Harmonization of Lipoprotein(a) Immunoassays Using A Serum Panel Value Assigned with The IFCC-Endorsed Mass Spectrometry-Based Reference Measurement Procedure as A First Step Towards Apolipoprotein Standardization.

Aim: Lipoprotein (a) [Lp(a)] is a well-established risk factor for cardiovascular disease independent of low-density lipoprotein-cholesterol (LDL-C). The Lp(a) concentrations were inconsistent between the immunoassays. This study aimed to investigate whether harmonization of Lp(a) measurements can be achieved using a serum panel value assigned with the IFCC-endorsed mass spectrometry-based reference measurement procedure (IFCC-MS-RMP).

Circulating TNF receptor levels are associated with estimated glomerular filtration rate even in healthy individuals with normal kidney function.

The association between serum tumor necrosis factor receptor (TNFRs: TNFR1, TNFR2) levels and estimated glomerular filtration rate (eGFR) observed in patients with diabetes has not been comprehensively tested in healthy subjects with normal kidney function. It also remains unclear whether TNFR levels differ by age and sex, and between healthy subjects and diabetics. We measured serum TNFR levels in 413 healthy subjects and 292 patients with type 2 diabetes.

Isolation and identification of from blood culture by MALDI-MS.

is a genus of budding yeast that is mainly isolated from environmental samples, and 40 species have been detected. The yeast isolated from human clinical samples usually only contain three species: , and . In this study, we isolated from a blood sample of a six-year-old female with a history of B-cell precursor lymphoblastic leukemia in Japan in 2022.

Investigation of the individual genetic evolution of SARS-CoV-2 in a small cluster during the rapid spread of the BF.5 lineage in Tokyo, Japan.

There has been a decreasing trend in new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and fatalities worldwide. The virus has been evolving, indicating the potential emergence of new variants and uncertainties. These challenges necessitate continued efforts in disease control and mitigation strategies.

Incidences of and risk factors for clinical and subclinical contrast-associated acute kidney injury in patients who underwent neuroendovascular surgery.

Background: Contrast-associated acute kidney injury (CA-AKI) can develop after intravascular administration of iodinated contrast media. Neutrophil gelatinase-associated lipocalin (NGAL) is an early marker for AKI that helps to detect subclinical CA-AKI. We investigated the incidence of and risk factors for clinical and subclinical CA-AKI in patients who underwent neuroendovascular surgery.

Performance evaluation of the Ortho VITROS SARS-CoV-2 Spike-Specific Quantitative IgG test by comparison with the surrogate virus neutralizing antibody test and clinical assessment.

Background: Despite the worldwide campaigns of COVID-19 vaccinations, the pandemic is still a major medical and social problem. The Ortho VITROS SARS-CoV-2 spike-specific quantitative IgG (VITROS S-IgG) assay has been developed to assess neutralizing antibody (NT antibody) against SARS-CoV-2 spike (S) antibodies. However, it has not been evaluated in Japan, where the total cases and death toll are lower than the rest of the world.

Performance evaluation of the Roche Elecsys® Anti-SARS-CoV-2 immunoassays by comparison with neutralizing antibodies and clinical assessment.

Quantitative measurement of SARS-CoV-2 neutralizing antibodies is highly expected to evaluate immune status, vaccine response, and antiviral therapy. The Elecsys® Anti-SARS-CoV-2 S (Elecsys® anti-S) was developed to measure anti-SARS-CoV-2 S proteins. We sought to investigate whether Elecsys® anti-S can be used to predict neutralizing activities in patients' serums using an authentic virus neutralization assay.

Activation of SARS-CoV-2 neutralizing antibody is slower than elevation of spike-specific IgG, IgM, and nucleocapsid-specific IgG antibodies.

COVID-19 antibody testing has been developed to investigate humoral immune response in SARS-CoV-2 infection. To assess the serological dynamics and neutralizing potency following SARS-CoV-2 infection, we investigated the neutralizing (NT) antibody, anti-spike, and anti-nucleocapsid antibodies responses using a total of 168 samples obtained from 68 SARS-CoV-2 infected patients. Antibodies were measured using an authentic virus neutralization assay, the high-throughput laboratory measurements of the Abbott Alinity quantitative anti-spike receptor-binding domain IgG (S-IgG), semiquantitative anti-spike IgM (S-IgM), and anti-nucleocapsid IgG (N-IgG) assays.

Molecular characterization of SARS-CoV-2 detected in Tokyo, Japan during five waves: Identification of the amino acid substitutions associated with transmissibility and severity.

Many variants of SARS-CoV-2 have emerged around the world. It is therefore important to understand its global viral evolution and the corresponding mutations associated with transmissibility and severity. In this study, we analyzed 112 whole genome sequences of SARS-CoV-2 collected from patients at Juntendo University Hospital in Tokyo and the genome data from entire Japan deposited in Global Initiative on Sharing Avian Influenza Data (GISAID) to examine the relationship of amino acid changes with the transmissibility and the severity of each strain/lineage.

Meals and Room Temperature Storage do not Significantly Affect Feasibility of Direct RT-PCR Tests for SARS-CoV-2 Using Saliva.

Background: Rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using saliva samples has emerged as a preferred technique since sample collection is easy and noninvasive. In addition, several commercial high-throughput PCR kits that do not require RNA extraction/purification have been developed and are now available for testing saliva samples. However, an optimal protocol for SARS-CoV-2 RT-PCR testing of saliva samples using the RNA extraction/purification-free kits has not yet been established.

Antibody response and seroprevalence in healthcare workers after the BNT162b2 vaccination in a University Hospital at Tokyo.

In 2020, we reported a low seroprevalence of N-specific antibodies in 4147 health care workers (HCWs) at a frontline hospital in Tokyo, Japan. In Japan, a vaccine campaign was launched in early 2021. We re-evaluated seroprevalences of N- and S-specific antibodies in 2202 HCWs who took two doses of the BNT162b2 vaccine.

Clinical Evaluation of Siemens SARS-CoV-2 Total Antibody assay and IgG assay using the Dimension EXL 200 in the Tokyo Metropolitan area.

Background: We evaluated the efficacy of the Siemens SARS-CoV-2 Total Antibody assay (CV2T) and IgG assay (CV2G) that can detect antibodies against the receptor binding domain of S antigen in patients with COVID-19 in a Tokyo metropolitan area.

Methods: Sensitivity and antibody levels were examined by CV2T and CV2G on Dimension EXL 200 using 236 serum samples obtained from 79 RT-PCR confirmed COVID-19 patients at multiple time points and were compared with disease severity by the World Health Organization criteria. The assay specificity was evaluated using samples collected before the COVID-19 pandemic.

Fibrinogen measurement by a novel point-of-care device with whole blood: comparison of values against Clauss method.

Timely fibrinogen replacement is key to treating critical hemorrhage. Measuring fibrinogen concentration by conventional laboratory tests requires centrifugation of blood samples and is often time-consuming. A point-of-care testing device (A&T, Yokohama, Japan), CG02N, has been available in Japan since 2011 to measure fibrinogen concentration without centrifugation.

SARS-CoV-2 seroprevalence in healthcare workers at a frontline hospital in Tokyo.

Healthcare workers (HCWs) are highly exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The actual coronavirus disease (COVID-19) situation, especially in regions that are less affected, has not yet been determined. This study aimed to assess the seroprevalence of SARS-CoV-2 in HCWs working in a frontline hospital in Tokyo, Japan.

Seroprevalence of anti-SARS-CoV-2 antibodies in Japanese COVID-19 patients.

Objectives: To determine the seroprevalence of anti-SARS-CoV-2 IgG and IgM antibodies in symptomatic Japanese COVID-19 patients.

Methods: Serum samples (n = 114) from 34 COVID-19 patients with mild to critical clinical manifestations were examined. The presence and titers of IgG antibody for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were determined by a chemiluminescent microparticle immunoassay (CMIA) using Alinity i SARS-CoV-2 IgG and by an immunochromatographic (IC) IgM/IgG antibody assay using the Anti-SARS-CoV-2 Rapid Test.

Comparison of the clinical performance and usefulness of five SARS-CoV-2 antibody tests.

We examined the usefulness of five COVID-19 antibody detection tests using 114 serum samples at various time points from 34 Japanese COVID-19 patients. We examined Elecsys Anti-SARS-CoV-2 from Roche, and four immunochromatography tests from Hangzhou Laihe Biotech, Artron Laboratories, Chil, and Nadal. In the first week after onset, Elecsys had 40% positivity in Group S (severe cases) but was negative in Group M (mild-moderate cases).

Pancreatic lipase activity in overnight effluent predicts high transport status in peritoneal dialysis patients.

Background: Long-term peritoneal dialysis (PD) causes peritoneal morphological and functional changes, resulting in high transport status featuring increased peritoneal permeability. High transport status is diagnosed by peritoneal equilibration test (PET), a reliable but time-consuming method. We identifed a reliable biomarker in peritoneal effluent to predict high transport status in PD patients.

[Relevance of urinary protein/creatinine ratio and urinary abnormal casts].

Objectives: The quantification of 24 hrs urinary protein excretion is valuable for diagnosing and monitoring renal disease. However, because of its practical difficulties, the spot urinary protein/creatinine (P/C) ratio has been utilized. We aimed to evaluate the analytical performance of P/C ratio by comparing with the qualitative urinary protein values and the microscopic urine sediment analysis.