Antibodies In Donors Research Articles

Seroprevalence of hepatitis C virus antibodies amongst blood donors in Ahmadu Bello University Teaching Hospital (ABUTH) Kaduna

Background: Hepatitis C virus (HCV) is one of the most common transfusion transmissible infections hence the introduction of routine screening for its antibodies in blood donors in most blood banks. Methods: This was a retrospective study in which the blood donor screening register for all intending donors were reviewed and analyzed. Results: There were 4,731 potential donors with age range 20-41years. Eighty six (1.8%) were sero-positive to HCV antibodies with a decreasing incidence over the period under review. The highest incidence was recorded the age group 31-40 years. Aim: To determine the sero-prevalence of HCV among blood donors in ABUTH Kaduna. Conclusion: HCV infection is not uncommon in our environment hence the need to emphasize it’s routine screening among all potential donors.

Impact of using different laboratory assays to detect human leukocyte antigen antibodies in female blood donors

HLA antibodies passively transferred to transfused recipients may cause transfusion reactions such as transfusion-related acute lung injury (TRALI), but in many of the reported TRALI incidents, no white blood cell antibodies have been identified. We investigated whether a higher number of anti-HLA would be detected in donor's plasma by using a method with potential higher sensitivity rate. Sera from 300 previously pregnant female blood donors were screened for anti-HLA using a solid-phase mixed-antigen assay (enzyme-linked immunosorbent assay [ELISA]). Samples from 60 women with three or more pregnancies with a negative ELISA were further tested using microbead-flow assays (LABScreen mixed, panel-reactive antibodies [PRA], and single antigen). Anti-HLA Class I and/or Class II were detected by ELISA in 26.7% (80/300) of all women and in 37.0% (37/100) of women with three or more pregnancies. The LABScreen assays detected additional anti-HLA specificities (44 Class I and 17 Class II) in 28.3% (17/60) of ELISA-negative donors with three or more pregnancies. HLA antibodies were detected in 8.3% (5/60), 18.3% (11/60), and 21.7% (13/60) of ELISA-negative women by LABScreen mixed, PRA, or single antigen, respectively. Our data showed that the microbead-flow detected more HLA antibodies than ELISA, but the clinical significance of these antibodies is currently unknown. Detecting anti-HLA is useful for donor management and could contribute to the decision to definitively defer blood donors involved in TRALI incidents. However, further studies are necessary to better determinate the relative risk of TRALI induced by anti-HLA detected only by techniques with higher sensitivity rate.

Investigation of the Prevalence of Human Parvovirus B19 DNA in Korean Plasmapheresis Donors

To ensure the safety of plasma derivatives, some countries have been screening for the human parvovirus B19 (B19V) antigen or DNA in blood donors. We investigated the prevalence of B19V DNA and anti-B19V antibodies in Korean plasmapheresis donors to evaluate the necessity of B19V DNA screening test. Plasma samples were collected between March and July 2008 from 10,032 plasmapheresis donors. The B19V DNA test was performed using the LightCycler 2.0 (Roche, Germany) with quantification kits. Anti-B19V IgM and IgG were tested in 928 randomly selected samples from the 10,032 donors using recomWell Parvovirus B19 ELISA IgM, IgG assay (Mikrogen, Germany). RecomLine Parvovirus B19 LIA IgG, IgM assay (Mikrogen, Germany) was used to analyze the epitopes of antibodies in donors showing positive results for B19V DNA and anti-B19V antibodies. DNA sequencing was performed to identify the genotypes. The prevalence of B19V DNA was 0.1% (10/10,032). Virus titers in B19V DNA positive donors were less than 10(5) IU/mL (range: 2.7 x 10(1)-3.2 x 10(4) IU/mL) except for 1 donor (1.33 x 10(8) IU/mL). All the isolated B19V DNAs from 6 donors were identified as genotype I. Nine out of 10 B19V DNA positive donors also possessed anti-B19V IgG only or IgG and IgM. The prevalence of anti-B19V IgG was 60.1% (558/928). The prevalence of B19V DNA in Korean blood donors was not high and most donors also possessed neutralizing anti-B19V antibodies. Thus, the implementation of a B19V screening test for Korean blood donors does not appear to be imperative.

Transfusion‐related acute lung injury reports in the Netherlands: an observational study

Transfusion-related acute lung injury (TRALI) is a serious, sometimes fatal complication of transfusion, attributed to white blood cell (WBC)-reactive antibodies present in the blood product. This study investigated incidence and etiology in the Netherlands. From January 2005 through July 2007, all TRALI cases reported to the Sanquin Blood Banks were evaluated. Only cases meeting the Canadian Consensus Conference criteria for TRALI were included and investigated for patient, donor, and product characteristics. Patients and donors were screened for HLA Class I, HLA Class II, and granulocyte antibodies. A total of 56 TRALI cases were reported of which 49 were completely evaluated. Seventy-eight percent of the patients needed monitoring or mechanical ventilation on the intensive care unit, 10 patients died. In 61% of cases large-volume plasma products were involved. WBC-reactive antibodies in donors were found in 73% of cases, with proven incompatibility in 21 of 44 (48%) investigated cases. Possible TRALI cases, as defined by the Canadian Consensus Conference, had significantly lower incompatibility rates compared to TRALI cases, 18% versus 58% (p = 0.036). In the 21 alloimmune cases, a total of 31 implicated donors were found, of which 26 were female, including 12 fresh-frozen plasma (FFP) products. TRALI is the most serious transfusion complication in the Netherlands, causing severe morbidity and mortality. Antibodies were found in the majority of the cases, but causality with proven incompatibility could be established in 21 cases (48%). Female FFP products were involved in 57% of proven alloimmune cases and would theoretically be prevented using male FFP only.

A prospective study of multiple donor exposure blood recipients: surveillance value and limitations for hemovigilance

There have been few recent systematic studies of blood recipients for direct evidence of blood safety, especially for emerging pathogens that may pose a threat to the blood supply. Recipients who would likely require transfusion from multiple donors were recruited and a blood specimen was collected before their first study transfusion and at intervals after their study transfusion(s). Blood samples associated with the units that were transfused to enrolled recipients were also collected. Part of each recipient specimen and selected donor specimens was tested for the targeted blood-borne agents, parvovirus B19 (B19) and Chlamydia pneumoniae (Cp), that were piloted in this study, and the remaining material was kept in a repository. Between April 2004 and December 2006, a total of 120 recipients were recruited with 4047 subsequent donor exposures. On average, each recipient was followed up seven times. Of recipients who were adequately followed up and were initially immunoglobulin G antibody negative, one in 31 and one to two in 49 seroconverted to B19 and Cp after a total of 922 and 1413 evaluable transfusions, respectively. The detection of seroconversion was complicated by passively acquired donor antibodies for these two seroprevalent agents. Negative results for nucleic acids of the agents limited our ability to further clarify the relationship of these seroconversions to transfusion-transmitted infection. The risk of transfusion-associated B19 infection appears to be low but no conclusion of transfusion transmission can be made for Cp. The approach piloted through this study offers added value beyond the current hemovigilance strategy in the United States.

Mechanism of Transfusion-Related Acute Lung Injury Induced by HLA Class II Antibodies.

Abstract 19 Introduction:Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated fatalities in developed countries. It has been demonstrated that antibodies to human neutrophil antigens (HNA) present in a blood product can precipitate a TRALI reaction in the blood recipient. In the majority of TRALI cases, however, HLA class II antibodies rather than HNA antibodies are detected in the implicated donor. HLA class II antigens are not present on neutrophils or endothelial cells, the cellular key players in TRALI pathophysiology. Whether or not HLA class II antibodies are capable of inducing TRALI is thus under discussion. Here, we investigated a possible mechanism of HLA class II antibody-induced TRALI via monocytes. Methods and Results: Plasma from blood donors containing HLA class II antibodies (H2+plasma) is capable of activating monocytes expressing cognate antigen(s) as demonstrated by the release of IL-8, GRO-alpha, and TNF-alpha in culture supernatants. H2+plasma does not activate monocytes that do not express the cognate HLA class II antigen(s). Culture supernatants from matched pairs, but not H2+plasma itself, induce a respiratory burst reaction in neutrophils. In Boyden chamber experiments, FITC-albumin transendothelial flux is significantly increased in the presence of H2+plasma, matched monocytes, and neutrophils, but unchanged in the presence of non-matched monocytes. Diphenyleneiodonium chloride inhibits this barrier breakdown. In the ex vivo rat lung model, supernatants from matched pairs, but not from non-matched pairs, are capable of inducing TRALI in the presence, but not in the absence, of neutrophils. H2+plasma precipitates a TRALI in this model if neutrophils and matched, but not non-matched, monocytes are present. IgG-depletion of H2+plasma abolishes this effect. Conclusions: HLA class II antibodies present in donor plasma can induce TRALI in a transfusion recipient via monocyte activation. Once activated, monocytes stimulate neutrophils to produce reactive oxygen species, which lead to an increase in endothelial permeability and subsequent lung edema. This cascade depends on a match between the donor's antibodies and the recipient's HLA class II antigens and can be reproduced in a rat lung model. Our findings have important impact on current strategies that aim to prevent TRALI by donor testing and/or exclusion. Disclosures:No relevant conflicts of interest to declare.

Persistence of Donor-Derived Protein in Host Myeloid Cells After Induced Rejection of Engrafted Allogeneic Bone Marrow Cells.

Abstract 63Anti-tumor effects of allogeneic hematopoietic cell transplantation have been attributed to engrafted donor lymphocytes and long-term donor engraftment is thought to be essential to cure hematological malignancies. However, following non-myeloablative hematopoietic cell transplantation (HCT), we have observed that some patients are cured of advanced hematologic malignancies despite rejection of their donor hematopoietic cell graft. This led us to hypothesize that host-versus-graft (HVG) reactions may induce host-derived anti-tumor effects.In a murine model, we established that HVG responses can indeed promote host-anti-tumor responses that are dependent on host-type CD8 T cells, host-type NKT cells, IFN-g, and initial donor engraftment (Rubio et al, Blood 2003 102:2300 and J Immunol 175:665,2005; Saito et al. manuscript submitted). Host CD8 T cells in the bone marrow secrete high levels of IFN-g even after peripheral donor chimerism has totally disappeared (Saito et al. manuscript submitted). Thus, we hypothesized that alloresponses may persist in the bone marrow, driven by the presence of alloantigens, either due to sustained engraftment of the donor cells (direct alloantigen presentation) or to presentation of alloantigens by host antigen-presenting cells (APC) (indirect alloantigen presentation) in the bone marrow.To assess this hypothesis, we used dynamic in vivo microscopy to directly visualize events in living animals. Two-photon microscopy allowed visualization of the bone marrow environment 150 mm below the skull bone surface of anesthetized mice. With these tools, we were able to track fluorescently labeled donor protein together with bone and blood vessels in real time.We established stable mixed allogeneic bone marrow chimeras using GFP+ C57BL/6 mice as donors and BALB/c mice as recipients using non-myeloablative conditioning. This system allows tracking of GFP as a model donor antigen and discrimination of donor cells from host cells engulfing donor proteins by examining both GFP staining and expression of specific major histocompatibility complex (MHC) alleles. Recipient leukocyte infusion (RLI) was performed to induce HVG reactions 7 to 10 weeks after initial allogeneic BMT in order to induce rejection of engrafted donor cells. GFP expression in the bone marrow was examined in stable mixed chimeras and in recipients of RLI.In stable mixed chimeras, clusters of GFPhigh donor cells were detected as green areas that were evenly distributed and located mainly around the blood vessels in the bone marrow. Fast-moving and rolling GFPhigh cells were observed inside the vessels. Even 11 to 22 days after RLI administration, we still observed static GFPdim cells surrounding the vessels, when donor chimerism in peripheral blood had become undetectable. When we gated out most of the RBCs on the basis of forward scatter, the majority of GFPdim cells in the bone marrow at 22 days post-RLI were Mac1+ cells, while a smaller proportion were of the B cell lineage. When we examined the origin of the Mac1+ GFPdim cells using donor and recipient MHC-specific antibodies, they were found to be recipient-derived Mac1+ cells.Our studies revealed the persistence of host-derived myeloid cells containing donor protein and residing around the bone marrow blood vessels after peripheral blood chimerism was lost. The results suggest that persistent presentation of donor-derived antigens on host APC may maintain alloreactive host CD8 T cell activation in the bone marrow, promoting the anti-tumor effect induced by HVG reactions. [Display omitted] Engraftment of donor bone marrow cells and remaining cells after rejection. GFP+ cells are shown in green, bone in blue and blood vessels in red. GFP+ cells are visualized in vivo inside the skull bone of chimeras (A) and of chimeras that received RLI 11 days earlier (B). Arrowheads point to GFP+ cells around the blood vessels and arrows point to GFP+ cells in the blood vessels. Data from one representative mouse of two mice are shown. [Display omitted] (A) GFP expression among Mac1+, B220+, CD4+, and CD8+ bone marrow cells in RLI recipient. (B) GFP positive leukocytes in the bone marrow are stained for H-2Db and H-2Dd. Data from representative mouse from two mice are shown. Disclosures:No relevant conflicts of interest to declare.

The Neutrophil Alloantigen HNA-3a (5b) Is Encoded by an Amino Acid Substitution in Choline Transporter-Like Protein 2 (CTL2)

Abstract LBA-4▪▪This icon denotes an abstract that is clinically relevant.The HNA-3a/b (5b/a) leukocyte alloantigens were identified in 1964 by van Leeuwen et al. as a biallelic system with gene frequencies of 0.82 (HNA-3a) and 0.18 (HNA-3b), respectively. Despite the passage of more than 40 years, the presumptive protein carrier for HNA-3a/b and the molecular composition of the antigens themselves is unknown. The importance of defining the HNA-3a/b antigens more fully has been heightened by the recognition that HNA-3a-specific antibodies are especially prone to cause severe, often fatal, transfusion-related lung acute injury (TRALI), now the single most important cause of transfusion-related mortality. About 4-5% of the general population is HNA-3a-negative and is at risk to produce HNA-3a-specific antibodies. We performed genome-wide single nucleotide polymorphism (SNP) scanning of DNA from 8 HNA-3a-negative (HNA-3b/b) and 107 unrelated normal individuals and found that each of the HNA-3a-negatives, but only 5 of the normal subjects was homozygous (AA) for a SNP (G>A) located at nt542 of the SLC44A2 gene encoding the choline transporter-like protein CTL2 (p<0.000001 corrected for the number of SNPs surveyed) (Table 1).Table 1Genotypes of unrelated HNA-3a-negative and normal subjects at SNPrs2288904 (G>A542) in the gene SLC44A2 encoding CTL2.HNA-3-a negative subjects (n = 8)Normal subjects (N = 107)GGGAAAGGGAAA008*64385*p = 2.4 × 10−12This SNP (rs2288904) is the only one known in SLC44A2 that correlates with the HNA-3a-negative phenotype and predicts an extracellular amino acid substitution (R>Q154) in the mature protein. Gene frequencies of the high and low frequency alleles of SNP rs2288904 are 0.82 and 0.18, respectively, identical to the gene frequencies of HNA-3a and HNA-3b determined by serologic typing. Although HNA-3a is widely considered to be a neutrophil antigen, we found that lymphocytes carry slightly more HNA-3a than neutrophils, and that persons heterozygous for HNA-3a have 50% as much antigen as homozygotes, allowing heterozygotes to be identified by flow cytometry. To validate the SNP analyses, we directly sequenced DNA encoding CTL2 from 4 HNA-3a/a, 4 HNA-3a/b and 8 HNA-3b/b subjects and found that, without exception, nt542G and nt542A correlated with the phenotypes HNA-3a and HNA-3b (determined serologically), respectively. To obtain direct evidence that HNA-3a is carried on CTL2, we sensitized leukocytes with anti-HNA-3a, immunoprecipitated antibody-bound proteins, performed SDS electrophoresis and subjected candidate bands to mass spectrometric analysis. In three independent assays, peptides derived from CTL2 spanning the entire length of the protein were identified (p<0.0001). We conclude that the HPA-3a antigen results from substitution of G for A at nt542 of the SLC44A2 gene, leading to insertion of R for Q at position 154 in the first extracellular loop of CTL2. CTL2 is predicted to have ten transmembrane domains, five extracellular loops, several N-linked oligosaccharides and intracytoplasmic tails at both C- and N-terminae; this complexity probably explains the failure of previous attempts to identify it as the carrier for the HNA-3a/b antigens by immunochemical methods. The function of CTL2 is unknown. However, cross-linking of the antigen by anti-HNA-3a in neutrophils triggers an explosive activation of primed cells, indicating that CTL2 is functional in this cell type and providing a possible explanation for severe TRALI reactions seen in patients transfused with CTL2-specific antibody. Recognition of the molecular basis for the HNA-3a/b antigen system will enable large scale, low cost screening of blood donors to identify the HNA-3a-negative subpopulation that may have HNA-3a-specific antibodies capable of causing TRALI and should facilitate the production of target molecules carrying these antigens that can be used to screen for such antibodies in blood donors and patients. Disclosures:No relevant conflicts of interest to declare.

Transfusion‐related acute lung injury (TRALI): a clinical review with emphasis on the critically ill

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related morbidity and mortality world-wide. Although first described in 1983, it took two decades to develop consensus definitions, which remain controversial. The pathogenesis of TRALI is related to the infusion of donor antibodies that recognize leucocyte antigens in the transfused host or the infusion of lipids and other biological response modifiers that accumulate during the storage or processing of blood components. TRALI appears to be the result of at least two sequential events and treatment is supportive. This review demonstrates that critically ill patients are more susceptible to TRALI and require special attention by critical care specialists, haematologists and transfusion medicine experts. Further research is required into TRALI and its pathogenesis so that transfusions are safer and administered appropriately. Avoidance including male-only transfusion practises, the use of leucoreduced components, fresher blood/blood components and solvent detergent plasma are also discussed.

Fight against TRALI

Transfusion‐related acute lung injury (TRALI) is a life‐threatening adverse reaction to transfusion. It is characterized by non‐cardiogenic pulmonary edema that develops during or within 6 h after transfusion. Transfusion of blood products or massive transfusion has long been known as a rare cause of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Because the main causes of ALI/ARDS are sepsis and/or pneumonia, little attention has been paid to transfusion as a cause of lung injury. Owing to indifference to and underrecognition of this complication, ALI after transfusion may be attributed to other causes. Moreover, physicians tend to attribute the cause of respiratory failure to more common complications of transfusion such as allergic reaction and circulatory overload. Even if an appropriate diagnosis of non‐cardiogenic pulmonary edema is made, transfusion may not be identified as its cause. Although anti‐leukocyte antibodies have been proved to be one of the main causes of TRALI, the precise mechanism of this syndrome is poorly understood. Anti‐HLA and ‐HNA antibodies in labile blood products are reported to cause TRALI, and animal models of TRALI show that these antibodies induce lung injury under certain experimental conditions. We have recently showed that anti‐CD36 antibody caused TRALI in two patients. This finding suggests that as‐yet‐unknown antibodies other than anti‐HLA or ‐HNA antibodies might cause TRALI. According to current haemovigilance reports and previous look‐back studies, the incidence of TRALI is not very high. This finding supports the concept of the two‐hit theory of ALI, where certain patients’ clinical conditions are prerequisite in addition to transfusion for developing TRALI. A recent study in the ICU of a tertiary care medical centre has revealed a high incidence of suspected TRALI cases. This study revealed that female plasma, number of pregnancies in donors, number of donor units positive for anti‐granulocyte antibodies and anti‐HLA class II antibodies and concentration of lysophophatidylcholine in donor products are associated with developing TRALI. Our recent prospective study has revealed the predominance of male Fresh frozen plasma (FFP) FFP in post‐transfusion respiratory function when comparing male only FFP and mixed FFP in surgical patients. The incidence of TRALI in the UK was successfully reduced by using preferentially male plasma. Although TRALI has a relatively better prognosis than ALI with other causes, TRALI has still been the leading cause of transfusion‐related death in the United States in recent years. The prevention of TRALI caused by plasma products has been successful, but TRALI caused by apheresis platelets is still problematic. A recent study has suggested that the prevalence of anti‐HLA antibodies in female donors increases with the number of pregnancies. Thus, screening for anti‐HLA antibodies has emerged as an effective measure to prevent TRALI caused by apheresis platelets. At present, no single measure can thoroughly eliminate TRALI; however, early diagnosis and intervention may improve the outcome for patients with TRALI. Further study is required to elucidate the mechanisms of TRALI, which may lead to the development of preventive measures and treatment.

Quantitation of human herpesvirus 8 (HHV‐8) antibody in patients transfused with HHV‐8–seropositive blood

Human herpesvirus 8 (HHV-8) is endemic in Uganda where seroprevalence is approximately 40%. In a previous study, Ugandan patients receiving blood transfusions had multiple serum specimens collected for 6 months after transfusion to monitor for HHV-8 infection. It was observed that several HHV-8-seronegative patients were unexpectedly HHV-8 seropositive after blood transfusion. This study measured HHV-8 antibody in serially collected serum specimens from 542 patients who received transfusions and evaluated the risk of HHV-8 infection as a function of HHV-8 antibody levels in the donors. HHV-8 antibody was observed in 52% of patients transfused with HHV-8-seropositive blood in amounts that corresponded with their donor's antibody titer and waned within 40 days. Higher levels of passive HHV-8 antibody in patients who received transfusions appeared to be associated with a lower risk of HHV-8 infection. The source of transient antibody in patients who received transfusions was determined to be the transfused blood. Donors with higher HHV-8 antibody titers may have been less likely to have infectious virus in the blood.

Outer membrane porin M35 of Moraxella catarrhalis mediates susceptibility to aminopenicillins

BackgroundThe outer membrane protein M35 is a conserved porin of type 1 strains of the respiratory pathogen Moraxella catarrhalis. It was previously shown that M35 is involved in the uptake of essential nutrients required for bacterial growth and for nasal colonization in mice. The aim of this study was (i) to characterize the potential roles of M35 in the host-pathogen interactions considering the known multifunctionality of porins and (ii) to characterize the degree of conservation in the phylogenetic older subpopulation (type 2) of M. catarrhalis.ResultsIsogenic m35 mutants of the type 1 strains O35E, 300 and 415 were tested for their antimicrobial susceptibility against 15 different agents. Differences in the MIC (Minimum Inhibitory Concentration) between wild-type and mutant strains were found for eight antibiotics. For ampicillin and amoxicillin, we observed a statistically significant 2.5 to 2.9-fold MIC increase (p < 0.03) in the m35 mutants. Immunoblot analysis demonstrated that human saliva contains anti-M35 IgA. Wild-type strains and their respective m35 mutants were indistinguishable with respect to the phenotypes of autoagglutination, serum resistance, iron acquisition from human lactoferrin, adherence to and invasion of respiratory tract epithelial cells, and proinflammatory stimulation of human monocytes. DNA sequencing of m35 from the phylogenetic subpopulation type 2 strain 287 revealed 94.2% and 92.8% identity on the DNA and amino acid levels, respectively, in comparison with type 1 strains.ConclusionThe increase in MIC for ampicillin and amoxicillin, respectively, in the M35-deficient mutants indicates that this porin affects the outer membrane permeability for aminopenicillins in a clinically relevant manner. The presence of IgA antibodies in healthy human donors indicates that M35 is expressed in vivo and recognized as a mucosal antigen by the human host. However, immunoblot analysis of human saliva suggests the possibility of antigenic variation of immunoreactive epitopes, which warrants further analysis before M35 can be considered a potential vaccine candidate.

PI-2 Detection of sandfly fever virus (sfv) igg antibodies in blood donors from Ankara, Turkey

PI-2 Detection of sandfly fever virus (sfv) igg antibodies in blood donors from Ankara, Turkey

Transfusion-related acute lung injury (TRALI): Current concepts and misconceptions

Transfusion-related acute lung injury (TRALI) is the most common cause of serious morbidity and mortality due to hemotherapy. Although the pathogenesis has been related to the infusion of donor antibodies into the recipient, antibody negative TRALI has been reported. Changes in transfusion practices, especially the use of male-only plasma, have decreased the number of antibody-mediated cases and deaths; however, TRALI still occurs. The neutrophil appears to be the effector cell in TRALI and the pathophysiology is centered on neutrophil-mediated endothelial cell cytotoxicity resulting in capillary leak and ALI. This review will detail the pathophysiology of TRALI including recent pre-clinical data, provide insight into newer areas of research, and critically assess current practices to decrease it prevalence and to make transfusion safer.

Evaluation of Immunoglobulin M and G Western Blot and ELISA for Screening Antibodies to Treponema pallidum in Blood Donors

Enzyme-linked immunosorbent assay (ELISA) is the most popular method used by blood banks in China to screen for antibodies to Treponema pallidum (TP). However, this method produces a high percentage of false-positive reactions.The current study aimed to propose a more effective procedure for screening anti-TP antibodies in blood donors. A total of 1009 serum samples showing repeat reactivity in routine blood bank procedures were tested with a TP particle agglutination assay (TPPA) and 3 commercially available ELISA tests. Samples showing reactivity with any of these methods were further tested by Western blot (WB) and ELISA immunoglobulin G (IgG)and immunoglobulin M (IgM) anti-TP assays. Of the 1009 samples tested, 170 were identified as reactive with at least one of our methods. In these 170 samples, excluding borderline cases, the agreement of the WB method with TPPA, Murex, BGI, and InTec ELISA tests was 76.0%, 77.8%, 78.4%, and 80.1%, respectively. With the WB results as the reference, the sensitivity of TPPA, Murex, BGI, and InTec ELISA tests was 91.5%, 95.4%, 99.2%, and 98.5%, respectively. TpN17 and TpN15 are the most important antigens in the antibody response of IgM and IgG, respectively. The WB IgM and IgG results suggest that the seroprevalence of anti-TP in blood donors in China is 0.49% (130/26,702). A combination of routine ELISA methods and WB IgM and IgG may be a valid procedure for the confirmatory testing of anti-TP antibodies and would be beneficial for screening blood donors.

Involvement of Human Leukocyte Antigen Class II Antibody in Pathogenesis of Transfusion-Related Acute Lung Injury (TRALI): Vascular Permeability Enhancement

Vascular endothelial cells regulate the passage of fluids, solutes, and cells from the vascular space to the tis- sues. Disruption of vascular integrity is involved in the pathogenesis of inflammatory diseases including transfusion- related acute lung injury (TRALI), a most severe nonhemolytic transfusion reaction with symptoms such as dyspnea and/or hypotension and fever. Pulmonary edema, due to increased vascular permeability for macromolecules and plasma, is a hallmark of TRALI. The mortality rate of TRALI ranges from 5 to 10%. While donor antibodies (Abs) against human leukocyte antigen (HLA) class I and granulocytes are regarded as causative factors, various clinical studies have demon- strated the roles of anti-HLA class II-Ab on the etiology of TRALI, although the detailed mechanisms have not been clari- fied. Over several years we have investigated to clarify the underlying mechanism by which anti-HLA class II Abs cause an increase in endothelial permeability. In this review, we show that anti-HLA class II Ab generates proinflammatory cy- tokines and chemokines from HLA class II positive mononuclear cells of peripheral blood in an Fc R-dependent manner. As a result, the produced interleukin-1 and tumor necrosis factor- lead to increased endothelial permeability via the nu- clear factor- B pathway but not apoptosis of endothelial cells. These findings provide a better understanding of the roles of anti-HLA class II Ab in the etiology of TRALI.

Dengue virus antibodies in blood donors from an endemic area

We evaluated the incidence of anti-Dengue virus (DENV) antibodies and dengue viremia in a region of Mexico with a high prevalence of dengue. DENV is the most important arthropod-borne virus in terms of human morbidity and mortality in America We tested 800 blood donors from a tertiary care teaching hospital that provides care in Northeast Mexico, to identify anti-DENV IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and DENV genome by reverse transcription polymerase chain reaction (RT-PCR). In addition, routine tests for donors including Brucella, Hepatitis C virus (HCV), Venereal Disease Research Laboratory (VDRL), HIV-1 and HBsAg identification were performed. We found that 59% of donors were reactive for anti-DENV IgG and none of them had reported recent DENV infection; however, 16 (2%) were reactive for anti-DENV IgM antibodies. None of them were viremic at the time of donation. Routine tests showed that the prevalence of anti-Brucella was 0.71%, anti-HCV 0.71%, anti-HIV-1-2 0.14%, HBsAg 0.14% and VDRL test 0.57%. Although DENV transmission by blood transfusion had not been confirmed in Mexico, the finding of a high prevalence of anti-DENV IgM-positive donors with asymptomatic manifestations and the recent viremia reported in blood donors suggests that this route of transmission might be possible.

Prevalence of Bartonella henselae Antibodies in Children and Blood Donors in Croatia

We collected serum samples from 54 randomly selected blood donors and 46 children. Exclusion criteria were any clinical history of lymphadenopathy and/or fever in the last 6 months.

Ten years of hemovigilance reports of transfusion‐related acute lung injury in the United Kingdom and the impact of preferential use of male donor plasma

From 1996 through 2006, 195 cases were reported as transfusion-related acute lung injury (TRALI) to the Serious Hazards of Transfusion scheme and from 1999 onward classified by probability, using clinical features and HLA and/or HNA typing. From late 2003, the National Blood Service provided 80 to 90 percent of fresh-frozen plasma (FFP) and plasma for platelet (PLT) pools from male donors. Forty-nine percent of reports were highly likely/probable TRALI, and 51 percent possible/unlikely. Of 96 investigations, donor antibodies recognizing recipient antigens were found in 73 cases (65%), with HLA Class I in 25 of those (40%), HLA Class II antibodies in 38 (62%), and granulocyte antibodies in 12 (17%). A review in 2003 revealed that the TRALI risk/component was 6.9 times higher for FFP and 8.2 times higher for PLTs than for red blood cells, and that in donors of implicated FFP/PLTs, white blood cell antibodies were found 3.6 times more often than by chance (p <or= 0.0001), with all implicated donors being female. Provision of male plasma was associated with a reduction in TRALI reports from 36 in 2003 to 23 in each of 2004 and 2005 and 10 in 2006. Highly likely/probable cases reduced from 22 in 2003 to 13, 6, and 3 [corrected] in the 3 subsequent years, with cases implicating FFP or PLTs with positive donor serology [corrected] falling from 16 to 9, 3, and 1 respectively. The risk of highly likely/probable TRALI due to FFP has fallen from 15.5 per million units issued during 1999 through 2004 to 3.2 per million during 2005 through 2006 (p = 0.0079) and from 14.0 per million to 5.8 per million for PLTs.

Prevalence of hepatitis C virus in Aligarh: A seven year experience

Prevalence of hepatitis C virus in Aligarh: A seven year experience