Antibodies In Donors Research Articles

Granulocyte antibodies in male blood donors: can they trigger transfusion-related acute lung injury?

White blood cell-associated antibodies can lead to transfusion-related acute lung injury (TRALI). Female donors with a history of pregnancies have been identified as a main cause for these antibodies. Male or female donors without a history of pregnancy are considered as safe donors. Following the identification of two TRALI cases associated with blood products from male donors, we investigated the frequency of granulocyte-specific and human leukocyte antigen (HLA) antibodies in the entire blood donor population using a high throughput automated flow-cytometry-based granulocyte immunofluorescence test (Flow-GIFT). We investigated sera from 14,343 whole blood donors (female, n = 6974, 48.7%; male, n = 7369, 51.3%) using automated Flow-GIFT. Of the female blood donors, 60.4% had a history of pregnancy. Positive sera were retested by the standard granulocyte immunofluorescence test and granulocyte agglutination test. For the detection of HLA Class I and II immunoglobulin G antibodies, we used a commercial screening enzyme-linked immunosorbent assay. We detected in 924 (21.9%) of the 4212 females with a history of pregnancy antibodies against granulocyte antigens (n = 62, 1.5%), HLA Class I and/or II antigens (n = 864, 20.5%). Notably, in 3.5% (n = 96) of 2762 females without a history of pregnancy and in 2.1% (n = 154) of 7369 males antibodies against granulocyte antigens (n = 13, 0.47% and n = 45, 0.6%), HLA Class I and/or II (n = 83, 3% and n = 109, 1.4%, respectively), were also detected. Human neutrophil antigen antibodies are rare in male and females without a history of pregnancy compared to females with a history of pregnancy, but their relevance is not negligible.

Prevalence of irregular red cell antibody in healthy blood donors attending a tertiary care hospital in North India.

BACKGROUND:Alloantibodies may be detected in blood donors who have either been transfused previously or female donors with previous obstetric events. These antibodies can occasionally cause severe transfusion reaction, if a large amount of plasma or whole blood is transfused, as in massive transfusions and pediatric patients.AIMS:The present study aims to assess the prevalence of red cell antibodies in healthy blood donors at a tertiary care hospital-based blood bank in India.MATERIALS AND METHODS:A total of 82,153 donor samples were screened for irregular red cell antibodies between January 2012 and December 2015 at the Department of Transfusion Medicine, Indraprastha Apollo Hospitals, New Delhi. Antibody screening was performed by solid phase method using Immucor Capture–R ready screen (pooled cells) on fully automated immunohematology analyzer Galileo Neo (Immucor Inc., Norcross, GA, USA). Positive tests were further confirmed using Capture-R ready screen (4 cell panel). Advanced investigations to identify the antibody/ies were performed on confirmed positive samples. Antibody identification was conducted using various cell panels (Immucor Capture-R Ready-ID, Panocell-10, Ficin Treated). An advanced technique such as adsorption and elution was performed as per requirement.RESULTS:Screening with pooled cells and 4 cell panel was positive in 227 donors (0.27%), 150 of these donors had autoantibodies, 1 had autoantibodies with underlying alloantibody anti-Jka (0.001%), and 76 had alloantibodies (0.09%) alone in their plasma. Anti-M was the most common antibody (43 donors) identified, followed by anti-D (21 donors). Anti-N was detected in 4; anti-Jka, anti-C, and anti-E in two donors each followed by anti-P1 and anti-Leb in 1 donor.CONCLUSION:Antibodies against red cells can be present in healthy donors detection of which is important in providing safe blood to the patient. The prevalence of red blood cell antibody in healthy donors in this study was found to be 0.27%, while the prevalence of alloantibodies was 0.09%. The majority of alloantibodies were anti-M (56.57%) and anti-D (27.63%).

Optimization of blood safety through essential characterization of naturally occurring lewis antibody

Background: Lewis (Le) antibodies are usually naturally occurring; however, they may be clinically significant, may be immunoglobulin G (IgG) type, and may cause hemolytic transfusion reactions. The present study depicts the clinical significance and detailed characterization of Le antibodies in blood donors and patient populations and their implication in safe blood transfusion. Materials and Methods: The prospective study included seven individuals who were detected with Le antibodies. Further investigations were performed for detailed characterization of these antibodies with regard to antibody type, thermal amplitude, titer, and enzyme study and secretor status of the individuals. Results: Of the 69,354 donors and patients subjected to antibody screening, anti-Lea was detected in 7 individuals with none having anti-Leb. All showed the Le (a−b−) phenotype with 4 individuals presenting with IgG anti-Lea optimally reacting at 37°C, with a highest titer of 32. Where all seven individuals were ABH secretors, however none revealed any Le substances. For patients requiring transfusion, compatible Lea antigen-negative red cell units were issued without any adverse events. Conclusions: As naturally occurring Le antibodies may be clinically significant and cause hemolytic transfusion reaction, therefore identification and detailed characterization of antibody in blood donor or recipient is very crucial to blood safety.

Transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI), an important non-infectious risk of blood transfusion is a leading cause of morbidity and mortality. Activation of polymorphonuclear (PMN) leucocytes by the mediators released due to the interaction of donor antibodies against the recipient monocytes is thought to trigger TRALI. Major histocompatibility complex Class II antibodies have been implicated in the direct causation of TRALI by direct activation of PMN leucocytes. TRALI has been reported in patients receiving all blood components that contain plasma. Awareness regarding TRALI among clinicians and a high index of suspicion will facilitate early diagnosis of the condition. TRALI is a clinical diagnosis that is suspected when new acute lung injury (ALI) develops within six hours of a transfusion. Diagnostic work-up should focus on ruling out other risk factors for ALI like sepsis, aspiration, among others. TRALI mitigation strategies are helpful to ensure blood safety and facilitate lessening of other transfusion reactions transfusion associated circulatory overload as well. The treatment for TRALI is symptomatic and supportive and is similar to that administered for ALI.

Antibody Exchange: Information extraction of biological antibody donation and a web-portal to find donors and seekers.

Bio-molecular reagents like antibodies required in experimental biology are expensive and their effectiveness, among other things, is critical to the success of the experiment. Although such resources are sometimes donated by one investigator to another through personal communication between the two, there is no previous study to our knowledge on the extent of such donations, nor a central platform that directs resource seekers to donors. In this paper, we describe, to our knowledge, a first attempt at building a web-portal titled Antibody Exchange (or more general ‘Bio-Resource Exchange’) that attempts to bridge this gap between resource seekers and donors in the domain of experimental biology. Users on this portal can request for or donate antibodies, cell-lines and DNA Constructs. This resource could also serve as a crowd-sourced database of resources for experimental biology. Further, we also studied the extent of antibody donations by mining the acknowledgement sections of scientific articles. Specifically, we extracted the name of the donor, his/her affiliation and the name of the antibody for every donation by parsing the acknowledgements sections of articles. To extract annotations at this level, we adopted two approaches – a rule based algorithm and a bootstrapped pattern learning algorithm. The algorithms extracted donor names, affiliations and antibody names with average accuracies of 57% and 62% respectively. We also created a dataset of 50 expert-annotated acknowledgements sections that will serve as a gold standard dataset to evaluate extraction algorithms in the future.

Investigation of human T-cell lymphocytic leukemia virus infections among voluntary blood donors in Foshan City

Objective To investigate the infection status of human T lymphocyte leukemia virus (HTLV) in voluntary blood donors in Foshan City of Guangdong Province, and to evaluate the risk of HTLV transmission through blood, in order to ensure safety of clinical blood transfusion in Foshan City. Methods From February to December 2016, a total of 69 275 blood donors in Foshan City were selected as study objects. Enzyme-linked immunosorbent assay(ELISA)was conducted to detect HTLV-Ⅰ/-Ⅱ antibodies in plasma from all blood donors, then reactivity samples were double-hole re-examined. The samples which were reactive by double-hole re-examined were determined primary screening results of HTLV-Ⅰ/-Ⅱ antibodies positive. And finally confirmed by Western blotting detection. The primary screening positive rates of HTLV-Ⅰ/-Ⅱ antibodies of blood donors from different gender, age, education degrees, household registration and times of blood donation were measured and compared by statistical method. Results ① In these 69 275 blood donors, HTLV-Ⅰ/-Ⅱ antibodies of 17 donors were positive, and primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies was 0.025%. Among them, only 2 samples were identified as positive for HTLV-Ⅰ/-Ⅱ antibodies by Western blotting, and confirmed positive rate was 0.003%. ② The primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies in female donors was 0.042% (11/26 291), which was higher than that of male donors (0.014%, 6/42 984) , and the difference was statistically significant (χ2=5.17, P=0.023). The primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies in 46-55 years old blood donors was the highest as 0.084% (4/4 768) among donors of different ages, and the total difference of HTLV-Ⅰ/-Ⅱ antibodies primary screening positive rates in donors of different ages was statistically significant (χ2=8.09, P= 0.044). The blood donors with junior middle school education or below has the highest primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies (0.063%, 7/11 113) among donors of different education degrees, and the total difference of primary screening positive rates was statistically significant (χ2=7.97, P=0.047). The primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies in nonlocal registered blood donors (0.033%, 15/45 274) was higher than that of local registered donors (0.008%, 2/24 001), and the difference was statistically significant (χ2=3.93, P=0.047). The primary screening positive rate of HTLV-Ⅰ/-Ⅱ antibodies in multipe blood donors (0.034%, 16/46 414) who donated blood twice or more, was higher than that of the first blood donors (0.004%, 1/22 861), and the difference was statistically significant (χ2=5.65, P=0.017). Conclusions The results show that Foshan City belongs to low-incidence or non-endemic area of HTLV infection among voluntary blood donors. The risk of infection with HTLV was higher among female, elderly, low education, nonlocal registered and multipe blood donors. In view of blood transfusion safety, it is recommended that HTLV-Ⅰ/-Ⅱ antibodies of all voluntary donors should be detected before blood donation, and the blood should deal with filter to remove white blood cells. Key words: HTLV-Ⅰantibodies; HTLV-Ⅱ antibodies; Blood donors; Enzyme-linked immunosorbent assay; Blotting, Western; Blood safety

Prevalence and predictors of hypertension in cardiac recipients

Aim. The study was aimed to assess the prevalence and risk factors of hypertension in cardiac recipients.Materials and methods. End-stage heart failure patients who received cardiac transplant between 01.01.2013 and 31.12.2016 in V.I. Shumakov Federal Research Center of Transplantology and Artificial Organs (Moscow) and survived 3 months after surgery were included and followed up for 999.4 ± 774.3 (108–1587) days. Young patients (<18 y/o) and patients after repeated (n = 18) or multi-organ transplantation (n = 3) were excluded.Results.353 cardiac recipients aged 45.6 ± 1.6 years (18.1% females and 81.9% males) were enrolled into the study. Hypertension was prevalent in 17.6, 42.8, 62.3 and 71.4%, respectively, before, in 3 months, in 1 year, and 3+ years after the transplantation. The study revealed significant relationship between post-transplant hypertension incidence and pre-op body mass index (р = 0.026), serum creatinine (р < 0.001), preexisting hypertension (RR = 1.36, р = 0.022) and renal failure, as well as donor heart posterior wall thickness (р = 0.034), post-transplant dialysis (RR = 1.85, р < 0.001), and antibody mediated rejection episodes (RR = 1.7, р = 0.001). Uncontrolled hypertension in cardiac recipients was related to poor compliance and new-onset post-transplant renal failure.Conclusion. Hypertension is highly prevalent among our population of cardiac recipients. The combination of various etiologic mechanisms, multiplex therapy and subjective factors calls for the careful individual patient management.

Penjadwalan Job Shop Dengan Pendekatan Algoritma Artificial Immune System

Production scheduling is an important activity in manufacturing. Optimal scheduling affects the time of completion of the work. PT. Interpack is a company that produces packaging machines. The job schedule of the product spare part still uses the random priority rules. Use of random rules makes a lot of time delay. Delay causes operator and machine idle. Delay also causes the total time of completion of the work (makespan) and delay the greater. So it needs to be rescheduled to work on the spare part of product. Job scheduling using the Artificial Immune System (AIS) algorithm. AIS was developed by Farmer et al. The AIS algorithm refers to the human immune system. The stages of the AIS algorithm begin with random initialization, antibody representation and gene classification, clone breeding, selection of donor antibodies, germ-line construction, gene fragment redesign, and ending with diversification of antibodies. AIS algorithm scheduling resulted in a more optimal new schedule. AIS algorithm scheduling generates a future of 6483.91 minutes. Company scheduling generates makespan of 7059.99 minutes. AIS Schedule finishes algorithm 4 days of the due date. AIS algorithm schedule increase machine utility by 1%.

Usutu Virus Antibodies in Blood Donors and Healthy Forestry Workers in the Lombardy Region, Northern Italy.

Usutu virus (USUV), a member of the genus Flavivirus, is known to circulate at low prevalence in Northern Italy, and has been reported to cause overt infection. USUV was first reported in Europe in 2001, but a retrospective study showed that it has been present in Italy at least since 1996. Seroprevalence data for USUV antibodies in sera are being collected in different European countries, showing circulation at low prevalence in human populations. Interestingly, two consecutive studies in Northern Italy indicate a possible increase in the presence of the virus, from 0% to 0.23% seroprevalence in blood donors. In this study, antibodies against USUV were measured in 3 consecutive blood samples collected from October 2014 to December 2015 from 33 forestry workers in the Po river valley, while samples from 200 blood donors from the same geographical area were tested in parallel. Neutralizing and IgG antibodies were found in six forestry workers (18.1%) and in two blood donors (1%). Our results indicate that USUV circulation in the examined area, part of a highly populated region in Northern Italy, is higher than expected. Healthy subjects exhibit a higher prevalence than what was found in a previous report in an adjoining region (0.23%), while the population at risk shows a much higher prevalence value (18.1%).

An evaluation of asymptomatic Dengue infections among blood donors during the 2014 Dengue outbreak in Guangzhou, China.

In 2014, an outbreak of dengue virus (DENV) infection led to 45 171 clinical cases diagnosed in Guangdong province, Southern China. However, the potential risk of blood donors asymptomatically infected with DENV has not been evaluated . In the current study we detected anti-DENV IgG antibody and RNA in volunteer Chinese blood donors. We found that anti-DENV IgG antibody was positively detected in 3.4% (51/1500) and two donors were detected as being DENV RNA positive out of 3000 blood samples. We concluded that the presence of potential DENV in blood donors might be potential risk for blood safety. Therefore, screening for DENV infection should be considered in blood donations during a period of dengue outbreak in high epidemic area of China.

Hepatitis E virus antibodies in HIV-infected patients and blood donors from western Poland: A preliminary report.

Hepatitis E virus (HEV) infection is an emerging problem in industrialized countries, including Europe. Little data exists on HEV seroprevalence in Poland. The aim of this study was to assess the prevalence of anti-HEV IgG antibodies in Polish patients infected with the human immunodeficiency virus (HIV) and blood donors. Two hundred and ten individuals (n = 105 of HIV-infected patients and n = 105 of ageand sex-matched blood donors from the same area; 178 men and 32 women), aged 18-50 (median age: 38 years), were tested for the presence of anti-HEV IgG antibodies with the EUROIMMUN Anti-Hepatitis E Virus (HEV) ELISA (IgG) tests (Lübeck, Germany). Additionally, some simple clinical and laboratory data was collected. The overall anti-HEV IgG prevalence was 2.4% (5/210). One HIV-positive patient (0.95%) and 4 blood donors (3.8%) were seropositive (p = 0.1745). All the HEV-exposed individuals were men with a history of travel abroad and no icteric disease in the past. Exposure to HEV infection among Polish HIV patients and blood donors seems to be uncommon. Data on this issue is scarce and conflicting for HIV-infected individuals. Further investigations applying different serological tests and concomitant HEV RNA testing are needed to reliably assess the risk and practical impact of HEV infection in Poland.

Quantitative analysis of the CD4+ T cell response to therapeutic antibodies in healthy donors using a novel T cell:PBMC assay.

Many biopharmaceuticals (BPs) are known to be immunogenic in the clinic, which can result in modified pharmacokinetics, reduced efficacy, allergic reactions and anaphylaxis. During recent years, several technologies to predict immunogenicity have been introduced, but the predictive value is still considered low. Thus, there is an unmet medical need for optimization of such technologies. The generation of T cell dependent high affinity anti-drug antibodies plays a key role in clinical immunogenicity. This study aimed at developing and evaluating a novel in vitro T cell:PBMC assay for prediction of the immunogenicity potential of BPs. To this end, we assessed the ability of infliximab (anti-TNF-α), rituximab (anti-CD20), adalimumab (anti-TNF-α) and natalizumab (anti-α4-integrin), all showing immunogenicity in the clinic, to induce a CD4+ T cells response. Keyhole limpet hemocyanin (KLH) and cytomegalovirus pp65 protein (CMV) were included as neo-antigen and recall antigen positive controls, respectively. By analyzing 26 healthy donors having HLA-DRB1 alleles matching the European population, we calculated the frequency of responding donors, the magnitude of the response, and the frequency of BP-specific T cells, as measured by 3[H]-thymidine incorporation and ELISpot IL-2 secretion. KLH and CMV demonstrated a strong T cell response in all the donors analyzed. The frequency of responding donors to the BPs was 4% for infliximab, 8% for adalimumab, 19% for rituximab and 27% for natalizumab, which is compared to and discussed with their respective observed clinical immunogenicity. This study further complements predictive immunogenicity testing by quantifying the in vitro CD4+ T cell responses to different BPs. Even though the data generated using this modified method does not directly translate to the clinical situation, a high sensitivity and immunogenic potential of most BPs is demonstrated.

Prevalence of IgG and IgM anti-Toxoplasma gondii Antibodies in Blood Donors at Urmia Blood Transfusion Organization, Iran.

The importance of toxoplasmosis lies in its global spread, opportunistic nature, and causative role in abortion or irreparable adverse effects on infants of infected pregnant women. Toxoplasma gondii has different transmission routes to humans, including blood transfusion. The objective of the present study was to evaluate the prevalence of IgG and IgM antibodies specific for T. gondii in blood donors at the Urmia Blood Transfusion Organization in west Azerbaijan, Iran. The present analytical, descriptive study evaluated the plasma of 270 randomly selected blood bags donated in 2013. The enzyme-linked immunosorbent assay (ELISA) test was employed to measure anti-T. gondii IgG and IgM antibodies. The results of the ELISA test showed that 102 samples (37.8%) from 270 blood bags had IgG antibodies in their plasma and none of them were IgM-positive, whereas 98 were men and four were women. Any increase in the level of IgM antibodies indicates the presence of an acute disease because the parasite is inside white blood cells and contaminates blood transfusion. Fortunately, all samples were IgM-negative. However, a province-wide seroepidemiological study is required for the Blood Transfusion Organization to consider including screening for anti-T. gondii antibodies in its screening programs.

T regulatory cells and dendritic cells protect against transfusion-related acute lung injury via IL-10

AbstractTransfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti–major histocompatibility complex class I antibodies, we found CD4+CD25+FoxP3+ T regulatory cells (Tregs) and CD11c+ dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion.

Modifiers of prion protein biogenesis and recycling identified by a highly parallel endocytosis kinetics assay

The cellular prion protein, PrPC, is attached by a glycosylphosphatidylinositol anchor to the outer leaflet of the plasma membrane. Its misfolded isoform PrPSc is the causative agent of prion diseases. Conversion of PrPC into PrPSc is thought to take place at the cell surface or in endolysosomal organelles. Understanding the intracellular trafficking of PrPC may, therefore, help elucidate the conversion process. Here we describe a time-resolved fluorescence energy transfer (FRET) assay reporting membrane expression and real-time internalization rates of PrPC The assay is suitable for high-throughput genetic and pharmaceutical screens for modulators of PrPC trafficking. Simultaneous administration of FRET donor and acceptor anti-PrPC antibodies to living cells yielded a measure of PrPC surface density, whereas sequential addition of each antibody visualized the internalization rate of PrPC (Z' factor >0.5). RNA interference assays showed that suppression of AP2M1 (AP-2 adaptor protein), RAB5A, VPS35 (vacuolar protein sorting 35 homolog), and M6PR (mannose 6-phosphate receptor) blocked PrPC internalization, whereas down-regulation of GIT2 and VPS28 increased PrPC internalization. PrPC cell-surface expression was reduced by down-regulation of RAB5A, VPS28, and VPS35 and enhanced by silencing EHD1. These data identify a network of proteins implicated in PrPC trafficking and demonstrate the power of this assay for identifying modulators of PrPC trafficking.

Toxoplasma Gondii Infection and Related Risk Factors Among Blood Donors in Northwest Iran

Background: Toxoplasmosis, a worldwide parasitic infection, is considered as a transfusion-transmitted disease. Objectives: Due to ignorance about Toxoplasma infection in blood donors monitoring and its important role in provision of safe blood and blood products and also poor information about the seroprevalence of T. gondii infection in blood donors, this study was conducted to assess anti-Toxoplasma gondii antibodies and associated risk factors among blood donors in northwest of Iran. Methods: In this cross- sectional study, 194 serum samples were collected from healthy blood donors who referred to Tabriz Blood transfusion organization (East Azerbaijan, Iran) during April and June 2014 and tested for anti-T. gondii IgM and IgG antibodies using chemiluminescence immunoassay. The questionnaire consisting of demographic and risk factors were filled for all the participants. Results: From 194 donors, 75 (38.66%) and 2 (1.03%) individuals were seropositive for anti-T. gondii IgG and IgM antibodies, respectively. In the present study, anti-T. gondii antibodies in first-time donors was significantly higher than those in regular blood donors (P < 0.05). A significant correlation was observed between T. gondii infection and age (P < 0.05); however, there were no relationship between Toxoplasma infection and other factors. Conclusions: Considering the medical importance of blood transfusion and high rate of anti- T. gondii antibodies in healthy blood donors, it seems that effective monitoring of infection is required to prevent transfusion- transmitted toxoplasmosis.

Prevalence of Trypanosoma Cruzi antibodies in blood donors from the Sao Paulo State, Brazil, between 2012 and 2014.

American tripanosomiasis (Chagas disease), the second most neglected disease in the world, is caused by the protozoan parasite Trypanosoma cruzi. Though natural transmission by insect vectors has been controlled, there is significant risk of T. cruzi transmission by blood transfusion in non-endemic regions, generally due to immigration processes from endemic areas. The objective of this study was to evaluate anti-T. cruzi seroprevalence in blood donors from the western part of São Paulo State, Brazil, by serologic and immunofluorescence confirmation tests for the period between 2012 and 2014. Currently, this region is regarded as a non-endemic area for Chagas disease. The confirmed overall T. cruzi seroprevalence among blood donors was 0.10%, which can be considered low compared to other Brazilian regions. Nevertheless, the distribution of the anti-T. cruzi antibodies within the examined region was uneven, and some areas of significantly higher prevalence were observed. We could consider two tendencies in the prevalence of T. cruzi: (i) residual older undiagnosed cases from São Paulo State, and (ii) immigration from endemic Brazilian or South American regions. The discordance obtained for T. cruzi prevalence by serologic and immunofluorescence methods demonstrates that more specific routine diagnosis is needed to diminish the cost of the assays and the loss of blood supply once all seropositive blood bags are immediately discarded.

Seroprevalence of anti-WNV IgG antibodies and WNV-RNA in Egyptian blood donors.

Transmission of West Nile virus (WNV) from asymptomatic donors has been reported during blood transfusions and organ transplants in humans. In this work, we aimed to investigate the presence of WNV antibody and WNV RNA in blood donors to evaluate the sero-prevalence of WNV and risk for WNV transmission. One hundred and sixty blood donors were tested for the presence of anti-WNV IgG by ELISA and for WNVs 1 and 2 RNA by RT-PCR. About 55% of blood donors were seropositive for WNV IgG antibodies, with significantly higher percentage of positive donors coming from rural areas and Nile Delta region compared to other donors. Using RT-PCR all donors were negative for viral RNA of both WNV lineages 1 and 2. High sero-prevelance of WNV antibodies in asymptomatic blood donors denotes endemicity of the WNV in Egypt and points to the importance of routine screening of blood donors for WNV RNA. On the other hand the absence of WNV RNA by RT-PCR indicates apparent low risk of the blood products as regards WNV transmission. Further studies into significance of WNV seronegativity among Rh negative donors and into the use of WNV seropositive blood in prophylaxis or treatment of WNV neuroinvasive disease are recommended. J. Med. Virol. 89:1323-1329, 2017. © 2017 Wiley Periodicals, Inc.

Males without apparent alloimmunization could have HLA antibodies that recognize target HLA specificities expressed on cells.

Human leukocyte antigen (HLA) antibodies, which are involved in the development of transfusion-related side effects such as transfusion-related lung injury, are sometimes found in males without a history of alloimmunization (eg, transplantation and transfusion). Whether HLA antibodies in male donors can interact with their target HLA specificities expressed on cells have not been completely investigated. The HLA antibodies detected in 7 male donors were characterized. Flow cytometry and immunocomplex capture fluorescence analysis were performed to evaluate the ability of these antibodies to bind with target HLA specificities expressed on cells. The association of these antibodies with complement was examined using anti-C1q antibody. Sustainability of HLA antibodies over time was compared in 26 male vs 57 female donors. The antibodies from all 7 donors recognized intact HLA molecules coated onto microbeads. The antibodies in 2 of 7 donors also recognized their target HLA specificities expressed on cells. Furthermore, the antibodies in one of these 2 donors showed HLA specificities that involved complement binding. Twenty-one of 26 initially positive male donors had turned negative for HLA antibody at least 1 year after their initial positive screening, whereas HLA antibody positivity was maintained for a long time in most female donors. Males without apparent alloimmunization could have HLA antibodies that recognize their target HLA specificities on cells and that could potentially modify molecular events in affected cells.

Significant variations in the seroprevalence of C6 ELISA antibodies in a highly endemic area for Lyme borreliosis: evaluation of age, sex and seasonal differences.

The purpose of this study was to assess the seroprevalence of C6 ELISA antibodies in healthy blood donors in Kalmar County, Sweden, in relation to age, sex and time of year (peak season vs off season). In addition, we wanted to assess serological status over time in a group of C6 ELISA seropositive blood donors. Sera were collected from 273 (131 women, 142 men) blood donors in autumn 2011 and 300 (144 women, 156 men) in winter 2014. All sera were analysed in the C6 ELISA and the results were interpreted according to the manufacturer's instructions. The seroprevalence was 22% (females 16%, males 28%) in 2011 and 24% (females 15%, males 33%) in 2014. The seroprevalence was significantly higher in males and increased with age. The highest seroprevalence was observed among elderly men, 60-70 years old (46% in 2011 and 52% in 2014). No significant difference was detected in seropositivity between the samples collected in winter and autumn. All (34/34) seropositive blood donors followed over time remained seropositive at follow-up after 22-29 months. C6 ELISA seroprevalence in healthy blood donors is high in Kalmar County, thereby reducing the specificity of a positive test result regarding the clinical diagnosis of Lyme borreliosis (LB). Although C6 seroprevalence appears not to be affected by seasonal sample time, it varies greatly with age and sex. A careful evaluation of pre-test probability is therefore of the utmost importance in the clinical diagnosis of LB, especially in elderly men. We suggest that colleagues in other endemic regions also consider initiating similar evaluations to optimize the laboratory and clinical diagnosis of LB in relation to age and sex.