Plasma Load Research Articles

SARS-CoV-2 RNAemia as a reliable predictor of long-term mortality among older adults hospitalized in pulmonary intermediate care units: a prospective cohort study

BackgroundSARS-CoV-2 viremia is associated with disease severity and high risk for in-hospital mortality. However, the impact of SARS-CoV-2 viremia on long-term outcomes in hospitalized patients with COVID-19 is poorly understood.MethodsWe conducted a prospective cohort study and recruited a group of older adult patients with COVID-19 admitted to pulmonary intermediate care units of Peking University Third Hospital during December 2022 and January 2023. The plasma level of SARS-CoV-2 RNA was determined by a standardized RT-PCR technique, and SARS-CoV-2 RNAemia was defined as a plasma viral load ≥ 50 copies/ml. In-hospital and follow-up (180-day) outcome data were collected.ResultsA total of 101 patients with an average of 80.4 years were recruited, and 63.4% of them were severe or very severe cases. Twenty-eight patients (27.7%) had SARS-CoV-2 RNAemia, with a median viral RNA load of 422.1 [261.3, 1085.6] copies/ml. Patients with SARS-CoV-2 RNAemia were more likely to develop critical cases and had a higher incidence of sepsis. Accordingly, they had a higher 180-day mortality (57.1% vs. 19.7%, P < 0.001), as well as in-hospital mortality (50.0% vs. 13.7%, P < 0.001), independent of age, disease severity, sepsis, lymphocyte count and C-Reactive protein. In addition, the risk for 180-day mortality increased with the SARS-CoV-2 RNA load in plasma. Plasma cytokines, including IL-6, IL-8 and IL-10, were higher in patients with SARS-CoV-2 RNAemia.ConclusionsOur study indicates that SARS-CoV-2 RNAemia serves as a useful biomarker for predicting mortality, especially long-term mortality, in older adult patients hospitalized in pulmonary intermediate care units.Trial registrationChinese Clinical Trial Registry website (No. ChiCTR2300067434).

Torque Teno Virus Loads as a Marker of Immunosuppression in Pediatric Kidney Transplant Recipients.

Long-term renal function and survival after kidney transplantation rely on appropriate immunosuppressive treatment to prevent the risk of rejection. New biomarkers are needed to accurately assess the degree of immunosuppression in renal transplant recipients in order to avoid organ rejection and the development of opportunistic infections. Highly prevalent in humans, torque teno virus (TTV), which belongs to the family Anelloviridae, is a small, nonenveloped, single-stranded DNA virus which has not been linked with any specific human illness, but which constitutes a major component of the human virome. Host antiviral responses allow TTV levels to be controlled; however, viral persistence remains, explaining the high prevalence in human populations, including healthy individuals. Important confounders of TTV load include time since transplantation, age, gender, obesity, and smoking status. TTV-based guidance of immunosuppressive drug dosing could help with risk stratification, reducing the risk of infection, graft rejection and oncologic disease on an individual level, enabling long-term patient and graft survival. Original studies were accessed by a systematic search from electronic databases including PubMed, ScienceDirect and Wiley Online Library. The presented data mainly derive from adult transplant recipients showing an association between TTV plasma levels and the immune status of the host: High-TTV load and high immunosuppression are associated with a risk of infection, and low-TTV load and low immunosuppression indicate a risk of rejection. However, there is minimal information on pediatric transplant recipients with further research required in this cohort. To date, it has been demonstrated that longer posttransplant times are significantly associated with lower TTV levels in children with renal transplant. Meanwhile, an association between lower TTV loads and increased risk of graft reject during the first year of transplantation was also reported. More recently, Eibensteiner etal. revealed a robust, independent association between TTV plasma load and the onset of Cytomegalovirus and BK virus infections. Data from randomized controlled trials are still missing, even in adults, but a multicenter randomized controlled trial for TTV-guided immunosuppression in adult kidney recipients (TTVguideIT) began in 2022. There is, therefore, great promise for TTV levels to be used as a biomarker that could potentially improve both graft and patient survival in transplantation.

Impact of baseline SARS-CoV-2 load in plasma and upper airways on the incidence of acute extrapulmonary complications of COVID-19: a multicentric, prospective, cohort study.

Extrapulmonary complications (EPCs) are common in patients hospitalized for COVID-19, but data on their clinical consequences and association with viral replication and systemic viral dissemination is lacking. Patients hospitalized for COVID-19 and enrolled in the TICO (Therapeutics for Inpatients with COVID-19) platform trial at 114 international sites between August 2020 and November 2021 were included in a prospective cohort study. We categorized EPCs into 39 event types within 9 categories and estimated their frequency through day 28 and their association with clinical outcomes through day 90. We analyzed the association between baseline viral burden (plasma nucleocapsid antigen [N-Ag] and upper airway viral load [VL]) and EPCs, adjusting for other baseline factors. 2,625 trial participants were included in the study. The median age was 57 years (IQR 46-68), 57.7% were male, and 537 (20.5%) had at least one EPC. EPCs were associated with higher day-90 all-cause mortality (HR 9.6, 95% CI 7.3, 12.7) after adjustment for other risk factors. The risk of EPCs increased with increasing baseline plasma N-Ag (HR 1.21 per log10 ng/L increase, 95% CI 1.09, 1.34), and upper airway VL (HR 1.12 per log10 copies/mL increase, 95% CI 1.04, 1.19), after adjusting for comorbidities, disease severity, inflammatory markers, and other baseline factors. Trial treatment allocation had no effect on EPC risk. Systemic viral dissemination as evidenced by high plasma N-Ag and high respiratory viral burden are associated with development of EPCs in COVID-19, which in turn are associated with higher 90-day mortality.

Technique of Reactor Experiments of Tin-Lithium Alloy Interaction with Hydrogen Isotopes Under Neutron Irradiation Conditions

The implementation of the ITER and DEMO projects currently includes the investigation of the structural and functional material properties of fusion reactors (FRs). Research to support the use of liquid metals and alloys as plasma-facing materials (PFMs) is a crucial area of work during the development of new FRs. Recent studies indicate the prospects of the tin-lithium (Sn-Li) alloy as a new liquid metal for protecting the in-vessel elements of a FR from the energy flows and high-density particles. Sn-Li alloy has been widely explored for utilization as PFM; however, there is a shortage of investigations being performed at nuclear reactors. The utilization of Sn-Li alloy as PFM in a FR must be fully justified by validated experimental results on tests under extremely high heat, plasma, and radiation loads. The paper presents the methodology of in-pile experiments performed at the IVG.1M research reactor (Kurchatov, Kazakhstan) to study the interaction of hydrogen isotopes with Sn-Li alloy under neutron irradiation conditions. A Sn-Li sample with 73 at. % tin and 27 at. % lithium was manufactured. A unique experimental ampoule device (AD) with a Sn-Li sample had been developed and manufactured for in-pile tests. The results of neutron-physical and thermophysical calculations of designs of the experimental device with Sn-Li alloy under irradiation conditions of the IVG.1M reactor were performed to justify the AD design. Methodical experiments were performed to determine the temperature dependence of the change in the composition of the gas phase in the chamber with Sn-Li alloy. The time dependence of the partial pressure of hydrogen, tritium, and tritium-containing molecules in the AD volume with the Sn-Li alloy on its temperature under reactor irradiation conditions at a power of 3 MW has been studied. Key findings include the successful measurement of tritium release, the determination of temperature conditions for tritium generation and release, and the validation of our experimental AD for conducting such studies.

Transplantation in adult patients with Epstein-Barr virus–associated hemophagocytic lymphohistiocytosis: yes or no?

AbstractHemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by aberrant immunological activity with a dismal prognosis. Epstein-Barr virus (EBV)–associated HLH (EBV-HLH) is the most common type among adults. Patients with EBV infection to B cells could benefit from rituximab, whereas lethal outcomes may occur in patients with EBV infection to T cells, nature killer cells, or multilineages. The necessity of allogeneic hematopoietic stem cell transplantation (HSCT) in adult patients with EBV-HLH remains controversial. A total of 356 adult patients with EBV-HLH entered this study. Eighty-eight received HSCT under medical recommendation. Four received salvage HSCT. The 5-year overall survival (OS) rate for patients who underwent HSCT was 48.7% (vs 16.2% in patients who did not undergo transplantation; P < .001). There was no difference in OS between patients who received transplantation at first complete response (CR1) and those at first partial response (PR1) nor between patients at CR1 and CR2. Patients who received transplantation at PR2 had inferior survival. The rate of reaching CR2 was significantly higher in patients with CR1 than PR1 (P = .014). Higher soluble CD25 levels, higher EBV-DNA loads in plasma after HSCT, poorer remission status, more advanced acute graft-versus-host disease (GVHD), and the absence of localized chronic GVHD were associated with inferior prognosis (P < .05). HSCT improved the survival of adult EBV-HLH significantly. For patients who achieved PR after initial treatment, HSCT was recommended. A wait-and-see strategy could be adopted for patients who achieved CR after initial treatment but with the risk of failing to achieve CR2.

A decade of data and hundreds of analytes: Legacy and emerging chemicals in North American herring gull plasma

Between 2010 and 2021, 199 herring gull serum samples were collected from Lake Michigan, Lake Huron, and Lake Erie, including two Areas of Concern: Saginaw Bay and the River Raisin. They were analyzed for 21 polybrominated diphenyl ether congeners, 10 non-PBDE flame retardants, 85 polychlorinated biphenyls, 17 legacy organochlorine pesticides, and 36 per- and polyfluoroalkyl substances. Σ36PFAS, Σ85PCB, Σ21PBDE, and Σ17Pesticide concentrations comprised 41–74%, 17–50%, 3–4%, and 5–9% of the total concentration, respectively. Median concentrations of the chemical groups ranged from 81.5 to 129 ng/g ww for PFAS, 26.3–158 ng/g ww for PCBs, 4.26–8.89 ng/g ww for PBDEs, and 8.08–23.0 ng/g ww for pesticides. The regional concentrations of all four classes of compounds are significantly decreasing when sites are combined with halving times of 11.3 ± 4.8, 8.2 ± 4.3, 5.9 ± 3.1, and 8.3 ± 4.2 years for the Penta-BDE mixture, ΣDDTs, Σ85PCBs and Σ36PFAS, respectively. These results suggest that, while PFAS has emerged as the dominant group of chemicals in the plasma, legacy pollutants continue to represent a threat to herring gulls and wildlife in the Great Lakes basin. PCBs were the largest contributors to the chemical load in plasma of birds whose colonies are located near the River Raisin, and continue to pose a threat to herring gulls within the two Areas of Concern.

The efficacy of adjuvant chemotherapy in patients with different midpoint-radiotherapy Epstein-Barr virus DNA plasma loads

ObjectivesThis study aimed to evaluate the efficacy of adjuvant chemotherapy (AC) in patients with different midpoint-radiotherapy (mid-RT) Epstein-Barr virus (EBV) DNA plasma loads for locoregionally advanced nasopharyngeal carcinoma (NPC), and to provide decision-making regarding the use of AC. Materials and methodsA total of 675 consecutive patients diagnosed with stage III–IVa NPC were enrolled in this study. All patients underwent concurrent chemoradiotherapy (CCRT), either with or without induction chemotherapy or AC, or a combination of both. The primary endpoint of this study was progression-free survival (PFS). ResultsAmong the 675 enrolled patients, 248 (36.7 %) received AC and 427 (63.3 %) were only observed after CCRT. In total, 149 (22.1 %) patients had detectable mid-RT EBV DNA levels, whereas 526 (77.9 %) had undetectable mid-RT EBV DNA levels. Patients with detectable mid-RT EBV DNA had worse 5-year PFS than those with undetectable mid-RT EBV DNA (74.8 % vs. 81.9 %, P = 0.045). AC group showed significantly better 5-year PFS than observation in patients with detectable mid-RT EBV DNA (82.8 % vs. 66.8 %; HR, 0.480; 95 % CI 0.250–0.919, P = 0.027). Multivariate analyses demonstrated that the treatment methods (AC vs. observation) were independent prognostic factors for PFS (HR, 0.37; 95 % CI 0.19–0.74, P = 0.005). However, in patients with undetectable mid-RT EBV DNA (5-year PFS: HR 0.873, 95 % CI 0.565–1.349, P = 0.52), AC group showed no survival benefit for observation. ConclusionAC could reduce the risk of disease progression compared to observation in patients with detectable mid-RT EBV DNA. Our findings suggest that AC is effective in patients at a high risk of treatment failure.

Performance evaluation of the Alinity m system for quantifying cytomegalovirus DNA in samples of the respiratory, gastrointestinal, and urinary tract.

Quantitation of cytomegalovirus (CMV) DNA load in specimens other than blood such as bronchoalveolar lavages, intestinal biopsies, or urine has become a common practice as an ancillary tool for the diagnosis of CMV pneumonitis, intestinal disease, or congenital infection, respectively. Nevertheless, most commercially available CMV PCR platforms have not been validated for CMV DNA detection in these specimen types. In this study, a laboratory-developed test based on Alinity m CMV ("Alinity LDT") was evaluated. Reproducibility assessment using spiked bronchial aspirate (BAS) or urine samples showed low standard deviations of 0.08 and 0.27 Log IU/mL, respectively. Evaluating the clinical performance of Alinity LDT in comparison to a laboratory-developed test based on RealTime CMV ("RealTime LDT") showed good concordance across 200 clinical specimens including respiratory specimens, intestinal biopsies, urine, and stool. A high Pearson's correlation coefficient of r = 0.92, a low mean bias of -0.12 Log IU/mL, a good qualitative agreement of 90%, and a Cohen's kappa value of 0.76 (substantial agreement) were observed. In separate analyses of the sample types BAS, tracheal aspirates, bronchoalveolar lavage, biopsies, and urine, the assay results correlated well between the two platforms with r values between 0.88 and 0.99 and a bias <0.5 Log IU/mL. Overall, the fully automated, continuous, random access Alinity LDT yielded good reproducibility, high concordance, and good correlation to RealTime LDT in respiratory, gastrointestinal, and urine samples and may enhance patient management with rapid result reporting.IMPORTANCEIn transplant recipients, a major cause for morbidity and mortality is end-organ disease by primary or secondary CMV infection of the respiratory or gastrointestinal tract. In addition, sensorineural hearing loss and neurodevelopmental abnormalities are frequent sequelae of congenital CMV infections in newborns. Standard of care for highly sensitive detection and quantitation of the CMV DNA load in plasma and whole blood specimens is real-time PCR testing. Beyond that, there is a need for quantitative determination of CMV DNA levels in respiratory, gastrointestinal, and urinary tract specimens using a highly automated, random access CMV PCR assay with a short turnaround time to enable early diagnosis and treatment. In the present study, clinical performance of the fully automated Alinity m analyzer in comparison to the current RealTime LDT assay was evaluated in eight different off-label sample types.

Structural design and preliminary feasibility analysis of a new stabilizing plate for the advanced tokamak in MD event

In tokamak devices, the stabilizing plates are installed in the vacuum vessel to mitigate the vertical instability of plasma. As the power and operating time of tokamak devices increase, the electromagnetic force generated by MD (Major Disruption) of plasma and thermal load will be greater than before. In order to maintain the performance of the stabilizing plate, a new concept about stabilizing plate for the advanced tokamak is introduced in this article. The new stabilizing plate is designed with a sturdy body and a composite cooling structure. Meanwhile, in order to reduce the contact resistance between stabilizing plates, an electrical connection structure is specially added for the stabilizing plate. Based on the electromagnetic analysis and thermal analysis, theoretical feasibility for the new stabilizing plate is provided. In order to verify the actual performance of the electrical connection structure, the contact resistance test is conducted. According to the experimental results, the total contact resistance of total stabilizing plates is less than 3.2 μΩ.

Evaluation of CMV DNA Antigenemia Status in Patients With Allogeneic Bone Marrow Transplant

Purpose: The risk of cytomegalovirus (CMV) reactivation following allogeneic hematopoietic stem cell transplantation (ASCT) reaches 30-50%, and there are numerous diagnostic tests to detect CMV replication. The most common tests used in this group of patients include 65kDa phosphoprotein (pp65) antigenemia immunofluorescence assay and nucleic-acid-based quantitative CMV-DNA polymerase chain reaction (qPCR). Material and Methods: In this study, patients who underwent ASCT and developed CMV positivity from 2009 to 2016 in our hospital were evaluated retrospectively. The study included samples of the same patient with antigenemia and CMV-DNA qPCR test for up to 48 hours. The study aimed to determine the factors affecting CMV DNA antigenemia and compare CMV DNA PCR and pp65 antigenemia immunofluorescence assay. Results: The results of 138 specimens of 39 patients who underwent ASCT were evaluated. The mean value of CMV PCR, which was positive for both tests, was 57.887 copies/ml (70- 1.213.633 copies/ml) and a significant correlation was found between the two tests and the positive samples (p = 0.018). The ROC analysis showed that 322 copies/ml CMV viral load in plasma corresponds to ≥1 antigen-positive cells/200 thousand leukocytes (Sensitivity: 68.5%; Specificity: 31.5%). CMV infection was observed in 32 samples; CMV DNA cut-off values of the reference according to CMV DNA PCR and antigenemia results, compared to the development of CMV infection, presented a significant correlation (p=0.004). Conclusion: Although there is a common agreement between antigenemia and CMV DNA PCR tests, one should keep in mind that the sensitivity of antigenemia test is low especially in the neutropenic period.

Associations of cold-inducible RNA-binding protein with bacterial load, proinflammatory cytokines and mortality from pneumonia.

Cold-inducible RNA-binding protein (CIRP) is a damage-associated molecular pattern that plays a critical role in triggering inflammatory responses. It remains unknown whether CIRP is strongly associated with bacterial load, inflammatory response, and mortality in sepsis model. Pneumonia was induced in specific pathogen-free 8-9-week old male rats by injecting bacteria via puncture of the tracheal cartilage. The expressions of CIRP and proinflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β] in lung tissues, alveolar macrophages (AMs), plasma, and bronchoalveolar lavage fluid (BALF) were determined by reverse transcription-polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay. The numbers of bacteria recovered from the lungs were correlated with the bacterial loads injected and mortality. The expressions of CIRP increased sharply as the bacterial loads increased in the lung tissues and AMs. The amounts of TNF-α, IL-6 and IL-1β proteins synthesized were dependent on the bacterial load in the lung tissues. Releases of CIRP, TNF-α, IL-6, and IL-1β increased with the bacterial load in the blood plasma. The proteins confirmed similar patterns in the BALF. CIRP was strongly associated with the releases of TNF-α, IL-6, and IL-1β in the lung tissues, blood plasma, and BALF, and showed a close correlation with mortality. CIRP demonstrated a strong association with bacterial load, which is new evidence, and close correlations with proinflammatory cytokines and mortality of pneumonia in rats, suggesting that it might be an interesting pneumonic biomarker for monitoring host response and predicting mortality, and a promising target for immunotherapy.

Semen Washing and Intrauterine Insemination for Reducing the Risk of Human Immunodeficiency Virus Transmission in Serodiscordant Couples: A Cross-sectional Study.

Antiretroviral therapy has helped human immunodeficiency virus (HIV)-infected people live an enhanced quality of life and attempt for a pregnancy, without placing their partner at risk. Although periconceptional pre-exposure prophylaxis for the uninfected partner and consistent antiretroviral therapy for the HIV-infected partner are important to prevent HIV transmission, semen washing could be a great option to further reduce the semen viral load. The aim of this study were as follows: to determine if semen washing with intrauterine insemination provides an added safety net to HIV-serodiscordant couples when the male partner is HIV-infected and virally suppressed and to determine if the U = U concept (undetectable = untransmittable) holds true in virally suppressed HIV-infected males. This was an observational study conducted in seropositive HIV men under treatment with highly active antiretroviral therapy (HAART) in collaboration with Metropolis Laboratory, a CAP recognised private Healthcare Laboratory in Mumbai, India. Blood and semen samples were collected from a total of 110 adult HIV-1-infected males virally suppressed on HAART. These samples were processed to assess the viral load in plasma as well as raw and processed semen fractions. Descriptive statistics were used to analyse the data. Only men with plasma viral loads < 1000 copies were selected in our study. Out of the 110 HIV-infected individuals, 102 (92.73%) patients had undetectable (<20 copies/ml) plasma viral load while 8 (7.27%) patients had a detectable (>20 copies/ml) viral load, who were excluded from the study. In the virally suppressed 102 men, the raw semen samples of 100 men showed an undetectable viral load, while 2 samples showed detectable contamination, even though their plasma samples from the blood showed a viral load of <20 copies/ml. The semen was then separated into the sperm and the seminal plasma samples. The seminal plasma had <20 copies/ml in 95 samples (93.14%) but a detectable viral load in 7 (6.86%) samples. After subjecting all the 102 processed (post-wash) sperm samples to quantitative analysis, an undetectable viral load of <20 copies/ml was found in all the samples. Thus, the raw sample (prewashed),seminal plasma and processed (postwash) samples were evaluated. The post-wash sperm sample showing zero contamination was frozen for intrauterine insemination (IUI) in the uninfected female partner. Semen washing with IUI should be advocated as a safe, efficacious way to increase the safety net and to further reduce the minimal risk of HIV transmission in serodiscordant couples in addition to the U = U concept.

The association of Torque Teno viral load with CMV and BKV infection in pediatric and adolescent kidney transplant patients.

Background: Long-term allograft and patient survival after kidney transplantation (KTX) depends on the balance between over- and under-immunosuppression (IS). High levels of IS predispose to opportunistic infections. Plasma load of Torque Teno Virus (TTV), a non-pathogenic highly prevalent Annellovirus, is associated with its hosts immune status, especially after solid organ transplantation. Objectives: To investigate the association of plasma TTV load and opportunistic viral infections after pediatric KTX. Study design: This retrospective study includes all pediatric KTX patients followed at the Medical University of Vienna 2014–2020. PCR for Cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), and TTV was performed every 4–8 weeks at routine follow-up visits. Results: 71 pediatric KTX patients were followed with TTV measurements for a median of 2.7 years. TTV plasma load was associated with CMV DNAemia at the next visit with an OR of 2.37 (95 % CI 1.15–4.87; p = 0.03) after adjustment for time after KTX and recipient age. For a cut-off of 7.68 log10 c/mL TTV a sensitivity of 100 %, a specificity of 61 %, a NPV 100 %, and a PPV of 46 % to detect CMV DNAemia at the next visit was calculated. TTV plasma loads were also associated with BKV DNAuria and BKV DNAemia at the next visit, but not with EBV DNAemia. Conclusions: This is the first study to analyse associations between TTV plasma loads and opportunistic viral infections in pediatric KTX. We were able to present a TTV cut-off for the prediction of clinically relevant CMV DNAemia that might be useful in clinical care.

Influence of AR injection on shielding layer properties and surface protection from transient high heat loads under the QSPA plasma exposures

The paper presents experimental studies of a shielding plasma layer formation in front of a tungsten surface exposed with hydrogen plasma in the QSPA-M test-bed facility under the conditions of additional seeding of argon (Ar) along the target surface into the zone of plasma-surface interaction. A pulsed gas injector on the base of a fast electromagnetic valve has been developed for the local injection of Ar. The injector is capable of generating a homogeneous argon gas flow with a maximum concentration above n Ar = 6 × 1023 m−3 and a pulse duration of 0.5 ms. It is shown that the increase in the argon gas density in front of the surface leads to an essential decrease (in 1.5–2 times) in the energy load delivered to the target surface. In the presence of a strong magnetic field (up to 1 T), both the thickness of the shielding layer and the fraction of energy dissipated by the shield increase further. Even for moderate energy densities of the QSPA plasma streams in the experiments with Ar gas injection, less than 40% of the impacting plasma load is absorbed by the tungsten surface. The results demonstrate that this additional shielding attributed to the formation of a dense Ar plasma layer in front of the exposed W surface would be favourable for the divertor armour performance, causing the decreasing erosion of plasma-facing components in the course of transient events in a fusion reactor.

Letermovir use may impact on the Cytomegalovirus DNA fragmentation profile in plasma from allogeneic hematopoietic stem cell transplant recipients.

Cytomegalovirus (CMV) DNA in plasma is mainly unprotected and highly fragmented. The size of the amplicon largely explains the variation in CMV DNA loads quantified across PCR platforms. In this proof-of-concept study, we assessed whether the CMV DNA fragmentation profile may vary across allogeneic hematopoietic stem cell transplant recipients (allo-SCT), within the same patient over time, or is affected by letermovir (LMV) use. A total of 52 plasma specimens from 14 nonconsecutive allo-SCT recipients were included. The RealTime CMV PCR (Abbott Molecular), was used to monitor CMV DNA load in plasma, and fragmentation was assessed with a laboratory-designed PCR generating overlapping amplicons (around 90-110 bp) within the CMV UL34, UL80.5, and UL54 genes. Intrapatient, inter-patient, and LMV-associated qualitative and quantitative variations in seven amplicons were observed. These variations were seemingly unrelated to the CMV DNA loads measured by the Abbott PCR assay. CMV DNA loads quantified by UL34_4, UL54.5, and UL80.5_1 PCR assays discriminate between LMV and non-LMV patients. Our observations may have relevant implications in the management of active CMV infection in allo-SCT recipients, either treated or not with LMV, although the data need further validation.

The kinetics of Torque Teno virus plasma load following calcineurin inhibitor dose change in kidney transplant recipients.

Torque Teno virus (TTV)is nonpathogenic, highly prevalent, and reflects the immune status of its host. Thus, TTV plasma load was suggested for the guidance of immunosuppression post solidorgan transplantation. The present study was designed to determine the kinetics of TTV following changes in calcineurin inhibitor (CNI)dose. A total of 48 adult recipients of a kidney graft transplanted at the Medical University of Vienna between 2018 and 2019 with isolated changes in CNI dose were selected from the prospective TTV-POETtrial. TTV plasma load was quantified by in-house PCR. At Day 30 following CNI dose adaptation (median 33% of daily dose) no changes in TTV load were noted. However, at Day 60, following CNI dose reduction a lower TTV load of 6.4 log10 c/mL (median; interquartile range[IQR] 4.9-8.1) compared with the baseline of 7.1 log10 c/mL (IQR5.3-8.9) was noted (p = 0.001); there was also a trend towarda higher TTV load following CNI increase (6.6 log10 c/mL, IQR 4.1-9.7 vs. 5.2 log10 c/mL, IQR 4.5-6.8; p = 0.09). The data suggested that TTV load changes become noticeable only 2 months after CNI dose adaptation, which might be the ideal time point for TTV load monitoring.

Context-dependent accuracy of the cobas plasma separation card for HCV RNA viral load measurement.

Collection and preservation of plasma are challenging in remote or under-resourced settings. The cobas® Plasma Separation Card (PSC) is an alternative specimen type for blood-borne pathogen nucleic acid quantitation. We assessed PSC as a specimen type for HCV RNA quantitation in Pakistan. Plasma from venous blood and PSC from finger prick blood were prepared at two sites: Site 1 (in Lahore, n = 199) consisted of laboratory-based outpatient clinics. Specimens were prepared in the same facility and stored frozen. Site 2 was a catchment area within a resource-limited, semi-urban locality of Islamabad with limited access to healthcare services (n = 151). Community public health outreach staff collected blood and prepared the PSC in the participants' homes. Specimens were transported to the central hepatitis laboratory in Lahore to be stored frozen until tested. HCV RNA testing was performed using the cobas HCV RNA test in a central laboratory. Concordance with respect to RNA detectability was high at Site 1 (97.4%), but lower at Site 2 (82.4%). At Site 1, HCV viral load in plasma and PSC were well correlated across the linear range with a 0.21 log10 IU/mL mean bias toward higher concentrations in PSC. At Site 2, HCV viral load in plasma and PSC were poorly correlated. There was a 0.11 log10 IU/mL mean bias toward higher concentrations in PSC. PSC performance can be excellent in underserved settings where refrigerated transport of traditional specimens is difficult. In very challenging field settings, extra support must be provided to ensure correct specimen collection and handling.

Les marqueurs virologiques des cancers associés au virus d’Epstein-Barr

AbstractEpstein-Barr virus is the first human virus related to human cancer and is currently associated with at least ten cancers mainly arisen from B or T lymphocytes or from epithelial cells. EBV-associated tumors are responsible for 1,8 % of all cancer-related deaths worldwide. The routinely detection in biopsy tissues of non coding RNA EBERs (EBv-Encoded small RNA) by in situ hybridization assay remains the hallmark of all EBV-associated malignancies. The EBV-associated cancers are also characterized by abnormal EBV DNA viral load in whole blood or plasma and atypical serological profiles (IgG/IgA against VCA, Viral Capsid Antigen ; EA Early Antigen ; EBNA1 Epstein-Barr Nuclear Antigen 1 ). The analysis of these virological biomarkers are recommended for the screening, diagnosis or the therapeutic follow up of patients at high risk of post transplant lymphoproliferative disease, patients with nasopharyngeal carcinoma and EBV associated T/NK lymphoma. Their clinical usefulness in Hodgkin lymphoma and gastric carcinoma is likely but less established.

Circadian rhythm and circulating cell-free DNA release on healthy subjects

In the last decade, clinical studies have investigated the clinical relevance of circulating cell-free-DNA (ccfDNA) as a diagnostic and prognosis tool in various diseases including cancers. However, limited knowledge on ccfDNA biology restrains its full development in the clinical practice. To improve our understanding, we evaluated the impact of the circadian rhythm on ccfDNA release in healthy subjects over a 24-h period. 10 healthy female subjects underwent blood sampling at 8am and 20 healthy male subjects underwent serial blood sampling (8:00 AM, 9:00 AM, 12:00 PM, 4:00 PM, 8:00 PM, 12:00 AM, 4 AM (+ 1 Day) and 8 AM (+ 1 Day)). We performed digital droplet-based PCR (ddPCR) assays to target 2 DNA fragments (69 & 243 bp) located in the KRAS gene to determine the ccfDNA concentration and fragmentation profile. As control, half of the samples were re-analyzed by capillary miniaturized electrophoresis (BIAbooster system). Overall, we did not detect any influence of the circadian rhythm on ccfDNA release. Instead, we observed a decrease in the ccfDNA concentration after meal ingestion, suggesting either a post-prandial effect or a technical detection bias due to a higher plasma load in lipids and triglycerides. We also noticed a potential effect of gender, weight and creatinine levels on ccfDNA concentration.

Viral Load Dynamics in Plasma and Semen When Antiretroviral Therapy Is Initiated During Early HIV-1 Infection.

We assessed human immunodeficiency virus (HIV) load in plasma and semen during primary HIV infection using serial samples of semen and plasma during the first 24 weeks after diagnosis in untreated participants and those who started antiretroviral therapy (ART) immediately at diagnosis. In the absence of treatment, semen viral load was >1000 copies/mL in almost all specimens (83%) collected 2-10 weeks after the estimated date of HIV acquisition and remained >1000 copies/mL in 35% of untreated participants at the last observed time point. Thus, in the absence of ART, semen viral load remained at a level consistent with transmissibility throughout primary infection.