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"Antigenemia"
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Multisystem inflammatory syndrome in children is driven by zonulin-dependent loss of gut mucosal barrier
2021
BACKGROUNDWeeks after SARS-CoV-2 infection or exposure, some children develop a severe, life-threatening illness called multisystem inflammatory syndrome in children (MIS-C). Gastrointestinal (GI) symptoms are common in patients with MIS-C, and a severe hyperinflammatory response ensues with potential for cardiac complications. The cause of MIS-C has not been identified to date.METHODSHere, we analyzed biospecimens from 100 children: 19 with MIS-C, 26 with acute COVID-19, and 55 controls. Stools were assessed for SARS-CoV-2 by reverse transcription PCR (RT-PCR), and plasma was examined for markers of breakdown of mucosal barrier integrity, including zonulin. Ultrasensitive antigen detection was used to probe for SARS-CoV-2 antigenemia in plasma, and immune responses were characterized. As a proof of concept, we treated a patient with MIS-C with larazotide, a zonulin antagonist, and monitored the effect on antigenemia and the patient's clinical response.RESULTSWe showed that in children with MIS-C, a prolonged presence of SARS-CoV-2 in the GI tract led to the release of zonulin, a biomarker of intestinal permeability, with subsequent trafficking of SARS-CoV-2 antigens into the bloodstream, leading to hyperinflammation. The patient with MIS-C treated with larazotide had a coinciding decrease in plasma SARS-CoV-2 spike antigen levels and inflammatory markers and a resultant clinical improvement above that achieved with currently available treatments.CONCLUSIONThese mechanistic data on MIS-C pathogenesis provide insight into targets for diagnosing, treating, and preventing MIS-C, which are urgently needed for this increasingly common severe COVID-19-related disease in children.
Journal Article
SARS-CoV-2 Nucleocapsid Plasma Antigen for Diagnosis and Monitoring of COVID-19
by
Sibai, Mamdouh
,
Solis, Daniel
,
Röltgen, Katharina
in
Antigenemia
,
Antigens
,
Antigens, Viral - blood
2021
Abstract
Background
Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen in blood has been described, but the diagnostic and prognostic role of antigenemia is not well understood. This study aimed to determine the frequency, duration, and concentration of nucleocapsid antigen in plasma and its association with coronavirus disease 2019 (COVID-19) severity.
Methods
We utilized an ultrasensitive electrochemiluminescence immunoassay targeting SARS-CoV-2 nucleocapsid antigen to evaluate 777 plasma samples from 104 individuals with COVID-19. We compared plasma antigen to respiratory nucleic acid amplification testing (NAAT) in 74 individuals with COVID-19 from samples collected ±1 day of diagnostic respiratory NAAT and in 52 SARS-CoV-2–negative individuals. We used Kruskal–Wallis tests, multivariable logistic regression, and mixed-effects modeling to evaluate whether plasma antigen concentration was associated with disease severity.
Results
Plasma antigen had 91.9% (95% CI 83.2%–97.0%) clinical sensitivity and 94.2% (84.1%–98.8%) clinical specificity. Antigen-negative plasma samples belonged to patients with later respiratory cycle thresholds (Ct) when compared with antigen-positive plasma samples. Median plasma antigen concentration (log10 fg/mL) was 5.4 (interquartile range 3.9–6.0) in outpatients, 6.0 (5.4–6.5) in inpatients, and 6.6 (6.1–7.2) in intensive care unit (ICU) patients. In models adjusted for age, sex, diabetes, and hypertension, plasma antigen concentration at diagnosis was associated with ICU admission [odds ratio 2.8 (95% CI 1.2–6.2), P=.01] but not with non-ICU hospitalization. Rate of antigen decrease was not associated with disease severity.
Conclusions
SARS-CoV-2 plasma nucleocapsid antigen exhibited comparable diagnostic performance to upper respiratory NAAT, especially among those with late respiratory Ct. In addition to currently available tools, antigenemia may facilitate patient triage to optimize intensive care utilization.
Journal Article
Development of cytomegalovirus retinitis after negative conversion of cytomegalovirus antigenemia due to systemic antiviral therapy
by
Namba Kenichi
,
Kitaichi Nobuyoshi
,
Iwata Daiju
in
Antigenemia
,
Antiviral agents
,
Antiviral drugs
2021
PurposeCytomegalovirus (CMV) antigenemia assays have been widely used as adjunct tests to diagnose tissue invasive CMV diseases, including cytomegalovirus retinitis (CMVR). In this study, we examined CMVR cases to assess the presence of CMV in sera and aqueous humor and antiviral therapy received prior to the onset of CMVR.MethodsA total of 37 eyes from 26 different cases of CMVR in patients who visited Hokkaido University Hospital between 2007 and 2015 were enrolled. The diagnosis of CMVR was established based on characteristic ophthalmoscopic findings and the presence of local and/or systemic CMV infection. Among the 26 cases, 3 cases (12%) were HIV-positive, while the other 23 cases (88%) were HIV-negative. The records of clinical and laboratory results were reviewed from clinical charts retrospectively.ResultsCMV antigenemia was positive at the onset of CMVR in 14 cases (53.8%) and negative in the other 12 cases. In 9 cases among the antigenemia-negative cases (75.0%), the antigenemia had been previously positive and had turned negative before the onset of CMVR. In 12 of the 14 antigenemia-positive cases (85.7%) and in 8 of the 9 antigenemia-negative cases (88.9%) that were previously positive, systemic antiviral therapies had never been used or had been used before but had been discontinued prior to the onset of CMVR.ConclusionEven if viremia turns negative, the risk of developing CMVR exists for more than several weeks after the completion of systemic therapy.
Journal Article
Efficacy of prophylactic letermovir for cytomegalovirus reactivation in hematopoietic cell transplantation: a multicenter real-world data
2021
A novel anti-cytomegalovirus (CMV) agent, letermovir (LMV), could reportedly improve the outcomes of allogeneic hematopoietic cell transplantation (allo-HCT) recipients because of its high potential to prevent CMV reactivation. Therefore, 685 Japanese allo-HCT recipients, of whom ~80% had a high risk of CMV reactivation, were retrospectively analyzed to assess the impacts of prophylactic LMV on the incidence of clinically significant CMV (csCMV) infection as well as their transplant outcome. By comparing 114 patients who received LMV prophylaxis for a median 92 days to 571 patients without prophylaxis, we observed that prophylactic LMV could significantly (1) reduce the 180-day cumulative incidence of csCMV infection (44.7 vs. 72.4%, p < 0.001), (2) delay the median time until initiation of CMV antigenemia-guided preemptive therapy (90 vs. 36 days, p < 0.001), (3) shorten the duration of anti-CMV preemptive treatment (21 vs. 25 days, p = 0.006), and (4) improve the overall survival rate at 180 days after transplant (80.4 vs. 73.0%, p = 0.033) with a trend of lower non-relapse mortality (8.9 vs. 14.9%, p = 0.052). Our findings demonstrate that prophylactic LMV treatment is highly effective in preventing the development of csCMV infection and ultimately reduces transplant-related mortality.
Journal Article
Cryptococcal antigenemia and its predictors among HIV infected patients in resource limited settings: a systematic review
by
Derbie, Awoke
,
Woldeamanuel, Yimtubezinash
,
Abebe, Tamrat
in
Acquired immune deficiency syndrome
,
AIDS
,
Antigenemia
2020
Background
Cryptococcosis is an opportunistic fungal infection that primarily affects people with advanced HIV/AIDS and is an important cause of morbidity and mortality around the globe. By far the most common presentation of the disease is cryptococcal meningitis (CM), which leads to an estimated 15–20% of all HIV related deaths worldwide, 75% of which are in sub-Saharan Africa. However, to the best of our knowledge there is quite limited reviewed data on the epidemiology of cryptococcal antigenemia in a large HIV-infected population in resource limited settings.
Methods
Articles published in English irrespective of the time of publication were systematically searched using comprehensive search strings from PubMed/Medline and SCOPUS. In addition, Google Scholar and Google databases were searched manually for grey literature. Two reviewers independently assessed study eligibility, extracted data, and assessed risk of bias. The pooled prevalence of cryptococcal antigenemia was determined with 95% confidence interval (CI).
Results
A
mong 2941 potential citations, we have included 22 studies with a total of 8338 HIV positive individuals. The studies were reported in ten different countries during the year (2007–2018). Most of the articles reported the mean CD4 count of the participants below 100 cells/μl. The pooled prevalence of cryptococcal antigenemia at different CD4 count and ART status was at 8% (95%CI: 6–10%) (ranged between 1.7 and 33%). Body mass index (BMI) < 18.5 kg/m
2
, CD4 count < 100 cells, patients presenting with headache and male gender were reported by two or more articles as an important predictors of cryptococcal antigenemia.
Conclusions
Implementing a targeted screening of HIV patients with low BMI, CD4 count < 100 cells, having headache and males; and treatment for asymptomatic cryptococcal disease should be considered. Additional data is needed to better define the epidemiology of cryptococcal antigenemia and its predictors in resource limited settings in order to optimize the prevention, diagnosis, and treatment strategies.
Journal Article
NS1 Antigenemia and Viraemia Load: Potential Markers of Progression to Dengue Fatal Outcome?
by
Damasceno dos Santos Rodrigues, Cintia
,
Dos Santos, Flávia Barreto
,
Nogueira, Rita Maria Ribeiro
in
Antigenemia
,
Antigens
,
Antigens, Viral - blood
2018
Dengue is a worldwide problem characterized by a multifactorial pathogenesis. Considering the viral components, it is known that high viremia or high levels of the secreted nonstructural protein 1 (NS1) may be associated with a more severe disease. We aimed to characterize the NS1 antigenemia and viremia in dengue fatal and non-fatal cases, as potential markers of progression to a fatal outcome. NS1 antigenemia and viremia were determined in Brazilian dengue fatal cases (n = 40) and non-fatal cases (n = 40), representative of the four dengue virus (DENV) serotypes. Overall, the fatal cases presented higher NS1 levels and viremia. Moreover, the fatal cases from secondary infections showed significantly higher NS1 levels than the non-fatal ones. Here, irrespective of the disease outcome, DENV-1 cases presented higher NS1 levels than the other serotypes. However, DENV-2 and DENV-4 fatal cases had higher NS1 antigenemia than the non-fatal cases with the same serotype. The viremia in the fatal cases was higher than in the non-fatal ones, with DENV-3 and DENV-4 presenting higher viral loads. Viral components, such as NS1 and viral RNA, may be factors influencing the disease outcome. However, the host immune status, comorbidities, and access to adequate medical support cannot be ruled out as interfering in the disease outcome.
Journal Article
Risk factors for cytomegalovirus reactivation in patients with kidney disease under immunosuppressive therapy
by
Iwatani Yosuke
,
Nitta Kosaku
,
Amemiya Nobuyuki
in
Antigenemia
,
Antineutrophil cytoplasmic antibodies
,
Autoantibodies
2022
BackgroundCytomegalovirus (CMV) is a herpes virus that causes latent infections, and its reactivation due to immunosuppression can cause fatal complications. CMV reactivation is a complication frequently occurring in patients with kidney disease who require immunosuppressive therapy, and, therefore, this study retrospectively examined its risk factors. MethodsPatients who received immunosuppressive therapy and underwent the CMV antigenemia test (CMV antigenemia: C7-HRP) for the treatment of primary nephritis (minimal change disease, membranous nephropathy, membranoproliferative glomerulonephritis, focal glomerulosclerosis, and IgA nephropathy) and anti-neutrophil cytoplasmic autoantibody (ANCA)-associated nephritis diagnosed at Saiseikai Kurihashi Hospital from January 2014 to December 2019 were recruited as study participants. Risk factors of CMV reactivation were examined using univariable and multivariable analyses.ResultsAmong the 64 patients (36 men and 28 women; median age, 72 years) included, 34 had primary nephritis (20 minimal disease changes, 10 membranous nephropathy, 1 membranoproliferative glomerulonephritis, 1 focal glomerulosclerosis, and 2 IgA nephropathy) and 30 had ANCA-associated nephritis. Regarding glucocorticoid (GC), 43 patients received oral GC therapy, whereas 21 received GC pulse therapy. CMV reactivation participants showed significant differences in age, ANCA-associated nephritis, hemoglobin level, lymphocyte count, maximum GC dosage, and hemodialysis in univariable analysis. Multivariate analysis showed significantly lower lymphocyte counts in CMV-reactivated patients, but no significant difference in other factors.ConclusionIn patients with kidney disease, who require immunosuppressive therapy, CMV reactivation risk is high in patients with low lymphocyte count, and monitoring CMV during the treatment course could lead to early diagnosis and treatment of CMV disease.
Journal Article
Underlying Cryptococcal Diseases and the Correlation With Serum Cryptococcal Antigen Titers in Hospitalized HIV-Infected Patients Screened Positive for Cryptococcal Antigenemia
2020
The prevalence of different underlying cryptococcal diseases in human immunodeficiency virus (HIV)-infected patients screened positive for cryptococcal antigenemia and the association between cryptococcal diseases and serum cryptococcal antigen (CrAg) titers were understudied.
HIV-infected patients with CD4 < 200 cells/ul, admitted to the second hospital of Nanjing, Nanjing, China, from January 2016 to September 2019, were retrospectively analyzed. Integrated into routine HIV care, all these patients were screened for cryptococcal antigenemia with CrAg lateral flow assay. Positive patients received extensive laboratory and radiological studies to evaluate underlying cryptococcal diseases.
A total of 872 HIV inpatients were screened for serum CrAg. The prevalence of cryptococcal antigenemia in the study population was 10.3% (95% CI, 8.3-12.3%), 87.6% of which with cryptococcal antigenemia had clinically cryptococcal diseases. The prevalence of cryptococcal meningitis (CM), cryptococcemia and pulmonary cryptococcosis (PC) in patients with cryptococcal antigenemia were 58.4% (95% CI, 48.0-68.9%), 50.7% (95% CI, 39.1-62.2%), and 68.5% (95% CI, 58.7-78.4%), respectively. The median (range) serum CrAg titers in severe cryptococcal diseases (CM or cryptococcemia), localized PC (without co-existing CM or cryptococcemia) and isolated cryptococcal antigenemia were 1:2560 (1:10-1:2560), 1:20 (1:2-1:320), and 1:5 (1:2-1:320), respectively. Serum CrAg titers ≥1:320 were independently associated with CM (adjusted OR 26.88; 95%CI, 8.36-86.42). Severe cryptococcal diseases were found in all patients with serum CrAg titers ≥1:640. None of the patients with serum CrAg titers ≤ 1:5 had CM.
The prevalence of cryptococcal antigenemia was high in HIV inpatients, supporting routine CrAg screening. Clinical cryptococcal diseases, most commonly the PC, existed in the majority of the patients with cryptococcal antigenemia. Since serum CrAg titer is correlated with cryptococcal disease severity, it may possibly guide anti-fungal treatment.
Journal Article
HERV-W ENV antigenemia and correlation of increased anti-SARS-CoV-2 immunoglobulin levels with post-COVID-19 symptoms
by
Charvet, Benjamin
,
Giménez-Orenga, Karen
,
Martín-Martínez, Eva
in
Antigenemia
,
Antigens
,
Biobanks
2022
Due to the wide scope and persistence of COVID-19´s pandemic, post-COVID-19 condition represents a post-viral syndrome of unprecedented dimensions. SARS-CoV-2, in line with other infectious agents, has the capacity to activate dormant human endogenous retroviral sequences ancestrally integrated in human genomes (HERVs). This activation was shown to relate to aggravated COVID-19 patient´s symptom severity. Despite our limited understanding of how HERVs are turned off upon infection clearance, or how HERVs mediate long-term effects when their transcription remains aberrantly on, the participation of these elements in neurologic disease, such as multiple sclerosis, is already settling the basis for effective therapeutic solutions. These observations support an urgent need to identify the mechanisms that lead to HERV expression with SARS-CoV-2 infection, on the one hand, and to answer whether persistent HERV expression exists in post-COVID-19 condition, on the other. The present study shows, for the first time, that the HERV-W ENV protein can still be actively expressed long after SARS-CoV-2 infection is resolved in post-COVID-19 condition patients. Moreover, increased anti-SARS-CoV-2 immunoglobulins in post-COVID-19 condition, particularly high anti-SARS-CoV-2 immunoglobulin levels of the E isotype (IgE), seem to strongly correlate with deteriorated patient physical function (r=-0.8057, p<0.01). These results indicate that HERV-W ENV antigenemia and anti-SARS-CoV-2 IgE serology should be further studied to better characterize post-COVID-19 condition pathogenic drivers potentially differing in subsets of patients with various symptoms. They also point out that such biomarkers may serve to design therapeutic options for precision medicine in post-COVID-19 condition.
Journal Article