Cellular Blood Products Research Articles

Direct detection of bacteria in cellular blood products using bacterial ribosomal RNA-directed probes coupled to electrochemiluminescence: R. Chaney, J. Rider, D. Pamphilon. Transfusion Medicine 9:177–188, 1998

Direct detection of bacteria in cellular blood products using bacterial ribosomal RNA-directed probes coupled to electrochemiluminescence: R. Chaney, J. Rider, D. Pamphilon. Transfusion Medicine 9:177–188, 1998

Prevalence of HTLV-I-associated T-cell lymphoma.

In order to assess the prevalence rate of HTLV-1-associated T-cell lymphomas and human retrovirus infection in general, approximately 21,000 individuals representing various patient populations, retroviral risk groups, and blood donors were examined for HTLV-I, HTLV-II, HIV-1, or HIV-2 infection using serologic and PCR assays. The prevalence rates among volunteer blood donors were 0.02% and 0% for HTLV and HIV, respectively. Significantly increased HTLV prevalence rates were observed among paid blood donors, African American health care clinic patients, Amerindians, recipients of HTLV-positive cellular blood products, intravenous drug users, sexual contacts and family members of HTLV-positive people, and patients with primary thrombocytosis and other-than-low-grade non-Hodgkin's lymphoma (NHL). Among some of these groups there were significant differences in the prevalence of HTLV-I versus HTLV-II. The eight HTLV-positive NHL patients all had mature, high-grade, CD4+ T-cell lymphomas with clonally integrated HTLV-I, for a prevalence of 4% among other-than-low-grade NHL patients. Seven of the eight died from their disease within 2 years despite treatment. Interestingly, two groups at risk for HTLV infection, namely needle stick victims and recipients of HTLV-infected and/or pooled plasma products, showed no evidence for infection. Significantly increased HIV-1 prevalence was observed among paid blood donors, African Americans, homosexuals, female prostitutes, hemophiliacs, and other-than-low-grade NHL patients. Only one patient was infected with HIV-2. Of the nine HIV-positive, other-than-low-grade NHL patients, seven HIV-1 positives had B-cell lymphomas, one HIV-1 positive had an HTLV-I-positive CD4+ T-cell lymphoma, and one infected with HIV-2 had a CD4+ T-cell lymphoma that was HTLV negative. The data indicate that HTLV-I lymphoma, while uncommon, is not necessarily rare among other-than-low-grade NHL cases in the United States and, given its poor prognosis, should probably be studied separately in clinical trials.

American Trypanosomiasis (Chagas' Disease) and Blood Banking in Mexico City: Seroprevalence and Its Potential Transfusional Transmission Risk

Background American trypanosomiasis (Chagas' disease), an anthropozoonosis fairly common in rural Latin America, has become an urban disease due to continuous migration, intra- and internationally. Blood transfusion, the second important pathway for transmission, increases its impact. Recognition of seropositive subjects among blood donors is now recommended, and clinical and serological screening enforced. Maneuvers to inactivate or remove Trypanosoma cruzi present in collected blood are recommended. Methods We surveyed voluntary donors at the National Institute of Cardiology in Mexico City in search of anti- T. cruzi by indirect immunofluorescence, ELISA, and Western blot analysis. Seropositive donors were identified and tested for immunoglobulin. We used types and fractions of donated blood to extract DNA and perform the PCR technique using kinetoplast primers seeking parasite DNA in blood. Results After 3,300 donors were screened, we identified 10 seropositive subjects (0.3%). These subjects were considered as indeterminate chagasic patients, came mainly from rural areas, and had IgG (100%) and IgA (30%) antibodies against a crude extract as well as a recombinant T. cruzi antigen. Identification of parasite DNA in red cell and platelet fraction was achieved from eight blood units. Conclusions The present data provide evidence that blood donors at an urban hospital are seropositive for T. cruzi and at least 50% of donors carry the parasite potentially able to transmit T. cruzi in their cellular blood products. Serological screening should be included in routine blood-banking. It is also necessary to adopt measures to inactivate or eliminate organisms in donated blood.

Direct detection of bacteria in cellular blood products using bacterial ribosomal RNA-directed probes coupled to electrochemiluminescence.

Various techniques for detecting bacteria in blood products exist; however, none has been widely accepted. Our method permits direct bacterial detection in both platelet concentrates (PC) and packed red blood cells (RBC). This novel procedure targets bacterial ribosomal RNA (rRNA) but does not utilize culture or nucleic acid amplification. The assay comprises five steps: (1) release of bacterial rRNA by cell lysis with a combination of detergents and high heat; (2) hybridization of bacterial rRNA using a biotin- and a ruthenium (ORIGEN)-labelled oligonucleotide probe pair; (3) capture of labelled rRNA with streptavidin-coated magnetic beads; (4) concentration of labelled rRNA/bead complexes out of solution and onto an electrode surface with a magnet; (5) detection of ruthenium-labelled bacterial rRNA by application of voltage and consequent generation of the electrochemiluminescent (ECL) signal. Results using PC and RBC samples, spiked with clinically relevant gram-negative and -positive bacterial species, consistently demonstrated a linear relationship between ECL signal (equates to rRNA level) and colony forming units (CFU) mL(-1). Signals were generated in the range of 1400-80000 and 3500-500000 ECL units for unwashed and washed samples, respectively. This is equivalent to 10(5)-10(8)CFU mL(-1). These data demonstrate that therapeutic blood products significantly contaminated with bacteria may be identified prior to issue.

Functional lymphocyte immunophenotypes observed in thalassaemia and haemophilia patients receiving current blood product preparations.

Immune abnormalities have been reported in recipients of cellular and plasma blood products. To document the effect of current transfusion practices, we performed ex vivo lymphocyte immunophenotypic studies on patients with thalassaemia major who had received multiple (leucocyte-depleted) transfusions and patients with haemophilia A and B who had received heat viral-inactivated factor concentrates. Patients with thalassaemia major showed a significant lymphocytosis, with mainly B-cell changes consistent with ongoing B-cell stimulation associated with chronic exposure to red cell antigens. Reduced T-cell IL-2Ralpha expression would be consistent with inhibition by desferrioxamine chelation therapy. In contrast, patients with haemophilia showed predominantly T-cell changes. Patients with haemophilia A showed significantly elevated activated CD8+ cytotoxic T lymphocytes whereas those with haemophilia B showed an increase in CD8+CD11adim and CD4+CD45RA+ suppressor T cells. Several of the immune abnormalities found may be due to the presence of cytokines not removed by leucocyte filtration or destroyed by factor concentrate production (e.g. TGF-beta) causing a T-helper-2-like response. The extensive lymphocyte characterization in this study has not previously been performed and has enabled a closer examination of the functional lymphocyte immunophenotypes seen in patients treated according to current transfusion practices.

Approaches to the detection of bacterial contamination in cellular blood products

Approaches to the detection of bacterial contamination in cellular blood products

Difficultés diagnostiques des incidents transfusionnels par contamination bactérienne à propos de deux observations

The French hemovigilance system has recently underlined the relative frequency of transfusion-associated bacterial sepsis and the necessity to remain constantly aware of this eventuality. We describe the experience of a hematology unit over a 18-month period: 189 acute transfusion reactions were registered and bacterial cultures of the implicated cellular blood products realized in 82 of them. A positive result was obtained in two cases. For both cases, clinical symptoms of transfusion reaction were limited to a lasting fever, and a skin rash occurred in aplastic patients with preexisting signs of sepsis. The causal relationship between this contamination and the transfusion reaction is difficult to establish. Clinical manifestations justifying a bacterial inquiry must therefore be more precisely defined, particularly in multitransfused patients.

Avoidance of cellular blood product transfusions in LVAD recipients does not prevent HLA allosensitization

Background Transfusion of cellular blood products during left ventricular assist device (LVAD) implantation has been associated with HLA allosensitization, resulting in the need for a negative prospective cross-match and prolonged transplant waiting times. In order to prevent this risk, we developed a protocol to avoid transfusion of cellular blood products. Methods The protocol included preoperative patient stabilization, perioperative recombinant erythropoietin and blood conservation strategies, and postoperative monitoring of mixed venous oxygen saturation (SVO 2) to assure adequate peripheral oxygen delivery. Panel reactive antibody (PRA) was measured in all patients pre and post LVAD placement to assess HLA sensitization. Results Seven consecutive patients underwent LVAD implantation without transfusion of blood or platelets, one of whom expired perioperatively. Mean hematocrit was 35.2% preoperatively, and 21.8% postoperatively, reaching a nadir of 20.2%. Postoperative SVO 2 was >60% in all patients. In the six survivors, mean hematocrit reach 24.3%, 27.3%, and 33.0% by postoperative day seven, fourteen, and thirty, respectively. PRA in three patients was 0% preoperatively and remained 0% until transplantation after 33, 34, and 50 days of support. In two patients, preoperative PRA was 7% and 17%, dropped to 3% and 0% after thirty days, then progressively rose to 96% and 100% after 60 and 90 days, respectively. In one other patient, preoperative PRA was 0%, remained at 0% after thirty days, then rose to 96% by 60 days. Conclusions Avoiding transfusion of cellular blood products in LVAD recipients is safe and well tolerated, but does not universally protect from HLA allosensitization. Other factors may also produce sensitization, such as immunogenic components of the LVAD, soluble antigen in fresh frozen plasma, or latent sensitization which is not initially evident in critically ill and possibly anergic patients.

Transfusion-transmitted diseases: risks, prevention and perspectives.

During the past decades major improvements in blood safety have been achieved, both in developed and developing countries. The introduction of donor counseling and screening for different pathogens has made blood a very safe product, especially in developed countries. However, even in these countries, there is still a residual risk for the transmission of several pathogens. For viruses such as the human immunodeficiency virus (HIV), and the hepatitis viruses B and C, this is due mainly to window-period donations. Furthermore, the threat of newly emerging pathogens which can affect blood safety is always present. For example, the implications of the agent causing new variant Creutzfeld-Jakob disease for transfusion practice are not yet clear. Finally, there are several pathogens, e.g. CMV and parvo B19, which are common in the general donor population, and might pose a serious threat in selected groups of immunosuppressed patients. In the future, further improvements in blood safety are expected from the introduction of polymerase chain reaction for testing and from the implementation of photochemical decontamination for cellular blood products. The situation in transfusion medicine in the developing world is much less favorable, due mainly to a higher incidence and prevalence of infectious diseases.

Risiko der HIV-, HCV- und HBV-Übertragung durch Blutpräparate. Aktuelle Daten 1997 und 1998 aus der Studie zur Epidemiologie von HIV und Hepatitisinfektionen bei Blutspendern in Deutschland

Objective: The risk of virus transmission by blood products is estimated from current data . Design, Setting, and Participants: In a multicenter study of all blood and plasma transfusion services in Germany the seromarkers of all donations obtained in 1997 and 1998 were recorded by a detailed questionnaire. The risks were calculated from the frequencies of seroconversions. Results:The seroconversion rates were constantly low, with <1.0 (in 100,000 donations) for HIV, <3.0 (in 100,000 donations) for HCV, and <1.5 (in 100,000 donations) for hepatitis B surface antigen. Conclusions:The safety of blood products in Germany is high. As documented by this study, the risk has remained constantly low over the last years, with less than 1:1 million for HIV, 1:100,000 for HCV, and 1:200,000 for HBV (related to cellular blood products).

Bacterial contamination and proliferation during the storage of cellular blood products.

Bacterial contamination and proliferation during the storage of cellular blood products.

Graft-versus-host disease: The influence of type 1 and type 2 T cell cytokines

G RAFT-VERSUS-HOST DISEASE (GVHD) has been associated with the infusion of unirradiated cellular blood products. ~ Manifestations of GVHD usually occur several weeks after the transfusion, and include rash, diarrhea, fever, liver abnormalities, and eventually pancytopenia. There is an extremely high fatality rate for transfusion-associated GVHD. 2 Transfusion from HLA homozygous donors into HLA heterozygous recipients who share one HLA haplotype with the donor are at particular risk for this complication. The development of GVHD in this setting is almost invariably fatal, despite therapy with high-dose corticosteroids and cyclosporine. GVHD is initiated by alloreactive donor T cells recognizing foreign major histocompatibility complex (MHC) antigens and/or minor histocompatibility antigens (minor HA) of the host. The subsequent induction of inflammatory effector mechanisms ultimately culminates in a complex syndrome in which specific host tissues, including the skin, liver, lung, gastrointestinal tract, and the immune system itself, are severely damaged. There is now substantial evidence to implicate the inappropriate production of cytokines, which are the central regulatory molecules of the immune system, as a primary cause for the induction and maintenance of experimental and clinical GVHD. 3-5 Dysregulation of complex cytokine networks occurring at different steps in the sequence is thought to be responsible for the manifestations of this disease. Because of the central role of cytokines in the pathophysiology of GVHD, advances in the understanding of cytokine networks should enable us to optimize preventive and therapeutic strategies. As will be discussed later in more detail, several protocols that include the intervention in cytokinemediated processes during the effector phase of GVHD have been initiated with varying success. The nature of the cytokine cascade makes it difficult to intervene in GVHD once clinical signs appear. Recent breakthroughs in the understanding of T-cell cytokine networks, particularly with the emergence of the Thl/Th2 paradigm, may provide valuable new tools for the directed intervention in

Is screening of Australian blood donors for HTLV-I necessary?

To re-examine the 1992 decision by Australian Red Cross for its blood banks to screen blood donors for antibody to human T-cell lymphotropic virus type I (HTLV-I) by determining the risk of its transmission by blood transfusion. Data on patterns of return behaviour by repeat blood donors in Victoria were modelled to deduce the number of donors giving repeat donations in Australia from March 1993 to December 1995. Data on annual donor and issued cellular blood products from 1992 to 1995 were obtained from national Red Cross statistics. From the numbers of donations given by repeat donors, together with the number of new donors, the number tested for HTLV-I was deduced. The number and characteristics of donors screened positive for HTLV-I antibody were collated. The crude prevalence of HTLV-I was calculated by dividing the number of donors with HTLV-I by the total number of donors (repeat donors and new donors). The incidence of HTLV-I was calculated by dividing the number of seroconversions in repeat donors by the cumulative period of donor exposure. Sixteen homologous and five autologous donors were found to be positive for HTLV-I; none seroconverted and no clear risk factors for HTLV-I were identified. The prevalence of HTLV-I in Australian donors is 1 in 100,000 and the incidence less than 1 in 1 million person-years. In the absence of HTLV-I screening, the calculated risk of a transfused patient developing HTLV-I infection is 1 in 370,000, with a risk of developing HTLV-I disease of 1 in 9 to 15 million. Three possible future courses of action for screening for HTLV-I are to screen every donation, to screen only new donors or to discontinue screening altogether. Using the information in this study, public discussion should be encouraged to assist stakeholders to agree on an acceptable level of risk and an appropriate level of screening for HTLV-I in Australia.

Viral risks associated with blood transfusion.

Great strides have been made within the last decade to help ensure the safety of the blood supply. Additional tests to detect infectious agents, as well as development of improved donor screening and deferral techniques have helped make the risk of transfusion-transmitted disease very low. Currently, blood banks perform seven tests to detect infectious agents. Prospective donors are carefully questioned about factors that place them at risk for transfusion-transmitted disease and donors known to test positive for certain viruses are permanently deferred. The risks of receiving a human immunodeficiency virus (HIV)-infected unit is now estimated to be 1 in 493,000, while the risk of hepatitis B is 1 in 63,000. However, changes in prevalence within the blood donor population brought about by changes in the factors that place an individual at risk for a transfusion-transmitted disease could significantly alter these risks. The American public continues to be concerned about the safety of blood transfusion. These concerns coupled with the fears that new viruses or new strains of viruses will be identified that escape detection has created the impetus for development of methods that will remove or inactivate viruses in cellular blood products.

Factors affecting growth of Yersinia enterocolitica in cellular blood products

Factors affecting growth of Yersinia enterocolitica in cellular blood products

Platelet transfusion support for patients with cancer and hematologic malignancies.

Advances in platelet transfusion have contributed to improved outcomes in the treatment of patients with cancer and leukemia. However, the optimal strategies to avoid some of the side effects that could result from platelet transfusions remain under investigation. These side effects include the development of refractoriness to transfusions, alloimmunization, transfusion reactions, the transmission of infectious agents, and transfusion-associated graft-versus-host disease. Leukodepletion by filtration is promising as a means of preventing the development of alloimmunization. Results of the Trial to Reduce Alloimmunization to Platelets will be reported shortly and will shed more light on that issue. Bedside filtration of cellular blood products also diminishes the transmission of cytomegalovirus infections by that route. Transfusion reactions are often mediated by cytokines in the plasma fraction of transfused platelet concentrates, and leukodepletion prior to storage reduces their incidence. Serious bacterial infections are sometimes transmitted by platelet transfusions and improved methods are needed for their detection and prevention. Photochemical methods that could inactivate bacteria and viruses in contaminated products deserve further study.

SULFOPHTHALOCYANINES FOR PHOTODYNAMIC INACTIVATION OF VIRUSES IN BLOOD PRODUCTS: EFFECT OF STRUCTURAL MODIFICATIONS

Transmission of infectious disease through blood transfusions is well known. Ultraviolet irradiation, solvents, and detergents provide a means of sterilizing noncellular blood components. However, these harsh methods are not applicable to cellular blood products. Recently, attempts have been made to sterilize biological fluids using photodynamic treatment and phthalocyanine (Pc) dyes have been advanced as photosensitizers for this purpose. We have evaluated a series of water-soluble Pc, chelated with different central metal ions, substituted to different degrees with sulfonato and t-butyl groups, for their effectiveness to reduce virus infectivity in red blood cell suspensions. Vaccinia virus cytopathogenicity was determined by endpoint serial dilutions in the CV-1 cell line. Anti-viral activity increased with the central metal ion in the following: Ga(III) < Al(III) < Zn(II), and varied inversely with the degree of sulfonation. Furthermore, addition of a t-butyl group onto the trisulfonated dyes (PcS3[t-Bu]) resulted in a 5-40-fold increase in anti-viral potency, suggesting that amphiphilicity enhances the photodynamic activity of the dye. Strong anti-viral photosensitizing properties cannot be the sole selection criterion. Of equal importance is the preservation of blood component integrity. Accordingly, the photohemolytic activity of the dyes was evaluated using the rate of hemolysis as a parameter and a toxicity index was defined. Among the most active dyes, the AlPcS3(t-Bu) complex exhibited the most favorable anti-viral properties combined with a low toxicity index. Our results suggest that trisulfophthalocyanines, bearing an additional t-butyl group to enhance amphiphilicity, are particularly promising dyes for photodynamic blood sterilization.

MAJOR INFECTIOUS COMPLICATIONS AFTER ORTHOTOPIC LIVER TRANSPLANTATION AND COMPARISON OF OUTCOMES IN PATIENTS RECEIVING CYCLOSPORINE OR FK506 AS PRIMARY IMMUNOSUPPRESSION

A retrospective cohort study was conducted to determine the incidence of major infectious complications after orthotopic liver transplantation and to compare outcomes in patients receiving either cyclosporine (CsA) or FK506 (tacrolimus) as primary immunosuppression. Of 133 transplants performed in 118 patients, 124 transplant episodes were evaluated. Cytomegalovirus (CMV) infection (INF) and disease (DIS), deep fungal infection (DFI), and intraabdominal bacterial infections (IAI) were catalogued. The overall incidences of major infectious outcomes were: CMV INF = 33%; CMV DIS = 19%; DFI = 15%; and IAI = 25%. Cox proportional hazard analysis identified donor seropositivity, OKT3 as secondary immunosuppression and initial intensive care unit (ICU) duration as risk factors for CMV INF and DIS in the overall population. Fungal colonization was the dominant risk factor associated with deep fungal infection. A choledochojejunostomy anastomosis, the number of cellular blood products transfused at the time of transplantation surgery, and prior CMV INF were independent risk factors for both fungal colonization and deep infection. The single risk factor identified for intraabdominal bacterial infections was the number of cellular blood products transfused at the time of surgery. In the Cox proportional hazards model the relative risk (RR) for each category of infection was lower in the FK506 group (CMV: RR = .87, 95% confidence interval [C.I.] = [.32-2.4]; DFI: .58 [.13-2.6]; IAI: .51 [.15-1.7]), but the effect was not statistically significant. Survival was similar in patients receiving FK506 or CsA. CMV INF and DFI were independent predictors of death for all patients. Risk factors identified for CMV INF and DIS support the findings of others. Higher intraoperative blood product requirements and complicated intraoperative or postoperative courses increase the risk for IAI or DFI. The development of effective strategies to prevent CMV and fungal infections in liver transplant recipients remains a priority for future endeavors.

The Leukodepletion of Cellular Blood Products in the Prevention of HLA-Alloimmunization and Refractoriness to Allogeneic Platelet Transfusions

The Leukodepletion of Cellular Blood Products in the Prevention of HLA-Alloimmunization and Refractoriness to Allogeneic Platelet Transfusions

Bacterial contamination of blood products and the value of pre-transfusion testing.

There has been a dramatic increase recently in the number of reports of septic episodes associated with both red cell and platelet concentrate transfusions. These reports suggest that transfusion-associated septic reactions may occur as often as 1 per 4000 platelet transfusions, however, the true incidence of the bacterial contamination of stored cellular blood components has not yet been established. Recently developed automated techniques for the detection of bacteria are much more rapid than direct plating techniques. Such rapid techniques can be used to monitor the sterility of cellular blood products with greater sensitivity than Gram staining; using a small aliquot of the blood product taken soon after collection. Using such equipment, the incidence of bacterial contamination of 15,838 random donor platelet concentrates collected over a six-month period was determined and evidence of bacterial contamination was found in 32. Seven were classified as confirmed, 10 as unconfirmed and 12 as non-confirmed positives. The confirmed positivity rate was thus 4.4 per 10,000. This rate represents the minimum incidence of bacterial contamination of platelet concentrates and the true rate is likely higher, as some of the unconfirmed positives are likely to have been found to be positives, had the original platelet concentrate been available for culture. The true positive rate is therefore estimated to be between 4.4 and 10.7 per 10,000. Given this rate of bacterial contamination, it is our contention that all platelet concentrate units be monitored for bacteriologic sterility prior to their issue.(ABSTRACT TRUNCATED AT 250 WORDS)