Novel risk patterns of vasovagal reactions in NZ blood donations complicated by COVID-19 restrictions.

Introduction: Vasovagal reactions (VVRs) are common but complex donor adverse reactions (DAEs) in blood donations. VVRs have been extensively studied with a multitude of risk factors identified including young age, female gender and first-time donor status. How they may interplay remains obscure. Methods: A total of 1,984,116 blood donations and 27,952 immediate VVRs (iVVRs) and 1,365 delayed VVRs (dVVRs) reported between 2011 and 2021 in NZ were used in multivariate logistic regression analyses each concerning donations with iVVRs as cases and those free of DAEs as controls. For each analysis stepwise selection was used to identify the best model and risk factors carrying significant main effects and/or interactions. Identified interactions informed further in-depth regression analyses to dissect iVVR risk patterns. Results: Over 95% of VVRs were iVVRs that had lower female preponderance and deferrals than dVVRs. iVVRs had a school seasonal pattern in whole blood donations driven by first-time donors from schools/colleges, and interactions between gender and age group differentiating the first-time from repeat donations. Subsequent regression analyses identified the known and novel risk factors of year and mobile collection sites and their interactions. iVVR rates were roundly elevated in 2020 and 2021 probably because of COVID-19 restrictions like facemask wearing. Exclusion of the 2020 and 2021 data removed the interactions with year, but confirmed interactions of gender with mobile collection sites (p = 6.2e-07) in first-time donations only and with age group in repeat donations only (p < 2.2e-16), together indicating young female donors at the highest risk of iVVRs. Our results also revealed that donation policy changes contributed to the year effects; donors had a lower iVVR risk at mobile sites than well-medicalized donation centers probably because of under-reporting. Conclusion: Modeling statistical interactions is valuable in identifying odds and revealing novel iVVR risk patterns and insights into blood donations.

A pilot randomized clinical trial of cryopreserved versus liquid-stored platelet transfusion for bleeding in cardiac surgery: The cryopreserved versus liquid platelet-New Zealand pilot trial.

BACKGROUND AND OBJECTIVES: Platelets for transfusion have a shelf-life of 7 days, limiting availability and leading to wastage. Cryopreservation at -80°C extends shelf-life to at least 1 year, but safety and effectiveness are uncertain. MATERIALS AND METHODS: This single centre blinded pilot trial enrolled adult cardiac surgery patients who were at high risk of platelet transfusion. If treating clinicians determined platelet transfusion was required, up to three units of either cryopreserved or liquid-stored platelets intraoperatively or during intensive care unit admission were administered. The primary outcome was protocol safety and feasibility. RESULTS: Over 13 months, 89 patients were randomized, 23 (25.8%) of whom received a platelet transfusion. There were no differences in median blood loss up to 48 h between study groups, or in the quantities of study platelets or other blood components transfused. The median platelet concentration on the day after surgery was lower in the cryopreserved platelet group (122 × 103 /µl vs. 157 × 103 /µl, median difference 39.5 ×103 /µl, p = 0.03). There were no differences in any of the recorded safety outcomes, and no adverse events were reported on any patient. Multivariable adjustment for imbalances in baseline patient characteristics did not find study group to be a predictor of 24-h blood loss, red cell transfusion or a composite bleeding outcome. CONCLUSION: This pilot randomized controlled trial demonstrated the feasibility of the protocol and adds to accumulating data supporting the safety of this intervention. Given the clear advantage of prolonged shelf-life, particularly for regional hospitals in New Zealand, a definitive non-inferiority phase III trial is warranted.

Therapeutic granulocyte infusion for patients with severe neutropaenia and neutrophilic dysfunction: New Zealand experience.

BACKGROUND AND OBJECTIVES: Studies have shown granulocyte transfusions (GTXs) may be beneficial in neutropaenic patients with severe systemic infections. New Zealand Blood Service has a policy for provision of granulocytes to New Zealand's District Health Boards. We set out to explore utilization of therapeutic granulocyte infusions in New Zealand. MATERIALS AND METHODS: Patients who received GTXs in the 16-year period between 2000 and 2016 were identified by the New Zealand electronic blood management system, eProgesa. Information pertaining to recipient demographics, disease-related factors, methods of granulocyte collection and clinical outcomes was obtained by the review of electronic transfusion and clinical records. RESULTS: Forty-five septic patients received granulocyte support for a total of 263 days. The median age of the recipients was 16 (range 0-74) years. Seventy-nine percent of the recipients had an underlying haematological malignancy with 50% having acute leukaemia. The median neutrophil count on the last day of GTX was 0.02 × 109 /L (range 0-16.32). Sixty-three percent (27/43 patients with available data) had persisting severe neutropaenia when the GTXs were stopped. The median duration of support was 3 (range 1-32) days. Forty-six percent of granulocyte collections were performed via apheresis. Of the 44 patients, for whom survival outcome was available, 18 (41%) survived the acute illness. CONCLUSION: GTXs were infrequently used, most commonly in the setting of an underlying haematological malignancy. This may be explained by the current weak evidence base supporting this therapeutic modality. Procuring a sufficiently large dose of granulocytes for infusion remains an issue for adult recipients.

Cryopreserved platelets compared with liquid-stored platelets for the treatment of surgical bleeding: protocol for two multicentre randomised controlled blinded non-inferiority trials (the CLIP-II and CLIPNZ-II trials).

INTRODUCTION: Cryopreservation at -80°C in dimethylsulphoxide extends platelet shelf-life from 7 days to 2 years. Only limited comparative trial data supports the safety and effectiveness of cryopreserved platelets as a treatment for surgical bleeding. Cryopreserved platelets are not currently registered for civilian use in most countries. METHODS AND ANALYSIS: CLIP-II and CLIPNZ-II are harmonised, blinded, multicentre, randomised, controlled clinical non-inferiority trials comparing bleeding, transfusion, safety and cost outcomes associated with cryopreserved platelets versus conventional liquid platelets as treatment for bleeding in cardiac surgery. CLIP-II is planning to enrol patients in 12 tertiary hospitals in Australia; CLIPNZ-II will recruit in five tertiary hospitals in New Zealand. The trials use near-identical protocols aside from details of cryopreserved platelet preparation. Patients identified preoperatively as being at high risk of requiring a platelet transfusion receive up to three units of study platelets if their treating doctor considers platelet transfusion is indicated. The primary endpoint is blood loss through the surgical drains in the 24 hours following intensive care unit (ICU) admission after surgery. Other endpoints are blood loss at other time points, potential complications, adverse reactions, transfusion and fluid requirement, requirement for procoagulant treatments, time to commencement of postoperative anticoagulants, delay between platelet order and commencement of infusion, need for reoperation, laboratory and point-of-care clotting indices, cost, length of mechanical ventilation, ICU and hospital stay, and mortality. Transfusing 202 (CLIP-II) or 228 (CLIPNZ-II) patients with study platelets will provide 90% power to exclude the possibility of greater than 20% inferiority in the primary endpoint. If cryopreserved platelets are not inferior to liquid-stored platelets, the advantages of longer shelf-life would justify rapid change in clinical practice. Cost-effectiveness analyses will be incorporated into each study such that, should clinical non-inferiority compared with standard care be demonstrated, the hospitals in each country that would benefit most from changing to a cryopreserved platelet blood bank will be known. ETHICS AND DISSEMINATION: CLIP-II was approved by the Austin Health Human Research Ethics Committee (HREC/54406/Austin-2019) and by the Australian Red Cross Lifeblood Ethics Committee (2019#23). CLIPNZ-II was approved by the New Zealand Southern Health and Disability Ethics Committee (21/STH/66). Eligible patients are approached for informed consent at least 1 day prior to surgery. There is no provision for consent provided by a substitute decision-maker. The results of the two trials will be submitted separately for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBERS: NCT03991481 and ACTRN12621000271808.

Charting elimination in the pandemic: a SARS-CoV-2 serosurvey of blood donors in New Zealand.

New Zealand has a strategy of eliminating SARS-CoV-2 that has resulted in a low incidence of reported coronavirus-19 disease (COVID-19). The aim of this study was to describe the spread of SARS-CoV-2 in New Zealand via a nationwide serosurvey of blood donors. Samples (n = 9806) were collected over a month-long period (3 December 2020-6 January 2021) from donors aged 16-88 years. The sample population was geographically spread, covering 16 of 20 district health board regions. A series of Spike-based immunoassays were utilised, and the serological testing algorithm was optimised for specificity given New Zealand is a low prevalence setting. Eighteen samples were seropositive for SARS-CoV-2 antibodies, six of which were retrospectively matched to previously confirmed COVID-19 cases. A further four were from donors that travelled to settings with a high risk of SARS-CoV-2 exposure, suggesting likely infection outside New Zealand. The remaining eight seropositive samples were from seven different district health regions for a true seroprevalence estimate, adjusted for test sensitivity and specificity, of 0.103% (95% confidence interval, 0.09-0.12%). The very low seroprevalence is consistent with limited undetected community transmission and provides robust, serological evidence to support New Zealand's successful elimination strategy for COVID-19.

Comprehensive analysis of SARS-CoV-2 antibody dynamics in New Zealand.

OBJECTIVES: Circulating antibodies are important markers of previous infection and immunity. Questions remain with respect to the durability and functionality of SARS-CoV-2 antibodies. This study explored antibody responses in recovered COVID-19 patients in a setting where the probability of re-exposure is effectively nil, owing to New Zealand's successful elimination strategy. METHODS: A triplex bead-based assay that detects antibody isotype (IgG, IgM and IgA) and subclass (IgG1, IgG2, IgG3 and IgG4) responses against Nucleocapsid (N) protein, the receptor binding domain (RBD) and Spike (S) protein of SARS-CoV-2 was developed. After establishing baseline levels with pre-pandemic control sera (n = 113), samples from PCR-confirmed COVID-19 patients with mild-moderate disease (n = 189) collected up to 8 months post-infection were examined. The relationship between antigen-specific antibodies and neutralising antibodies (NAbs) was explored with a surrogate neutralisation assay that quantifies inhibition of the RBD/hACE-2 interaction. RESULTS: While most individuals had broad isotype and subclass responses to each antigen shortly after infection, only RBD and S protein IgG, as well as NAbs, were relatively stable over the study period, with 99%, 96% and 90% of samples, respectively, having responses over baseline 4-8 months post-infection. Anti-RBD antibodies were strongly correlated with NAbs at all time points (Pearson's r ≥ 0.87), and feasibility of using finger prick sampling to accurately measure anti-RBD IgG was demonstrated. CONCLUSION: Antibodies to SARS-CoV-2 persist for up to 8 months following mild-to-moderate infection. This robust response can be attributed to the initial exposure without immune boosting given the lack of community transmission in our setting.

Disruption of the tumour-associated EMP3 enhances erythroid proliferation and causes the MAM-negative phenotype.

The clinically important MAM blood group antigen is present on haematopoietic cells of all humans except rare MAM-negative individuals. Its molecular basis is unknown. By whole-exome sequencing we identify EMP3, encoding epithelial membrane protein 3 (EMP3), as a candidate gene, then demonstrate inactivating mutations in ten known MAM-negative individuals. We show that EMP3, a purported tumour suppressor in various solid tumours, is expressed in erythroid cells. Disruption of EMP3 by CRISPR/Cas9 gene editing in an immortalised human erythroid cell line (BEL-A2) abolishes MAM expression. We find EMP3 to associate with, and stabilise, CD44 in the plasma membrane. Furthermore, cultured erythroid progenitor cells from MAM-negative individuals show markedly increased proliferation and higher reticulocyte yields, suggesting an important regulatory role for EMP3 in erythropoiesis and control of cell production. Our data establish MAM as a new blood group system and demonstrate an interaction of EMP3 with the cell surface signalling molecule CD44.

Paraprotein implicated in hardware failures in nucleic acid testing of blood donors.

BACKGROUND AND OBJECTIVES: Analyser blockage due to gel formation by paraproteins leading to invalid results is a rare problem in viral nucleic acid testing (NAT) at New Zealand Blood Service (NZBS) despite many blood samples tested without problems from individuals with known paraproteins. This study aimed to identify common factors in samples causing blockages. METHOD: Retrospective data were gathered on blood samples known to have blocked analysers at NZBS testing sites. Patients with plasma cell dyscrasia undergoing haematopoietic stem cell (HSC) harvest formed the comparator arm. These patients were identified from registry data of individuals undergoing autologous stem cell transplantation at Auckland City Hospital between 2013 and 2017. RESULTS: Four individuals were identified as having blocked analysers between 2010 and 2018. A total of 184 HSC transplant patients were identified, with contemporaneous paraprotein levels available for 177 (96%). Patients with intact immunoglobulin subtypes (134, 73%) were further analysed. Of these, 119 patients (65%) also had total protein and globulin levels available. Mean paraprotein (37.5 g/l), total protein (95.3 g/l), globulin levels (51.5 g/l) and proportion of lambda subtype (75%) were higher in the blocker group compared with non-blocking comparators (4.7 g/l, 66.8 g/l, 27.7 g/l, 36.6% respectively) (P = 0·03, 0·02, 0·007, 0·12). The highest paraprotein and total protein levels from the non-blocking cohort overlapped with the lowest of the blocker group. DISCUSSION: High protein levels (paraprotein >20 g/l, total protein >75 g/l) and a trend towards lambda subtype were associated with NAT analyser blockage. The overlap with non-blocking donor samples suggests factors in addition to protein quantity that are also important.

In vitro comparison between gamma-irradiated cryopreserved and Day 7 liquid-stored buffy coat-derived platelet components.

BACKGROUND: Cryopreserved platelet (PLT) components stored at -80°C in 5% to 6% dimethyl sulfoxide (DMSO) demonstrate enhanced hemostatic activity. Alterations in PLT surface glycoprotein expression and release of procoagulant microparticles during the freeze/thaw cycle result in PLT activation. Nothing is known of the effect of gamma irradiation on the in vitro quality of reconstituted cryopreserved PLTs. STUDY DESIGN AND METHODS: Gamma-irradiated (25-50 Gy) buffy coat-derived PLT components were either stored at room temperature for 7 days (the current expiry in New Zealand) or cryopreserved at -80°C using 5% to 6% DMSO. Cryopreserved PLTs were thawed at 37°C and reconstituted in ABO-identical plasma or PAS-E and compared to Day 7 gamma-irradiated liquid-stored PLTs. In vitro assays were performed to assess glycoprotein expression, PLT functionality and soluble cytokine release. RESULTS: Cryopreserved PLTs after thawing and reconstitution in ABO-matched plasma or PAS-E displayed differing recoveries (82.7 and 75.9%, respectively). Key expression levels of glycoproteins GPIbα (CD42b) and GPIIb (CD41a) were reduced. Cryopreserved PLTs retained the ability to form an effective functional clot, while showing accelerated initiation of clot formation (R-time) compared to Day 7 gamma-irradiated liquid-stored PLTs. CONCLUSION: Gamma-irradiated buffy coat-derived liquid-stored and cryopreserved PLTs have distinctly differing phenotypes. Cryopreserved PLTs reconstituted in ABO plasma have enhanced clot strength driven by coagulation factors and fibrinogen levels not present in PAS-E. Irradiated cryopreserved PLTs maintain a similar in vitro quality profile and hemostatic behavior to previously published, nonirradiated cryopreserved PLTs.

Overnight transfusions in New Zealand hospitals: potential risk to patients.

AIMS: This audit aimed to assess how frequently overnight transfusions were taking place and compare it to the previous 2004 audit. METHOD: All red cell units transfused between 20:00 and 08:00 hours in low acuity areas over 4 weeks in 2010 in 8 of New Zealand's largest public hospitals were identified prospectively, followed by review of clinical notes and laboratory results by the hospital Transfusion Nurse Specialist (TNS). RESULTS: 535 red cell units were transfused overnight, or 9% of the total units administered over the study period. Indications for transfusion were symptomatic anaemia, active bleeding or haemolysis (66%), but 16% of patients were asymptomatic. Of the non-urgent overnight transfusions (OTs), 42% were assessed as non-essential during the night. 49% of post-transfusion haemoglobin (Hb) levels were >100 g/L indicating a liberal transfusion practice. Although frequently cited as a reason for OT, only 16% of patients were discharged the following day. The median interval from pre-transfusion haemoglobin testing and starting the OT was approximately 9 hours, far exceeding the time needed to obtain routine full blood results. Adherence to recommended best transfusion practice was poor at night, with 12% of transfusions exceeding the 4 hour recommendation. End of transfusion observations fell to less than 80%, with the lowest compliance rate (69%) occurring at 06:00 hours. In addition to the 4 adverse reactions reported to the Haemovigilance programme, another 9 unreported reactions were identified by the auditors from the clinical notes. CONCLUSIONS: This audit has shown an improvement from 22% to 9% in the rate of OT compared to the 2004 audit. Nevertheless, 42% of transfusions were not considered appropriate based on current guidelines, and there is therefore room for improvement. A mean delay of 9 hours from haemoglobin sampling to transfusion suggests that reasons for this delay could be explored to help optimise transfusion start time. Some aspects of OT were worse than previously, with 12% of the OT exceeding 4 hours duration, double the rate of the previous audit. Results showing poor documentation and a high rate of unreported transfusion reactions (69% of reactions) suggest if an adverse transfusion reaction occurs overnight, there is a significant risk that it is less likely to be recognised, treated and/or reported.

Utilisation of intravenous immunoglobulin in New Zealand: a clinical audit.

AIM: To identify what diagnoses account for the utilisation of intravenous immunoglobulin (IVIG) in New Zealand (NZ), to establish regional differences in prescribing patterns, and to audit the appropriateness of its use in a subset of patients. METHODS: We accessed NZ Blood Service and NZ Health Information Service data to retrospectively determine the quantities of IVIG issued by each District Health Board (DHB) during 2004 and the diagnoses associated with each treatment episode. DHB-of-domicile data was used to explore the influence of cross boundary flow of patients. In a further prospective audit performed over 6 months we collected data on all utilisation of IVIG in eight DHB. The indications for IVIG were checked for compliance with the Australian Health Minister's Advisory Council (AHMAC) and Auckland District Health Board (ADHB) guidelines. RESULTS: Retrospective audit--The rates at which IVIG was prescribed varied 11-fold across the different DHB, from 100.5 g/1000 population in Capital and Coast DHB to 8.8 g/1000 in Nelson-Marlborough DHB. With cross-boundary flow analysis, the rates at which the residents of different DHB received IVIG (from any DHB) varied 10-fold. The Auckland DHB (and to a lesser extent some other DHB) provided substantial amounts of IVIG to treat patients resident in other DHB. Eccentric patterns of utilisation (e.g. obstetric) were found in some regions. Prospective audit--We captured 466 treatment episodes. Primary antibody deficiency was by far the most frequent diagnosis. Five diagnoses accounted for 69% of the total IVIG utilisation. 80.6% of the diagnoses were in AHMAC category 1 (convincing evidence of benefit) and 71.5% were approved diagnoses in the ADHB guidelines. Compliance with the two sets of guidelines varied significantly across the different DHB. CONCLUSION: A limited set of disorders accounts for most of the IVIG prescribed in NZ. The wide variation in the patterns of utilisation in different regions is probably due to a range of factors and could usefully be studied further. There is almost certainly under- and over-utilisation in some regions for certain diagnostic categories. Up-to-date, evidence-based guidelines and a rigorous authorisation process have the potential to promote appropriate utilisation.