Safety aspects in the manufacturing of plasma-derived coagulation factor concentrates.

Plasma-derived coagulation factor concentrates, prepared using traditional manufacturing processes, have transmitted viral diseases, especially AIDS, hepatitis B and hepatitis C to patients. To date, more extensive selection of blood donors, improved screening procedures of each plasma donation for direct and indirect viral markers, and newly developed virucidal procedures, especially pasteurization and solvent-detergent, together with extraction technologies of plasma proteins based on high-resolution chromatographic separations, have diminished considerably the risks of transmitting these pathogenic agents. To ensure safety, each production process must be carefully validated, following a rigorous scientific approach to assess its ability to inactivate or eliminate viruses. In addition, Good Manufacturing Practices must avoid any variation from these validated viral inactivation processes and must eliminate risks of potential downstream contamination of purified plasma fractions following viral inactivation or elimination steps. Other side-effects associated with conventional low-purity preparations, such as acute haemolytic anemia due to contamination by isohaemagglutinins, or immunosuppression possibly due to an overload in fibrinogen and immunoglobulins, have not been reported following infusion of highly purified coagulation factor concentrates. Present state-of-the-art virus inactivation and protein-purification technologies have significantly improved the safety of plasma coagulation factor concentrates.     

Clinical use of blood,blood components and blood products.

The goal of modern transfusion therapy is to provide appropriate replacement therapy with blood components as opposed to whole blood for patients with specific hematologic deficiencies. A prerequisite of component therapy is, therefore, correct identification of the deficiency. Appropriate use of components avoids many of the hazards associated with the use of whole blood, and at the same time makes maximal use of this valuable resource. Blood components separated from whole blood soon after collection and appropriately stored can, in combination, provide all the factors present in fresh whole blood. Red cell concentrates prepared from multiple packs have a hematocrit of approximately 70%. They may be stored for up to 3 weeks at 4 degrees C and are recommended for most situations requiring red cell transfusions. Platelet concentrates, which can be stored for up to 72 hours at 22 degrees C, may be used for thrombocytopenic patients. Fresh frozen plasma, stored plasma, cryoprecipitated factor VIII, factor VIII concentrate and factor IX complex concentrate are available for the proper treatment of patients with hemorrhagic disorders due to coagulation factor deficiencies. Similarly, albumin and immune serum globulin are available for their oncotic and antibody properties respectively. Thus, the availability and appropriate use of the various blood products allows not only optimal transfusion therapy for each patient, but also fuller utilization of national blood resources.     

The French National Program for the Prevention and Control of AIDS

The French policy concerning the fight against the acquired immunodeficiency syndrome (AIDS) is a complete and well-balanced one, using information not only for the general awareness of the general population, but also with the help of specific actions aimed at high risk groups. Screening is mandatory for blood, organ and cell donors, but it must absolutely respect individual rights and the rules of ethics. Therefore it must be voluntary and totally respect privacy and professional confidence. France does not undertake screening at the border, but does inform people traveling to and from the country. The monitoring and medical care will be given daily for ambulatory patients, and in specific hospital services according to the symptoms of the others. To save money and to be more efficient, tests will be grouped in specific laboratories. Research is, with prevention, the only hope of stopping the spread of AIDS. More than 50 laboratories are at this moment working, and important funds and materials have been allocated. International cooperation is needed, along with the coordination of the World Health Organization, and the action undertaken by the European Community, to establish the most efficient methods of preventing the spread of this new viral infection that now concerns the whole world.     

Blood protein derivative viral safety: observations and analysis

The well-documented viral safety of albumin arises from several factors operating in concert, including virus removal during preparation, immune neutralization, serendipitous inactivation, virus sterilization through pasteurization. Safety with respect to HBV transmission was achieved even prior to the development of sensitive screening tests for HBsAg, as can be predicted given the initial virus load and the influence of factors affecting removal and inactivation. Coagulation factor concentrates, as traditionally prepared, are known to have transmitted the viral agents of hepatitis and AIDS with high frequency. Application of virucidal procedures to these concentrates, in some cases, appears to have eliminated virus transmission, raising the question as to whether absolute safety has now been achieved. Clinical proof of absolute safety is made difficult by the small number of eligible patients who can be monitored, lengthy and expensive monitoring procedures, and opportunity for transmission of virus by product-independent routes. Based on viral load analysis, modern coagulation factor concentrates are predicted to have the same probability of freedom from HIV, HBV, and HCV transmission as that exhibited by albumin.     

Excluding blood donors at high risk of HIV infection in a west African city.

OBJECTIVE--To examine the potential impact of deferral of blood donors at high risk of HIV infection in a west African city where blood is screened for HIV antibodies but no other special measures are taken to protect the blood supply. DESIGN--Cross sectional study. SETTING--National Blood Transfusion Centre and Project RETRO-CI, an international collaborative AIDS research project, Abidjan, Côte d''Ivoire. SUBJECTS--1257 male first time blood donors. INTERVENTIONS--Blood donors were interviewed about demographic and behavioural characteristics and tested for HIV antibodies by enzyme immunoassay and, if positive, synthetic peptide based tests. MAIN OUTCOME MEASURES--HIV antibody status in relation to presence of behavioural risk factors; calculation of sensitivity, specificity, and predictive values of specific criteria for excluding HIV infected donors. RESULTS--The overall prevalence of HIV infection was 11.4%. The most important risk factors for HIV positivity were prostitute contact and being aged 30-39 years. For identifying seropositive donors individual criteria had sensitivity, specificity, and positive predictive values ranging from 15% to 98%, 38% to 91%, and 17% to 30% respectively. Prostitute contact in the past five years would have excluded 31% of all donors and 73% of HIV infected donors. 27% of those excluded would have been HIV positive. CONCLUSIONS--The widespread assumption that donor deferral is not feasible in sub-Saharan Africa needs reassessment. In Abidjan this approach was well accepted and potentially effective. Donor deferral requires evaluation as a strategy for improving blood safety in resource poor areas with high rates of HIV infection.     

Automated data processing system at the National Center for Blood Transfusion

1) Data processing of blood unit test result on Groupamatic with manual labelling listings:--according to unit numbers;--according to blood results. 2) Blood donor file (updating):--114 473 donors;--150 characters/standard donors;--250 characters/precious donors. 3) Automatic print-out of:--call-ups;--donor data cards;--national blood donor cards:--diplomas;--red cards of badges;--particular listings of blood donors for medical checking, calling up, selecting units with special characteristics;--general listings. 4) Automatic labelling of blood units, by reading the unit identification number, and by printing out the corresponding labels.     

Scottish attitudes to blood donation and AIDS.

OBJECTIVE--To see whether the issue of AIDS has influenced the observed decline in blood donation in Scotland. DESIGN--Two methods: a quantitative survey using personal interviews based on a questionnaire and a qualitative survey based on group discussions. SETTING--Interviews based on the questionnaire were conducted in the respondents'' homes. The group discussions were held in the homes of professional market research interviewers. PARTICIPANTS--For the quantitative survey a representative sample of 976 Scottish adults was selected by multistage sampling. In the qualitative survey 16 groups of five to eight respondents assigned according to donating experience and sociodemographic criteria took part. MAIN RESULTS--AIDS was not mentioned as a discouraging factor in donation, and off putting aspects identified before AIDS became a public issue remained salient--for example, fear of needles. Many (75%) thought it unlikely that donation entailed a risk of developing AIDS. Nevertheless, respondents were reluctant to consider the AIDS issue personally. Being asked to do so, as in the routine screening of donors, aroused fears and resentment. CONCLUSIONS--The issue of AIDS, including fear of infection, has not directly influenced the declining numbers of donors, but the unpleasant associations of AIDS have had an indirect effect, particularly in undermining the emotional benefits of giving blood. For example, the screening process, which requires potential donors to consider their personal risk from AIDS, had had the effect of discouraging donors in general. Redressing the balance is difficult as screening must be universally applied. Rather than minimising the issue of AIDS, publicity needs urgently to reassert the positive benefits of and rewards from giving blood.     

AIDS, related syndromes and hemophilia: the situation in France and studies in progress

A mail survey sent to 25 hemophilia centers in France enquiring on the occurrence of AIDS or AIDS-related disorders was done in May 1983. Of 2 388 hemophiliacs representing approximately 60% of the total expected population, no case of AIDS was found. Four patients had lymphodenopathies. A relatively high frequency of lymphopenia (8%) and hyper gammaglobulinemia (21%) was found. Only 37 patients were tested for T-lymphocyte populations, 14 of whom had a T4/T8 ratio below 1. A state funded multicenter prospective study has been designed in order to evaluate the relationship between the type (domestic or imported factor VIII or IX concentrate), the dose of blood product and various clinical, immunological and virological parameters related to AIDS. Approximately 400 hemophiliacs will enter the study together with a small population of patients with thalassemia receiving packed red cells.     

Biological studies and research of immunologic deficiencies in blood donors from a prison environment

The prison population may be considered as a population at risk for AIDS. Biological parameters were studied in order to detect significant anomalies commonly observed in AIDS patients. With respect to are age matched control population of donors, there are no statistically significant differences concerning the nutritional and inflammatory states of the two populations. The investigation of the humoral immunity shows comparable levels of circulating antibodies in the two groups: a high level of anti-cytomegalovirus and anti-herpes antibodies is more frequently found in the penal population. The markers for hepatitis B were also studied. None of the individuals is a carrier of the HBs antigen. The percentage of individuals having biological markers of hepatitis B is higher in the at risk group (45%) than in the control group (10%). The evaluation of the cell-mediated immunity shows that there are no significant differences between the mean values found in the two groups for OKT3, T11, OKT4 and OKT8. There is no inversed OKT4/OKT8 ratio in the at risk group while one donor in the control group shows an inversed OKT4/OKT8 ratio.     

Experience with a blood component program in surgical hemotherapy

Within the component concept applied during the past 6 years at the University Hospital in Berne (Switzerland), 85% of all red cell units are transfused as concentrates with a hematocrit of 70%, and the remaining 15% as fresh whole blood. The rationale in surgical patients is to exploit the different "critical levels" of the blood volume, hematocrit, total serum protein, plasmatic coagulation factors, and platelets. A colloid plasma substitute compensating for the plasma deficit of the red cell concentrates is an integral part of the system. A carefully checked, retrospective study in 372 patients revealed no disadvantages for the postoperative course. During the first 4 1/2 years after its introduction it did not increase the demand for human plasma protein solutions. With the red cells as a pacemaker for the number of blood donations, this system can simultaneously cover a reasonable national demand for albumin and factor VIII.     

Blood coagulation and fibrinolysis in blood donors after plasmapheresis]

Authors were interested in blood coagulation proteins and fibrinolysis in blood donors following several plasmaphereses. This interest was related to the occurrence of thrombo-embolic and hemorrhagic complications in these subjects. Blood morphology, serum protein, blood coagulation and fibrinolysis have been examined in 40 healthy blood donors, aged between 19 and 46 years, who gave blood plasma by plasmapheresis technique for 1-59 times. Results did not show any significant changes in blood morphology and serum protein levels prior to and after consecutive plasmaphereses. No significant decrease in blood coagulation proteins and fibrinolysis has been noted. However, a significant increase in factors VIII and IX activities was noted in several blood donors, who underwent the largest number of plasmaphereses. It may predispose these donors to thrombo-embolic complications.     

AIDS risk and prevention in transfusions

Transfusion of blood and blood products range from 2 to 8% of the cases of AIDS. The identification of HIV viral agent and the appearance of tests designed to detect antibodies associated with mechanisms of autologous transfusions and inactivation of virus of clotting factors concentrates have contributed to decrease this mean of transmission. Some aspects such as the difference of sensitivity in the tests, immunologic windows, and the appearance of new viruses such as the HIV 2 increase the complexity of the problem. Therefore, the services of hemotherapy all over the world must be aware of mechanisms of exclusion of potentially infected donors, in addition to education, and, mainly, the development of new techniques that can guarantee transfusion safety.     

High prevalence anti-Trypanosoma cruzi antibodies,among blood donors in the State of Puebla,a non-endemic area of Mexico

Blood transfusion is the second most common transmission route of Chagas disease in many Latin American countries. In Mexico, the prevalence of Chagas disease and impact of transfusion of Trypanosoma cruzi-contaminated blood is not clear. We determined the seropositivity to T. cruzi in a representative random sample, of 2,140 blood donors (1,423 men and 647 women, aged 19-65 years), from a non-endemic state of almost 5 millions of inhabitants by the indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) tests using one autochthonous antigen from T. cruzi parasites, which were genetically characterized like TBAR/ME/1997/RyC-V1 (T. cruzi I) isolated from a Triatoma barberi specimen collected in the same locality. The seropositivity was up to 8.5% and 9% with IHA and ELISA tests, respectively, and up to 7.7% using both tests in common. We found high seroprevalence in a non-endemic area of Mexico, comparable to endemic countries where the disease occurs, e.g. Brazil (0.7%), Bolivia (13.7%) and Argentina (3.5%). The highest values observed in samples from urban areas, associated to continuous rural emigration and the absence of control in blood donors, suggest unsuspected high risk of transmission of T. cruzi, higher than those reported for infections by blood e.g. hepatitis (0.1%) and AIDS (0.1%) in the same region.     

Increasing trend of hyperbilirubinemia incidence in the blood donors population

Blood donors' screening has been performed during the last twenty years and it has reached a considerable post-transfusion hepatitis prevention due to disqualifying hyperbilirubinemic donors. Since 1981, AST screening has been combined with the attention paid to bilirubin--conditioned plasma colour. In the following years a steep exponential increase of hyperbilirubinemic donors incidence has been observed from 1.3% in 1983 and 1984 to 4.0% in 1988. The possibilities of a relationship to hepatitis epidemic of the years 1979-80 or to other factors are discussed. The hyperbilirubinemias are suggested to be of a posthepatitic character, produced in the unrecognised hepatitis cases who had been subclinical at the time of the epidemic. More information is expected from the development of the trend in the next years.     

Transfusion medicine and safety

Advances in safety of blood transfusion in clinical practice principally relate to preventing transfusion-transmitted infections (TTI). Epidemiological studies of TTI have resulted in the development, standardization, and implementation of an expanding array of immunoassays employed worldwide in routine screening of blood donated by voluntary blood donors. Exclusion of infected blood and their donors has remarkably reduced the risk of transmitting HBV, HCV, HIV-1/2, and HTLV-I/II infections. Nucleic acid tests (NAT) using enzymatic amplification of viral gene sequences have augmented the risk reduction in “window period” infections that are undetectable by the serological tests. Improved viral safety of transfusion therapy has led us to recognize the risk of bacterial contamination, especially in platelet concentrates stored optimally at room temperature. Besides the current effort devoted to microbial risk reduction, pathogen inactivation technologies promise reduction of the residual risk of known and emerging infectious agents. The clinical effectiveness of the foregoing measures, international harmonization/standardization of practices and procedures, and continued hemovigilance portend safest possible safety in the clinical practice of blood transfusion.     

Hepatitis B virus markers and lymphocyte populations in the asymptomatic multiple-drug addict

The authors have studied in particular hepatitis B virus markers and the ratio of OKT4+/OKT8+ cells in two subgroups of 52 deprived asymptomatic drug addicts. In the group 1 (deprived for 19 days on an average), 52% of the subjects showed a ratio of OKT4+/OKT8+ less than 1, whereas in the group 2 (deprived for 30 months on an average), this percentage is only of 25%. HBV markers were present in 90% of the subjects in each group. We would like to point out the high frequency of the anti-HBc positivity without other markers in these two groups, respectively 20% in the group 1 and 32% in the group 2. These results emphasize the interest in screening systematically this marker in all blood donors.     

Risk factors for Trypanosoma cruzi infection among blood donors in central Brazil.

Characteristics and possible risk factors associated with Trypanosoma cruzi infection among blood donors were assessed within a routine screening programme in blood banks in an endemic area of Chagas disease. 6,172 voluntary blood donors were interviewed and tested for anti-T. cruzi antibodies by Haemagglutination and Complement Fixation tests in six blood banks in Goiania-Central Brazil from October 1988 to April 1989. An overall prevalence of 2.3% for T. cruzi infection was obtained, being 3.3% for first-time blood donors and 1.9% for regular ones (p < 0.01). Considering this seropositivity among regular blood donors, selection of candidates relying only on the history of previous donation was found to be inadequate. The risk of infection increased inversely with the degrees of education and monthly income. There was a 9.2 risk of infection (95% CI 3.8-22.6) for those who had lived more than 21 years in an endemic area compared to subjects who had never lived in rural settings, after multivariate analysis. These informations may help to review the criteria of selection of donors in order to improve quality of blood products in endemic areas.     

Circadian and seasonal changes of the inducer:suppressor ratio (OKT4+:OKT8+) in venous blood of healthy adults

Circadian and seasonal variations in the T helper: T suppressor-cytotoxic ratio were investigated in peripheral blood from five healthy young men. Mononuclear cells were isolated on Ficoll-Paque gradient, then incubated with OKT4 and OKT8 monoclonal antibodies. Plasma cortisol was determined in four of these seven time series. Large interindividual differences were documented and statistically validated for the 24-hr.-means of total lymphocytes, OKT4+:OKT8+ ratio, and of plasma cortisol (both total and free). For a pooled data, a circadian rhythm was demonstrated by cosinor (p less than 0.001) for total lymphocytes (acrophase at 1.00 hr.), total plasma cortisol (acrophase at 10.30 hrs.) and free plasma cortisol (acrophase at 9.50 hrs.), but not for OKT4+:OKT8+ ratio. This index however exhibited a statistically significant circadian rhythm in April and August, but not in November. Its double-amplitude exceeded 80% of the 24-hour-mean and its acrophase was localized at 6.40 hrs. in April and at 22.30 hrs. in August. Its 24-hr-mean was higher in August as compared to April and November. The circadian rhythm in the OKT4+:OKT8+ ratio did not seem to be related to that of plasma cortisol. Both circadian and seasonal variations need to be taken into account when investigating the regulations of immune variables such as T helper: T suppressor-cytotoxic ratio.     

Qualification of serological infectious disease assays for the screening of samples from deceased tissue donors

Whilst some of the assays used for serological screening of post-mortem blood samples from deceased tissue donors in some countries have been specifically validated by the manufacturer for this purpose, a significant number of those currently in use globally have not. Although specificity has previously been considered a problem in the screening of such samples, we believe that ensuring sensitivity is more important. The aim of this study was to validate a broader range of assays for the screening of post-mortem blood samples from deceased tissue donors. Six microplate immunoassays currently in use within National Health Service Blood and Transplant (NHSBT) for the screening of blood, tissue and stem cell donations were included. Representative samples from confirmed positive donors were titrated in screen negative post-mortem samples in parallel with normal pooled negative serum to determine if there was any inhibition with the post-mortem samples. There were no significant differences seen (P < 0.005) between the dilution curves obtained for the positive samples diluted in post-mortem samples and normal pooled sera. Although small numbers of samples were studied, it can be surmised that the post-mortem blood samples from deceased tissue donors, collected according to United Kingdom guidelines, are a suitable substrate for the assays evaluated. No diminution of reactivity was seen when dilution with sera from deceased donors was compared to dilution using pooled serum from live donors. In the absence of genuine low titre positive post-mortem samples, the use of samples spiked with various levels of target material provides a means of qualifying serological screening assays used by NHSBT for the screening of post-mortem blood samples from deceased tissue donors.     

Reversal of Apixaban Induced Alterations in Hemostasis by Different Coagulation Factor Concentrates: Significance of Studies In Vitro with Circulating Human Blood

Apixaban is a new oral anticoagulant with a specific inhibitory action on FXa. No information is available on the reversal of the antihemostatic action of apixaban in experimental or clinical settings. We have evaluated the effectiveness of different factor concentrates at reversing modifications of hemostatic mechanisms induced by moderately elevated concentrations of apixaban (200 ng/ml) added in vitro to blood from healthy donors (n = 10). Effects on thrombin generation (TG) and thromboelastometry (TEM) parameters were assessed. Modifications in platelet adhesive, aggregating and procoagulant activities were evaluated in studies with blood circulating through damaged vascular surfaces, at a shear rate of 600 s⁻¹. The potential of prothrombin complex concentrates (PCCs; 50 IU/kg), activated prothrombin complex concentrates (aPCCs; 75 IU/kg), or activated recombinant factor VII (rFVIIa; 270 μg/kg), at reversing the antihemostatic actions of apixaban, were investigated. Apixaban interfered with TG kinetics. Delayed lag phase, prolonged time to peak and reduced peak values, were improved by the different concentrates, though modifications in TG patterns were diversely affected depending on the activating reagents. Apixaban significantly prolonged clotting times (CTs) in TEM studies. Prolongations in CTs were corrected by the different concentrates with variable efficacies (rFVIIa≥aPCC>PCC). Apixaban significantly reduced fibrin and platelet interactions with damaged vascular surfaces in perfusion studies (p<0.05 and p<0.01, respectively). Impairments in fibrin formation were normalized by the different concentrates. Only rFVIIa significantly restored levels of platelet deposition. Alterations in hemostasis induced by apixaban were variably compensated by the different factor concentrates investigated. However, effects of these concentrates were not homogeneous in all the tests, with PCCs showing more efficacy in TG, and rFVIIa being more effective on TEM and perfusion studies. Our results indicate that rFVIIa, PCCs and aPCCs have the potential to restore platelet and fibrin components of the hemostasis previously altered by apixaban.