Robustness of nanofiltration for increasing the viral safety margin of biological products

Impact of proteins and protein fouling on virus retention during virus removal filtration

Virus filtration is a crucial step in ensuring the high levels of viral clearance required in the production of biotherapeutics produced in mammalian cells or derived from human plasma. Previous studies have reported that virus retention is often reduced in the presence of therapeutic proteins due to membrane fouling; however, the underlying mechanisms controlling this behavior are still not well understood. Experimental studies were performed with a single layer of the commercially available dual-layer PegasusTM SV4 virus removal filter to more easily interpret the experimental results. Bacteriophage ФX174 was used as a model parvovirus, and human immunoglobulin (hIgG) and Bovine Serum Albumin (BSA) were used as model proteins. Data obtained with 5 g/L solutions of hIgG showed more than a 100-fold reduction in virus retention compared to that in the protein-free solution. Similar effects were seen with membranes that were pre-fouled with hIgG and then challenged with ФX174. The experimental data were well-described using an internal polarization model that accounts for virus capture and accumulation within the virus filter, with the hIgG nearly eliminating the irreversible virus capture while also facilitating the release of previously captured virus. These results provide important insights into the performance and validation of virus removal filters in bioprocessing.

Therapeutic Plasma Exchange in Certain Immune-Mediated Neurological Disorders: Focus on a Novel Nanomembrane-Based Technology

Therapeutic plasma exchange (TPE) is an efficient extracorporeal blood purification technique to remove circulating autoantibodies and other pathogenic substances. Its mechanism of action in immune-mediated neurological disorders includes immediate intravascular reduction of autoantibody concentration, pulsed induction of antibody redistribution, and subsequent immunomodulatory changes. Conventional TPE with 1 to 1.5 total plasma volume (TPV) exchange is a well-established treatment in Guillain-Barre Syndrome, Chronic Inflammatory Demyelinating Polyradiculoneuropathy, Neuromyelitis Optica Spectrum Disorder, Myasthenia Gravis and Multiple Sclerosis. There is insufficient evidence for the efficacy of so-called low volume plasma exchange (LVPE) (<1 TPV exchange) implemented either by the conventional or by a novel nanomembrane-based TPE in these neurological conditions, including their impact on conductivity and neuroregenerative recovery. In this narrative review, we focus on the role of nanomembrane-based technology as an alternative LVPE treatment option in these neurological conditions. Nanomembrane-based technology is a promising type of TPE, which seems to share the basic advantages of the conventional one, but probably with fewer adverse effects. It could play a valuable role in patient management by ameliorating neurological symptoms, improving disability, and reducing oxidative stress in a cost-effective way. Further research is needed to identify which patients benefit most from this novel TPE technology.

Removal of minute virus of mice-mock virus particles by nanofiltration of culture growth medium supplemented with 10% human platelet lysate

BACKGROUND AIMS

Platelet concentrates (PCs) are pooled to prepare human platelet lysate (HPL) supplements of growth media to expand primary human cells for transplantation; this increases the risk of contamination by known, emerging, and unknown viruses. This possibility should be of concern because viral contamination of cell cultures is difficult to detect and may have detrimental consequences for recipients of cell therapies. Viral reduction treatments of chemically defined growth media have been proposed, but they are not applicable when media contain protein supplements currently needed to expand primary cell cultures. Recently, we successfully developed a Planova 35NPlanova 20N nanofiltration sequence of growth media supplemented with two types of HPL. The nanofiltered medium was found to be suitable for mesenchymal Stromal cell (MSC) expansion.

METHODS

Herein, we report viral clearance achieved by this nanofiltration process used for assessing a new experimental model using non-infectious minute virus of mice-mock virus particle (MVM-MVP) and its quantification by an immunoqPCR. Then, high doses of MVM-MVP (1012 MVPs/mL) were spiked to obtain a final concentration of 1010 MVPs/mL in Planova 35N-nanofiltered growth medium supplemented with both types of HPLs [serum converted platelet lysate SCPL) and intercept human platelet lysate (I-HPL)] at 10% (v/v) and then filtering through Planova 20N.

RESULTS

No substantial interference of growth medium matrices by the immune-qPCR assay was first verified. Log reduction values (LRVs) were ≥ 5.43 and ≥ 5.36 respectively, SCPL and I-HPL media. MVM-MVPs were also undetectable by dynamic light scattering and transmission electron microscopy.

CONCLUSIONS

The nanofiltration of growth media supplemented with 10% HPL provides robust removal of small nonenveloped viruses, and is an option to improve the safety of therapeutic cells expanded using HPL supplements.

Human platelet lysates for human cell propagation

A pathogen-free and standardized xeno-free supplement of growth media is required for the ex vivo propagation of human cells used as advanced therapeutic medicinal products and for clinical translation in regenerative medicine and cell therapies. Human platelet lysate (HPL) made from therapeutic-grade platelet concentrate (PC) is increasingly regarded as being an efficient xeno-free alternative growth medium supplement to fetal bovine serum (FBS) for clinical-grade isolation and/or propagation of human cells. Most experimental studies establishing the superiority of HPL over FBS were conducted using mesenchymal stromal cells (MSCs) from bone marrow or adipose tissues. Data almost unanimously concur that MSCs expanded in a media supplemented with HPL have improved proliferation, shorter doubling times, and preserved clonogenicity, immunophenotype, in vitro trilineage differentiation capacity, and T-cell immunosuppressive activity. HPL can also be substituted for FBS when propagating MSCs from various other tissue sources, including Wharton jelly, the umbilical cord, amniotic fluid, dental pulp, periodontal ligaments, and apical papillae. Interestingly, HPL xeno-free supplementation is also proving successful for expanding human-differentiated cells, including chondrocytes, corneal endothelium and corneal epithelium cells, and tenocytes, for transplantation and tissue-engineering applications. In addition, the most recent developments suggest the possibility of successfully expanding immune cells such as macrophages, dendritic cells, and chimeric antigen receptor-T cells in HPL, further broadening its use as a growth medium supplement. Therefore, strong scientific rationale supports the use of HPL as a universal growth medium supplement for isolating and propagating therapeutic human cells for transplantation and tissue engineering. Efforts are underway to ensure optimal standardization and pathogen safety of HPL to secure its reliability for clinical-grade cell-therapy and regenerative medicine products and tissue engineering.

COVID-19 and immunomodulation treatment for women with reproductive failures

COVID-19 pandemic is affecting various areas of health care, including human reproduction. Many women with reproductive failures, during the peri-implantation period and pregnancy, are on the immunotherapy using immune modulators and immunosuppressant due to underlying autoimmune diseases, cellular immune dysfunction, and rheumatic conditions. Many questions have been raised for women with immunotherapy during the COVID-19 pandemic, including infection susceptibility, how to manage women with an increased risk of and active COVID-19 infection. SARS-CoV-2 is a novel virus, and not enough information exists. Yet, we aim to review the data from previous coronavirus outbreaks and current COVID-19 and provide interim guidelines for immunotherapy in women with reproductive failures.

Nanofiltration of growth media supplemented with human platelet lysates for pathogen-safe xeno-free expansion of mesenchymal stromal cells

Background aims

Human platelet lysate can replace fetal bovine serum (FBS) for xeno-free ex vivo expansion of mesenchymal stromal cells (MSCs), but pooling of platelet concentrates (PCs) increases risks of pathogen transmission. We evaluated the feasibility of performing nanofiltration of platelet lysates and determined the impact on expansion of bone marrow–derived MSCs.

Methods

Platelet lysates were prepared by freeze-thawing of pathogen-reduced (Intercept) PCs suspended in 65% storage solution (SPP+) and 35% plasma, and by serum-conversion of PCs suspended in 100% plasma. Lysates were added to the MSC growth media at 10% (v/v), filtered and subjected to cascade nanofiltration on 35- and 19-nm Planova filters. Media supplemented with 10% starting platelet lysates or FBS were used as the controls. Impacts of nanofiltration on the growth media composition, removal of platelet extracellular vesicles (PEVs) and MSC expansion were evaluated.

Results

Nanofiltration did not detrimentally affect contents of total protein and growth factors or the biochemical composition. The clearance factor of PEVs was >3 log values. Expansion, proliferation, membrane markers, differentiation potential and immunosuppressive properties of cells in nanofiltered media were consistently better than those expanded in FBS-supplemented media. Compared with FBS, chondrogenesis and osteogenesis genes were expressed more in nanofiltered media, and there were fewer senescent cells over six passages.

Conclusions

Nanofiltration of growth media supplemented with two types of platelet lysates, including one prepared from pathogen-reduced PCs, is technically feasible. These data support the possibility of developing pathogen-reduced xeno-free growth media for clinical-grade propagation of human cells.

Two-Step Size-Exclusion Nanofiltration of Prothrombin Complex Concentrate Using Nanocellulose-Based Filter Paper

Coagulation Factor IX-rich protrhombin complex concentrate (FIX-PCC) is a therapeutic biologic product that consists of a mixture of several human plasma-derived proteins, useful for treating hemophilia B. Due to its complex composition, FIX-PCC is very challenging to bioprocess through virus removing nanofilters in order to ensure its biosafety. This article describes a two-step filtration process of FIX-PCC using a nanocellulose-based filter paper with tailored porosity. The filters were characterized with scanning electron microscopy (SEM), cryoporometry with differential scanning calorimetry, and nitrogen gas sorption. Furthermore, in order to probe the filter's cut-off size rejection threshold, removal of small- and large-size model viruses, i.e., ΦX174 (28 nm) and PR772 (70 nm), was evaluated. The feed, pre-filtrate, and permeate solutions were characterized with mass-spectrometric proteomic analysis, dynamic light scattering (DLS), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analytical size-exclusion high-performance liquid chromatography (SEHPLC). By sequential filtration through 11 μm pre-filter and 33 μm virus removal filter paper, it was possible to achieve high product throughput and high virus removal capacity. The presented approach could potentially be applied for bioprocessing other protein-based drugs.

Microscopic visualization of virus removal by dedicated filters used in biopharmaceutical processing: Impact of membrane structure and localization of captured virus particles

Virus filtration with nanometer size exclusion membranes (“nanofiltration”) is effective for removing infectious agents from biopharmaceuticals. While the virus removal capability of virus removal filters is typically evaluated based on calculation of logarithmic reduction value (LRV) of virus infectivity, knowledge of the exact mechanism(s) of virus retention remains limited. Here, human parvovirus B19 (B19V), a small virus (18–26 nm), was spiked into therapeutic plasma protein solutions and filtered through Planova™ 15N and 20N filters in scaled‐down manufacturing processes. Observation of the gross structure of the Planova hollow fiber membranes by transmission electron microscopy (TEM) revealed Planova filter microporous membranes to have a rough inner, a dense middle and a rough outer layer. Of these three layers, the dense middle layer was clearly identified as the most functionally critical for effective capture of B19V. Planova filtration of protein solution containing B19V resulted in a distribution peak in the dense middle layer with an LRV >4, demonstrating effectiveness of the filtration step. This is the first report to simultaneously analyze the gross structure of a virus removal filter and visualize virus entrapment during a filtration process conducted under actual manufacturing conditions. The methodologies developed in this study demonstrate that the virus removal capability of the filtration process can be linked to the gross physical filter structure, contributing to better understanding of virus trapping mechanisms and helping the development of more reliable and robust virus filtration processes in the manufacture of biologicals.

A Prospective, Randomized, Phase III Study to Evaluate the Efficacy and Safety of Fibrin Sealant Grifols as an Adjunct to Hemostasis as Compared to Cellulose Sheets in Hepatic Surgery Resections

BACKGROUND

Local hemostatic agents have a role in limiting bleeding complications associated with liver resection.

METHODS

In this randomized, phase III study, we compared the efficacy and safety of Fibrin Sealant Grifols (FS Grifols) with oxidized cellulose sheets (Surgicel®) as adjuncts to hemostasis during hepatic resections. The primary efficacy endpoint was the proportion of patients achieving hemostasis at target bleeding sites (TBS) within 4 min (T₄) of treatment application. Secondary efficacy variables were time to hemostasis (TTH) at a later time point if re-bleeding occurs and cumulative proportion of patients achieving hemostasis by time points T₂, T₃, T₅, T₇, and T₁₀.

RESULTS

The rate of hemostasis by T₄ was 92.8% in the FS Grifols group (n = 163) and 80.5% in the Surgicel® group (n = 162) (p = 0.01). The mean TTH was significantly shorter (p < 0.001) in the FS Grifols group (2.8 ± 0.14 vs. 3.8 ± 0.24 min). The rate of hemostasis by T₂, T₅, and T₇ was higher and statistically superior in the FS Grifols group compared to Surgicel®. No substantial differences in adverse events (AE) were noted between treatment groups. The most common AEs were procedural pain (36.2 vs. 37.7%), nausea (20.9 vs. 23.5%), and hypotension (14.1 vs 6.2%).

CONCLUSIONS

FS Grifols was safe and well tolerated as a local hemostatic agent during liver resection surgeries. Overall, data demonstrate that the hemostatic efficacy of FS Grifols is superior to Surgicel® and support the use of FS Grifols as an effective local hemostatic agent in these surgical procedures.

A Prospective, Single-Blind, Randomized, Phase III Study to Evaluate the Safety and Efficacy of Fibrin Sealant Grifols as an Adjunct to Hemostasis During Soft Tissue Open Surgery

BACKGROUND/PURPOSE

Rapid hemostasis, an essential prerequisite of good surgical practice during surgical bleeding, including soft tissue open surgery, often requires adjunctive treatment. We evaluated the safety and hemostatic effectiveness of a human plasma-derived fibrin sealant (FS Grifols) in soft tissue open surgery.

METHODS

Patients with moderate soft tissue bleeding during open, urologic, gynecologic or general surgery were studied. The trial consisted of a preliminary phase (to familiarize investigators with the technique for FS Grifols application and the intraoperative procedures required by the clinical protocol) and a primary phase: in both phases, patients were randomized 1:1 to FS Grifols or Surgicel^®. The primary efficacy endpoint, based on analysis of subjects in the primary phase of the study, was to evaluate whether FS Grifols was non-inferior to Surgicel^® in achieving hemostasis, based on the proportion of subjects in both treatment groups who achieved hemostasis at the target bleeding site (TBS) by 4 min (T₄) following the start of treatment application. Safety assessments included adverse events (AEs), vital signs, physical assessments, common clinical laboratory tests, viral markers, and immunogenicity.

RESULTS

A total of 224 subjects were randomized (primary phase): FS Grifols (N = 116), Surgicel^® (N = 108). The 95% CI at T₄ for the ratio of the proportion of patients achieving hemostasis in the two treatment groups was 1.064 (0.934, 1.213), indicating non-inferiority for FS Grifols vs. Surgicel^®. The rate of hemostasis at the TBS by T₄ in both phases of the study was higher in the FS Grifols treatment group (preliminary phase: 90.2%; primary phase: 82.8%) than in the Surgicel^® treatment group (preliminary phase: 78.8%; primary phase: 77.8%). Overall, reported AEs were as expected in surgical patients and were similar between the two treatment groups.

CONCLUSIONS

This study shows the non-inferiority in time to hemostasis of FS Grifols vs. Surgicel as an adjunct to hemostasis in patients undergoing soft tissue open surgery, and a similar rate of AEs.

A Prospective, Randomized, Multicenter Clinical Trial on the Safety and Efficacy of a Ready-to-Use Fibrin Sealant as an Adjunct to Hemostasis during Vascular Surgery

BACKGROUND

Anastomotic or "stitch hole" bleeding is common during vascular surgery with synthetic material such as Dacron or polytetrafluoroethylene. Hemostatic adjuncts such as fibrin sealant (FS) may reduce blood loss and operating time in such circumstances. We evaluated the safety and the hemostatic effectiveness of a ready-to-use human plasma-derived FS in vascular surgery.

METHODS

Patients with mild/moderate suture line bleeding during elective, open, vascular surgery using synthetic grafts or patches were studied. In an initial Exploratory Study, all patients were treated with FS Grifols, and in a subsequent Primary Study were randomized in a 2:1 ratio to FS Grifols or manual compression (MC). The primary efficacy end point was time to hemostasis (TTH), assessed at defined intervals from the start of treatment application, during a 10-min observational period. Safety end points (in Exploratory + Primary Studies) included adverse events (AEs), vital signs, physical assessments, common clinical laboratory tests (coagulation, complete blood count, serum clinical chemistry parameters, microscopic urinalysis), viral markers, and immunogenicity.

RESULTS

In the Primary Study, the proportion of patients who achieved hemostasis at the 3-min time point was higher in the FS Grifols group (46.4%, n = 51/110) than in the MC group (26.3%, n = 15/57) (P < 0.05). The benefit was maintained at successive time intervals: 69 FS Grifols patients (62.7%) and 18 MC patients (31.6%) at 4 min; 82 FS Grifols patients (74.5%) and 28 MC patients (49.1%) at 5 min. The differences between the groups persisted for TTH ≤ 7 min and TTH ≤ 10 min. Treatment failure was reported for 13 FS Grifols patients (11.8%) and 16 MC patients (28.1%). TTH was shorter after FS Grifols application than after MC application. Differences were statistically significant in favor of FS Grifols for each TTH category and for the overall comparison (P < 0.001) as well as for each TTH category (cumulative) and for treatment failure (P = 0.016). Overall, AE experience and types of AEs reported were those expected in this patient population and were similar between the 2 treatment groups. The most frequently reported AEs were procedural pain (59.9% and 69.2% of patients in the FS Grifols [n = 72 + 111] and MC [n = 57] groups, respectively) and nausea (23.5% and 19.2% of patients, respectively).

CONCLUSIONS

FS Grifols was efficacious and safe as an adjunct to anastomotic hemostasis in patients undergoing arterial surgery using prosthetic material with mild to moderate bleeding.

Characterizing the impact of pressure on virus filtration processes and establishing design spaces to ensure effective parvovirus removal

Virus filtration provides robust removal of potential viral contaminants and is a critical step during the manufacture of biotherapeutic products. However, recent studies have shown that small virus removal can be impacted by low operating pressure and depressurization. To better understand the impact of these conditions and to define robust virus filtration design spaces, we conducted multivariate analyses to evaluate parvovirus removal over wide ranges of operating pressure, solution pH, and conductivity for three mAb products on Planova™ BioEX and 20N filters. Pressure ranges from 0.69 to 3.43 bar (10.0–49.7 psi) for Planova BioEX filters and from 0.50 to 1.10 bar (7.3 to 16.0 psi) for Planova 20N filters were identified as ranges over which effective removal of parvovirus is achieved for different products over wide ranges of pH and conductivity. Viral clearance at operating pressure below the robust pressure range suggests that effective parvovirus removal can be achieved at low pressure but that Minute virus of mice (MVM) logarithmic reduction value (LRV) results may be impacted by product and solution conditions. These results establish robust design spaces for Planova BioEX and 20N filters where high parvovirus clearance can be expected for most antibody products and provide further understanding of viral clearance mechanisms. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 33:1294–1302, 2017

Cellulose-based virus-retentive filters: a review

Viral filtration is a critical step in the purification of biologics and in the monitoring of microbiological water quality. Viral filters are also essential protection elements against airborne viral particles. The present review first focuses on cellulose-based filter media currently used for size-exclusion and/or adsorptive filtration of viruses from biopharmaceutical and environmental water samples. Data from spiking studies quantifying the viral filtration performance of cellulosic filters are detailed, i.e., first, the virus reduction capacity of regenerated cellulose hollow fiber filters in the manufacturing process of blood products and, second, the efficiency of virus recovery/concentration from water samples by the viradel (virus adsorption-elution) method using charge modified, electropositive cellulosic filters or conventional electronegative cellulose ester microfilters. Viral analysis of field water samples by the viradel technique is also surveyed. This review then describes cellulose-based filter media used in individual protection equipment against airborne viral pathogens, presenting innovative filtration media with virucidal properties. Some pros and cons of cellulosic viral filters and perspectives for cellulose-based materials in viral filtration are underlined in the review.

Pathogen Safety of a New Intravenous Immune Globulin 10% Liquid

BACKGROUND

The manufacturing process of a new intravenous immune globulin (IVIG) 10% liquid product incorporates two dedicated pathogen safety steps: solvent/detergent (S/D) treatment and nanofiltration (20 nm). Ion-exchange chromatography (IEC) during protein purification also contributes to pathogen safety. The ability of these three process steps to inactivate/remove viruses and prions was evaluated.

OBJECTIVES

The objective of this study was to evaluate the virus and prion safety of the new IVIG 10% liquid.

METHODS

Bovine viral diarrhea virus (BVDV), human immunodeficiency virus type 1 (HIV-1), mouse encephalomyelitis virus (MEV), porcine parvovirus (PPV), and pseudorabies virus (PRV) were used as models for common human viruses. The hamster-adapted scrapie strain 263K (HAS 263K) was used for transmissible spongiform encephalopathies. Virus clearance capacity and robustness of virus reduction were determined for the three steps. Abnormal prion protein (PrP^Sc) removal and infectivity of the samples was determined.

RESULTS

S/D treatment and nanofiltration inactivated/removed enveloped viruses to below detection limits. IEC supplements viral safety and nanofiltration was highly effective in removing non-enveloped viruses and HAS 263K. Overall virus reduction factors were: ≥9.4 log₁₀ (HIV-1), ≥13.2 log₁₀ (PRV), ≥8.2 log₁₀ (BVDV), ≥11.7 log₁₀ (MEV), ≥11.6 log₁₀ (PPV), and ≥10.4 log₁₀ (HAS 263K).

CONCLUSION

Two dedicated and one supplementing steps in the manufacturing process of the new IVIG 10% liquid provide a high margin of pathogen safety.

Virome of US bovine calf serum

Using viral metagenomics we analyzed four bovine serum pools assembled from 715 calves in the United States. Two parvoviruses, bovine parvovirus 2 (BPV2) and a previously uncharacterized parvovirus designated as bosavirus (BosaV), were detected in 3 and 4 pools respectively and their complete coding sequences generated. Based on NS1 protein identity, bosavirus qualifies as a member of a new species in the copiparvovirus genus. Also detected were low number of reads matching ungulate tetraparvovirus 2, bovine hepacivirus, and several papillomaviruses. This study further characterizes the diversity of viruses in calf serum with the potential to infect fetuses and through fetal bovine serum contaminate cell cultures.

Zika virus infection and biological treatment for reproductive medicine

The recent Zika virus (ZIKV) epidemic is particularly challenging in the field of reproductive medicine as various biological tissues and byproducts, such as intravenous immunoglobulin G or cells are utilized during reproductive cycles, and an infected mother has an increased risk of having babies with fetal microcephaly and other congenital brain anomalies. In this review, current guidelines for prevention of sexual transmission of ZIKV, ZIKV testing, and tissue and blood product usages are summarized for physicians caring for those planning pregnancy or going through infertility treatment.

Anti-Human Platelet Antigen-1a Immunoglobulin G Preparation Intended to Prevent Fetal and Neonatal Alloimmune Thrombocytopenia

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a severe disease that is caused by maternal alloantibodies generated during pregnancy or at delivery as a result of incompatibility between maternal and fetal human platelet antigens (HPAs) inherited from the father. Antibody-mediated immune suppression using anti-HPA-1a immunoglobulins is thought to be able to prevent FNAIT caused by HPA-1a. A fractionation process to prepare anti-HPA-1a immunoglobulin (Ig) G (IgG) from human plasma was therefore developed. Anti-HPA-1a plasma was obtained from volunteer mothers who underwent alloimmunization against HPA-1a during a previous pregnancy. Plasma was cryoprecipitated and the supernatant treated with caprylic acid and solvent/detergent (S/D), purified by chromatography, nanofiltered, concentrated, and sterile-filtered. The anti-HPA-1a immunoglobulin fraction was characterized for purity and safety. PAK12 and quantitative monoclonal antibody immobilization of platelet antigen (MAIPA) assays were used to detect anti-HPA-1a IgG. Hepatitis C virus (HCV) removal during nanofiltration was assessed by spiking experiments, using cell culture-derived reporter HCV and luciferase analysis. The caprylic acid treatment precipitated non-Ig proteins yielding a 90% pure Ig supernatant. S-HyperCel chromatography of the S/D-treated supernatant followed by HyperCel STAR AX provided high IgG recovery (>80%) and purity (>99.5%), and efficient IgA and IgM removal. Concentrations of complement factors C3 and C4 were < 0.5 and < 0.4 mg/dL, respectively. The final IgG could be nanofiltered on Planova 20N under conditions removing more than 3 log HCV infectivity to baseline mock infection level, and concentrated to ca. 30 g/L. Proteolytic activity and thrombin generation were low in the final fraction. The Pak12 and MAIPA assays showed good recovery of anti-HPA-1a throughout the process. Clinical-grade HPA-1a IgG can be prepared using a process compliant with current quality requirements opening perspectives for the prevention of FNAIT.