Investigating Age Appropriate Coagulation Reference Intervals to Support Patient Blood Management in the Elderly: A Verification Study.

Reference intervals are vital for interpreting coagulation results. Current interval ranges have no upper age limit, although there is evidence that coagulation function changes with age. This study compared coagulation results from healthy people aged >60 years against adult reference intervals for routine clotting assays and thromboelastography (TEG) to determine if reference intervals are relevant to older adults.Samples from healthy blood donors aged >60 years (n=30 male, n=30 female) were tested by TEG® 6s, prothrombin time (PT), activated partial thromboplastin time (aPTT), and derived fibrinogen.All older donor-derived fibrinogen results were within the adult reference intervals, however levels were significantly higher in females. A proportion of TEG® 6s and aPTT results were not within the reference intervals. As populations around the world live longer, these findings question whether older adults require age specific coagulation reference intervals.

Calibration of the 7th British Working Standard for factors II, IX and X, concentrate.

Seven laboratories from 5 different countries participated in the calibration of the 7th British Working Standard (BWS) for blood coagulation factors II, IX and X. The candidate, 15/182, was assayed for Factors II and X potencies against the 4th International Standard (IS) for Factors II and X, Concentrate (11/126) and for Factor IX potency against the 5th IS for Factor IX, Concentrate (14/148). Intra-laboratory GCVs for all 3 factors were less than 10%, with the majority less than 5%. Inter-laboratory GCVs were 3.4%, 3.2% and 2.3% for FII, IX and X respectively. All participants agreed with the value assigned and preparation 15/182 was established by NIBSC in October 2017 as the 7th BWS for FII, IX, X Concentrate with potencies of 6.0 IU/ampoule, 6.7 IU/ampoule and 4.9 IU/ampoule for FII, IX and X respectively.

Comparison of 3-Factor Versus 4-Factor Prothrombin Complex Concentrate With Regard to Warfarin Reversal, Blood Product Use, and Costs.

BACKGROUND: Prothrombin complex concentrates (PCCs) are drug products containing varying amounts of vitamin K-dependent coagulation factors II, VII, IX, and X. The evidence comparing 3-factor PCC (3-PCC) versus 4-factor PCC (4-PCC) for warfarin reversal is conflicting. It has been hypothesized that 3-PCC may be less effective than 4-PCC because of relatively lower factor VII content. STUDY QUESTION: The primary objective of this study was to compare international normalized ratio (INR) reversal between 3-PCC and 4-factor PCC (4-PCC) in warfarin-treated patients. The secondary objectives include comparing blood product use, total reversal costs, and cost-effectiveness between the groups. STUDY DESIGN: This was a retrospective cohort study conducted in 2 affiliated, academic institutions in the United States. Consecutive adult patients who received 3-PCC or 4-PCC for warfarin reversal were included. MEASURES AND OUTCOMES: The primary outcome was adequate INR reversal defined as a final INR ≤1.5. Secondary outcomes were the utilization of plasma, red blood cells and platelets, reversal costs, and the cost-effectiveness ratio. RESULTS: There were 89 patients who were included in the overall cohort (3-PCC = 57, 4-PCC = 32). Adequate INR reversal occurred less commonly with 3-PCC (45.6%) compared with 4-PCC (87.5%) (P < 0.001). There was no significant difference in the proportion of patients who received plasma (32% vs. 28%, P = 0.813), red blood cells (37% vs. 47%, P = 0.377), or platelets (16% vs. 28%, P = 0.180) between the 3-PCC and 4-PCC groups, respectively. The median reversal cost of 3-PCC ($3663) was lower than 4-PCC ($5105) (P = 0.001). The cost-effective ratio favored 4-PCC ($5105/87.5% = $5834) compared with 3-PCC ($3663/45.6% = $8033). CONCLUSIONS: Four-PCC was more effective than 3-PCC with regard to INR reversal in patients taking warfarin, but blood product use was similar. Although 4-PCC is associated with increased reversal costs, it may be cost-effective in terms of INR reversal.

Pathogen safety of a pasteurized four-factor human prothrombin complex concentrate preparation using serial 20N virus filtration.

BACKGROUND: Beriplex P/N/Kcentra/Coaplex/Confidex is a four-factor human prothrombin complex concentrate (PCC). Here, we describe the pathogen safety profile and biochemical characteristics of an improved manufacturing process that further enhances the virus safety of Beriplex P/N. STUDY DESIGN AND METHODS: Samples of product intermediates were spiked with test viruses, and prions were evaluated under routine production and robustness conditions of the scale-down version of the commercial manufacturing process for their capacity to inactivate or remove pathogens. The PCC was characterized by determining the activity of Factor (F)II, FVII, FIX, FX, protein C, and protein S and the concentration of heparin and antithrombin III in nine product lots. RESULTS: The manufacturing process had a very high virus reduction capacity for a broad variety of virus challenges (overall reduction factors ≥15.5 to ≥18.4 log for enveloped viruses and 11.5 to ≥11.9 log for nonenveloped viruses). The high virus clearance capacity was provided by two dedicated virus reduction steps (pasteurization and serial 20N virus filtration) that provided effective inactivation and removal of viruses and a purification step (ammonium sulfate precipitation and adsorption to calcium phosphate) that contributed to the overall virus removal capacity. The diethylaminoethyl (DEAE) chromatography and ammonium sulfate precipitation steps removed prions to below the limit of detection. The levels of different clotting factors in the final product were well balanced. CONCLUSION: The improved manufacturing process of Beriplex P/N further enhances the margin of pathogen safety based on its capacity to remove and inactivate a wide range of virus challenges.

Pathogen inactivation and removal methods for plasma-derived clotting factor concentrates.

Pathogen safety is crucial for plasma-derived clotting factor concentrates used in the treatment of bleeding disorders. Plasma, the starting material for these products, is collected by plasmapheresis (source plasma) or derived from whole blood donations (recovered plasma). The primary measures regarding pathogen safety are selection of healthy donors donating in centers with appropriate epidemiologic data for the main blood-transmissible viruses, screening donations for the absence of relevant infectious blood-borne viruses, and release of plasma pools for further processing only if they are nonreactive for serologic markers and nucleic acids for these viruses. Despite this testing, pathogen inactivation and/or removal during the manufacturing process of plasma-derived clotting factor concentrates is required to ensure prevention of transmission of infectious agents. Historically, hepatitis viruses and human immunodeficiency virus have posed the greatest threat to patients receiving plasma-derived therapy for treatment of hemophilia or von Willebrand disease. Over the past 30 years, dedicated virus inactivation and removal steps have been integrated into factor concentrate production processes, essentially eliminating transmission of these viruses. Manufacturing steps used in the purification of factor concentrates have also proved to be successful in reducing potential prion infectivity. In this review, current techniques for inactivation and removal of pathogens from factor concentrates are discussed. Ideally, production processes should involve a combination of complementary steps for pathogen inactivation and/or removal to ensure product safety. Finally, potential batch-to-batch contamination is avoided by stringent cleaning and sanitization methods as part of the manufacturing process.

Factor VIII Bypassing Activity (FEIBA) assays: standardization and development of the 1st NIBSC Working Standard for FEIBA--results from a collaborative study.

Factor-Eight-Inhibitor-Bypassing-Activity (FEIBA) is a bypassing-agent used to control spontaneous bleeding or cover surgical interventions in Haemophiliacs who develop neutralizing antibodies against FVIII/FIX. The market lot-release of FEIBA is dependent on specific clot-based assays, carried out by both the manufacturer and regulatory authorities, relative to manufacturer's in-house standards, which are produced on a small-scale and are replaced frequently. We sought to standardize the FEIBA assay by developing a FEIBA primary standard which would be internationally available in sufficiently large quantities, with a predicted lifetime of many years. A collaborative study involving the manufacturer and three regulatory authorities, was carried out in which a candidate material, sample B (06/172), was calibrated by assays relative to the manufacturer's in-house FEIBA standards (C and D). All laboratories used their routine validated methods (16 APTT-assays, 8 ACTIN-FS-assays and 27 DAPTTIN-assays). Intra-laboratory geometric coefficients of variation (GCVs) for candidate B ranged from 3% to 29% (GCVs <9% from majority of labs). Assessment of inter-laboratory variability gave overall GCV values of 6.9% and 4.4% relative to standards C and D, respectively, for all methods. There was good agreement in potency estimation between laboratories using each of the three methods, with the overall potencies by the three methods differing by less than 10% of the overall mean, giving an overall combined potency of 28.0 units per ampoule. All participants agreed that candidate B (06/172) be established as the 1st NIBSC Working Standard for FEIBA with an assigned potency of 28.0 units per ampoule, based on combined results for both methods, relative to either standard C or D.

International reference standards in coagulation.

Measurement of coagulation factor activity using absolute physico-chemical techniques is not possible and estimation therefore relies on comparative bioassay relative to a reference standard with a known or assigned potency. However the inherent variability of locally prepared and calibrated reference standards can give rise to poor agreement between laboratories and methods. Harmonisation of measurement between laboratories at the international level relies on the availability of a common source of calibration for local reference standards and this is provided by the World Health Organization (WHO) International Standards which define the International Unit for the analyte. This article describes the principles, practices and problems of biological standardisation and the development and use of reference standards for assays of coagulation factors, with particular emphasis on WHO International Standards for both concentrates and plasma.

The improved factor concentrate.

The current treatment of haemophilia with coagulation protein replacement therapy is both effective and safe. Nevertheless, this therapy requires frequent, repeated intravenous infusions and approximately 25% of treated haemophilia A patients develop antibodies to the replacement protein. Furthermore, the cost and limited availability of current concentrates has restricted access to therapy to less than 30% of the global haemophilia population. With this background, efforts are now underway to develop coagulation concentrates with enhanced biological properties that further improve the quality of care for haemophiliacs. The specific areas of enhancement that are being explored include improved biosynthetic processes, prolonging the circulating half-life and reducing concentrate immunogenicity. Coincident with these approaches, it is hoped that there will be more widespread availability of these concentrates and that their cost will be contained.

Frequency of contamination of coagulation factor concentrates with novel human parvovirus PARV4.

Human parvovirus, PARV4 was identified in a plasma sample from a patient presenting with symptoms resembling acute HIV infection. Further strains of PARV4 and those of a closely related variant virus, were identified in plasma pools used in the manufacture of blood derivatives. DNA sequence analysis of these strains demonstrated two distinct PARV4 genotypes. It has subsequently been proposed that transmission of PARV4 occurs by parenteral routes. To investigate the risk of contamination of plasma-derived coagulation factor concentrates, we analysed 169 lots for PARV4 DNA by polymerase chain reaction. Positive samples were confirmed by nucleotide sequence analysis and quantification of the viral load. Twenty-one lots, representing eight different products were administered until the beginning of the 1980s and were not virally inactivated. Two lots examined were used in 1997, and 146 lots representing 13 products had been administered between October 2000 and February 2003. PARV4 DNA was detected in 7(33%) of the formerly administered lots, in one lot used in 1997, and in 13(9%) recently used lots. PARV4 genotype 2 DNA was predominantly present in the older concentrates, whilst genotype 1 was found more frequently in recently used lots. In three lots, both PARV4 genotypes were detected. Viral loads ranged between <100 and 10(5.8) copies mL(-1) of product, with higher viral loads in the older concentrates. The results show that PARV4 contamination can be detected in an appreciable proportion of clotting factor concentrates. Further studies are needed to determine whether or not PARV4 contamination of coagulation factors causes harm to the product recipients.

A biochemical quality study of a pharmaceutically licenced coagulation active plasma (Octaplas) thawed by the SAHARA-III dry tempering system compared to the regular use of a water bath.

BACKGROUND AND OBJECTIVES: The most common way to thaw frozen coagulation-active plasma products for transfusion is the use of a water bath with good circulation at 30-37 degrees C. The aim of this study was to perform an extensive biochemical characterization of the pharmaceutically licenced solvent/detergent-treated plasma, Octaplas, thawed using the SAHARA-III dry tempering system from the company Sarstedt GmbH, Austria. A regular water bath was used in parallel for comparison. MATERIALS AND METHODS: Six batches Octaplas with different blood groups were thawed in a water bath or using the SAHARA-III dry tempering system in parallel. Thawed plasma was investigated on screening tests for blood coagulation, as well as on the activities of important coagulation factors and protease inhibitors. In addition, markers of activated coagulation and fibrinolysis were tested and von Willebrand factor multimeric analysis was performed. RESULTS: There were neither significant differences in the blood coagulation parameters, coagulation factors, protease inhibitors, nor of markers of activated coagulation and fibrinolysis when Octaplas thawed by the two different methods was tested. The von Willebrand factor analyses showed no influence on the overall profile of the multimeric pattern when using the SAHARA-III dry tempering system. CONCLUSION: Octaplas can be thawed using the SAHARA-III dry tempering system without any negative influences on the demonstrated quality of this product. The SAHARA-III dry tempering system enables standardized thawing and warming procedure. Furthermore, tempering of Octaplas in the emergency unit or operating theatre, where no water baths can be utilized, is safe and can be fully endorsed.

Collaborative study for the establishment of replacement batches for human coagulation factor IX concentrate reference standards.

The European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) batch 1, the World Health Organisation (WHO) 3rd International Standard, Human (IS, 96/854) and the FDA Standard for human blood coagulation Factor IX concentrate have been available since 1996, following their establishment by a common collaborative study. Due to dwindling stocks of all three standards, a new WHO-EDQM-FDA tri-partite collaborative study was launched to establish replacement batches. Thirty laboratories from fourteen countries took part in the collaborative study to assign potency values to candidate preparations. Three candidates, one of recombinant and two of human plasma-derived origins, were assayed against the 3rd IS for Blood Coagulation Factor IX, Concentrate, Human (96/854). The 3rd IS for Blood Coagulation Factors II, VII, IX and X, Plasma, Human (99/826) was also included to evaluate the relationship between the factor IX plasma and concentrate unitage. Thirty-two sets of clotting assay results and two sets of chromogenic assay data were analysed. There was a significant difference in potency estimates by these two methods for the recombinant candidate (sample B) and the plasma IS (sample P). Similar potency values were obtained for the plasma derived products (monoclonal antibody- and chromatography-purified factor IX, samples C and D) by clotting and chromogenic assays. For the clotting assays, intra-laboratory variability (GCV) was found to range from 0.5 - 21.7%, with the GCV for the majority of laboratories being less than 10%. Good inter-laboratory agreement, with the majority of the GCV being less than 10% (GCV range = 4.7 - 10.6 %) was also obtained. The mean potency values estimated by the clotting assay using plasma as pre-diluent (as directed by the Ph. Eur. general chapter method) did not differ from values obtained using buffer. Taking into account the preliminary stability data, the intra- and inter-laboratory variability, and the differences between the clotting and chromogenic assay results, sample C (07/182) was established as the Human coagulation factor IX concentrate BRP batch 2, with a potency value of 7.9 IU/ampoule assigned with clotting assay results. As an outcome of this tri-partite collaborative study, the same sample C (07/182) has also been adopted as the 4th International Standard for Blood Coagulation Factor IX, Concentrate, Human by the Expert Committee on Biological Standardisation (ECBS) of the World Health Organisation (WHO), and as the replacement batch for the reference standard for Human coagulation factor IX concentrate by the FDA.

Robust, routine haematology reference ranges for healthy adults.

Accurate, reliable laboratory reference ranges are essential for effective clinical evaluation and monitoring. We present robust reference ranges established for haematology, coagulation and haematinic parameters using the Sysmex XE 2100, CA 1500 and Beckman-Coulter Access analysers. Blood samples were taken from 250 healthy laboratory personnel and routine haematology, coagulation and haematinic parameter analysis performed. Our data represent findings from an extensive study to establish reference ranges in healthy adults.

International biological standards for coagulation factors and inhibitors.

The use of international biological standards during the last 30 years has proved extremely successful in promoting global harmonization of estimates between laboratories and methods. Experience has led to the identification of physical criteria essential for standards to be suitable for long-term use. High precision of liquid filling coupled with low residual moisture and oxygen and the use of sealed glass ampoules have been found consistent with homogeneous and stable International Standards (ISs). Most plasma coagulation factors and inhibitors are calibrated in International Units (IU), which are defined as the amount of analyte in 1 mL of normal pooled plasma. Adoption of the IU has provided clarity in the definition of normal and abnormal states and has facilitated dose calculation for replacement therapy. The assay of like-versus-like materials (e.g., concentrate versus concentrate) has been found to improve interlaboratory agreement and there are now both plasma and concentrate ISs available for many coagulation factors and inhibitors. Studies into the assay of recombinant factor VIII have indicated that additional measures, such as modifications to assay methodology, are necessary to reduce interlaboratory variability. This experience may prove valuable in the future, when we have to deal increasingly with the challenges to standardization associated with the products of bioengineering.