Viral Reduction Research Articles

Modeling Surface Disinfection Needs To Meet Microbial Risk Reduction Targets.

Nosocomial viral infections are an important cause of health care-acquired infections where fomites have a role in transmission. Using stochastic modeling to quantify the effects of surface disinfection practices on nosocomial pathogen exposures and infection risk can inform cleaning practices. The purpose of this study was to predict the effect of surface disinfection on viral infection risks and to determine needed viral reductions to achieve risk targets. Rotavirus, rhinovirus, and influenza A virus infection risks for two cases were modeled. Case 1 utilized a single fomite contact approach, while case 2 assumed 6 h of contact activities. A 94.1% viral reduction on surfaces and hands was measured following a single cleaning round using an Environmental Protection Agency (EPA)-registered disinfectant in an urgent care facility. This value was used to model the effect of a surface disinfection intervention on infection risk. Risk reductions for other surface-cleaning efficacies were also simulated. Surface reductions required to achieve risk probability targets were estimated. Under case 1 conditions, a 94.1% reduction in virus surface concentration reduced infection risks by 94.1%. Under case 2 conditions, a 94.1% reduction on surfaces resulted in median viral infection risks being reduced by 92.96 to 94.1% and an influenza A virus infection risk below one in a million. Surface concentration in the equations was highly correlated with dose and infection risk outputs. For rotavirus and rhinovirus, a >99.99% viral surface reduction would be needed to achieve a one-in-a-million risk target. This study quantifies reductions of infection risk relative to surface disinfectant use and demonstrates that risk targets for low-infectious-dose organisms may be more challenging to achieve.IMPORTANCE It is known that the use of EPA-registered surface disinfectant sprays can reduce infection risk if used according to the manufacturer's instructions. However, there are currently no standards for health care environments related to contamination levels on surfaces. The significance of this research is in quantifying needed reductions to meet various risk targets using realistic viral concentrations on surfaces for health care environments. This research informs the design of cleaning protocols by demonstrating that multiple applications may be needed to reduce risk and by highlighting a need for more models exploring the relationship among microbial contamination of surfaces, patient and health care worker behaviors, and infection risks.

Evaluation of a computer-based and counseling support intervention to improve HIV patients’ viral loads

ABSTRACTWe sought to integrate a brief computer and counseling support intervention into the routine practices of HIV clinics and evaluate effects on patients’ viral loads. The project targeted HIV patients in care whose viral loads exceeded 1000 copies/ml at the time of recruitment. Three HIV clinics initiated the intervention immediately, and three other HIV clinics delayed onset for 16 months and served as concurrent controls for evaluating outcomes. The intervention components included a brief computer-based intervention (CBI) focused on antiretroviral therapy adherence; health coaching from project counselors for participants whose viral loads did not improve after doing the CBI; and behavioral screening and palm cards with empowering messages available to all patients at intervention clinics regardless of viral load level. The analytic cohort included 982 patients at intervention clinics and 946 patients at control clinics. Viral loads were assessed at 270 days before recruitment, at time of recruitment, and +270 days later. Results indicated that both the control and intervention groups had significant reductions in viral load, ending with approximately the same viral level at +270 days. There was no evidence that the CBI or the targeted health coaching was responsible for the viral reduction in the intervention group. Results may stem partially from statistical regression to the mean in both groups. Also, clinical providers at control and intervention clinics may have taken action (e.g., conversations with patients, referrals to case managers, adherence counselors, mental health, substance use specialists) to help their patients reduce their viral loads. In conclusion, neither a brief computer-based nor targeted health coaching intervention reduced patients’ viral loads beyond levels achieved with standard of care services available to patients at well-resourced HIV clinics.

Antiviral activity of Ribavirin nano-particles against measles virus

Measles virus considers an important cause of child morbidity and mortality in some areas as Africa. Ribavirin's activity as a nucleoside analog can disclose the surprisingly broad spectrum action against several RNA viruses under laboratory cell culture conditions. The Current study aimed to investigate the antiviral activity of ribavirin Nano gold particles (AuNPs) against measles virus on vero cell line. Ribavirin- AuNPs was prepared, characterization and the cytotoxicity of ribavirin, AuNPs and ribavirin -AuNPs were tested on vero cells using MTT assay. Antiviral activiry of ribavirin, AuNPs and ribavirin- AuNPswere determined on vero cells using simultaneous, pre-infection and post-infection protocols. Results indicated safety of ribavirin and ribavirin-AuNPs on vero cells, there was a reduction by 78.1% when vero cells treated with ribavirin -AuNPs at 99.5µg/ml while, the viral reduction was 25.4% when ribavirin 500 µg /ml was used for the same viral concentration. Our results concluded that ribavirin - AuNPs had a higher antiviral activity with lower dose than ribavirin alone and the maximal activity showed when it used after the virus infection.

Virus reduction through microfiltration membranes modified with a cationic polymer for drinking water applications

Virus penetration is a significant problem in water treatment membrane filtration. To effectively remove waterborne viruses nano-filtration, reverse osmosis or ultrafiltration must be used, all of which are high energy filtration schemes. Novel approaches and technologies for the production of virus-free drinking water are therefore warranted. In this study, we modified model surfaces and commercial polyether sulfone, (PES) microfiltration (MF) membranes to achieve a substantial virus reduction under gravity based filtration membranes. The successful modification using the cationic polymer polyethyleneimine (PEI) was confirmed by Fourier transform infrared spectroscopy (FTIR) and zeta potential measurements. MS2 bacteriophages, a surrogate for human pathogenic waterborne viruses like norovirus were used to challenge the modified surfaces. The membrane modification resulted in ∼22% loss of the membrane permeability while an increase of ≥3 log10-units (≥99.9%) in MS2 reduction was observed. These reductions were comparable to the reduction of PEI-coated model surfaces tested for contact reduction. This simple modification of a commercially available MF membrane led to substantial viral reductions with a significant flux of 5000 L/m2 in approximately 2.5 h. This work therefore, highlights the potential modified MF membranes for gravity-based filtrations to produce safe drinking water. Further studies should be done to show similarly enhanced reductions of human pathogenic viruses.

Bronchial mucosal IFN-α/β and pattern recognition receptor expression in patients with experimental rhinovirus-induced asthma exacerbations

BackgroundThe innate immune system senses viral infection through pattern recognition receptors (PRRs), leading to type I interferon production. The role of type I interferon and PPRs in rhinovirus-induced asthma exacerbations in vivo are uncertain.ObjectivesWe sought to compare bronchial mucosal type I interferon and PRR expression at baseline and after rhinovirus infection in atopic asthmatic patients and control subjects.MethodsImmunohistochemistry was used to detect expression of IFN-α, IFN-β, and the PRRs: Toll-like receptor 3, melanoma differentiation–associated gene 5, and retinoic acid–inducible protein I in bronchial biopsy specimens from 10 atopic asthmatic patients and 15 nonasthmatic nonatopic control subjects at baseline and on day 4 and 6 weeks after rhinovirus infection.ResultsWe observed IFN-α/β deficiency in the bronchial epithelium at 3 time points in asthmatic patients in vivo. Lower epithelial IFN-α/β expression was related to greater viral load, worse airway symptoms, airway hyperresponsiveness, and reductions in lung function during rhinovirus infection. We found lower frequencies of bronchial subepithelial monocytes/macrophages expressing IFN-α/β in asthmatic patients during infection. Interferon deficiency at baseline was not accompanied by deficient PRR expression in asthmatic patients. Both epithelial and subepithelial PRR expression were induced during rhinovirus infection. Rhinovirus infection–increased numbers of subepithelial interferon/PRR-expressing inflammatory cells were related to greater viral load, airway hyperresponsiveness, and reductions in lung function.ConclusionsBronchial epithelial IFN-α/β expression and numbers of subepithelial IFN-α/β–expressing monocytes/macrophages during infection were both deficient in asthmatic patients. Lower epithelial IFN-α/β expression was associated with adverse clinical outcomes after rhinovirus infection in vivo. Increases in numbers of subepithelial cells expressing interferon/PRRs during infection were also related to greater viral load/illness severity.

<i>In ovo</i> antiviral activity of the constituents of <i>Artabotrys monteiroae</i> and <i>Artabotrys modestus</i> against Infectious Bursal Disease and Newcastle Disease Viruses

Infectious bursal disease virus (IBDV) and Newcastle disease virus (NDV) are among the avian pathogenic agents of economic importance affecting both subsistence and commercially produced chickens worldwide. With exception of vaccination, there is no treatment of the diseases caused by these viruses to date. The chemical constituents from the two Tanzanian Artabotrys species, A. monteiroae and A. modestus (Annonaceae) were screened for their antiviral activities against IBDV and NDV in ovo (in the egg). The nine-day-old embryonated eggs in a set of five were used for testing antiviral efficacy through the allantoic route inoculation assay for each tested compound and controls. For NDV assay, the allantoic fluids from the specimens were further harvested to determine viral infection. Artamonteirine (1) from A. monteiroae and quebrachitol (2) from A. modestus showed significant effective treatment against IBDV. The rest of the tested compounds showed moderate or weak antiviral activity at 360 μg/mL screening concentration. The tested compounds also exhibited in ovo antiviral activity against NDV, showing viral titre reduction at a range of 1:128 - 1:256 in the haemagglutination test, indicating 16 and 8 times viral load decline compared with untreated embryo (positive control; 1:2048). Further studies to determine the mode of action and toxicity of the potent compounds need to be undertaken towards the development of such antiviral agents. © 2017 International Formulae Group. All rights reserved. Keywords: Antiviral, IBDV, NDV, Artabotrys monteiroe , Artabotrys modestus , Annonaceae

English

Respiratory syncytial virus (RSV) causes viral infection of a global proportion. Currently, there is no approved vaccine or useful antiviral drug against it. Natural products hold potential for discovery of anti-RSV agents. The present study assessed the anti-RSV activities of Alchornea cordifolia (AC) (Shumach. and Thonn.) MÏ‹ll. Arg. and Alchornea floribunda (AF) MÏ‹ll. Arg., Antiviral activities of AC and AF leaf extracts were evaluated by a modified viral plaque reduction assay. Parallel assays for effect of the antiviral agents on cell viabilities were carried out the cells using the 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (MTT) reduction assays. Mechanism of anti-RSV action of the extracts was done based on time-of-addition assay. Extracts of AC and AF, showed anti-RSV activities with IC50 = 5.64 ± 1.16, and 75.62 ± 3.38 µg/ml, respectively while the cell cytotoxic effect of extracts were TC50 = 103.14 ± 3.98, and 333.82 ± 6.32 µg/ml, respectively. Time-of-addition assay results suggested that AC and AF interfere with viral replication at a viral post-entry step. The extracts of AC and AF exhibited profound anti-RSV activities warranting their development for further possible clinical utility against RSV. Key words: Alchornea cordifolia, Alchornea floribunda, respiratory syncytial virus (RSV), antiviral, time-of-addition, cell culture. &nbsp

Hepatitis A Virus Disinfection in Water by Solar Photo–Fenton Systems

This study evaluates and compares the effectiveness of solar photo-Fenton systems for the inactivation of hepatitis A virus (HAV) in water. The effect of solar irradiance, dark- Fenton reaction and three different reactant concentrations (2.5/5, 5/10 and 10/20mg/L of Fe2+/H2O2) on the photo-Fenton process were tested in glass bottle reactors (200mL) during 6h under natural sunlight. Disinfection kinetics were determined both by RT-qPCR and infectivity assays. Mean water temperatures ranged from 25 to 27.3°C, with a maximum local noon UV irradiances of 22.36W/m2. Photo-Fenton systemsyielded increased viral reduction rates in comparison with the isolated effect under the Fenton reaction in darkness (negligible viral reduction) or the solar radiation (0.25 Log of RNA reduction). With the highest concentration employed (10-20mg/L Fe2+-H2O2), an average RNA reduction rate of ~1.8 Log (initial concentration of 105 pfu/mL) and a reduction of 80% in the infectivity capacity were reached. Results showed a strong synergistic effect between Fe2+/H2O2 and sunlight, demonstrating that significant disinfection rates of HAV under photo-Fenton systems may occur with relatively higher efficiency at middle environmental temperatures and without the need for an energy-intensive light source.

Impacts of virus processing on human norovirus GI and GII persistence during disinfection of municipal secondary wastewater effluent

Noroviruses cause significant global health burdens and waterborne transmission is a known exposure pathway. Chlorination is the most common method of disinfection for water and wastewater worldwide. The purpose of this study was to investigate the underlying causes for discrepancies in human norovirus (hNoV) resistance to free chlorine that have been previously published, and to assess hNoV GI and GII persistence during disinfection of municipal secondary wastewater (WW) effluent. Our results reveal that choice of hNoV purification methodology prior to seeding the viruses in an experimental water matrix influences disinfection outcomes in treatment studies. Common hNoV purification processes such as solvent extraction and 0.45-μm filtration were ineffective in removing high levels of organics introduced into water or wastewater samples when seeding norovirus positive stool. These methods resulted in experimental water matrices receiving an additional 190 mg/L as Cl2 of 15-s chlorine demand and approximately 440 mg/L as Cl2 of 30-min chlorine demand due to seeding norovirus positive stool at 1% w/v. These high organic loads impact experimental water chemistry and bias estimations of hNoV persistence. Advanced purification of norovirus positive stool using sucrose cushion ultracentrifugation and ultrafiltration reduced 15-s chlorine demands by 99% and TOC by 93% for loose (i.e. unformed diarrhea) stools. Using these methods, hNoV GI and GII persistence was investigated during free chlorination of municipal WW. A suite five of kinetic inactivation models was fit to viral reverse transcription-qPCR reduction data, and model predicted CT values for 1, 2, and 3 log10 reduction of hNoV GI in municipal WW by free chlorine were 0.3, 2.1, and 7.8 mg-min/L, respectively. Model predicted CT values for reduction of hNoV GII in WW were 0.4, 2.0, and 7.0 mg-min/L, respectively. These results indicate that current WW treatment plant disinfection practices employing free chlorine are likely protective for public health with regards to noroviruses, and will achieve at least 3-log reduction of hNoV GI and GII RNA despite previous reports of high hNoV resistance.

Neutralization of antibody-enhanced dengue infection by VIS513, a pan serotype reactive monoclonal antibody targeting domain III of the dengue E protein.

Dengue virus (DENV) infection imposes enormous health and economic burden worldwide with no approved treatment. Several small molecules, including lovastatin, celgosivir, balapiravir and chloroquine have been tested for potential anti-dengue activity in clinical trials; none of these have demonstrated a protective effect. Recently, based on identification and characterization of cross-serotype neutralizing antibodies, there is increasing attention on the potential for dengue immunotherapy. Here, we tested the ability of VIS513, an engineered cross-neutralizing humanized antibody targeting the DENV E protein domain III, to overcome antibody-enhanced infection and high but brief viremia, which are commonly encountered in dengue patients, in various in vitro and in vivo models. We observed that VIS513 efficiently neutralizes DENV at clinically relevant viral loads or in the presence of enhancing levels of DENV immune sera. Single therapeutic administration of VIS513 in mouse models of primary infection or lethal secondary antibody-enhanced infection, reduces DENV titers and protects from lethal infection. Finally, VIS513 administration does not readily lead to resistance, either in cell culture systems or in animal models of dengue infection. The findings suggest that rapid viral reduction during acute DENV infection with a monoclonal antibody is feasible.

Aedes aegypti antiviral adaptive response against DENV-2

Priming is the conceptual term defining memory phenomenon in innate immune response. Numerous examples of enhanced secondary immune response have been described in diverse taxa of invertebrates; which naturally lacks memory response. In mosquitoes, a previous non-lethal challenge with some specific pathogens modify their immune response against the same microorganism; developing an improved antimicrobial reaction. In this work, we explore the ability of Aedes aegypti to mount a higher antiviral response upon a second oral DENV challenge. When previously challenged with inactive virus, we observed that the posterior infection showed a diminished number of DENV infectious particles in midguts and carcasses. In challenged tissues, we detected higher de novo midgut DNA synthesis than control group, as determined by DNA incorporation of 5-bromo-2-deoxyuridine. We demonstrated that inactive DENV particle are capable to induce DNA synthesis levels comparable to infective DENV. We considered the Drosophila melanogaster hindsight and Delta-Notch mosquitoes orthologues as potential de novo DNA synthesis pathway components (as observed in fly oocyte development and midgut tissue renewal). We showed that Aedes aegypti hindsight transcript relative expression levels were higher than control during DENV infection and inactive DENV particle alimentation. Also, Aedes aegypti second challenge with active DENV induced higher hindsight, Delta and Notch transcriptions in the primed mosquitoes (compared with the primary infection levels). Considering that the mosquito de novo DNA synthesis is concomitant to viral particle reduction, this finding opens a new perspective on the mechanisms underlying the vector antiviral immune response and the effector molecules involved.

Assessment of drug discontinuation among adult patients who are taking antiretroviral treatment at Yeka Sub-City Woreda 9 and 10 health centers Addis Ababa, Ethiopia

Background: Antiretroviral therapy has led to a substantial reduction in HIV-associated morbidity and mortality. Efficacy of antiretroviral treatment in HIV/AIDS is showing inhibition of viral replication and reduction of viral load to a point where viral particles are undetectable in the blood of infected individuals. This has led to the realization that HIV/AIDS is a chronic illness. Objective: The main objective of this study was to assess drug discontinuation patients who are taking antiretroviral treatment at yeka sub-city woreda 9 and 10 Addis Ababa Ethiopia. Methods: A cross-sectional descriptive study was employed using quantitative approach to assess drug discontinuation among patients who are taking antiretroviral treatment among HIV/AIDS infected persons. Result: At the end of one month study period 219 patients from the total 620 returned to the pharmacy to refill their medication were interviewed and the drug discontinuation to ARV medication was 27 (12.3)% of all prescribed doses. Conclusion and Recommendation: Drug discontinuation to antiretroviral regimen is critical, patient must take 95 percent of the prescribed pills to achieve an 80% of the likelihood of HIV suppression below 50 copies per ml, regarding to the present study the drug discontinuation was 12.3%.

Clinical and virologic effects of four neuraminidase inhibitors in influenza A virus-infected children (aged 4–12 years): an open-label, randomized study in Japan

ABSTRACTBackground: Neuraminidase inhibitors (NAIs) reduce influenza symptoms but clear evidence of relationships between viral titer reduction and symptom alleviation is lacking. This open-label, randomized study evaluated differences in viral dynamics between NAIs, and relationships between viral dynamics and influenza symptoms (trial registration number: UMIN000012670).Methods: Patients (n = 123) aged 4–12 years with influenza A virus infection were randomized to intravenous peramivir, oral oseltamivir, inhaled zanamivir, or inhaled laninamivir. Patients received regular viral assessments of nasal discharge, at least until rapid antigen tests were negative. Time to virus clearance, based on influenza virus titer, was the primary endpoint.Results: Peramivir recipients had a significantly shorter time to virus clearance than oseltamivir recipients (adjusted p = 0.035). Comparisons between the peramivir group and other NAI groups were not significant. There were no significant inter-group differences in other clinical efficacy endpoints (time to resolution of fever, time to alleviation of symptoms). However, the peramivir group showed a smaller numerical proportion of relapses with fever or positive virus than the other groups.Conclusions: The time to virus clearance was significantly shorter with peramivir than with oseltamivir. Although no clear relationship between virus dynamics and symptoms was observed, ongoing studies should clarify the situation.

Pegylated Interferon-α-Induced Natural Killer Cell Activation Is Associated With Human Immunodeficiency Virus-1 DNA Decline in Antiretroviral Therapy-Treated HIV-1/Hepatitis C Virus-Coinfected Patients.

Interferon alpha (IFN-α) can potently reduce human immunodeficiency virus type 1 (HIV-1) replication in tissue culture and animal models, but may also modulate residual viral reservoirs that persist despite suppressive antiretroviral combination therapy. However, mechanisms leading to viral reservoir reduction during IFN-α treatment are unclear. We analyzed HIV-1 gag DNA levels in CD4 T cells by digital droplet polymerase chain reaction and CD8 T-cell and natural killer (NK) cell phenotypes by flow cytometry in a cohort of antiretroviral therapy-treated HIV-1/hepatitis C virus-coinfected patients (n = 67) undergoing treatment for hepatitis C infection with pegylated IFN-α and ribavirin for an average of 11 months. We observed that IFN-α treatment induced a significant decrease in CD4 T-cell counts (P < .0001), in CD4 T-cell-associated HIV-1 DNA copies (P = .002) and in HIV-1 DNA copies per microliter of blood (P < .0001) in our study patients. Notably, HIV-1 DNA levels were unrelated to HIV-1-specific CD8 T-cell responses. In contrast, proportions of total NK cells, CD56brightCD16- NK cells, and CD56brightCD16+ NK cells were significantly correlated with reduced levels of CD4 T-cell-associated HIV-1 DNA during IFN-α treatment, especially when coexpressing the activation markers NKG2D and NKp30. These data suggest that the reduction of viral reservoir cells during treatment with IFN-α is primarily attributable to antiviral activities of NK cells.

Pharmacophore modelling, virtual screening and molecular docking studies on PLD1 inhibitors

Lipid metabolism plays a significant role in influenza virus replication and subsequent infection. The regulatory mechanism governing lipid metabolism and viral replication is not properly understood to date, but both Phospholipase D (PLD1 and PLD2) activities are stimulated in viral infection. In vitro studies indicate that chemical inhibition of PLD1 delays viral entry and reduction of viral loads. The current study reports a three-dimensional pharmacophore model based on 35 known PLD1 inhibitors. A sub-set of 25 compounds was selected as the training set and the remaining 10 compounds were kept in the test set. One hundred and twelve pharmacophore models were generated; a six-featured pharmacophore model (AADDHR.57) with survival score (2.69) produced a statistically significant three-dimensional quantitative structure–activity relationship model with r2 = 0.97 (internal training set), r2 = 0.71 (internal test set) and Q2 = 0.64. The predictive power of the pharmacophore model was validated with an external test set (r2 = 0.73) and a systematic virtual screening work-flow was employed showing an enrichment factor of 23.68 at the top 2% of the dataset (active and decoys). Finally, the model was used for screening of the filtered PubChem database to fetch molecules which can be proposed as potential PLD1 inhibitors for blocking influenza infection.

Covering the Cover

Covering the Cover

Inhibition of human cytomegalovirus immediate early gene expression and growth by a novel RNase P ribozyme variant.

We have previously engineered new RNase P-based ribozyme variants with improved in vitro catalytic activity. In this study, we employed a novel engineered variant to target a shared mRNA region of human cytomegalovirus (HCMV) immediate early proteins 1 (IE1) and 2 (IE2), which are essential for the expression of viral early and late genes as well as viral growth. Ribozyme F-R228-IE represents a novel variant that possesses three unique base substitution point mutations at the catalytic domain of RNase P catalytic RNA. Compared to F-M1-IE that is the ribozyme derived from the wild type RNase P catalytic RNA sequence, the functional variant F-R228-IE cleaved the target mRNA sequence in vitro at least 100 times more efficiently. In cultured cells, expression of F-R228-IE resulted in IE1/IE2 expression reduction by 98–99% and in HCMV production reduction by 50,000 folds. In contrast, expression of F-M1-IE resulted in IE1/IE2 expression reduction by less than 80% and in viral production reduction by 200 folds. Studies of the ribozyme-mediated antiviral effects in cultured cells suggest that overall viral early and late gene expression and viral growth were inhibited due to the ribozyme-mediated reduction of HCMV IE1 and IE2 expression. Our results provide direct evidence that engineered RNase P ribozymes, such as F-R228-IE, can serve as a novel class of inhibitors for the treatment and prevention of HCMV infection. Moreover, these results suggest that F-R228-IE, with novel and unique mutations at the catalytic domain to enhance ribozyme activity, can be a candidate for the construction of effective agents for anti-HCMV therapy.

Selective recruitment of nucleoporins on vaccinia virus factories and the role of Nup358 in viral infection

Vaccinia virus (VACV), a member of the Poxviridae family, uses cytoplasmic factories for its replication. Recent studies indicated that VACV infection requires a set of nucleoporins. However, how the nucleoporins contribute to viral life cycle remains unclear. Here, we report that the nucleoporins Nup62 and Nup358 localize to the cytoplasmic viral factories (VFs). Nup358 was targeted to the VFs at 6h post-infection (hpi), whereas Nup62, along with the previously reported translation factors such as eIF4E, eIF3η and G3BP1, was recruited to the VFs at 8 hpi. Nup358 depletion led to a decrease in the size and number of viral factories and reduction in viral yield. Further studies showed that Nup358 is involved in recruiting Nup62 and eIF4E to the VFs. Collectively, our results reveal spatio-temporal regulation in the recruitment of nucleoporins and translation factors to VFs, and particularly the importance of Nup358 in VACV infection.

Do we need cryoprecipitate in the era of fibrinogen concentrate and other specific factor replacement options?

Cryoprecipitate was first used in the 1960s as a source of factor VIII (FVIII) for the treatment of bleeding in haemophilia A. Although still used in some countries for this purpose, its main use now is as a concentrated source of fibrinogen, commonly administered as part of major haemorrhage therapy for patients with uncontrolled bleeding. Fibrinogen is recognized as the first clotting protein to fall to clinically significant low levels during major haemorrhage, and there has been a recent explosion of interest around the potential importance of fibrinogen replacement therapy in this setting. This has led many to question the relative benefits of cryoprecipitate as compared to fibrinogen concentrate. This review will explore whether cryoprecipitate, in the era of specific factor concentrates, is an outmoded treatment. Cryoprecipitate is manufactured from frozen plasma after controlled thawing. It is not only a rich source of FVIII and fibrinogen but also contains von Willebrand Factor (VWF), FXIII and fibronectin. In UK, cryoprecipitate is available as single donor units or as pools of 5 units and requires thawing before transfusion. Variability in clotting factor levels in blood donors means that the fibrinogen concentration in cryoprecipitate may vary. With the exception of donor screening and viral testing at the time of donation, no viral reduction steps are taken during manufacture. Fibrinogen concentrate is an alternative concentrated source of fibrinogen but is not licensed in every country for acquired bleeding. It is a plasma‐derived product manufactured from pooled plasma. Many view fibrinogen concentrate as a superior product to cryoprecipitate with reasons including: standardization of production–vials contain a known fibrinogen concentration; lyophilization making it easily portable and not requiring storage or thawing in blood bank; viral inactivation; a consideration for the UK is a likely lower risk for vCJD transmission. Gram for gram, fibrinogen concentrate is four times the cost of cryoprecipitate. The UK haemophilia centre doctors organisation (UKHCDO) recommends the use of single‐factor agents above pooled blood components for replacement therapy in inherited bleeding conditions, where possible, for many of these reasons. But what about cryoprecipitate as therapy for acquired bleeding where patients develop a complex coagulopathy affecting multiple coagulation and fibrinolytic factors? Might cryoprecipitate therapy confer an advantage? Theoretically, higher concentrations of VWF, FVIII and FXIII might promote more rapid primary and secondary haemostasis. Clinical efficacy for the two products in observational studies and one RCT has been reported to be similar, where increases in fibrinogen blood levels are comparable. However, no study has yet been large enough to look at comparative clinical efficacy or indeed safety. In the era of single‐factor concentrates, cryoprecipitate may seem outdated, but at present–in particular in relation to therapy for major haemorrhage–insufficient evidence is available which confirms or refutes it place in major haemorrhage therapy.

Effect of zymosan and poly (I:C) adjuvants on responses to microneedle immunization coated with whole inactivated influenza vaccine

Microneedles are the micrometer size devices used for the delivery of vaccines and biotherapeutics. In order to increase the vaccine efficacy and reduce the antigen dose, there is a significant need to find some adjuvants for the microneedle vaccination. In this study, zymosan, which is the cell wall preparation of Saccharomyces cerevisiae, or poly (I:C) was coated on a microneedle with inactivated influenza virus, and then immunized into BALB/c mouse to determine the immunogenicity, protection and synergetic effect between two adjuvants. As a result, the group administered with zymosan and vaccine antigen showed significantly stronger IgG response, HI titer and IgG subtypes without any adverse effects, compared to the group immunized with the vaccine antigen alone. Also, there were enhanced cellular immune responses in the group received adjuvant with vaccine antigen. In addition, they showed superior protection and lung viral reduction against lethal viral challenge. Taken together, this study confirms that zymosan can be used as an immunostimulant for microneedle vaccination.