Severe Thrombocytopenia, Thrombosis and Anti-PF4 Antibody after Pfizer-BioNTech COVID-19 mRNA Vaccine Booster-Is It Vaccine-Induced Immune Thrombotic Thrombocytopenia?

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a serious and life-threatening complication occurring after adenovirus-vector COVID-19 vaccines, and is rarely reported after other vaccine types. Herein, we report a case of possible VITT after the Pfizer-BioNTech mRNA vaccine booster, who presented with extensive lower limb deep vein thrombosis, severe thrombocytopenia, markedly elevated D-dimer and positive anti-PF4 antibody occurring 2 weeks post-vaccination, concurrent with a lupus anticoagulant. A complete recovery was made after intravenous immunoglobulin, prednisolone and anticoagulation with the oral direct Xa inhibitor rivaroxaban. The presenting features of VITT may overlap with those of antiphospholipid syndrome associated with anti-PF4 and immune thrombocytopenia. We discuss the diagnostic considerations in VITT and highlight the challenges of performing VITT confirmatory assays in non-specialized settings. The set of five diagnostic criteria for VITT is a useful tool for guiding initial management, but may potentially include patients without VITT. The bleeding risks of severe thrombocytopenia in the face of thrombosis, requiring anticoagulant therapy, present a clinical challenge, but early recognition and management can potentially lead to favorable outcomes.

An unusual presentation of Idiopathic hypereosinophilic syndrome.

Hypereosinophilic syndrome (HES) is a rare but life-threatening multi-organ disease which can be complicated by stroke, with devastating outcomes. Eosinophils can accumulate in multiple organs, most commonly involving the heart, skin, lungs, spleen, and liver. Neurological end-organ complications in hypereosinophilic syndrome are unusual and have been established to be of three types: brain infarction, encephalopathy and sensory polyneuropathy. We present a case where acute ischaemic stroke and encephalopathy are early manifestations of Idiopathic HES. It is important to consider HES as an aetiology for stroke and a high eosinophil count is an initial diagnostic clue. Early initiation of steroid therapy can potentially prevent disease progression.

Getting patient blood management Pillar 1 right in the Asia-Pacific: a call for action.

Preoperative anaemia is common in the Asia-Pacific. Iron deficiency anaemia (IDA) is a risk factor that can be addressed under patient blood management (PBM) Pillar 1, leading to reduced morbidity and mortality. We examined PBM implementation under four different healthcare systems, identified challenges and proposed several measures: (a) Test for anaemia once patients are scheduled for surgery. (b) Inform patients about risks of preoperative anaemia and benefits of treatment. (c) Treat IDA and replenish iron stores before surgery, using intravenous iron when oral treatment is ineffective, not tolerated or when rapid iron replenishment is needed; transfusion should not be the default management. (d) Harness support from multiple medical disciplines and relevant bodies to promote PBM implementation. (e) Demonstrate better outcomes and cost savings from reduced mortality and morbidity. Although PBM implementation may seem complex and daunting, it is feasible to start small. Implementing PBM Pillar 1, particularly in preoperative patients, is a sensible first step regardless of the healthcare setting.

Evaluation of Thalassaemia Screening Tests in the Antenatal and Non-Antenatal Populations in Singapore.

INTRODUCTION: Haemoglobinopathy testing is performed for carrier screening and evaluation of microcytic anaemia. We evaluated the effectiveness of thalassaemia screening tests at our institution and suggest ways of improving the testing algorithm. MATERIALS AND METHODS: A total of 10,084 non-antenatal and 11,364 antenatal samples with alkaline gel electrophoresis (AGE), capillary electrophoresis (CE), haemoglobin H (HbH) inclusion test, mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were retrospectively reviewed. A subgroup of 187 samples with genetic testing was correlated with HbH inclusions and MCH/ MCV. The effect of iron deficiency on percentage hemoglobin A2 (HbA2) was studied. RESULTS: HbH inclusion test showed low sensitivity of 21.43% for α-thalassaemia mutations but higher sensitivity of 78.95% for --SEA deletion. By receiver operating characteristic (ROC) analysis, MCH ≤28 pg or MCV ≤80 fl for non-antenatal samples and MCH ≤27 pg or MCV ≤81 fl for antenatal samples had >98% sensitivity for HbH inclusions. Above these thresholds, the probability that HbH inclusions would be absent was <99% (negative predictive value [NPV] >99%). MCH ≥28 pg had 100% sensitivity (95% CI 95.63%-100%) for α-thalassaemia mutations and 97.68% calculated NPV in the antenatal population. Detection of haemoglobin variants by CE correlated highly with AGE (99.89% sensitivity, 100% specificity). Severe iron deficiency reduced HbA2 in hemoglobin (P <0.001) and α-thalassaemia (P = 0.0035), but not in ß-thalassaemia. CONCLUSION: MCH/MCV thresholds have adequate sensitivity for α-thalassaemia in the antenatal population, and genotyping plays an important role as HbH inclusion test shows low sensitivity. CE without AGE, may be used as initial screening for haemoglobin variants. Our study provides contemporary data to guide thalassaemia screening algorithms in Singapore.