An abrupt rise of coagulation error messages on ACL TOP automated analysers

Introduction: Blood coagulation tests (BCT) are very important for clinicians to diagnose bleeding or thrombotic disorders and to monitor anticoagulant therapy. Case description: On a Saturday morning, a laboratory technician noted an abrupt rise in the number of coagulation error messages on our ALC TOP analysers. Visual inspection revealed the presence of partially and/or fully clotted citrate tubes and prompted the clinical biologist to further investigate a potential preanalytical cause. Considered causes: Partially or fully clotted blood in citrate tubes can have multiple causes including improper mixing of the tube, under- or overfilling or combining blood samples from different tubes into one citrate tube. What happened: The affected citrate tubes originated mostly from the same clinical departments. Moreover, all the affected tubes shared the same lot number (1 of 7 in use at the time). Visual inspection of 7 unopened boxes of 100 citrate tubes of this lot number revealed one box with nine completely empty and two partially filled tubes and one box with two partially filled tubes. No under-filled tubes were found in the other 5 boxes. Discussion: The blood to additive ratio is crucial for BCT. A sudden rise in clot errors should trigger a thorough investigation to identify the cause. Main lesson: Laboratories should regularly monitor and evaluate the percentage of clotted samples as a quality indicator at scheduled time points. A problem with the volume of additive in citrate tubes should be considered as a possible cause

An abrupt rise of coagulation error messages on ACL TOP automated analysers

Introduction: Blood coagulation tests (BCT) are very important for clinicians to diagnose bleeding or thrombotic disorders and to monitor anticoagulant therapy. Case description: On a Saturday morning, a laboratory technician noted an abrupt rise in the number of coagulation error messages on our ALC TOP analysers. Visual inspection revealed the presence of partially and/or fully clotted citrate tubes and prompted the clinical biologist to further investigate a potential preanalytical cause. Considered causes: Partially or fully clotted blood in citrate tubes can have multiple causes including improper mixing of the tube, under- or overfilling or combining blood samples from different tubes into one citrate tube. What happened: The affected citrate tubes originated mostly from the same clinical departments. Moreover, all the affected tubes shared the same lot number (1 of 7 in use at the time). Visual inspection of 7 unopened boxes of 100 citrate tubes of this lot number revealed one box with nine completely empty and two partially filled tubes and one box with two partially filled tubes. No under-filled tubes were found in the other 5 boxes. Discussion: The blood to additive ratio is crucial for BCT. A sudden rise in clot errors should trigger a thorough investigation to identify the cause. Main lesson: Laboratories should regularly monitor and evaluate the percentage of clotted samples as a quality indicator at scheduled time points. A problem with the volume of additive in citrate tubes should be considered as a possible cause.status: publishe

High Incidence of SARS-CoV-2 Variant of Concern Breakthrough Infections Despite Residual Humoral and Cellular Immunity Induced by BNT162b2 Vaccination in Healthcare Workers: A Long-Term Follow-Up Study in Belgium

To mitigate the massive COVID-19 burden caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several vaccination campaigns were initiated. We performed a single-center observational trial to monitor the mid- (3 months) and long-term (10 months) adaptive immune response and to document breakthrough infections (BTI) in healthcare workers (n = 84) upon BNT162b2 vaccination in a real-world setting. Firstly, serology was determined through immunoassays. Secondly, antibody functionality was analyzed via in vitro binding inhibition and pseudovirus neutralization and circulating receptor-binding domain (RBD)-specific B cells were assessed. Moreover, the induction of SARS-CoV-2-specific T cells was investigated by an interferon-γ release assay combined with flowcytometric profiling of activated CD4+ and CD8+ T cells. Within individuals that did not experience BTI (n = 62), vaccine-induced humoral and cellular immune responses were not correlated. Interestingly, waning over time was more pronounced within humoral compared to cellular immunity. In particular, 45 of these 62 subjects no longer displayed functional neutralization against the delta variant of concern (VoC) at long-term follow-up. Noteworthily, we reported a high incidence of symptomatic BTI cases (17.11%) caused by alpha and delta VoCs, although vaccine-induced immunity was only slightly reduced compared to subjects without BTI at mid-term follow-up