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Rheumatoid arthritis (RA) is a systemic autoimmune disease characterised by the presence of autoantibodies that are used for classification of the disease. Though routine diagnostics is commonly restricted to measuring rheumatoid factor (RF) and anti-citrullinated protein antibodies, detection of RF IgM, IgG and IgA isotypes, may increase the power of RA serodiagnosis by reducing the number of seronegative patients as well as provide prognostic information. The agglutination-based RF assays, such as nephelometry or turbidimetry, are unable to differentiate isotypes. We compared three different immunoassays used in current laboratory practice to detect RF isotypes. We tested 117 consecutive serum samples that were positive for total RF at nephelometry, from 55 RA and 62 non-RA subjects. IgA, IgG, and IgM isotypes of RF were tested by immunoenzymatic (ELISA, Technogenetics), fluoroenzymatic (FEIA, ThermoFisher) and chemiluminescence (CLIA, YHLO Biotech Co.) immunoassays. Diagnostic performance differed considerably between the assays, especially with regard to RF IgG isotype. Agreement among methods by Cohen's kappa ranged from 0.05 (RF IgG CLIA vs. FEIA) to 0.846 (RF IgM CLIA vs. FEIA). The poor agreement observed in this study indicates substantial lack of comparability among assays for RF isotypes. Harmonization of these tests requires further efforts before their measurement can be used in clinical practice. [ABSTRACT FROM AUTHOR]

Immune response, vaccine, antibody kinetics, anti-SARS-CoV-2 antibodies, health care workers, neutralizing antibodies, surrogate virus neutralization test Keywords: antibody kinetics; anti-SARS-CoV-2 antibodies; health care workers; immune response; neutralizing antibodies; surrogate virus neutralization test; vaccine EN antibody kinetics anti-SARS-CoV-2 antibodies health care workers immune response neutralizing antibodies surrogate virus neutralization test vaccine 934 940 7 05/12/22 20220501 NES 220501 Introduction Since the beginning of the coronavirus disease (COVID-19) pandemic [[1]], the public health measures implemented to prevent the spread of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) has led to social, political, and economic consequences [[2]]. Healthy individuals show high levels of the anti-SARS-CoV-2 Spike S1 protein IgG (anti-S1 IgG) antibodies and NAbs, as well as a persistent germinal center B-cell response following vaccination [[15]], [[16]], [[17]], [[18]], [[19]], [[20]], [[21]], [[22]]. [Extracted from the article]

EDTA plasmaEDTA plasma most consistentDale I. (1990)533 HBDSerumEDTA plasmaACD plasmaCPD plasmaBlood was allowed to clot at 4 °C for 0, 3 and 17 days before centrifugation at 800 g for 10 minSamples were stored at -70 °C for no longer than 2 months1Results higher in serum vs. Keywords: biomarker; circulating calprotectin; neutrophil-related inflammation; pre-analytical phase EN biomarker circulating calprotectin neutrophil-related inflammation pre-analytical phase e317 e321 5 07/01/21 20210801 NES 210801 To the Editor, Due to the increased recognition of serum or plasma calprotectin as a biomarker for neutrophil-mediated inflammation, we would like to point out some important pre-analytical aspects. Both serum and citrate plasma matrices showed consistent results for all test conditions, with overall percent recovery values between 100.3 and 103.0% for serum and between 97.4 and 102.0% for citrate plasma. [Extracted from the article]

Currently available computer-aided diagnosis (CAD) systems for the detection of anti-nuclear antibodies (ANA) by indirect immunofluorescence (IIF) assay enable a standardized measurement of system-specific fluorescent intensity (FI) measures. We aimed to evaluate an internal quality control (iQC) program that controls the total ANA IIF process in routine practice. In addition to the kit iQC materials, supplemental quality indicators were integrated in a total quality assurance (QA) program: patient-derived iQC's samples (negative, 1/160 fine speckled and 1/160 homogeneous), median sample FI per run and percentage of ANA IIF positive samples per run. Analytical rejection criteria were based on the imprecision of the positivity index (PI) measure of the Zenit PRO system (Menarini). Clinical rejection criteria were based on changes in FI that correspond to a change in ANA IIF titer of ≥2. To evaluate the QA program, different artificial errors were introduced during the ANA IIF process. After every run, quality indicators were evaluated and compared to the pre-set target values. Rescanning the ANA IIF slides five times, using an old conjugate and a needle obstruction resulted in analytically and even clinically relevant errors in ANA IIF results. All errors were correctly detected by the different defined quality indicators. Traditional Westgard rules, including analytically (and clinically) defined rejection limits were useful in monitoring quality indicators. The integration of a total process iQC program in CAD systems, based on the specific FI measurands and performance criteria of the system, adds value to QA. [ABSTRACT FROM AUTHOR]

It has been shown that in patients with rheumatoid arthritis, switched to a second anti-TNF drug for the development of ADAs against the starting agent, the clinical outcome may significantly ameliorate, even better than in patients not developing ADAs [7]. The immunogenicity to the first anti-TNF therapy determines the outcome of switching to a second anti-TNF therapy in spondyloarthritis patients. [Extracted from the article]

The World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) published the general guidelines for managing SARS-CoV-2 infection in prison [[5]], [[6]]. Keywords: anti-SARS-CoV-2 antibodies; COVID-19; prison EN anti-SARS-CoV-2 antibodies COVID-19 prison e239 e241 3 06/03/21 20210601 NES 210601 To the Editor, Due to the dramatic diffusion of the coronavirus disease 2019 (COVID-19), an infectious disease caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for an acute respiratory syndrome that has spread rapidly all over the world causing thousands of deaths, we consider both the prevention and control of SARS-CoV-2 virus fundamental in prisons. In Italy, the Minister of Justice declared specific measures for detention institutions, such as blocking prison visits between inmates and external people, replaced by video calls; halting prisoner transfers between different prisons; transforming prison detention into house arrest for minor crimes and short arrests and adopting alternative sentences to reduce prison overpopulation. [Extracted from the article]

Background: The dense fine speckled (DFS) is one of the most common patterns that can be observed as a result of the anti-nuclear antibodies (ANA) test on HEp-2 cells and is mostly caused by antibodies to DFS70 as the main antigenic target. As was recently demonstrated, isolated anti-DFS70 positivity can be used as an aid in the exclusion of ANA associated rheumatic diseases (AARD) due to the opportunity to better interpret unexplained positive IIF ANA results. Methods: Our study included 333 subjects with AARD, 51 undifferentiated connective tissue disease (UCTD) patients, 235 disease controls and 149 healthy blood donors from an Italian cohort. All samples were tested for anti-DFS70 and anti-ENA antibodies using QUANTA Flash assays (Inova Diagnostics, San Diego, CA, USA). Results: No differences in the prevalence of anti-DFS70 antibodies were seen among AARD, non-AARD and UCTD (2.1% [7/333] vs. 2.3% [9/384] vs. 5.9% [3/51], respectively; p-value = 0.188). AARD patients positive for anti-DFS70 antibodies showed in all cases an accompanying anti-ENA specificity. In contrast, monospecific anti-DFS70 antibodies showed a significantly different distribution with a clear trend across the main groups (AARD vs. non-AARD vs. UCTD: 0% [0/7] vs. 22% [2/9] vs. 100% [3/3], p = 0.007). Anti-DFS70 antibody levels among AARD, non-AARD and UCTD patients were not significantly different (p = 0.094). Within the anti-DFS70 antibody positive cases, AARD cohort showed a higher variability (median [min–max]: 3.2 [3.2–450.8] CU) compared to non-AARD (median [min–max]: 3.2 [3.2–75.7] CU) and UCTD patients (median [min–max]: 3.2 [3.2–59.0] CU). Conclusions: Our preliminary data showed a similar frequency of anti-DFS70 antibodies in AARD, UCTD and non-AARD cohorts. Monospecificity of anti-DFS70 antibodies but not their mere presence is the key element in the diagnostic algorithm. Mono-specific anti-DFS70 antibodies might be a helpful biomarker to discriminate individuals with AARD from non-AARD presenting with a positive ANA. [ABSTRACT FROM AUTHOR]