BACKGROUND: Virus inactivation procedures are used to prevent contamination of plasma‐derived blood products with viruses. Pasteurization or prolonged dry heat has proven effective against several ...enveloped and nonenveloped viruses and provides an additional layer of safety for plasma products.
STUDY DESIGN AND METHODS: The resistance of porcine circovirus 2 (PCV2) and chicken anemia virus (CAV), two small, nonenveloped viruses, to standard (pasteurization, 10 hr at 60°C; dry heating, 80°C for 72 hr) and more extreme heat inactivation procedures (temperatures up to 120°C) was determined. The ability of these procedures to inactivate PCV2 and CAV was measured by comparison of in vitro infectivity before and after treatment.
RESULTS: Infectivity of PCV2 and CAV was reduced by approximately 1.6 and 1.4 log by pasteurization and by 0.75 and 1.25 log by dry‐heat treatment, both substantially more resistant than other viruses previously investigated. PCV2 and CAV were additionally almost completely resistant to dry‐heat treatment up to 120°C for 30 minutes (mean log infectivity reductions, 1.25 and 0.6), although both were more effectively inactivated when the temperature of wet‐heat treatment was increased to 80°C (>3.2 and >3.6 log infectivity reduction).
CONCLUSION: Although neither PCV2 nor CAV are known to infect humans, their inactivation properties may represent those of other small DNA viruses known to be present (e.g., TT virus, small anellovirus) or potentially present in human plasma. Findings of extreme thermal resistance demonstrate that recipients of plasma‐derived therapeutics may potentially still be exposed to small DNA viruses, despite the implementation of viral inactivation steps.
Limbal stem cell deficiency (LSCD) is a disease resulting from the loss or dysfunction of epithelial stem cells, which seriously impairs sight. Autologous limbal stem cell transplantation is ...effective in unilateral or partial bilateral disease but not applicable in total bilateral disease. An allogeneic source of transplantable cells for use in total bilateral disease can be obtained from culture of donated cadaveric corneal tissue. We performed a controlled multicenter study to examine the feasibility, safety, and efficacy of allogeneic corneal epithelial stem cells in the treatment of bilateral LSCD. Patients were randomized to receive corneal epithelial stem cells cultured on amniotic membrane (AM): investigational medicinal product (IMP) or control AM only. Patients received systemic immunosuppression. Primary endpoints were safety and visual acuity, secondary endpoint was change in composite ocular surface score (OSS). Sixteen patients were treated and 13 patients completed all assessments. Safety was demonstrated and 9/13 patients had improved visual acuity scores at the end of the trial, with no significant differences between IMP and control groups. Patients in the IMP arm demonstrated significant, sustained improvement in OSS, whereas those in the control arm did not. Serum cytokine levels were measured during and after the period of immune suppression and we identified strongly elevated levels of CXCL8 in the serum of patients with aniridia, which persisted throughout the trial. This first randomized control trial of allogeneic corneal epithelial stem cells in severe bilateral LSCD demonstrates the feasibility and safety of this approach. Stem Cells Translational Medicine 2019;8:323–331
Patients with severe ocular surface disorder received transplants of amniotic membrane with (black bars) or without (gray bars) cadaveric‐donor‐derived cultured limbal stem cells. All patients received immune suppression. Only patients who received transplants containing limbal stem cells showed sustained significant improvements (reductions) in combined ocular surface scores (5 factors scored 0–3 where 0 is a normal eye score).
Results of small-scale studies have suggested that stem-cell therapy is safe and effective in patients with liver cirrhosis, but no adequately powered randomised controlled trials have been done. We ...assessed the safety and efficacy of granulocyte colony-stimulating factor (G-CSF) and haemopoietic stem-cell infusions in patients with liver cirrhosis.
This multicentre, open-label, randomised, controlled phase 2 trial was done in three UK hospitals and recruited patients with compensated liver cirrhosis and MELD scores of 11·0–15·5. Patients were randomly assigned (1:1:1) to receive standard care (control), treatment with subcutaneous G-CSF (lenograstim) 15 μg/kg for 5 days, or treatment with G-CSF for 5 days followed by leukapheresis and intravenous infusion of three doses of CD133-positive haemopoietic stem cells (0·2 × 106 cells per kg per infusion). Randomisation was done by Cancer Research UK Clinical Trials Unit staff with a minimisation algorithm that stratified by trial site and cause of liver disease. The coprimary outcomes were improvement in severity of liver disease (change in MELD) at 3 months and the trend of change in MELD score over time. Analyses were done in the modified intention-to-treat population, which included all patients who received at least one day of treatment. Safety was assessed on the basis of the treatment received. This trial was registered at Current Controlled Trials on Nov 18, 2009; ISRCTN, number 91288089; and the European Clinical Trials Database, number 2009-010335-41.
Between May 18, 2010, and Feb 26, 2015, 27 patients were randomly assigned to the standard care, 26 to the G-CSF group, and 28 to the G-CSF plus stem-cell infusion group. Median change in MELD from day 0 to 90 was −0·5 (IQR −1·5 to 1·1) in the standard care group, −0·5 (−1·7 to 0·5) in the G-CSF group, and −0·5 (−1·3 to 1·0) in the G-CSF plus stem-cell infusion group. We found no evidence of differences between the treatment groups and control group in the trends of MELD change over time (p=0·55 for the G-CSF group vs standard care and p=0·75 for the G-CSF plus stem-cell infusion group vs standard care). Serious adverse events were more frequent the in G-CSF and stem-cell infusion group (12 43% patients) than in the G-CSF (three 11% patients) and standard care (three 12% patients) groups. The most common serious adverse events were ascites (two patients in the G-CSF group and two patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with ascites twice), sepsis (four patients in the G-CSF plus stem-cell infusion group), and encephalopathy (three patients in the G-CSF plus stem-cell infusion group, one of whom was admitted to hospital with encephalopathy twice). Three patients died, including one in the standard care group (variceal bleed) and two in the G-CSF and stem-cell infusion group (one myocardial infarction and one progressive liver disease).
G-CSF with or without haemopoietic stem-cell infusion did not improve liver dysfunction or fibrosis and might be associated with increased frequency of adverse events compared with standard care.
National Institute of Health Research, The Sir Jules Thorn Charitable Trust.
Cell therapy is an emerging and exciting novel treatment option for cardiovascular disease that relies on the delivery of functional cells to their target site. Monitoring and tracking cells to ...ensure tissue delivery and engraftment is a critical step in establishing clinical and therapeutic efficacy. The study aims were (1) to develop a Good Manufacturing Practice-compliant method of labeling competent peripheral blood mononuclear cells with superparamagnetic particles of iron oxide (SPIO), and (2) to evaluate its potential for magnetic resonance cell tracking in humans.
Peripheral blood mononuclear cells 1-5 × 10(9) were labeled with SPIO. SPIO-labeled cells had similar in vitro viability, migratory capacity, and pattern of cytokine release to unlabeled cells. After intramuscular administration, up to 10(8) SPIO-labeled cells were readily identifiable in vivo for at least 7 days using magnetic resonance imaging scanning. Using a phased-dosing study, we demonstrated that systemic delivery of up to 10(9) SPIO-labeled cells in humans is safe, and cells accumulating in the reticuloendothelial system were detectable on clinical magnetic resonance imaging. In a healthy volunteer model, a focus of cutaneous inflammation was induced in the thigh by intradermal injection of tuberculin. Intravenously delivered SPIO-labeled cells tracked to the inflamed skin and were detectable on magnetic resonance imaging. Prussian blue staining of skin biopsies confirmed iron-laden cells in the inflamed skin.
Human peripheral blood mononuclear cells can be labeled with SPIO without affecting their viability or function. SPIO labeling for magnetic resonance cell tracking is a safe and feasible technique that has major potential for a range of cardiovascular applications including monitoring of cell therapies and tracking of inflammatory cells. Clinical Trial Registration- URL: http://www.clinicaltrials.gov; Unique identifier: NCT00972946, NCT01169935.
BACKGROUND:Virus inactivation procedures are used to prevent contamination of plasma-derived blood products with viruses. Pasteurization or prolonged dry heat has proven effective against several ...enveloped and nonenveloped viruses and provides an additional layer of safety for plasma products. STUDY DESIGN AND METHODS:The resistance of porcine circovirus 2 (PCV2) and chicken anemia virus (CAV), two small, nonenveloped viruses, to standard (pasteurization, 10 hr at 60 degree C; dry heating, 80 degree C for 72 hr) and more extreme heat inactivation procedures (temperatures up to 120 degree C) was determined. The ability of these procedures to inactivate PCV2 and CAV was measured by comparison of in vitro infectivity before and after treatment. RESULTS:Infectivity of PCV2 and CAV was reduced by approximately 1.6 and 1.4 log by pasteurization and by 0.75 and 1.25 log by dry-heat treatment, both substantially more resistant than other viruses previously investigated. PCV2 and CAV were additionally almost completely resistant to dry-heat treatment up to 120 degree C for 30 minutes (mean log infectivity reductions, 1.25 and 0.6), although both were more effectively inactivated when the temperature of wet-heat treatment was increased to 80 degree C (>3.2 and >3.6 log infectivity reduction). CONCLUSION:Although neither PCV2 nor CAV are known to infect humans, their inactivation properties may represent those of other small DNA viruses known to be present (e.g., TT virus, small anellovirus) or potentially present in human plasma. Findings of extreme thermal resistance demonstrate that recipients of plasma-derived therapeutics may potentially still be exposed to small DNA viruses, despite the implementation of viral inactivation steps.
Bone allografts are commonly used in a variety of surgical procedures, to reconstruct lost bone stock and to provide mechanical support during the healing process. Due to concerns regarding the ...possibility of disease transmission from donor to recipient, and of contamination of grafts during retrieval and processing procedures, it is common practice to sterilise bone allografts prior to issue for clinical use. It is vital that the sterilisation processes applied to allografts are validated to demonstrate that they achieve the required level of bioburden reduction, and by extension that validated models are used for these studies. Two common sterilisation protocols applied to bone allografts are gamma irradiation and ethylene oxide gas sterilisation, and there are currently no validated models available for measuring the anti-viral efficacy of ethylene oxide treatment with regard to bone allografts or readily useable models for assessing the anti-viral efficiency of gamma irradiation treatment. We have developed and validated models for both these sterilisation processes, using the bacteriophage varphix174, and utilised the models to measure the antiviral activity of the standard ethylene oxide and gamma irradiation sterilisation processes applied to bone allografts by the National Blood Service. For the irradiation model, we also utilised bacterial spores (Bacillus pumilus). Our results show that ethylene oxide sterilisation (which can only be applied to lyophilised grafts) inactivated > 6.1 log(10) of the model virus, and gamma irradiation (at 25 -40 kGy and applied to frozen allografts) inactivated 3.6 - 4.0 log(10) of the model virus and > 4 log(10) of the bacterial spores. Gamma irradiation at this dosage is therefore not in itself a sterilisation process with respect to viruses.
The ability of ultraviolet (UV) light to inactivate viruses is well established. However, attempts to apply this to the manufacture of pharmaceutical proteins have been limited by incomplete ...treatment, low capacity or excessive dilution. Effective processing of large-scale batches of UV-opaque protein solutions has been achieved using a continuous-flow device. The operation of this device has been modelled and a design equation derived to relate the processing conditions and product characteristics to the degree of virus inactivation obtained. Variables included in the model are UV-absorbance at 254
nm (
A
254), hydrodynamic properties of the protein solution, residence time, intensity of UV light and diameter and length of irradiation tube. With this information a specific constant was calculated for each virus which denotes its relative sensitivity to UV and from which the degree of virus inactivation expected can be estimated.
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