Seronegative Donors Research Articles

A flow cytometry-based proliferation assay for clinical evaluation of T-cell memory against SARS-CoV-2

In general, the method of choice for evaluating immunity against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is detection of antibodies against the virus in patient sera. However, this is not feasible in patients who do not produce antibodies, either due to a primary immunodeficiency or secondary to treatment with immunosuppressive drugs. Assessment of the antiviral T cell response is an alternative to serological tests, but most T cell assays are labor-intensive and unsuitable for a clinical routine laboratory.We developed a flow cytometry-based assay for T cell proliferative responses against SARS-CoV-2, based on the detection of blast transformation of activated cells. The assay was validated on previously SARS-CoV-2 infected individuals and healthy seronegative blood donors, displaying 74% sensitivity and 96% specificity for previous infection with SARS-CoV-2. The usefulness of the assay was demonstrated in a patient with common variable immunodeficiency with a history of COVID-19. The described T-cell assay is a clinically relevant complement to serology in the evaluation of cellular immunity against SARS-CoV-2, which can be emulated by any routine lab with flow cytometric competence.

Incidence and Predictors of Progression to Chagas Cardiomyopathy: Long-Term Follow-Up of Trypanosoma cruzi-Seropositive Individuals.

There are few contemporary cohorts of Trypanosoma cruzi-seropositive individuals, and the basic clinical epidemiology of Chagas disease is poorly understood. Herein, we report the incidence of cardiomyopathy and death associated with T. cruzi seropositivity. Participants were selected in blood banks at 2 Brazilian centers. Cases were defined as T. cruzi-seropositive blood donors. T. cruzi-seronegative controls were matched for age, sex, and period of donation. Patients with established Chagas cardiomyopathy were recruited from a tertiary outpatient service. Participants underwent medical examination, blood collection, ECG, and echocardiogram at enrollment (2008-2010) and at follow-up (2018-2019). The primary outcomes were all-cause mortality and development of cardiomyopathy, defined as the presence of a left ventricular ejection fraction <50% or QRS complex duration ≥120 ms, or both. To handle loss to follow-up, a sensitivity analysis was performed using inverse probability weights for selection. We enrolled 499 T. cruzi-seropositive donors (age 48±10 years, 52% male), 488 T. cruzi-seronegative donors (age 49±10 years, 49% male), and 101 patients with established Chagas cardiomyopathy (age 48±8 years, 59% male). The mortality in patients with established cardiomyopathy was 80.9 deaths/1000 person-years (py) (54/101, 53%) and 15.1 deaths/1000 py (17/114, 15%) in T. cruzi-seropositive donors with cardiomyopathy at baseline. Among T. cruzi-seropositive donors without cardiomyopathy at baseline, mortality was 3.7 events/1000 py (15/385, 4%), which was no different from T. cruzi-seronegative donors with 3.6 deaths/1000 py (17/488, 3%). The incidence of cardiomyopathy in T. cruzi-seropositive donors was 13.8 (95% CI, 9.5-19.6) events/1000 py (32/262, 12%) compared with 4.6 (95% CI, 2.3-8.3) events/1000 py (11/277, 4%) in seronegative controls, with an absolute incidence difference associated with T. cruzi seropositivity of 9.2 (95% CI, 3.6-15.0) events/1000 py. T. cruzi antibody level at baseline was associated with development of cardiomyopathy (adjusted odds ratio, 1.4 [95% CI, 1.1-1.8]). We present a comprehensive description of the natural history of T. cruzi seropositivity in a contemporary patient population. The results highlight the central importance of anti-T. cruzi antibody titer as a marker of Chagas disease activity and risk of progression.

Circulating NKG2C + NK cell expressing CD107a/LAMP-1 subsets at the onset of CMV reactivation in seropositive kidney transplant recipients

Cytomegalovirus (CMV) infection contributes to morbidity and mortality among kidney transplant recipients. Natural killer (NK) cells can battle against CMV in kidney transplant recipients (KTRs). This study aimed to analyze the association between CMV reactivation and the proportion of NK cell subsets and their activity. In a cross-sectional study, ten CMV reactivated KTRs, and ten non- CMV reactivated ones were recruited. Ten matched healthy controls were also included in this cohort. The presence of anti-CMV-IgG Ab in both KTR subgroups from seronegative donors and healthy controls was determined. The frequency of distinct subsets of memory-like NK cells was analyzed through NKG2C, NKG2A, and CD57 using flow cytometry. The activity of NK cells was evaluated after stimulation via coculture with K562 cell line and then assessment of the frequency of CD107a and granzyme B. The mRNA levels of transcription factors, including T-bet, EAT, and inflammatory proteins, including IFN-γ and perforin contributing to NK cell activation, were also evaluated.Results showed a significantly lower frequency of NKG2C + NKG2A-CD57+ NK cell population in CMV-reactivated KTRs compared to non-reactivated ones (P-value:0.003). NKG2C+ NK cells expressing CD107a/LAMP-1 significantly was increased in CMV-reactivated KTRs compared to non-reactivated ones (P-value: 0.0002). The mRNA level of IFN-γ had a significant increase in the CMV-reactivated KTRs vs. nonreactive ones (P-value: 0.004). Finally, evaluation of the NK cells' cytotoxicity and activity through assessment of CD107a/LAMP-1 expression and IFN-γ secretion may be helpful for the identification of the risk of CMV reactivation in KTRs.

Spike-directed vaccination elicits robust spike-specific T-cell response, including to mutant strains

Although most studies describing coronavirus disease 2019 vaccine responses have focused on antibodies, there is increasing evidence that T cells play a critical role. Here the authors evaluated T-cell responses in seronegative donors before and after vaccination to define responses to the severe acute respiratory syndrome coronavirus 2 reference strain as well as to mutations in the variant strains Alpha/B.1.1.7 and Beta/B.1.351. The authors observed enhanced T-cell responses to reference and variant spike strains post-vaccination.

Lack of neutralizing activity in nonconvalescent sera, regardless of ABO blood group and anti-A isoagglutinin titer

BackgroundSeveral ABO blood groups have been associated with the likelihood of infection, severity, and/or outcome of COVID-19 in hospitalized cohorts, raising the hypothesis that anti-A isoagglutinins in non-A-group recipients could act as neutralizing antibodies against SARS-CoV-2.Materials and methodsWe run live virus neutralization tests using sera from 58 SARS-CoV-2 seronegative blood donors (27 O-group and 31 A-group) negatives for SARS-CoV-2 IgG to investigate what degree of neutralizing activity could be detected in their sera and eventual correlation with anti-A isoagglutinin titers.ResultsWe could not find clinically relevant neutralizing activity in any blood group, regardless of anti-isoagglutinin titer,DiscussionOur findings suggest that mechanisms other than neutralization explain the differences in outcomes from COVID19 seen in different ABO blood groups.

High Yield of Minipool NAT in India using a Sensitive Multiplex Assay for Blood Donor Screening

Background and Objectives: Nucleic acid amplification testing (nucleic acid testing [NAT]) for blood donor screening is increasingly being adopted in India to reduce the risk of transfusion-transmitted diseases. The high sensitivity of NAT enables testing of a large volume of donations in minipool format; reducing the costs of testing compared to individual donation testing. This study was aimed at evaluating the yield of minipool NAT testing for hepatitis B, hepatitis C, and human immunodeficiency virus (HIV) in blood donors from Uttar Pradesh. Methods: Samples from routine blood donors collected between August 16, 2016, and December 31, 2020, that were seronegative for hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV, syphilis, and malaria were further screened by NAT in pools of six donations (MP6) using the cobas TaqScreen MPX Test, version 2.0 (MPX2) on the cobas s 201 System. Members of reactive pools were tested to identify the reactive donation(s). Viral load testing was performed on randomly selected NAT-reactive samples. Results: Of 172,443 seronegative donors, 463 were NAT reactive: 369 HBV, 89 HCV, 2 HIV, and 3 co-infected with HBV and HCV. The overall NAT yield was 0.27%, with individual virus yield rates of 1/464 for HBV, 1/1874 for HCV, and 1/86,222 for HIV. Viral load testing of 19 HBV NAT-yield donations showed low concentrations in 16 samples and undetectable viral load in three; the two HCV NAT-yield donations tested had high viral loads. Conclusion: Screening of blood donations by minipool NAT using the highly sensitive MPX2 assay identified a high yield of serology negative, NAT-positive donations, including HBV reactive donations with low viral concentrations.

Reliable Estimationof CD8 T Cell Inhibition of In Vitro HIV-1 Replication.

The HIV-1 viral inhibition assay (VIA) measures CD8 T cell-mediated inhibition of HIV replication in CD4 T cells and is increasingly used for clinical testing of HIV vaccines and immunotherapies. The VIA has multiple sources of variability arising from in vitro HIV infection and co-culture of two T cell populations. Here, we describe multiple modifications to a 7-day VIA protocol, the most impactful being the introduction of independent replicate cultures for both HIV infected-CD4 (HIV-CD4) and HIV-CD4:CD8 T cell cultures. Virus inhibition was quantified using a ratio of weighted averages of p24+ cells in replicate cultures and the corresponding 95% confidence interval. An Excel template is provided to facilitate calculations. Virus inhibition was higher in people living with HIV suppressed on antiretroviral therapy (n=14, mean: 40.0%, median: 43.8%, range: 8.2 to 73.3%; p < 0.0001, two-tailed, exact Mann-Whitney test) compared to HIV-seronegative donors (n = 21, mean: -13.7%, median: -14.4%, range: -49.9 to 20.9%) and was stable over time (n = 6, mean %COV 9.4%, range 0.9 to 17.3%). Cross-sectional data were used to define 8% inhibition as the threshold to confidently detect specific CD8 T cell activity and determine the minimum number of culture replicates and p24+ cells needed to have 90% statistical power to detect this threshold. Last, we note that, in HIV seronegative donors, the addition of CD8 T cells to HIV infected CD4 T cells consistently increased HIV replication, though the level of increase varied markedly between donors. This co-culture effect may contribute to the weak correlations observed between CD8 T cell VIA and other measures of HIV-specific CD8 T cell function.

Residual Risk of HIV in African Transfusional Setting: Systematic Review and Meta-Analysis

Context: The residual risk of HIV transmission is still a real problem into the transfusional settings of limited resources countries. Blood banks of African countries confront the risk of transmitting HIV to recipients. The objective of this study is to estimate the residual risk of HIV in African transfusion settings and to compare this residual risk with that of other countries in the South (developping countries).&#x0D; Methods: This study resulted of a systematic review with meta-analysis of data from several comprehensive studies carried out between 2011 and 2017 whose purpose was focused on the residual risk of HIV transmission through blood transfusion. The studies on the residual risk were systematically searched in the different databases (PubMed, Medline and Google Scholar). The eligibility criteria were based on published studies which had blood donors as participants, looking at the residual risk of HIV in developing countries and the technique was based on the search for antibodies-P24 Antigen of the HIV or on nucleic acid (RNA) testing. Studies carried out before 2011 and after 2017 were excluded. Studies in rich countries were also excluded. The Cochrane tool was used to assess the risk of bias.&#x0D; Results: A total of 327,278 seronegative donors (for 12 eligible studies) were admitted for this study, i.e. 75.5% of men and 24.5% of women. The median age of all donors was 30.4 years. For studies carried out in the Africa zone (Burkina Faso, Ivory Coast, Nigeria, Democratic Republic of Congo, Tanzania and Zimbabwe), 327,278 donors were initially seronegative, of which 626 were found to be positive. Indeed, out of 742 incident cases in this study from African countries and other countries of the South, 84.4% of positive donors came from African studies and 15.6% of positive donors came from other countries of the South in this study. The residual risk (RR) of HIV in Africa has been estimated at 13 per 1,000,000 donations, with an incidence rate (IR) of 21.5 per 100,000 person-years. And in the other countries of the South (Brazil, Croatia, India, Iran, Malaysia and Pakistan), the RR of HIV has been estimated at 0.6 per 1,000,000 donations, or an incidence rate of 1.1 per 100,000 person-years.&#x0D; Conclusion: The residual risk of HIV in the transfusion environment is still high and still persists in blood banks in southern countries in general and in Africa in particular.

SARS-CoV-2 seroprevalence among blood donors in Québec, and analysis of symptoms associated with seropositivity: a nested case-control study.

ObjectivesA substantial proportion of individuals infected with SARS-CoV-2 do not experience noticeable symptoms typical of COVID-19. Our objectives were to evaluate the impact of the first wave of the pandemic in Québec by measuring SARS-CoV-2 antibody seroprevalence in a convenience sample of healthy blood donors and to study the association between seropositivity and the occurrence of COVID-19 symptoms.MethodsThe study design was a cross-sectional serological survey with a nested case-control study. Residual blood samples from donations collected between May 25 and July 9, 2020 (well before vaccination rollout) in the province of Québec were tested for anti-Spike RBD antibodies by ELISA. Seropositive donors and a control group of seronegative donors were questioned about prior COVID-19 symptoms. All qualified blood donors were eligible for participation.ResultsA total of 7691 blood donors were included in the study. After adjustments, the seroprevalence rate was 2.2% (95% CI 1.9–2.6). Seropositive donors reported one or more symptoms in a proportion of 52.2% (95% CI 44.2–60.1); this proportion was 19.1% (95% CI 13.4–26.1) among seronegative donors, suggesting that approximately 50–66% of all infections were asymptomatic. Univariate analysis of associations between symptoms and seropositivity revealed that except for rhinorrhea, all symptoms were significantly associated with seropositivity.ConclusionAssuming that blood donors are fairly representative of the general adult population, this study shows that less than 3% of 18–69-year-olds have been infected during the first wave of the pandemic in the province of Québec. Our data also confirm that many infections escaped detection, including a substantial proportion that were asymptomatic.Supplementary InformationThe online version contains supplementary material available at 10.17269/s41997-021-00531-6.

The effect of donor cytomegalovirus serological status on the outcome of allogeneic stem cell transplantation

Objective: Donor cytomegalovirus (CMV) serological negative status may have an adverse effect on the outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT), while there is inadequate data for Chinese people. This study is to explore the impact of donor CMV serological status on the outcome of CMV seropositive patients receiving allo-HSCT. Methods: Our study retrospectively analyzed 16 CMV seropositive patients with hematological malignancies receiving allogeneic grafts from CMV seronegative donors (antibody IgG negative) at Peking University People's Hospital from March 2013 to March 2020, which was defined as D-/R+ group. The other 64 CMV seropositive patients receiving grafts from CMV seropositive donors at the same period of time were selected as matched controls through a propensity score with 1∶4 depending on age, disease state and donor-recipient relationship (D+/R+ group). Results: Patients in D-/R+ group developed CMV DNAemia later than patients in the D+/R+ group (+37 days vs. +31 days after allo-HSCT, P=0.011), but the duration of CMV DNAemia in D-/R+ group was longer than that of D+/R+ group (99 days vs. 34 days, P=0.012). The rate of CMV reactivation 4 times or more in D-/R+ group was 4/16, significantly higher than that of D+/R+ group (4.7%, 3/64, P=0.01). The incidences of refractory CMV DNAemia (14/16 vs. 56.3%, P=0.021) and CMV disease (4/16 vs. 4.7%, P=0.01) in D-/R+ group were both higher than those in D+/R+ group. In addition, the application of CMV-CTL as the second-line antiviral treatment in D-/R+ group was more than that in D+/R+ group. Univariate analysis and multivariate analysis suggested that CMV serological negativity is an independent risk factor for refractory CMV DNAemia and the duration of CMV infection. The cumulative incidence of aGVHDⅡ-Ⅳ, cGVHD, 3-year probability of NRM, overall survival, and the cumulative incidence of relapse were all comparable in two groups. Conclusions: Although there is no significant effect on OS and NRM, the incidence of refractory CMV DNAemia, the frequency of virus reactivation, and the development of CMV disease in D-/R+ group are higher than those in controls. Therefore, CMV seropositive donors are preferred for CMV seropositive patients.

A novel association of efavirenz induced severe cutaneous adverse reactions with HLA- DRB1*03:01: A case-control study from North-East India.

HIV-infected patients have a higher risk of developing cutaneous reactions to drugs than the general population. Severe cutaneous adverse reactions (SCARs) are not uncommon in patients taking antiretroviral therapy (HAART]. To evaluate HLA class I and II allele frequencies in HIV patients on HAART who develop SCARs due to nevirapine (NVP] or efavirenz (EFZ] containing regime and compare this genotype composition with HAART tolerant patients and healthy organ donors. A case-control study for 4 years was conducted with four subsets of patients hailing from north-east India:Cohort 1- HIV seropositive patients who developed SCARs due to EFZ (n = 8];Cohort 2 - HIV seropositive patients who developed SCARs due to NVP (n = 15]; Cohort 3 -HIV seropositive NVP/EFZ-tolerant patients (n = 18]; Cohort 4 - Healthy HIV seronegative organ donors (n = 169].Cohort 3 & 4 acted as control-group. These patients were genotyped for the HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1, and HLA-DPB1 by a sequence-based HLA typing method. HLA-DRB1*03:01 allele revealed a significant association with EFZ regimen-induced SCARs in 62.5% patients compared with only 5.56% observed in HAART-tolerant patients and 4.14% in healthy organ. HLA-B*3505was found to be significantly associated with NVP induced SCARs. We found significant novel association of HLA-DRB1*03:01 with EFZ induced SCARs in North-East Indian HIV patients. Thus, HLA-DRB*03:01 may be useful as a genetic marker to avoid EFZ induced serious cutaneous rashes. The molecular HLA characterization of these alleles may provide a novel insight into the immunological basis of the antiretroviral drug reactions.

Trends in Discard of Kidneys from Hepatitis C Viremic Donors in the United States.

Kidneys from hepatitis C virus (HCV) viremic donors have become more commonly accepted for transplant, especially after effective direct-acting antiviral therapy became available in 2014. We examined the contemporary trend of kidney discard from donors with HCV seropositivity and viremia. Data from the Organ Procurement and Transplantation Network were used to identify deceased donor kidneys recovered for transplant. The exposure was donor HCV antibody status in the first analyses, and donor HCV antibody and viremia status in the second analyses. Multilevel, multivariable logistic regression was used to assess the association of these HCV exposure measures with kidney discard, adjusted for donor characteristics. Multilevel analyses were conducted to account for similar kidney discard pattern within clusters of organ procurement organizations and regions. Among 225,479 kidneys recovered from 2005 to 2019, 5% were from HCV seropositive donors. Compared with HCV seronegative kidneys, the odds of HCV seropositive kidney discard gradually declined, from a multivariable-adjusted odds ratio (aOR) of 7.06 (95% confidence interval [95% CI], 5.65 to 8.81) in 2014, to 1.20 (95% CI, 1.02 to 1.42) in 2019. Among 82,090 kidneys with nucleic acid amplification test results in 2015-2019, 4% were from HCV viremic donors and 2% were from aviremic seropositive donors. Compared with HCV aviremic seronegative kidneys, the odds of HCV viremic kidney discard decreased from an aOR of 4.89 (95% CI, 4.03 to 5.92) in 2018, to 1.48 (95% CI, 1.22 to 1.81) in 2019. By 2018 and 2019, aviremic seropositive status was not associated with higher odds of discard (2018: aOR, 1.13; 95% CI, 0.88 to 1.45; and 2019: aOR, 0.97; 95% CI, 0.76 to 1.23). Despite the decrease in kidney discard in recent years, kidneys from viremic (compared with aviremic seronegative) donors still had 48% higher odds of discard in 2019. The potential of these discarded organs to provide successful transplantation should be explored.

Role of Adoptive T- Cell Therapy in Post Hematopoietic Stem Cells Transplant Viral Infections-: A Systemic Review

Introduction Allogenic hematopoietic stem cell transplantation (Allo-HSCT) used for the treatment of multiple hematological malignancies requires immunosuppression, that can lead to the reactivation of viruses like EBV, CMV, adenovirus (AdV). These viruses pose a life-threatening risk to an individual like Graft vs Host Disease (GVHD) and other virus-specific complications. Adoptive T cell therapy (ATC) is an approach to treat refractory post-Allo-HSCT transplant viral infections. The aim of this study is to assess the efficacy of various ATCs being developed against various viruses. Methods A systematic search on PubMed, Embase, Clinicaltrials.gov, and Web of Science was performed for adoptive immunotherapy in viral infections after stem cell transplantation from inception to May 28, 2020. Out of 604 studies, 13 phase I and II clinical trials were selected for the systematic review. Results A total of 13 studies were included of which two studies included data on the pediatric population (n=13). A total of 335 patients (pts) were enrolled in 13 studies of which 264 were evaluable. CMV Perruccio et al. (2005) in a randomized controlled trial (RCT) assessed the efficacy of ATC against both Aspergillus and CMV after alloSCT. Median follow up (f/u) was six months. For Aspergillus (n=23), 90% and 54% achieved clearance, while for CMV (n=68) 92% and 9% didn't develop CMV reactivation in treatment and control group respectively. Overall Survival (OS) and progression-free survival (PFS) rate at two years were 92% and 80% respectively. Smith et al. (2018) (n=21) in a phase I trial studied the transfusion of virus-specific T cells (VST) (n=13) against CMV infection after undergoing alloSCT. After a median f/u of 28 weeks, overall response rate (ORR) was 85%. Bao et al. (2012) (n=10) conducted a study with VST transfusion against CMV infection (n=7). ORR was 85% of which 3 pts who were on immunosuppressive had shown reactivation. Miej et al. (2012) in phase I/II study (n=6) assessed the response of VST against refractory CMV with CR of 100% Neuenhahn et al. (2017) studied a phase I/II prospective trial (n=17) (CMV Seropositive graft donor (D+) 9/17 and CMV Seronegative graft donor (D-) 8/17) with CR of 62% in D+ group. In D- group only 37% developed T cells after Third-Party Donor transfer and only these achieved CR, while pts with no T cell detection in D- group (63%), only one achieved CR. Micklethwaite et al. (2008) did a phase I clinical trial (n=12) of CMV specific T cells given prophylactically. Only four pts showed CMV reactivation. Adenovirus Feucht et al. (2019) performed a phase I/II clinical trial (n=30) of VST against refractory AdV infection. 47% showed CR, 13% with negative blood AdV cleared virus from other sites, 10% showed PR. OS at six months was 71%. Winnie et al. (2018) (n=8) conducted phase I/II RCT among pediatric pts. Median f/u was six months. All patients have shown a decrease in AdV viral load. Qasim et al. (2013) conducted a prospective trial (n=5) among pediatric pts with CR of 60% until six weeks f/u. 20% died due to AdV viremia. Multi-virus CTLs Gerdemann et al. (2013) (n=36) did a clinical trial by infusing multi-virus cytotoxic T lymphocytes (CTLs) (n=10), reactive against CMV, EBV, and AdV. CR in 80% of the pts. Muranski et al. (2017) performed a phase I trial (n=9) and infused multi-virus CTLs prophylactically. No AdV, BK, or EBV related disease was observed in any pts while 11% pts had asymptomatic AdV viremia. Only those pts who received steroid therapy had CMV reactivation (44%). Ma et al. (2015) performed a phase I/II RCT with an intervention group (n=19, evaluable=10) and control group (n=33) with an infusion of multi-virus CTLs against CMV, EBV, AdV, and VZV after alloSCT, prophylactically. Pts in the intervention group had no reactivation of EBV, AdV, or VZV. 6 (60%) pts with CMV had reactivation; four before T cell therapy and two in the context of steroid therapy. OS at one year was 89% and 81% in the intervention and control group respectively. Third-Party Donor T-cells Tzannou et al. (2017) (n=37) in a phase II study demonstrated ORR of 92% (95% CI, 78.1% to 98.3%) in various viruses with ORR for BK virus 100%, CMV 94%, Adv 71%, EBV 100% and HHV-6 67%. Conclusion Adoptive T cell therapy for viral infections has shown efficacy in Post- allo-SCT pts who achieved complete clearance of infection in many cases, showed only minimal adverse events, and no major risk for GVHD related to this therapy was noted. Disclosures Anwer: Incyte, Seattle Genetics, Acetylon Pharmaceuticals, AbbVie Pharma, Astellas Pharma, Celegene, Millennium Pharmaceuticals.: Honoraria, Research Funding, Speakers Bureau.

Seroprevalence of SARS-CoV-2 antibodies among healthy blood donors in Karachi, Pakistan

BackgroundCovid-19 spread through blood transfusion has not yet been reported. Despite the prevailing pandemic, there are no recommendations available as yet for testing SARS-CoV-2 antibodies as part of blood screening. ObjectiveTo determine the seroprevalence of SAR-CoV-2 antibodies, its clinical significance and to identify if total antibodies(IgA, IgM, IgG) should be tested or just the specific IgG antibodies only. MethodConsecutive blood donors donated were screened for standard serological panel of HbsAg, Anti-HCV, Anti-HIV and Syphilis using Cobas-411 analyser and Malaria. All seronegative donors were then screened for COVID serology using the same instrument. These results were compared with the blood donors’ seroprevalence checked in a cohort in the first week of June 2020. Pre-COVID-19 period (October 2019) blood donors’ archived samples were also compared. Donors who were positive on ECLIA were then tested for specific antibodies (IgM or IgG) by ELISA. ResultsA total of 380 healthy blood donors were included. All were males with the mean age being 30.6 ± 6.3 years. Ten pre-pandemic samples did not show COVID-19 antibodies, whereas out of 70 samples in the 3rd week of June, only 15 (21.4 %) were positive. However, in July out of the 300 blood donors, 113 (37.7 %) were found to be reactive. To reconfirm our findings, these 113 donors were then tested on ELISA for presence of IgG specifically. Out of these 128 samples, 81 were IgG positive, 23 were borderline positive and 24 were negative. ConclusionAlmost 40 % of blood donors are now seroconverted for COVID-19. This is a reflection of widespread seroprevalence in the adult male population.

Hematopoietic cell transplant outcomes after myeloablative conditioning with fludarabine, busulfan, low-dose total body irradiation, and rabbit antithymocyte globulin.

Optimal conditioning and graft-vs-host disease (GVHD) prophylaxis for hematopoietic cell transplantation (HCT) are unknown. Here, we report on outcomes after low toxicity, myeloablative conditioning consisting of fludarabine, busulfan, and 4Gy total body irradiation, in combination with thymoglobulin and post-transplant methotrexate and cyclosporine. Weretrospectively studied 700 patients with hematologic malignancies who received blood stem cells from 7 to 8/8 HLA-matched unrelated or related donors. Median follow-up of surviving patients was 5years. At 5years, overall survival (OS), relapse-free survival (RFS), and chronic GVHD/relapse-free survival (cGRFS) were 58%, 55%, and 40%. Risk factors for poor OS, RFS, and cGRFS were (1). high to very high disease risk index (DRI), (2). high recipient age, and (3). cytomegalovirus (CMV)-seropositive recipient with seronegative donor (D-R+). The latter risk factor applied particularly to patients with lymphoid malignancies. Neither donor other than HLA-matched sibling (7-8/8 unrelated) nor one HLA allele mismatch was risk factors for poor OS, RFS, or cGRFS. In conclusion, the above regimen results in excellent long-term outcomes. The outcomes are negatively impacted by older age, high or very high DRI, and CMVD-R+ serostatus, but not by donor unrelatedness or one HLA allele mismatch.

Cytomegalovirus serologic matching in deceased donor kidney allocation optimizes high- and low-risk (D+R- and D-R-) profiles and does not adversely affect transplant rates.

Cytomegalovirus (CMV) is a major cause of infection-related morbidity and mortality in kidney transplantation. The most significant risk for developing CMV infection after transplant depends upon donor (D) and recipient (R) CMV serostatus. In 2012, our Organ Procurement Organization (OPO) began a novel pretransplant CMV prevention strategy via matching deceased kidney donors and recipients by CMV serostatus. Prior to the matching protocol, our distribution of seropositive and seronegative donors and recipients was similar to the United States at large. After the matching protocol, high-risk D+R- were reduced from 18.5% to 2.9%, whereas low-risk D-R- were increased from 13.5% to 24%. There was no adverse effect on transplant rates and no differential effect on waiting times for R+ vs R- after the protocol was implemented. This protocol could be implemented on a regional or national level to optimize low and high-risk CMV seroprofiles and potentially improve CMV-related outcomes in kidney transplantation.

Transfusion-transmitted and community-acquired cytomegalovirus infection in seronegative solid organ transplant recipients receiving seronegative donor organs.

Solid organ transplant (SOT) recipients who are cytomegalovirus (CMV) seronegative (R-) and receive seronegative donor (D-) organs have a small but currently unquantified risk of both transfusion-transmitted CMV (TT-CMV) and community-acquired CMV (CA-CMV). We retrospectively studied the incidence and clinical symptoms of TT-CMV (infection <1year posttransplant) and CA-CMV (infection >1year posttransplant) in a cohort of D-/R- adult and pediatric SOT recipients receiving leukoreduced blood products not screened for CMV seronegativity transplanted at our center between 2000 and 2011. CMV infection was defined as IgG seroconversion or detectable CMV antigenemia/DNAemia. Among 536 consecutive D-/R- recipients, 398 (81.8%) had adequate follow-up, and 231 (58%) received cellular blood products (total: 1626 red blood cell units, 470 platelet units) 30days pretransplant to 90days posttransplant. We observed no confirmed TT-CMV cases, but 14 CA-CMV cases (64% symptomatic) were seen. The estimated incidence rate of CA-CMV was higher in children (3.0/100 patient years) than adults (0.46/100 patient years, incident rate ratio of 6.52). The absence of TT-CMV over 11years suggests neither seronegative blood products nor CMV DNA blood donor screening would provide significant incremental safety when blood is already leukoreduced. D-/R- SOT recipients, particularly children, have a significantly higher and ongoing risk of CA-CMV.

Insights into the role of Epstein-Barr virus infection in multiple sclerosis using a novel humanized mouse model of disease

Abstract Multiple sclerosis (MS) is an autoimmune disease of the central nervous system without a clear cause. Epstein-Barr virus (EBV) is proposed to contribute to the pathogenesis of MS through unknown mechanisms. Evidence for a role of EBV infection in MS comes from both epidemiological and experimental studies, however, due to its narrow host tropism, there are currently few suitable animal models of MS that incorporate EBV infection. Recent advancements in humanized mouse modelling has enabled direct infection for the study of EBV-associated malignancies. We therefore chose to evaluate the role of EBV infection in humanized mice with experimental autoimmune encephalomyelitis (EAE), a widely used model of MS. Immunocompromised mice were engrafted with peripheral blood mononuclear cells (PBMC) derived from individuals with relapsing MS (RRMS) or from matched healthy EBV seropositive or seronegative donors. We observed that HuPBMC mice induced with EAE developed ascending paralysis, weight loss and signs of discomfort consistent with classical EAE models. Further, HuPBMC EAE showed significant T cell infiltration of both the brain and spinal cord, notably of IFN gamma-expressing CD4 and CD8 T cells, resulting in spinal cord and cerebellar demyelination. HuPBMC EAE mice derived from EBV seropositive donors developed earlier disease onset with more severe clinical symptoms compared to EBV seronegative donor-derived mice. We also observed increase disease severity among mice derived from RRMS patients compared to healthy controls. With continued improvement and characterization of this novel humanized EAE model, additional environmental and genetic risk factors can be evaluated in a system with human immune-mediated pathology.

Utilization of deceased organ donors based on HIV, hepatitis B virus, and hepatitis C virus screening test results.

Potential deceased organ donors are screened for human immunodeficiency virus (HIV-1), hepatitis B virus (HBV), and hepatitis C virus (HCV) with serologic tests and nucleic acid tests (NATs). The results of these tests on the utilization of donors have not been directly measured. Twenty-six organ procurement organizations (OPOs) provided primary HIV, HBV, and HCV screening results and utilization information for donor referrals evaluated from 2004 to 2017. Additional information regarding donor organ utilization was obtained from the Organ Procurement and Transplantation Network database. Data were analyzed using logistic regression. Test results were submitted for 38166 potential deceased organ donors; 31 (0.1%) were HIV NAT-negative but seropositive, 5.2% were HBV core antibody-positive and NAT-negative, while 1.8% were HCV antibody-positive and NAT-negative. Organ utilization of HBV and/or HCV NAT-negative organs increased over time despite positive antibody status. Nucleic acid test detected infections in seronegative donors, especially for HCV. The use of NAT for deceased donor screening correlated with increased utilization of donor organs.

Transfusion-transmitted cytomegalovirus: behaviour of cell-free virus during blood component processing. A study on the safety of labile blood components in Switzerland.

Nowadays, most blood products are leukocyte-reduced. After this procedure, the residual risk for transfusion transmitted cytomegalovirus (TT-CMV) is mostly attributed to cell-free viruses in the plasma of blood donors following primary infection or viral reactivation. Here, objectives are: 1) to study the behaviour of cell-free CMV through the blood component processing; 2) to determine the anti-CMV seroprevalence, the level of viremia, the window-period in blood donor population; and 3) to identify cases of TT-CMV in bone marrow transplant (BMT) recipients. Cell-free CMV was injected into blood bags originating from regular donors. Blood components were processed according to either the CompoSelect® or the CompoFlow® (Fresenius Kabi AG) techniques. Samples were analysed at each step for presence of virus DNA using quantitative polymerase chain reaction (PCR). The anti-CMV seroprevalence in our donor population was taken from our donor data system. The viremia was assessed in pooled plasmas samples from routine donations by quantitative PCR. Medical charts of 165 BMT anti-CMV seronegative recipients/anti-CMV seronegative donors who received CMV-unscreened blood products were reviewed. Cell-free CMV passes without any decrease in viral load through all stages of blood processing. The anti-CMV seroprevalence was 46.13%. Four DNA positive samples out of 42,240 individual blood donations were identified (0.009%); all had low levels of viremia (range 11-255 IU/mL). No window-period donation was identified. No TT-CMV was found. Cell-free CMV remains a concern with current blood component processing as it passes through all the processes. However, since low levels of CMV DNA were identified in the donations tested, and no BMT recipients had TT-CMV, the residual threat of TT-CMV after leukocyte reduction appears to be very low.