included questions about the frequency of consumption of various products, awareness of the importance of informing physicians and laboratory staff about it and information about influence of preanalytical factors in general on laboratory test results. Results In total, 68% of patients were regularly taking at least one OTC drug or dietary supplement. The frequency of patients consuming at least one OTC drug or dietary supplement differed between countries (p=0.001). Vitamins (38%), minerals (34%), cranberry juice (20%), acetylsalicylic acid (ASA) (17%) and omega fatty acids (17%) were the most commonly used in our study. Conclusions The use of various OTC drugs and dietary supplements is highly prevalent in Europe and patients are often not willing to disclose this information to the laboratory staff and ordering physician. The education of both patients and healthcare staff is needed.

Ascorbic acid in urine still compromises urinalysis results

Background

The aim of this work was to determine the frequency of ascorbic acid-positive urine samples and to evaluate the potential risk on patient safety.

Materials and methods

A total of  27,856 samples submitted for urinalysis in previous year were retrospectively analysed from the laboratory information system. Urinalysis was done on Iris IQ200 analyzer using 11-parameter iChem Velocity test strips. Risk analysis combined the impact of potentially erroneous results (due to ascorbic acid interference) on patient safety (severity – S) with their frequency (occurrence – O). Potential risk was identified as high, intermediate and low.

Results

One thousand one hundred and ninety-nine (4.3%) and 1646 (5.9%) samples were mildly (20 mg/dL, 1+) and highly positive (40 mg/dL, 2+) for ascorbic acid, respectively. Severity (S1 to S5) was assigned to four possible errors: false-negative glucose (U-Glc: S2), blood (U-Hb: S5), nitrite (U-Nit: S4) and bilirubin (U-Bil: S1). Based on the frequency of errors, occurrence was categorized as: O2 for U-Glc, and O3 for U-Bil, U-Nit and U-Hb. The risk analysis matrix revealed that false-negative U-Hb was associated with potentially high risk, false-negative U-Nit with intermediate risk, while false-negative U-Glc and U-Bil were associated with low risk on patient safety.

Conclusions

Positive ascorbic acid can cause potentially high risk for patient safety by missing positive blood in urine.

Croatian laboratories have a good knowledge of the proper detection and management of hemolyzed, icteric and lipemic samples

Endogenous interferences are an important source of biased laboratory results. Hemolysis, lipemia and icteria are the main source of endogenous interference in laboratory medicine. Accreditation according to ISO 15189 improves the overall quality of the laboratory procedures. The aim of our study was i) to assess the level of knowledge of Croatian medical biochemists about the proper detection and management of hemolysis, lipemia and icteria; and ii) to identify possible differences in the level of knowledge respective to the laboratory accreditation status.

An on-line self-report survey was carried out by the Working Group for Preanalytical Phase of the Croatian Society of Medical Biochemistry and Laboratory Medicine during April to May 2015. Survey included 14 statements (Q1–Q14) about procedures for samples with interferences and participants were asked to assess the degree of agreement with the statement using a 4-point Likert scale.

The lowest level of knowledge was observed for statements Q10 (dealing with icteric sample; 40.9% participants agreed with the correct procedure), Q12 (allowable error for interference; 47.2%) and Q11 (dealing with lipemic sample; 60.1%). Almost all participants (97.4%) agreed that laboratories in Croatia should have a harmonized protocol for management of samples with interferences. Participants from accredited laboratories showed higher knowledge of hemolysis detection (p=0.031), rejection of hemolyzed sample (p<0.001), management of icteric samples (p=0.038) and allowable error for interferences (p=0.040).

Croatian laboratories have a good knowledge of the proper detection and management of hemolyzed, icteric and lipemic samples. Accreditation is associated with higher knowledge about management of samples with interferences.