Comparative Analysis of Antigen-Specific Anti-SARS-CoV-2 Antibody Isotypes in COVID-19 Patients.

Serological tests for detection of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Abs in blood are expected to identify individuals who have acquired immunity against SARS-CoV-2 and indication of seroprevalence of SARS-CoV-2 infection. Many serological tests have been developed to detect Abs against SARS-CoV-2. However, these tests have considerable variations in their specificity and sensitivity, and whether they can predict levels of neutralizing activity is yet to be determined. This study aimed to investigate the kinetics and neutralizing activity of various Ag-specific Ab isotypes against SARS-CoV-2 in serum of coronavirus disease 2019 (COVID-19) patients confirmed via PCR test. We developed IgG, IgM, and IgA measurement assays for each Ag, including receptor-binding domain (RBD) of spike (S) protein, S1 domain, full-length S protein, S trimer, and nucleocapsid (N) domain, based on ELISA. The assays of the S protein for all isotypes showed high specificity, whereas the assays for all isotypes against N protein showed lower specificity. The sensitivity of all Ag-specific Ab isotypes depended on the timing of the serum collection and all of them, except for IgM against N protein, reached more than 90% at 15-21 d postsymptom onset. The best correlation with virus-neutralizing activity was found for IgG against RBD, and levels of IgG against RBD in sera from four patients with severe COVID-19 increased concordantly with neutralizing activity. Our results provide valuable information regarding the selection of serological test for seroprevalence and vaccine evaluation studies.

Pulmonary Vascular Alterations on Computed Tomography Imaging and Outcomes in Heart Failure With Preserved Ejection Fraction: a Preliminary Data.

BACKGROUND: Pulmonary vascular disease may play an important role in the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF). However, no study has demonstrated noninvasive quantification of pulmonary vascular alterations in HFpEF. This study sought to determine the association between pulmonary vascular alterations quantified by chest computed tomography scan and clinical outcomes in HFpEF. METHODS AND RESULTS: Pulmonary vascular alterations were quantified in 151 patients with HFpEF who underwent noncontrast chest computed tomography scan by measuring the percentage of total cross-sectional area (CSA) of pulmonary vessels less than 5 mm2 to the total lung area (%CSA<5). We divided the patients by the median value of %CSA<5 (=1.45%) and examined the association between %CSA<5 and a composite outcome of all-cause mortality or HF hospitalization. During a median follow-up of 17.3 months, there were 44 (29%) composite outcomes. Event rates were significantly higher in patients with higher %CSA<5 than those with lower %CSA<5 (log-rank P = .02). %CSA<5 was associated with an increased risk of the outcome (hazard ratio per 1.0% increment, 1.46; 95% confidence interval 1.06-1.98; P = .02) in an unadjusted Cox model, and was independently and incrementally associated with the outcome over age, the presence of atrial fibrillation, E/e' ratio, and estimated pulmonary artery systolic pressure (global χ2 17.3 vs 11.5, P = .02). CONCLUSIONS: A higher %CSA<5 was associated with an increased risk of all-cause mortality or HF hospitalization in patients with HFpEF, with an incremental prognostic value over age, atrial fibrillation, E/e' ratio, and pulmonary artery systolic pressure.

Interstitial lung disease with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis in elderly patients.

Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74 years, n = 29; 75-79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.

Clinical features of dermatomyositis associated with anti-MDA5 antibodies by age.

OBJECTIVES: Anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody-positive and age at onset ≥60 years are poor prognosis factors in polymyositis (PM) and dermatomyositis (DM) associated with interstitial lung disease (ILD) among Japanese patients. However, the influence of age on the clinical features of anti-MDA5 autoantibody-positive patients with DM remains unclear. METHODS: We retrospectively examined 40 patients with DM and anti-MDA5 autoantibodies according to age. We compared patients aged <60 and ≥60 years with respect to clinical features including laboratory test findings, high-resolution lung computed tomography data, treatment content, and complications such as infections and prognosis. We also examined clinical features between surviving and deceased patients in the older patient group. RESULTS: Of 40 enrolled patients, 13 were classified as old and 27 as young. Older patients had significantly fewer clinical symptoms including arthralgia/arthritis (p < .01), skin ulceration (p = .02), and higher mortality than younger patients (p = .02) complicated with rapidly progressive ILD (RP-ILD), combination immunosuppressive therapy, and strictly controlled infections. CONCLUSION: Clinical features and mortality of anti-MDA5 autoantibody-positive DM patients were influenced by age. Patients aged ≥60 years had a worse prognosis, and combination immunosuppressive therapy was often ineffective for RP-ILD in older patients.

Higher levels of progranulin in cerebrospinal fluid of patients with lymphoma and carcinoma with CNS metastasis.

Assessing central nervous system (CNS) involvement in patients with lymphoma or carcinoma is important in determining therapy and prognosis. Progranulin (PGRN) is a secreted glycosylated protein with roles in cancer growth and survival; it is highly expressed in aggressive cancer cell lines and specimens from many cancer types. We examined PRGN levels by Enzyme Immuno-Assay (EIA) in cerebrospinal fluid (CSF) samples from 230 patients, including 18 with lymphoma [12 with CNS metastasis (CNS+); 6 without CNS metastasis (CNS-)], 21 with carcinomas (10 CNS+; 11 CNS-), and 191 control patients with non-cancer neurological diseases, and compared PRGN levels among these disease groups. Median CSF PGRN levels in the CNS+ lymphoma group were significantly higher than in the CNS- lymphoma and control non-cancer groups; and were also significantly higher in the CNS+ carcinoma group than in the CNS- carcinoma and control groups, except for patients with infectious neurological disorders. Receiver operating characteristic curve analyses revealed that CSF PGRN levels distinguished CNS+ lymphoma from CNS- lymphoma and non-cancer neurological diseases [area under curve (AUC): 0.969]; and distinguished CNS+ carcinomas from CNS- carcinomas and non-cancer neurological diseases (AUC: 0.918). We report here, for the first time, that CSF PGRN levels are higher in patients with CNS+ lymphoma and carcinomas compared to corresponding CNS- diseases. This would imply that measuring CSF PGRN levels could be used to monitor CNS+ lymphoma and metastasis.

Association between naturally occurring anti-amyloid ß autoantibodies and medial temporal lobe atrophy in Alzheimer's disease.

BACKGROUND: Naturally occurring autoantibodies against amyloid ß (Aß) peptide exist in the serum and cerebrospinal fluid (CSF) of healthy individuals. Recently, it was reported that administration of intravenous immunoglobulin at the mild cognitive impairment (MCI) stage of Alzheimer's disease (AD) reduces brain atrophy. OBJECTIVE: To examine the association between naturally occurring anti-Aß autoantibodies and brain atrophy in patients with cognitive impairment. METHODS: Serum and CSF levels of anti-Aß autoantibodies and CSF biomarkers were evaluated in 68 patients with cognitive impairment, comprising 44 patients with AD, 19 patients with amnestic MCI and five patients with non-Alzheimer's dementia. The degree of brain atrophy was assessed using the voxel-based specific regional analysis system for AD, which targets the volume of interest (VOI) in medial temporal structures, including the whole hippocampus, entorhinal cortex and amygdala. RESULTS: CSF levels of anti-Aß autoantibodies were inversely correlated with the extent and severity of VOI atrophy, and the ratio of VOI/grey matter atrophy in patients with AD, but not in MCI or non-AD patients. Serum levels of anti-Aß autoantibodies were not associated with these parameters in any of the patient groups. CONCLUSIONS: These results indicate that CSF levels of naturally occurring anti-Aß autoantibodies are inversely associated with the degree of the VOI atrophy in patients with AD. Although the mechanism is unclear, CSF levels of naturally occurring anti-Aß autoantibodies may be implicated in the progression of atrophy of the whole hippocampus, entorhinal cortex and amygdala, in AD.

[Molecular-Targeted Therapy and Autoimmune Disease].

Recently, biological treatment agents such as antibody preparations have been widely used in clinical fields, and these agents provide benefits for many patients. They actually show effectiveness against lymphoma, as well as rheumatoid arthritis, which is an autoimmune disease. Accordingly, such biological treatment has altered the concept of treatment, from symptomatic therapy to maintenance of remission. However, it is a fact that there are also some patients for whom this treatment has little benefit. Antibodies for the treat- ment of rheumatoid arthritis can be divided into two groups: tumor necrosis factor (TNF) as cytokine signal blockade, and interleukin-6 (IL-6) as signal blockade from CTLA-4 on the T-cell membrane. It is well- known that the action mechanism of these biological treatment agents can affect the immune system. Thus, cases with side effects, including abnormal laboratory data, must be reported for further study. Since these agents are extremely expensive, their benefit will be marked only when biomarkers for the early detection of complications and prediction of beneficial effects are developed. The aim of this symposi- um is to discuss the role of the clinical laboratory in this molecular-targeted therapy. [Review].

Cohort profile: rationale and design of the Resource Center for Health Science (RECHS) project - a study of health hazards and medical cost burden among the Japanese population.

PURPOSE: The increased global burden of non-communicable diseases and mental disorders is an urgent health challenge for countries around the entire world, especially those experiencing super-ageing societies, where over 21% of the population is age 65 years or older. Japan is the world's most rapidly ageing society, and as a result, medical costs are also rising dramatically. With the aims of establishing a foundational framework for future research efforts, primarily focusing on the development of a personal health record (PHR) system, and creating a long-term repository for bioresources integrated with PHRs, this study investigated potential health risks and future healthcare burdens based on a longitudinal analysis of health records. PARTICIPANTS: The Resource Center for Health Science (RECHS) project is a long-term, prospective biobank project, population and health check-up-based cohort that primarily investigates the associations between lifestyle and environmental factors and some surrogate markers of non-communicable diseases, such as diabetes, hypertension, cardiovascular disease and cancer. Starting in 2010, we initiated an annual cohort study among voluntary participants recruited from health check-up programmes and collected data from the following sources: a self-administered baseline questionnaire that included items on dietary habits and stress, a Brief Self-Administered Diet History Questionnaire, the Centre for Epidemiologic Studies Depression Scale and the General Health Questionnaire-28. FINDINGS TO DATE: For this prospective cohort study, we planned to enrol approximately 10 000 participants. We collected and stored serum samples from all participants for future analyses. The study participants who still were able to participate in these health check-ups and their outcomes were then obtained from the measurements and questionnaire responses. FUTURE PLANS: Insights emerging from the RECHS study can provide researchers and public health policy administrators with evidence to aid in the prevention of non-communicable diseases and clarify the most malleable status to implement preventive measures.

Corticosteroid therapy in a patient with cerebral amyloid angiopathy-related inflammation.

We studied longitudinal changes of the levels of anti-amyloid ß (anti-Aß) antibody, amyloid ß (Aß) protein, and interleukin 8 (IL-8) in cerebrospinal fluid (CSF) of a patient with cerebral amyloid angiopathy-related inflammation (CAA-ri) in whom steroid treatment resulted in clinical improvement. The diagnosis of CAA-ri was established with brain biopsy. Levels of anti-Aß 42 antibody, Aß 40, Aß 42 and IL-8 in CSF were measured in the CAA-ri patient at 23 time points in the 8-month clinical course. These CSF samples were divided into 2 groups: those obtained before (n = 12) and those after (n = 11) oral corticosteroid therapy was started. We compared these levels between CSF samples obtained before and after therapy. The mean levels of anti-Aß 42 antibody and IL-8 were significantly higher in CSF samples of the CAA-ri patient before oral corticosteroid therapy than those after therapy. A positive correlation was noted between levels of anti-Aß 42 antibodies and IL-8 in CSF of this patient. There were no significant differences of mean levels of Aß 40 and Aß 42 between CSF samples obtained before and after oral corticosteroid therapy. It was possible that the autoinflammatory process with anti-Aß 42 antibodies and IL-8 may have been involved in the pathogenesis of CAA-ri, and that corticosteroid therapy directly affected levels of anti-Aß 42 antibody and IL-8. In summary, CAA-ri encephalopathy is a relapsing or progressive disorder and may be treatable by adequate immunosuppressive therapy. The anti-Aß 42 antibody in CSF is a useful biological marker for therapeutic monitoring of CAA-ri.

Serum level of soluble tumor necrosis factor receptor 2 is associated with the outcome of patients with diffuse large B-cell lymphoma treated with the R-CHOP regimen.

BACKGROUND: Serum soluble tumor necrosis factor receptor 2 (sTNFR2) concentration predicted the clinical outcome of patients with aggressive non-Hodgkin's lymphoma including diffuse large B-cell lymphoma (DLBCL) treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) in our previous study. However, after rituximab (R) was introduced in clinical practice, R-CHOP replaced CHOP as the standard therapy for DLBCL. PATIENTS AND METHODS: In this study, we re-evaluated the prognostic significance of serum sTNFR2 in 154 patients with DLBCL treated with R-CHOP. RESULTS: Five-yr overall survival (5-yr OS) rates with sTNFR2 ≥20 ng/mL and <20 ng/mL were 29.2% and 83.3% (P < 0.0001), respectively, and the corresponding 5-yr progression-free survival (5-yr PFS) rates were 26.9% and 76.4% (P < 0.0001), respectively. A multivariate analysis revealed that serum sTNFR2 and complete remission (CR) were independent prognostic factors for both OS (CR: P < 0.0001, sTNFR2: P = 0.0001) and PFS (CR: P < 0.0001, sTNFR2: P = 0.0001). The prognosis of patients with poor risk groups according to the revised International Prognostic Index who also had high serum sTNFR2 was especially poor. CONCLUSION: Serum sTNFR2 might be a powerful prognostic factor for patients with DLBCL in the rituximab era.

Total IgE at 6 months predicts remittance or persistence of atopic dermatitis at 14 months.

Some patients with infantile atopic dermatitis (AD) achieve remission around 1 year old, but in others it persists. The difference between them is unclear. We performed a birth cohort study to find the markers predicting the outcome of infantile AD. We followed up a cohort (n = 314) from birth to 14 months of age, and cord blood was taken from the participants. Some of them (n = 144) had a physical examination and a blood test at 6 and 14 months of age. The subjects who had AD at 6 months (n = 34) were divided into two groups, named the transient group (those who had no AD at 14 months of age; n = 16) and the persistent group (those who still had AD at 14 months of age; n = 18). Then, laboratory data were compared between these two groups. Percentage of CD8 in cord blood lymphocytes and total IgE at 6 months of age in the persistent group was significantly higher than those of the transient group. The area under the curves of a receiver operating characteristic analysis were 0.792 (p = 0.007) and 0.722 (p = 0.027). In the persistent group, total IgE, percentages of T-helper (Th) 2 and phytohemagglutinin-induced IL-4 production from peripheral blood mononuclear cells at 14 months of age were also significantly higher than those of the transient group. Thus Th2 polarization in the persistent group was confirmed. In clinical use, total IgE at 6 months of age is the most useful predictive marker to know the outcome of infantile AD. The clinical trial registration ID is UMIN000002926.

[Clinical significance of the measurement of serum cytokeratin-18 in patients with non-alcoholic steatohepatitis].

Epidemiologic data suggest that non-alcoholic fatty liver disease (NAFLD) have an increased tendency to occur in patients who are associated with metabolic conditions such as obesity, type 2 diabetes mellitus, and dyslipidemia. NAFLD represents a wide spectrum of conditions ranging from fatty liver, which in general follows a benign, no-progressive clinical course, to non-alcoholic steatohepatitis (NASH), a more serious form of NAFLD that may progress to cirrhosis and end stage liver disease. However, currently the diagnosis of NASH requires an invasive liver biopsy. The aim of this study is to evaluate whether Cytokeratin 18 (CK-18) has potential non-invasive diagnostic capability for the NASH. Serum levels of alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transpeptidase, adiponectin, leptin, and CK-18 were measured in 27 patients (8 patients with simple fatty liver, 6 fatty liver with fibrosis patients, 13 patients with NASH) and 23 healthy controls. Regarding gender difference in the control group, although both adiponectin and leptin significantly increased in the female compared with the male (p < 0.002 and p < 0.01, respectively), there were no significant gender differences in CK-18. For the conventional liver function tests, there were no significant differences in 4 groups. Serum levels of adiponectin was significantly lower in patients with NASH compared with the control group(p < 0.001), and both leptin and CK-18 were markedly higher in patients with NASH compared with control group (p < 0.001). These results suggested that measurement of serum CK-18 is useful for assessing the NASH.

Dataset dependency of low-density lipoprotein-cholesterol estimation by machine learning.

OBJECTIVES: We evaluated the applicability of a machine learning-based low-density lipoprotein-cholesterol (LDL-C) estimation method and the influence of the characteristics of the training datasets. METHODS: Three training datasets were chosen from training datasets: health check-up participants at the Resource Center for Health Science (N = 2664), clinical patients at Gifu University Hospital (N = 7409), and clinical patients at Fujita Health University Hospital (N = 14,842). Nine different machine learning models were constructed through hyperparameter tuning and 10-fold cross-validation. Another test dataset of another 3711 clinical patients at Fujita Health University Hospital was selected as the test set used for comparing and validating the model against the Friedewald formula and the Martin method. RESULTS: The coefficients of determination of the models trained on the health check-up dataset produced coefficients of determination that were equal to or inferior to those of the Martin method. In contrast, the coefficients of determination of several models trained on clinical patients exceeded those of the Martin method. The means of the differences and the convergences to the direct method were higher for the models trained on the clinical patients' dataset than for those trained on the health check-up participants' dataset. The models trained on the latter dataset tended to overestimate the 2019 ESC/EAS Guideline for LDL-cholesterol classification. CONCLUSION: Although machine learning models provide valuable method for LDL-C estimates, they should be trained on datasets with matched characteristics. The versatility of machine learning methods is another important consideration.

Clinical differences among patients with myeloperoxidase-antineutrophil cytoplasmic antibody-positive interstitial lung disease.

INTRODUCTION: Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis and idiopathic interstitial lung diseases (IIPs) are positive for myeloperoxidase (MPO)-ANCA. MPO-ANCA-positive vasculitis mainly comprises microscopic polyangiitis (MPA) and unclassifiable vasculitis. These diseases are frequently complicated by interstitial lung disease (ILD). Few studies have reported the clinical differences between the subtypes of MPO-ANCA-positive ILD. Therefore, this study aimed to examine the clinical findings and courses of MPO-ANCA-positive ILD. METHOD: This retrospective study enrolled 100 patients with MPO-ANCA-positive ILD who were categorized into three groups: MPA (n = 44), unclassifiable vasculitis (n = 29), and IIP (n = 27). Our study compared the clinical findings and prognosis of these patients and analyzed the poor prognostic factors. Furthermore, we assessed the association between the patients with and without acute exacerbation of ILD (AE-ILD). RESULTS: Our study found clinical differences in serum markers, clinical symptoms, and treatment regimens among the three groups. ILD complications, as the main cause of death, differed among the three groups (P = 0.04). Patients with unclassifiable vasculitis showed higher survival rates than those with IIP (P = 0.046). Patients with AE-ILD showed fewer general symptoms (P = 0.02) and lower survival rates (P < 0.01) than those without AE-ILD. In multivariate analysis, AE-ILD development was a strong poor prognostic factor for MPO-ANCA-positive ILD. CONCLUSIONS: The subtypes of MPO-ANCA-positive ILD have different clinical features and prognoses. Patients who develop AE-ILD require careful evaluation of clinical courses. Key Points • In myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-positive interstitial lung disease (ILD), patients with unclassifiable vasculitis showed a better prognosis than those with idiopathic ILD.. • Development of acute exacerbation in ILD was a strong poor prognostic factor in patients with MPO-ANCA-positive ILD..

Inhibition of increased indoleamine 2,3-dioxygenase activity attenuates Toxoplasma gondii replication in the lung during acute infection.

The regulation of local L-tryptophan concentrations by tryptophan-degrading enzyme, indoleamine 2,3-dioxygenase (IDO) induced by various stimuli such as interferon-γ (IFN-γ) is one of the key mechanisms in antimicrobial effect. Recently, IDO is also focused on an immunosuppressive mechanism shared by several different immune cell types. Here, we show that inhibition of increased IDO activity maybe involved in the antiparasitic mechanism during Toxoplasma gondii (T. gondii) infection in vivo. In this study, we investigated the role of IDO by using IDO-gene-deficient (IDO KO) mice and by administering a competitive enzyme inhibitor, 1-methyl-D,L-tryptophan (1MT), to wild-type mice following T. gondii infection. Although depletion of lung l-tryptophan did not occur in IDO KO mice after T. gondii infection, the increased mRNA expression of T. gondii surface antigen gene 2 (SAG2) and the inflammatory cytokines in the lung were drastically reduced in the IDO KO mice following infection. We also found that complete depletion of lung l-tryptophan was observed in wild-type mice after infection, but not in mice treated with 1MT. At the same time, 1MT suppressed the increased mRNA expression of SAG2. Taken together, we observed that the inflammatory damage was significantly decreased by the administration of 1MT in the lung after infection. Inhibition of the IDO activity or the elimination of IDO's substrate may be an effective therapy against microbial diseases.

The absence of IDO upregulates type I IFN production, resulting in suppression of viral replication in the retrovirus-infected mouse.

Indoleamine 2,3-dioxygenase, the L-tryptophan-degrading enzyme, plays a key role in the powerful immunomodulatory effects on several different types of cells. Because modulation of IDO activities after viral infection may have great impact on disease progression, we investigated the role of IDO following infection with LP-BM5 murine leukemia virus. We found suppressed BM5 provirus copies and increased type I IFNs in the spleen from IDO knockout (IDO(-/-)) and 1-methyl-D-L-tryptophan-treated mice compared with those from wild-type (WT) mice. Additionally, the number of plasmacytoid dendritic cells in IDO(-/-) mice was higher in the former than in the WT mice. In addition, neutralization of type I IFNs in IDO(-/-) mice resulted in an increase in LP-BM5 viral replication. Moreover, the survival rate of IDO(-/-) mice or 1-methyl-D-L-tryptophan-treated mice infected with LP-BM5 alone or with both Toxoplasma gondii and LP-BM5 was clearly greater than the survival rate of WT mice. To our knowledge, the present study is the first report to observe suppressed virus replication with upregulated type I IFN in IDO(-/-) mice, suggesting that modulation of the IDO pathway may be an effective strategy for treatment of virus infection.

Elevated anti-heat shock protein 60 antibody titer is related to white matter hyperintensities.

BACKGROUND: There are many reports that the antibody against heat shock protein 60 (Hsp60) is present in most patients with coronary artery disease and atherosclerosis, and that its titer correlates with disease severity. However, few reports have described the association between anti-Hsp60 antibody and cerebrovascular disease. METHODS: We determined the anti-Hsp60 antibody titer in patients with neurologic diseases and healthy subjects using enzyme-linked immunosorbent assay (ELISA) and evaluated their findings of brain magnetic resonance imaging (MRI) of the white matter. White matter hyperintensities (WMHs) on T2-weighted and fluid-attenuated inversion recovery (FLAIR) images were classified into 2 categories: periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH). The lesions in each category were then divided into 4 grades (grades 0-3) according to the Fazekas rating scale. RESULTS: There were no significant differences in the titer between patients with neurologic diseases and healthy subjects. The mean grade of DWMHs (mean ± SD, 1.56 ± 0.70) was significantly higher in 18 subjects in the high-titer group (≥39.8 ng/mL; mean titer + 2 SD in sera from 23 healthy subjects) than in 86 subjects (mean ± SD, 0.09 ± 0.76) in the normal-titer group (<39.8 ng/mL; P < .003). The mean grade of PVHs (mean ± SD, 1.50 ± 0.71) was also significantly higher in the high-titer group than in the normal-titer group (mean ± SD, 1.17 ± 0.62; P < .02). CONCLUSIONS: A significant correlation was noted between anti-Hsp60 antibody titer and the severity of WMHs on brain MR images. We suggest that an elevated titer of the anti-Hsp60 antibody could be a risk factor for cerebral small-vessel disease.

Validation of the Martin method to estimate low-density lipoprotein cholesterol concentrations in Japanese populations and a modified method for laboratory information system application.

OBJECTIVES: High concentrations of low-density lipoprotein cholesterol (LDL-C) are a risk factor for cardiovascular disease. We validated the efficacy of the Martin method is useful in the estimation of LDL-C concentrations was validated in Japanese populations and derived a modified Martin method for easy laboratory information system applications. METHODS: We created 3 subject groups, including 2664 health check-up participants registered with the Resource Center for Health Science, 29,806 clinical patients (A) in the Gifu University Hospital, and 113,716 clinical patients (B) in the Fujita Health University Hospital. Each method to estimate serum LDL-C concentrations (Friedewald formula, Martin method and modified Martin method) was validated by correlation analysis with serum LDL-C concentrations measured using a direct method. RESULTS: The correlation coefficients with the direct method in terms of the Friedewald formula, Martin method, and modified Martin method were 0.963, 0.972 and 0.970 in the health check-up participants; 0.946, 0.962 and 0.961 in clinical patients A; and 0.961, 0.979 and 0.978 in clinical patients B, respectively. Concordance ratios with using the direct method in the Friedewald formula, Martin method and modified Martin method were 82.8%, 85.5% and 85.3% in the health check-up participants; 76.4%, 80.5% and 80.2% in clinical patients A; and 76.1%, 82.6% and 82.6% in clinical patients B, respectively. CONCLUSION: Our results show that the Martin and modified Martin methods display good performance in terms of the estimation of LDL-C concentrations among triglyceride concentrations of a wide range, and they may thus be useful for estimating LDL-C concentrations.

Antibody Responses to BNT162b2 Vaccination in Japan: Monitoring Vaccine Efficacy by Measuring IgG Antibodies against the Receptor-Binding Domain of SARS-CoV-2.

To fight severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), mass vaccination has begun in many countries. To investigate the usefulness of a serological assay to predict vaccine efficacy, we analyzed the levels of IgG, IgM, and IgA against the receptor-binding domain (RBD) of SARS-CoV-2 in the sera from BNT162b2 vaccinated individuals in Japan. This study included 219 individuals who received two doses of BNT162b2. The levels of IgG, IgM, and IgA against RBD were measured by enzyme-linked immunosorbent assay before and after the first and second vaccination, respectively. The relationship between antibody levels and several factors, including age, gender, and hypertension were analyzed. Virus-neutralizing activity in sera was measured to determine the correlation with the levels of antibodies. A chemiluminescent enzyme immunoassay (CLEIA) method to measure IgG against RBD was developed and validated for the clinical setting. The levels of all antibody isotypes were increased after vaccination. Among them, RBD-IgG was dramatically increased after the second vaccination. The IgG levels in females were significantly higher than in males. There was a negative correlation between age and IgG levels in males. The IgG levels significantly correlated with the neutralizing activity. The CLEIA assay measuring IgG against RBD showed a reliable performance and a high correlation with neutralizing activity. Monitoring of IgG against RBD is a powerful tool to predict the efficacy of SARS-CoV-2 vaccination and provides useful information in considering a personalized vaccination strategy for COVID-19. IMPORTANCE Mass vaccination campaigns using mRNA vaccines against SARS-CoV-2 have begun in many countries. Serological assays to detect antibody production may be a useful tool to monitor the efficacy of SARS-CoV-2 vaccination in individuals. Here, we reported the induction of antibody isotype responses after the first and second dose of the BNT162b2 vaccine in a well-defined cohort of employees in Japan. We also reported that age, gender, and hypertension are associated with differences in antibody response after vaccination. This study not only provides valuable information with respect to antibody responses after BNT162b2 vaccination in the Japanese population but also the usefulness of serological assays for monitoring vaccine efficacy in clinical laboratories to determine a personalized vaccination strategy for COVID-19.

The Trajectory of the COVID-19 Vaccine Antibody Titers Over Time and the Association of Mycophenolate Mofetil in Solid Organ Transplant Recipients.

The COVID-19 vaccine will be safe and effective in solid organ transplant recipients (SOTs). However, the blunted antibody responses were also of concern. Few studies have reported prolonged serologic follow-up after 2 doses of BNT162b2 vaccine in SOTs. We performed a single-center, prospective observational study of 78 SOTs who received 2 doses of BNT162b2 vaccine. We identified the trajectory of antibody titers after vaccination among SOTs with or without mycophenolate mofetil (MMF) or withdrawn from MMF. We found low seroconversion rates (29/42: 69%) and low antibody titers in SOTs treated with MMF. An inverse linear relationship between neutralizing antibody titers and MMF concentration was confirmed in restricted cubic spline plots (P for effect < .01, P for nonlinearity = .08). For the trajectory of antibody responses, seroconversion and improved antibody titers were observed after withdrawal from MMF in SOTs who showed seronegative or low antibody titers at the first visit after 2 doses of vaccine (P for effect < .01, P for nonlinearity < .05, and P for interaction < .01). We identified increased B-cell counts after withdrawal from MMF (P < .01). The recovery of antibody responses was seen in SOTs withdrawn from MMF. The trajectories of antibody responses were modified by MMF administration.