Residual cell content in plasma produced by three centrifugal apheresis procedures

BACKGROUND: Understanding the impact of collection procedures on the residual amount of blood cells in plasma for transfusion and for fractionation is of current interest. This prospective work evaluated plasma donations collected on an apheresis machine (PCS 2, Haemonetics) with three different automatic centrifugal apheresis procedures, currently largely used in the US (Revision G) and in Europe (Revision F), and included a new procedure that uses a high-separation core (HSC) that is designed with a second separation chamber to further separate cells from plasma. STUDY DESIGN AND METHODS: A total of 90 collection procedures have been performed from a population of 37 donors, under comprehensively standardized conditions. There were 30 well-matched donors in each group. Plasma aliquots were taken from the plasma units within 30 minutes of the end of the collection procedures and immediately assessed for WBCs, RBCs, PLTs, and supernatant Hb. RESULTS: In Revision F and Revision G plasma donations, the mean numbers of WBCs were 83.1 x 10(4) and 311 x 10(4) per L; PLTs, 5.01 x 10(9) and 20 x 10(9) per L; and RBCs, 58 x 10(6) and 43 x 10(6) per L, respectively [corrected]. Significantly lower values were found with the HSC procedure (mean WBC, RBC, and PLT counts, 3.01 x 10(4)/L [p < 0.05], 9 x 10(6)/L [p < 0.001], and 3.5 x 10(9)/L [p < 0.001], respectively). The amount of free Hb was similar in all three procedures. CONCLUSION: Significant differences in numbers of cells in plasma were found depending on the centrifugal procedures used and the design of the separation bowl. The lowest level of cell contamination was found with the new HSC bowl, which without a filtration step, yielded plasma that met the standard for WBC-reduced plasma. Plasma collectors can select the most appropriate method of plasma collection based on donor criteria, use of plasma (transfusion, viral inactivation, or fractionation), and local or international regulations, when in place.     

A process for solvent/detergent treatment of plasma for transfusion at blood centers that use a disposable-bag system

BACKGROUND: Solvent/detergent (S/D) inactivates enveloped viruses in plasma. The current technology requires a plasma fractionation facility and is applied to large plasma pools, which increases the cost and risks of exposure to S/D-resistant pathogens and lowers the content of protein S and alpha2-antiplasmin. Two S/D treatment procedures for single donations or minipools of plasma have been developed with a single-use bag system. STUDY DESIGN AND METHODS: Frozen plasma samples were thawed and treated in disposable bags with either 2 percent tri(n-butyl)phosphate (TnBP) at 37 degrees C or 1 percent TnBP and 1 percent Triton X-45 at 31 degrees C for 4 hours. Plasma samples were extracted three times with 7.5 percent sterile castor oil to remove TnBP and Triton X-45. The TnBP-treated plasma samples were further subjected to a clarifying centrifugation (3800 x g, 30 min). Final plasma samples were dispensed into individual bags and frozen at -30 degrees C. Plasma quality was assessed at each step of the procedures. RESULTS: Both processes yielded greater than 90 percent mean recovery of coagulation factors (clottable fibrinogen, von Willebrand factor, and factors VIII, V, VII, IX, X, and XI), anticoagulants (protein C, protein S), protease inhibitors (antithrombin, alpha2-antiplasmin), total protein, albumin, and immunoglobulins. Global coagulation tests of the treated plasma samples were normal. Final TnBP and Triton X-45 content was less than 10 and 50 ppm, respectively. CONCLUSION: S/D treatment of plasma can be performed in a closed-bag system under conditions that maintain plasma protein quality. The technology is simple, presents advantages over the industrial large-scale S/D plasma process, and could be performed in blood centers.     

Coagulation profile of liquid‐state plasma

BACKGROUND: Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh‐frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days. STUDY DESIGN AND METHODS: LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at ?70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors. RESULTS: There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D‐dimer, or thrombin‐antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF. CONCLUSION: These data demonstrate that LP maintains at least 50% of factor activity and thrombin‐generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients.     

Evaluation and comparison of coagulation factor activity in fresh-frozen plasma and 24-hour plasma at thaw and after 120 hours of 1 to 6°C storage

BACKGROUND: Current transfusion-related acute lung injury reduction strategies include avoiding transfusion of plasma products collected from female donors or female donors that have been pregnant to reduce transfusion of plasma-containing HLA antibodies. Such a policy considerably decreases the number of donors available for generation of fresh-frozen plasma (FFP). To increase the supply of FFP, substitution of 24-hour plasma (FP24) and thawed plasma (TP) derived from either FFP or FP24 may be viable substitutes. To justify such a policy the coagulation factor content of FFP, FP24, and TP derived from both product types was assessed.
STUDY DESIGN AND METHODS: Coagulation factor (F)II, FV, FVII, FVIII, F IX, and FX; protein C (PC) and protein S (PS); von Willebrand factor antigen and ristocetin cofactor; fibrinogen; and antithrombin activities were analyzed in nonpaired FFP and FP24 at the time of product thaw and again after 120 hours of 1 to 6°C storage.
RESULTS: At thaw, mean FVIII and PC activities were lower in FP24 than FFP. Mean PC and PS activities were lower in FP24- than FFP-derived 120-hour-old TP. No other differences in mean activity reached significance. Activity levels were generally lower in TP; FVIII, FV, and FVII showed the largest changes. However, prestorage leukoreduction appears to improve the stability of FV.
CONCLUSION: FFP, FP24, and the derived TP all contain adequate coagulation factor activities to maintain hemostatic activity. As FFP becomes less available, increased use of FP24 and TP are viable alternatives for most clinical situations.     

A genetic basis for the interrelation of coagulation factors

BACKGROUND: Evidence found in the literature for a strong correlation between coagulation factors suggests that single genes might influence the plasma concentrations of multiple coagulation factors (i.e. pleiotropically acting genes). OBJECTIVE: To determine whether there is a genetic basis for the correlation among coagulation factors by assessing the heritability of interrelated coagulation factors. PATIENTS/METHODS: We performed principal components analysis, and subsequently variance components analysis, to estimate the heritability of principal components of coagulation factors in family members of a large French-Canadian kindred. RESULTS: Four clusters were identified by principal components analysis in 200 family members who did not carry the protein C 3363C mutation. Cluster 1 consisted of prothrombin, factor VII (FVII), FIX, FX and protein S; cluster 2 consisted of FV, FIX, protein C and tissue factor pathway inhibitor; cluster 3 consisted of FVIII and von Willebrand factor; and cluster 4 consisted of antithrombin, protein C and FVII. The heritability of the principal components estimated by variance components analysis was, respectively, 37%, 100%, 37%, and 37%. CONCLUSION: Our findings support the hypothesis that genes can influence plasma levels of interrelated coagulation factors.     

Coagulation function in fresh-frozen plasma prepared with two photochemical treatment methods: methylene blue and amotosalen

BACKGROUND: Pathogen inactivation of plasma intended for transfusion is now the standard of care in Belgium. Two methods for treatment of single plasma units are available: amotosalen plus ultraviolet A light and methylene blue plus visible light. This study compared the quality and stability of plasma treated with these two methods. STUDY DESIGN AND METHODS: Plasma units made from a pool of two ABO-matched fresh apheresis units were photochemically treated with either amotosalen (PCT-FFP) or methylene blue (MB-FFP). A total of 12 paired samples were evaluated. Plasma coagulation function was assessed at three time points: immediately after treatment, after 30 days of frozen storage, and an additional 24 hours at 4 degrees C after thawing. Comparison between PCT-FFP and MB-FFP was assessed with the paired t test and a p value of less than 0.05 indicated statistical significance. RESULTS: Based on statistical analysis, mean levels of factor (F)II, FXII, FXIII, von Willebrand antigen, ADAMTS-13, D-dimers, and protein C were equivalent between PCT-FFP and MB-FFP for all three time points. PCT-FFP exhibited shorter mean prothrombin time, activated partial thromboplastin time (two time points), and thrombin time and higher mean levels of fibrinogen, FXI, and protein S than MB-FFP. Retention of FV, FVII, FVIII, FX, or von Willebrand factor:ristocetin cofactor in PCT-FFP was either equivalent to or higher than MB-FFP. MB-FFP contained higher mean levels of plasminogen, antithrombin, and plasmin inhibitor than PCT-FFP. Retention of F IX in MB-FFP was higher than PCT-FFP only after the 4 degrees C storage after thawing. CONCLUSION: There is adequate preservation of therapeutic coagulation factor activities in both PCT-FFP and MB-FFP. The overall coagulation factor levels and stability of PCT-FFP were better preserved than MB-FFP.     

Coagulation factors and the protein C system as determinants of thrombin generation in a normal population.

BACKGROUND: Thrombin generation is a powerful tool to probe overall plasma coagulability. OBJECTIVE: To determine which plasma factors influence the various parameters of the thrombin generation curve, for example lag time, peak height and endogenous thrombin potential (ETP), under different experimental conditions. PATIENTS AND METHODS: Plasma levels of coagulation factors and inhibitors, as well as thrombin generation at 1 pm tissue factor (TF) +/- thrombomodulin (TM) and at 13.6 pm TF +/- activated protein C (APC), were determined in plasma from 140 healthy individuals. Data were analysed by multiple regression models. RESULTS: Thrombin generation increased with age and was higher in females than in males. Under all conditions, the lag time was mainly dependent on the levels of free tissue factor pathway inhibitor (TFPI), free protein S (PS), factor VII (FVII), FIX and fibrinogen. The major determinants of thrombin generation (ETP and peak height) at 1 pm TF were fibrinogen, FXII (despite inhibition of contact activation), free TFPI and antithrombin (AT), both in the absence and in the presence of TM. Thrombin generation in the presence of TM was also dependent on protein C levels. At 13.6 pm TF, thrombin generation was determined by prothrombin, AT, fibrinogen, free TFPI and FV levels in the absence of APC, and by free TFPI, free PS and FX levels in the presence of APC. CONCLUSIONS: The lag time, ETP and peak height of thrombin generation depend on the levels of multiple coagulation factors and inhibitors. The specific assay determinants vary with the experimental conditions.     

Induction of a hypercoagulability state and endothelial cell activation by granulocyte colony-stimulating factor in peripheral blood stem cell donors

In June, 1997, we initiated a prospective study to analyze the effect of granulocyte colony-stimulating factor (G-CSF) on coagulation system in peripheral blood stem cells (PBSC) donors following G-CSF administration. Since, 25 consecutively healthy donors received G-CSF (filgrastim) to mobilize and collect PBSC and 20 donors were finally included in the study. Blood samples were collected immediately before starting G-CSF and prior to PBSC collection to analyze the following parameters: prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, hypercoagulability markers (D-dimer, TAT complex, F1 + 2), natural anticoagulants (antithrombin, protein C, protein S), endothelial activation markers [von Willebrand factor antigen (vWF:Ag) and angiotensin converting enzyme (ACE)], and resistance to activated protein C. We found a significant increase in F1 + 2 and D-dimer while a significant decrease of antithrombin and protein C activity was evidenced. Regarding endothelial cell activation markers, a significant increase of vWF:Ag with a slightly significant decrease of ACE were also observed. Therefore, in PBSC donors receiving G-CSF our results reveal activation of both coagulation and endothelial cells that could favor the developing of thrombotic events. In consequence, a careful monitoring should be considered in those cases with risk factors for thrombosis.     

The impact of the intensity of serial automated plasmapheresis and the speed of deep-freezing on the quality of plasma

BACKGROUND: Data are lacking on the impact that the intensity of serial donor plasmapheresis has on the quality of source plasma. A study was conducted to examine the quality of source plasma produced by intensive plasmapheresis and slow deep-freezing and to compare it to source plasma manufactured by moderate plasmapheresis and rapid freezing. STUDY DESIGN AND METHODS: Seventy-five plasma samples from intensive plasmapheresis programs (Group 1) and 75 plasma units from moderate plasmapheresis programs (Group 2) were examined. The plasma had been deep-frozen either slowly at -30 degrees C in walk-in freezers (Group 1) or rapidly within 1 hour to a core temperature below -30 degrees C (Group 2). Determinations were made of the plasma levels of citrate; total protein; albumin; IgG; fibrinogen; factors II, V, VII, VIII, and IX; vWF; antithrombin; protein C; D-dimers; and prothrombin fragments 1+ 2. RESULTS: Plasma units of Group 2 contained substantially greater levels of citrate, IgG, FVIII, and FV than samples of Group 1 (p<0.0001). Plasma levels of total protein, albumin, and fibrinogen also were higher in Group 2 (p<0.0001, p = 0.007, and p = 0.006, respectively). Neither plasmapheresis intensity nor freezing procedure had any influence on the levels of factors II, VII, and IX, antithrombin, or protein C. There was no evidence of substantial coagulation activation in the plasma units of either group. However, higher FVIII clotting activity/chromogenic substrate activity ratios in rapidly frozen plasmas and a significant correlation between these ratios and prothrombin fragment 1+ 2 levels suggest that rapid freezing yields both more native FVIII and greater partial activation of FVIII. CONCLUSION: Source plasma collected from donors undergoing intensified plasmapheresis contains markedly lower levels of IgG than plasma units produced by moderate serial plasmapheresis. The combination of intensified plasmapheresis and slower freezing of source plasma results in substantially lower levels of FV and FVIII than does moderate plasmapheresis with rapid freezing. Prospective studies should establish the optimum conditions required for the safe and economic production of source plasma for fractionation.     

Plasma and cryoprecipitate manufactured from whole blood held overnight at room temperature meet quality standards

BACKGROUND: With buffy coat (BC) processing of whole blood (WB) donations, the preparation of plasma occurs within 24 hours rather than 8 hours of collection. The effect of this change on coagulation factor function in plasma and cryoprecipitate was evaluated during the validation of this production method and with routine production. STUDY DESIGN AND METHODS: Plasma frozen after an overnight hold of WB was prepared via BC or whole blood filtration (WBF) methods and quality control (QC) variables were measured. Additionally, plasma prepared with the BC method was compared to plasma produced using the platelet‐rich plasma (PRP) method with an extended plasma factor analysis. Selected plasma factor levels were also measured in both cryoprecipitate and cryosupernatant plasma prepared using the WBF method from plasma frozen on the day of collection or after an overnight hold of WB. RESULTS: When comparing BC plasma to PRP plasma, coagulation factors (F)II, VII, VIII, IX, X, and XI had somewhat lower levels, and fibrinogen and antithrombin levels were elevated. As expected the most sensitive to the prolongation of production time was FVIII with 72 and 78% of the activity of PRP plasma and cryoprecipitate, respectively. However, both still met QC standards. Similarly, products made in routine production show acceptable levels of FVIII. CONCLUSION: Plasma and cryoprecipitate products, prepared using methods in which the plasma is frozen close to 24 hours after collection, meet current quality standards. The longer WB storage time has been implemented into general use in Canada.     

Effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma

BACKGROUND: The aim of this study was to investigate the effect of gamma irradiation with 30 Gy on the coagulation system in leukoreduced fresh-frozen plasma (FFP). STUDY DESIGN AND METHODS: In 74 FFP units that had been stored for 352 +/- 103 days below -30 degrees C, the following variables were determined in parallel in an irradiated and not irradiated half: prothrombin time (PT); activated partial thromboplastin time (APTT); thrombin time; antithrombin III; protein C; protein S; von Willebrand factor antigen; ristocetin cofactor; plasminogen-alpha(2)-antiplasmin; the coagulation factors fibrinogen, factor (F)II, FV, FVII, VIII, F IX, FX, FXI, FXII, FXIII, and activated factor XII (FXIIa); D-dimer; fibrin monomer; thrombin-antithrombin complex; prothrombin fragment 1 + 2 (F1+2); plasmin-alpha(2)-antiplasmin complexes (PAPs); and platelet factor 4. The FVII activity ratio was assayed to quantify activation of FVII. RESULTS: Irradiation with 30 Gy resulted in a reduction of APTT (35.0 +/- 4.1 sec vs. 34.4 +/- 4.1 sec; p = 0.00000006) and PT (89.8 +/- 8.2% vs. 90.7 +/- 8.0%; p = 0.002) and a significant increase of the activities of the coagulation factors FII, FV, FVII, F IX, FX, and FXII. FVIII activity decreased from 118 +/- 31 to 116 +/- 32 percent (p = 0.02). Activation of the coagulation system was shown by an increase in the FVII activity ratio (1.19 +/- 0.29 vs. 1.31 +/- 0.34; p = 0.0000001), FXIIa (0.81 +/- 0.50 ng/mL vs. 0.90 +/- 0.51 ng/mL; p = 0.006), and F1+2 (1.19 +/- 0.20 nmol/L vs. 1.24 +/- 0.20 nmol/L; p = 0.000005) after irradiation with 30 Gy, whereas an increase of PAP (16.2 +/- 11.5 ng/mL vs. 20.2 +/- 12.0 ng/mL; p = 0.0004) demonstrated activation of the fibrinolytic system. No negative influence of irradiation with 30 Gy on inhibitors of coagulation was observed. CONCLUSION: Gamma irradiation of leukoreduced FFPs with 30 Gy results in a significant but very weak activation of the coagulation and fibrinolytic system in FFPs.     

Photochemical treatment of plasma with amotosalen and long-wavelength ultraviolet light inactivates pathogens while retaining coagulation function

BACKGROUND: The INTERCEPT Blood System, a photochemical treatment (PCT) process, has been developed to inactivate pathogens in platelet concentrates. These studies evaluated the efficacy of PCT to inactivate pathogens in plasma and the effect of PCT on plasma function. STUDY DESIGN AND METHODS: Jumbo (600 mL) plasma units were inoculated with high titers of test pathogens and treated with 150 micromol per L amotosalen and 3 J per cm(2) long-wavelength ultraviolet light. The viability of each pathogen before and after treatment was measured with biological assays. Plasma function was evaluated through measurement of coagulation factors and antithrombotic protein activities. RESULTS: The levels of inactivation expressed as log-reduction were as follows: cell-free human immunodeficiency virus-1 (HIV-1), greater than 6.8; cell-associated HIV-1, greater than 6.4; human T-lymphotropic virus-I (HTLV-I), 4.5; HTLV-II, greater than 5.7; hepatitis B virus (HBV) and hepatitis C virus, greater than 4.5; duck HBV, 4.4 to 4.5; bovine viral diarrhea virus, 6.0; severe acute respiratory syndrome coronavirus, 5.5; West Nile virus, 6.8; bluetongue virus, 5.1; human adenovirus 5, 6.8; Klebsiella pneumoniae, greater than 7.4; Staphylococcus epidermidis and Yersinia enterocolitica, greater than 7.3; Treponema pallidum, greater than 5.9; Borrelia burgdorferi, greater than 10.6; Plasmodium falciparum, 6.9; Trypanosoma cruzi, greater than 5.0; and Babesia microti, greater than 5.3. Retention of coagulation factor activity after PCT was expressed as the proportion of pretreatment (baseline) activity. Retention was 72 to 73 percent of baseline fibrinogen and Factor (F)VIII activity and 78 to 98 percent for FII, FV, FVII, F IX, FX, FXI, FXIII, protein C, protein S, antithrombin, and alpha2-antiplasmin. CONCLUSION: PCT of plasma inactivated high levels of a wide range of pathogens while maintaining adequate coagulation function. PCT has the potential to reduce the risk of transfusion-transmitted diseases in patients requiring plasma transfusion support.     

Sepsis-associated coagulation disorders

Coagulation activation with intravascular fibrin formation is a general finding in patients with sepsis. Low coagulation factors may be caused by disseminated intravascular coagulation, as well as by loss of plasma and impaired hepatic synthesis in the course of sepsis. The leading clinical symptom in consumption coagulopathy is bleeding. Therefore, treatment mainly consists of substitution of coagulation factors and platelets. Meningococcal and pneumococcal, as well as some other infections may lead to sepsis-induced purpura fulminans, a condition associated with microvascular thrombosis, necrosis, and haemorrhage. A typical laboratory sign is a very low plasma protein C level. Treatment with protein C concentrate or recombinant activated protein C (Drotrecogin alfa, activated) has been shown to be beneficial in sepsis-induced purpura fulminans. Unfractionated heparin or low molecular weight heparin has been recommended for prophylaxis of venous thrombosis, but there are no clinical studies specifically on patients with sepsis. Antithrombin concentrate is used in patients with antithrombin deficiency treated with heparin for acute venous thrombosis or embolism, extracorporeal circulation procedures or other invasive procedures. There is no indication for general use of antithrombin concentrate in patients with sepsis even in patients with low plasma antithrombin levels. Drotrecogin alfa, activated, is used for treatment of patients with severe sepsis. Its use is not limited to patients with sepsis-induced disseminated intravascular coagulation, although these patients appear to benefit especially from this therapy.     

Effect of 24-hour whole-blood storageon plasma clotting factors

BACKGROUND: The current requirements for the preparation of fresh-frozen plasma within 8 hours of whole-blood collection were designed to maintain clotting factor activities. These requirements, however, limit the production of fresh-frozen plasma in a large blood center. There are few data on the effect of the extension of CPD whole-blood storage to 24 hours on clotting factor activity. STUDY DESIGN AND METHODS: A 500-mL unit of whole blood was collected from 10 volunteer donors. At 1 hour after collection, a plasma sample was separated by centrifugation, and each unit was equally divided into 2 half-units, with 1 half-unit stored at 4 degrees C (range, 1-6 degrees C) and 1 half-unit stored at 22 degrees C (range, 20-24 degrees C) for 8 hours after collection. Each half-unit was then placed at 4 degrees C for further storage for 16 hours. At 8 and 24 hours after collection, plasma samples were separated from each half-unit. All plasma samples were frozen at -18 degrees C. Factors V, VII, VIII, and X; fibrinogen; antithrombin III; protein C; and protein S were measured. RESULTS: No significant changes were noted in factors V, VII, and X; fibrinogen; antithrombin III; protein C; and protein S over the 24-hour storage period. Factor VIII in both half-units was significantly reduced, by 13 percent, from the baseline sample as compared to the level in the 8-hour storage sample (p<0.05). Factor VIII was further reduced by 15 to 20 percent after the 24-hour storage period (p<0.05). CONCLUSION: The coagulation factor activity for all factors measured, with the exception of factor VIII, showed no significant change over the 24-hour storage period. Factor VIII was significantly decreased by 13 percent in 8-hour storage and by an additional 15 to 20 percent in 24-hour storage. For clinical situations not requiring the replacement of factor VIII only, 24-hour frozen plasma has properties comparable to those of fresh-frozen plasma.     

The selection of donors in multicomponent collection management.

The use of cell separators in multicomponent collection (MCC) makes it possible to use donors effectively by personalising the donation on the basis of their haemotological and physical profiles and thereby standardising the product. We have applied the selection parameters currently used in our collection centre to 6687 donors using a common software programme for all: 57.6% were eligible for the various forms of MCC, although our parameters are even stricter than those required by law. Between 01 September 2001 and 28 February 2002, 345 MCC (9% of all the donations made) were performed and assessed: 111 donations of double red cell units, 153 donations of red cells and plasma, 62 donations of plasma and platelets, 19 donations of double platelet units: only slight, adverse reactions were encountered in 6% of the procedures. 68 double red cell unit donors and 65 red cell and plasma donors were then reassessed 6 months after MCC: the parameters assessed (hemoglobin, serum iron, ferritin, and total protein) were the same as the pre-donation data. All the units collected complied with legal requirements. With the use of parameters based on donor hematological and physical characteristics we can move from the concept of tailored transfusions to the concept of tailored donations thereby ensuring donor safety and meeting patient needs.     

Fresh frozen plasma prepared with amotosalen HCl (S-59) photochemical pathogen inactivation: transfusion of patients with congenital coagulation factor deficiencies

BACKGROUND: Photochemical treatment (PCT) with amotosalen HCl (S-59) was developed to inactivate pathogens and white blood cells in plasma (PCT-FFP) used for transfusion support. STUDY DESIGN AND METHODS: An open-label, multicenter trial was conducted in patients with congenital coagulation factor deficiencies (factors [F]I, FII, FV, FVII, FX, FXI, and FXIII and protein C) to measure the kinetics of specific coagulation factors, hemostatic efficacy, and safety of PCT-FFP. Posttransfusion prothrombin time (PT), partial thromboplastin time (PTT), and clinical hemostasis were evaluated before and after PCT-FFP transfusions. RESULTS: Thirty-four patients received 107 transfusions of PCT-FFP for kinetic studies or therapeutic indications (mean dose, 12.8 +/- 8.5 mL/kg). Incremental factor recoveries ranged from 0.9 to 2.4 IU per dL per IU per kg (FII, FV, FVII, FX, FXI, and protein C). Mean pretransfusion PT (20.7 +/- 22.2 sec) corrected after PCT-FFP (13.8 +/- 2.4 sec, p < 0.001). Mean pretransfusion PTT (51.2 +/- 29.3 sec) corrected after PCT-FFP (32.0 +/- 5.1 sec, p < 0.001). Thirteen patients required 77 transfusions for therapeutic indications. PCT-FFP provided effective hemostasis and was well tolerated. CONCLUSIONS: Replacement coagulation factors in PCT-FFP exhibited kinetics and therapeutic efficacy consistent with conventional FFP.     

Plasma concentrations of blood coagulation factor VII measured by immunochemical and amidolytic methods

Ever since the coagulant activity of blood coagulation factor VII (FVII:C) was identified as a risk indicator of cardiac death, a large number of studies have measured FVII protein concentrations in plasma. FVII protein concentrations are either measured immunologically with an ELISA method (FVII:Ag) or estimated with an amidolytic method (FVII:Am). We have investigated whether FVII:Am is a valuable alternative to FVII:Ag. FVII:Ag and FVII:Am were measured in 147 plasma samples from blood donors, patients on oral anticoagulant therapy, postmenopausal women on hormone replacement therapy, in postprandial plasma, in cold activated plasma and in FVII deficient plasma. There was a positive correlation (r=0.96) between FVII:Ag and FVII:Am with slightly but significantly higher values for FVII:Ag (FVII:Ag= 106 U/ml and FVII:Am=100 U/ml; p <0.001). A significant correlation (r=0.93) was still observed after omitting the data from patients on oral anticoagulant therapy, with mean values of 113 U/ml for FVII:Ag and 110 U/ml for FVII:Am (p < 0.01). In a linear regression analysis, the intercept (alpha=-21.50) was different from zero (p < 0.0001) and the slope (beta=1.16) was different from 1.0 (p < 0.001). Only a few points (3.1%) in a difference plot were present outside the expected 95% interval calculated from the analytical imprecision of the two methods. Therefore, we consider the amidolytic method an acceptable alternative to the ELISA method when analysing citrated plasma samples containing only enzymatically functional FVII protein, but the results cannot be directly transferred from one method to the other.     

Heritability of plasma concentrations of clotting factors and measures of a prethrombotic state in a protein C-deficient family

Summary.  Background : Earlier studies found strong support for a genetic basis for regulation of coagulation factor levels and measures of a prethrombotic state ( d -dimer, prothrombin fragment 1.2). Objectives : Estimation of how much of the variation in the levels of coagulation factors and measures of a prethrombotic state, including measures of protein C activation and inactivation, could be attributed to heritability and household effect. Patients and methods : Blood samples were collected from 330 members of a large kindred of French-Canadian origin with type I protein C deficiency. Heritability and common household effect were estimated for plasma concentrations of prothrombin, factor (F)V, factor VIII, factor (F)IX, fibrinogen, von Willebrand factor (VWF), antithrombin, protein C, protein S, protein Z, protein Z-dependent protease inhibitor (ZPI), fibrinopeptide A (FPA), protein C activation peptide (PCP), activated protein C–protein C inhibitor complex (APC–PCI), activated protein C–α₁-antitrypsin complex (APC–α1AT), prothrombin fragment 1.2 (F1.2) and d -dimer, using the variance component method in sequential oligo-genic linkage analysis routines (SOLAR). Results : The highest heritability was found for measures of thrombin activity (PCP and FPA). High estimates were also found for prothrombin, FV, FIX, protein C, protein Z, ZPI, APC–PCI and APC–α1AT. An important influence of shared household effect on phenotypic variation was found for VWF, antithrombin, protein S and F1.2. Conclusions : We found strong evidence for the heritability of single coagulation factors and measures of a prethrombotic state. Hemostatic markers with statistically significant heritability constitute potential targets for the identification of novel genes involved in the control of quantitative trait loci.     

急性白血病五种血浆凝血因子测定及临床意义

目的 探讨急性白血病(AL)血浆凝血因子V、Ⅶ、Ⅷ、Ⅸ、X活性(FV：c，FⅦ：c，FⅧ：c，FⅨ：c和FX：c)的变化。方法 采用COAG—MATE—XM型血凝自动分析仪测定36例AL患者(ANLL28例，ALL8例)五种凝血因子活性水平，并与30例正常人作对照。结果 ①AL患者FV：c，FⅦ：c，Ⅷ：c和FX：c大多降低，ANLL较ALL更显著；②组间比较：高危组FⅧ：c、FX：c降低；出血组FV：c、FⅦ：c、FⅧ：c和FX：c降低；缓解组FV：c、FⅦ：c、FⅧ：c和FX：c升高，前三项已恢复正常水平。结论 检测上述凝血因子水平对AL病情和预后判断有一定意义。