Non-lipid Enveloped Viruses Research Articles

Indications for use and cost-effectiveness of pathogen-reduced ABO-universal plasma

Donor selection and viral screening methods combined with pathogen reduction have increased the safety of pooled plasma to a level which makes reintroduction of ABO-universal plasma an important option. Solvent detergent-treated pooled plasma has proved to be well suited for the production of pathogen-reduced ABO-universal plasma. One such product, Bioplasma FDP, was licensed in South Africa in 1994 and has since 1996 been in successful clinical use. A clinical study with this product and two studies with the European product, Uniplas, have confirmed the efficacy and safety of pathogen-reduced ABO-universal plasma. Pooling of plasma enables the production of ABO-universal plasma. Pathogen reduction with solvent detergent eliminates lipid-enveloped viruses, whereas neutralizing antibodies in the plasma pool and nucleic acid amplification testing ensures the safety for recognized nonlipid-enveloped viruses. Pooling also eliminates transfusion-associated acute lung injury (the leading cause of plasma transfusion-related death), reduces immunologic/allergic adverse events by 60-80% and standardizes plasma protein content. Thus, in addition to ABO compatibility, pathogen-reduced ABO-universal plasma has important supplementary benefits that improve the product's cost-effectiveness.

Potential and limitation of UVC irradiation for the inactivation of pathogens in platelet concentrates

Pathogen contamination, causing transfusion-transmitted diseases, is an ongoing concern in transfusion of cellular blood products. In this explorative study, the pathogen-inactivating capacity of UVC irradiation in platelet (PLT) concentrates was investigated. The dose dependencies of inactivation of several viruses and bacteria were compared with the effect on PLT quality. The potential of UVC irradiation was studied with a range of lipid-enveloped (LE) and non-lipid-enveloped viruses (NLE) and bacteria. LE viruses were bovine viral diarrhea virus (BVDV), human immunodeficiency virus (HIV), pseudorabies virus (PRV), transmissible gastroenteritis virus (TGEV), and vesicular stomatitis virus (VSV). NLE viruses were canine parvovirus (CPV) and simian virus 40 (SV40). Bacteria were Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, and Bacillus cereus. After spiking and irradiation, samples were tested for residual infectivity and reduction factors (RFs) were calculated. Furthermore, the effect of UVC irradiation on PLT quality was determined by measuring in vitro quality variables. A UVC dose of 500 J per m(2) resulted in acceptable PLT quality (as measured by pH, lactate production, CD62P expression, and exposure of phosphatidylserine) and high RFs (>4 log) for CPV, TGEV, VSV, S. epidermidis, S. aureus, and E. coli. Intermediate RFs (approx. 3 log) were observed for BVDV, PRV, and B. cereus. Low RFs (approx. 1 log) were found for HIV and SV40. No differences in virus reduction were observed between cell-free and cell-associated virus. UVC irradiation is a promising pathogen-reducing technique in PLT concentrates, inactivating bacteria, and a broad range of viruses (with the exception of HIV) under conditions that have limited effects on PLT quality. Further optimization of the UVC procedure, however, is necessary to deal with blood-borne viruses like HIV.

Enhanced virus safety of a solvent/detergent-treated antihemophilic factor IX concentrate by dry-heat treatment

With particular regards to the hepatitis A virus (HAV), a terminal dry-heat treatment (100°C for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor IX concentrate. The loss of factor IX activity during dry-heat treatment was of about 3%, as estimated by a clotting assay. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor IX compared with those of the factor IX before dry-heat treatment. The dry-heat-treated factor IX was stable for up to 24 months at 4°C. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV and murine encephalomyocarditis virus (EMCV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Porcine parvovirus (PPV) and bovine herpes virus (BHV) were potentially sensitive to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ≥5.60 for HAV, ≥6.08 for EMCV, 2.64 for PPV, and 3.59 for BHV. These results indicate that dry-heat treatment improves the virus safety of factor IX concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of nonlipid enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

Viral safety of Nanogam®, a new 15 nm‐filtered liquid immunoglobulin product

Producers of plasma derivatives continuously improve the viral safety of their products by, for example, introducing additional virus-reducing steps into the manufacturing process. Here we present virus-elimination studies undertaken for a number of steps employed in a new manufacturing process for liquid intravenous immunoglobulin (Nanogam) that comprises two specific virus-reducing steps: a 15-nm filtration step combined with pepsin treatment at pH 4.4 (pH 4.4/15NF); and solvent-detergent (SD) treatment. The manufacturing process also includes precipitation of Cohn fraction III and viral neutralization, which contribute to the total virus-reducing capacity of the manufacturing process. In addition, the mechanism and robustness of the virus-reducing steps were studied. Selected process steps were studied with spiking experiments using a range of lipid enveloped (LE) and non-lipid-enveloped (NLE) viruses. The LE viruses used were bovine viral diarrhoea virus (BVDV), human immunodeficiency virus (HIV) and pseudorabies virus (PRV); the NLE viruses used were parvovirus B19 (B19), canine parvovirus (CPV) and encephalomyocarditis virus (EMC). After spiking, samples were collected and tested for residual infectivity, and the reduction factors were calculated. For B19, however, removal of B19 DNA was measured, not residual infectivity. To reveal the contribution of viral neutralization, bovine parvovirus (BPV) and hepatitis A virus (HAV) were used. For the pH 4.4/15NF step, complete reduction (> 6 log(10)) was demonstrated for all viruses, including B19, but not for CPV (> 3.4 but < or = 4.2 log(10)). Robustness studies of the pH 4.4/15NF step with CPV showed that pH was the dominant process parameter. SD treatment for 10 min resulted in complete inactivation (> 6 log(10)) of all LE viruses tested. Precipitation of Cohn fraction III resulted in the significant removal (3-4 log(10)) of both LE and NLE viruses. Virus-neutralization assays of final product revealed significant reduction (> or = 3 log(10)) of both BPV and HAV. The manufacturing process of Nanogam comprises two effective steps for the reduction of LE viruses and one for NLE viruses. In addition, the precipitation of Cohn fraction III and the presence of neutralizing antibodies contribute to the total virus-reducing capacity of Nanogam. The overall virus-reducing capacity was > 15 log(10) for LE viruses. For the NLE viruses B19, CPV and EMC, the overall virus-reducing capacities were > 10, > 7 and > 9 log(10), respectively. Including the contribution of immune neutralization, the overall virus-reducing capacity for B19 and HAV is estimated to be > 10 log(10).

Development of a new 10% liquid, triple virus reduced intravenous immune globulin product, new generation IGIV

Rationale While immune globulin products after introduction of dedicated virus inactivation steps have an excellent safety record, patient concerns around transmission of particularly viruses still exist, and are fueled by newly emerging viruses. Methods To address these concerns, the manufacturing process of this new liquid IGIV contains three dedicated virus reduction steps: (1) a three component solvent-detergent (SD) treatment, (2) a 35 N nanofiltration step, and (3) a prolonged incubation period at low pH and elevated temperature. Results (1) SD treatment resulted in complete inactivation of all the lipid-enveloped viruses tested, already after only 1 minute of the 60 minutes treatment, and also at drastically reduced concentrations of the SD reagents. (2) Nanofiltration effectively removed lipid-enveloped viruses. Also, HAV and parvovirus B19, viruses which are smaller than the nominal pore size of the filter used, were reproducibly and robustly removed by antibody-enhanced nanofiltration which occurred at a wide range of HAV and B19 antibody concentrations. (3) Incubation at low pH and elevated temperature effectively inactivated lipid-enveloped viruses, and resulted in significant levels of inactivation for non-lipid enveloped viruses, including parvoviruses. Inactivation was shown to depend on a combination of low pH and elevated temperature. Conclusions The incorporation of three dedicated and mechanistically different virus reduction steps for this new liquid immunoglobulin product results in unprecedented safety margins.

The virucidal spectrum of a high concentration alcohol mixture

The virucidal spectrum of a high concentration alcohol mixture (80% ethanol and 5% isopropanol) was determined for a broad series of lipid-enveloped (LE) and non-lipid-enveloped (NLE) viruses covering all relevant blood-borne viruses. LE viruses were represented by human immunodeficiency virus (HIV), bovine viral diarrhoea virus (BVDV), a specific model virus for hepatitis C virus (HCV), pseudorabies virus (PRV), and vaccinia virus. For the NLE viruses hepatitis A virus, canine parvovirus (a model for human parvovirus B19), and reovirus type 3 (Reo-3) were used. PRV, vaccinia, and Reo-3 served as general model viruses. The alcohol mixture was spiked with 5% (v/v) virus, mixed and tested for residual virus after 5min treatment. Complete clearance (reduction by a factor of >106) was observed for LE viruses, whereas incomplete to insignificant clearance (ranging from no reduction up to a maximum factor of 104) was found for NLE viruses. In a second series of spiking experiments using the LE viruses BVDV, HIV, and PRV, complete clearance (reduction by a factor of >106) was found after 20s treatment. These data strongly suggest that treatment with a high concentration alcohol mixture has a high virucidal potential in particular for the blood-borne LE-viruses HIV, hepatitis B virus, and HCV. Such mixtures are well suited for rapid and frequent disinfection in dental practice being non-hazardous and non-toxic.

Intravenous immunoglobulins: clinical experience and viral safety.

To discuss the current procedures and processes by which viral safety is ensured for intravenous immunoglobulins (IVIGs), to place in context the current increase in clinical indications for IVIGs, and to describe the safety issues that have led to product shortages. Articles on viral safety retrieved from MEDLINE using the search terms gamma globulin, intravenous, adverse reaction, and infection and information from the manufacturers' literature and Food and Drug Administration package inserts. Studies that specifically addressed the areas of major concern or advancement in viral safety of IVIGs, including donor selection, plasma screening, and other quality control procedures to ensure safety of source plasma; detection of viruses that may have escaped antibody screening tests through the use of polymerase chain reaction-based assays, which are capable of detecting small amounts of viral genomic material (e.g., hepatitis C virus, hepatitis B virus, and human immunodeficiency virus [HIV]) in small plasma pools; and industrial-scale, validated viral inactivation methods, such as pasteurization and solvent/detergent treatment, that have been incorporated into the manufacturing processes of immunoglobulins to further minimize the risk of viral transmission. In addition to the treatment of primary immunodeficiency disorders, the clinical uses of IVIGs have expanded to include treatment of Kawasaki's syndrome, idiopathic thrombocytopenic purpura, infection following bone marrow transplantation, secondary immunologic disorders (e.g., pediatric HIV infection), hematologic disorders (e.g., chronic lymphocytic leukemia), and neurologic indications (e.g., Guillain-Barré syndrome). Although IVIG preparations are derived from human plasma, they have a long safety record and a low risk for transmitting viral infections. Viral validation studies demonstrated that the processes discussed herein differ in their capabilities to inactivate lipid-enveloped and nonlipid-enveloped viruses.

Effectiveness of alternative treatments for reducing potential viral contaminants from plasma-derived products

An issue of great importance and continuing concern with regard to all products derived from human plasma is their safety from potential contaminants in the source material from which they are purified. Since viral contaminants are a major safety consideration with these products, a number of different methods, including dry heating, vapor heating, filtration and nanofiltration, ultraviolet and gamma irradiation, pasteurization, solvent/detergent (S/D) treatment, sodium thiocyanate treatment, and chromatography (immunoaffinity, metal chelation, affinity, and ion exchange), have been developed to remove or inactivate potentially contaminating viruses. Pasteurization and S/D treatment have emerged as the dominant viral inactivation methods. Results summarized in this review demonstrate that pasteurization is the broadest and most rigorous currently available method for removal of potential viral contaminants from plasma-derived products. S/D treatment requires control over a large number of manufacturing parameters and has no ability to inactivate nonlipid-enveloped viruses. Pasteurization requires control over only a small number of manufacturing variables, is easily monitored, and remains effective even if deviations are encountered from specified protein and stabilizer concentrations and temperature. In addition, pasteurization is effective against a wide range of lipid- and nonlipid-enveloped viruses.

Viral inactivation of fresh frozen plasma.

Viral inactivation of fresh frozen plasma.

Efficacy of a high purity, chemically treated and nanofiltered factor IX concentrate for continuous infusion in haemophilia patients undergoing surgery.

We have evaluated the haemostatic efficacy of plasma derived, highly purified, solvent-detergent treated factor IX concentrate (Nanotiv), to which a nanofiltration step has recently been added to improve safety with regard to parvovirus B19, hepatitis A and other nonlipid enveloped viruses. Thirteen surgical procedures, including eight orthopaedic operations, were carried out using continuous infusion of Nanotiv in 10 haemophilia B patients (nine severe and one mild). Tranexamic acid was used for 11 of the 13 procedures. The mean factor IX levels on the day of surgery and postoperative days 1-3 were 0.77, 0.89, 0.80 and 0.73 IU mL(-1), respectively. The haemostatic effect was rated as normal or excellent and no blood transfusions were needed. One patient had thrombophlebitis twice at the infusion site. The remaining cases received heparin, 5 units per 100 IU of Nanotiv, and had neither superficial nor deep venous thromboembolic complications. The requirement for factor IX in the four joint replacement operations was 663 IU kg(-1) during the first 9 days, which compares favourably with previous materials. Thus, continuous infusion with this highly purified factor IX concentrate with improved viral safety is effective for surgery in haemophilia B.

Improvement of Virus Safety of a S/D-Treated Factor VIII Concentrate by Additional Dry Heat Treatment at 100°C

Abstract.In order to increase the virus safety of a solvent/detergent-treated Factor VIII concentrate in regard to non-lipid coated viruses and to respond to the continuous discussion about reports on hepatitis A transmission by Factor VIII preparations, we have investigated the effect of a terminal dry heat treatment (30 min 100°C) on HAV and various other viruses. By this treatment Hepatitis A virus was inactivated below detectable level after a few minutes (>5·3 log 10). Other RNA viruses such as the Human Immunodeficiency Virus (>6·6 log 10), bovine viral diarrhoea virus (>6·6 log 10) and vesicular stomatitis virus (>5·8 log 10) were also inactivated below detectable level. Pseudo rabies virus and reovirus Type 3 are inactivated by 5·7 and >6·0 log 10, respectively. SV40 and bovine parvo virus showed significant resistance to dry heat treatment. We conclude that the involvement of two strong virus inactivation steps, acting by different mechanisms, improves the virus safety of Factor VIII concentrates without destroying the Factor VIII activity. Moreover, the terminal 100°C heat treatment for 30 min represents an effective measure to inactivate non-lipid enveloped viruses, in particular hepatitis A, which is resistant to solvent/detergent treatment.

Iodine-Mediated Inactivation of Lipid- and Nonlipid-Enveloped Viruses in Human Antithrombin III Concentrate

Human plasma-derived protein concentrates intended for clinical use must be treated for viral inactivation to ensure patient safety. This study explored the use of liquid iodine for inactivation of several lipid- and nonlipid-enveloped viruses in an antithrombin III (AT-III) concentrate. Iodine at levels of 0.01% to 0.02% caused between 43% and 94% loss of AT-III activity, as well as degradation of AT-III as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. However, addition of up to 0.1% human albumin protected the AT-III against both inactivation and fragmentation. At albumin levels sufficient to retain greater than 75% of AT-III activity, greater than 6 logs of sindbis, encephalomyocarditis, and vesicular stomatitis viruses, greater than 4 logs of pseudorabies, and greater than 3 logs of human immunodeficiency virus were inactivated. Except with sindbis virus, this represented complete inactivation of all the viruses spiked into the AT-III concentrate.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

To improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100 degrees C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (S/D) method during the manufacturing process. The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.