Heparin-induced Thrombocytopenia Research Articles

Berberis aristata Boosts Platelet Count in Heparin-Induced Thrombocytopenia Model

Background and purpose of the study: This study investigated the effectiveness of Berberis aristata, a medicinal plant commonly used in Ayurvedic medicine, in increasing platelet count in a heparin-induced thrombocytopenia model in rats. Research rationale: Conditions like dengue fever, and certain immunological disorders result in thrombocytopenia. No standard treatment for such conditions is available. The only way of treatment is to increase platelet count naturally with alternative medicines. Therefore, well well-known medicinal plant Berberis aristata and its main constituent berberine are tested for platelet-enhancing potential in this study. Method: Dried stem powder of Berberis aristata was extracted by using methanol and HCl (2:3, v/v) by Soxhlet extractor at 45-50 0C. The crude extract was used to obtain an alkaloidal fraction. Both the crude extract and the alkaloidal fraction were analysed by developing TLC using n-butanol: glacial acetic acid: water (7:2:1, v/v/v) as a solvent system. Platelet-enhancing potential screening was done by administering the crude extract, alkaloidal fraction as well as berberine in rats with heparin-induced thrombocytopenia. Statistical analysis was applied. Result: The results showed that increase in platelet count in Berberis aristata extract, alkaloidal fraction, and berberine-treated groups as compared to the control group. Conclusion: All the test groups showed significant platelet-enhancing activity in comparison to the control group. Among the entire test groups, the extract of Berberis aristata was found to have the most significant platelet-enhancing potential.

A disproportionality analysis of low molecular weight heparin in the overall population and in pregnancy women using the FDA adverse event reporting system (FAERS) database.

Low molecular weight heparin (LMWH) is extensively utilized as an anticoagulant for the prevention and management of various thrombotic conditions. However, despite the widespread use of LMWH in clinical indications, its adverse events (AEs) have not received substantial attention, and there is a lack of systematic and comprehensive AE studies. This study aims to evaluate AE signals associated with LMWH in the overall population and in pregnancy women from the FDA Adverse Event Reporting System database. We used the Standardized MedDRA Query to identify pregnancy-related AE reports. Disproportionality analyses were employed to identify LMWH-related AE by calculating the reporting odds ratios (ROR), proportional reporting ratios (PRR), bayesian confidence propagation neural network (BCPNN), and the empirical Bayesian geometric mean (EBGM). For the overall population, the significantly reported adverse signals in SOCs were pregnancy, puerperium, and perinatal conditions, vascular disorders, blood and lymphatic system disorders, and product issues. The five strongest AEs signal of LMWH-related were anti factor X antibody positive (n = 6, ROR 506.70, PRR 506.65, IC 8.31, EBGM 317.03), heparin-induced thrombocytopenia test positive (n = 19, ROR 263.10, PRR 263.02, IC 7.65, EBGM 200.79), anti factor X activity increased (n = 10, ROR 255.93, PRR 255.89, IC 7.62, EBGM 196.61), heparin-induced thrombocytopenia test (n = 14, ROR 231.85, PRR 231.80, IC 7.51, EBGM 182.09), and spontaneous heparin-induced thrombocytopenia syndrome (n = 3, ROR 230.31, PRR 230.30, IC 7.50, EBGM 181.16). For pregnancy women, the five strongest AEs signals of LMWH-related included sternal fracture (n = 3, ROR 243.44, PRR 243.35, IC 6.61, EBGM 97.94), syringe issue (n = 12, ROR 97.49, PRR 97.34, IC 5.94, EBGM 61.21), bleeding time prolonged (n = 3, ROR 97.38, PRR 97.34, IC 5.94, EBGM 61.21), spinal compression fracture (n = 10, ROR 90.24, PRR 90.13, IC 5.87, EBGM 58.30), and injection site haematoma (n = 19, ROR 79.23, PRR 79.04, IC 5.74, EBGM 53.47). Additionally, unexpected AEs associated with LMWH in pregnancy women were observed, including premature baby death, placental necrosis, abortion, antiphospholipid syndrome, systolic dysfunction, compartment syndrome, body height decreased, rubella antibody positive, and ultrasound doppler abnormal. This study identified unexpected AE signals of LMWH-relate in pregnancy women. Our study could provide valuable evidence for the clinical practice of LMWH, especially for identifying AEs and ensuring safe usage in pregnancy women.

Management of Heparin-Induced Thrombocytopenia: A Contemporary Review.

Heparin-induced thrombocytopenia (HIT) is a life- and limb-threatening immune-mediated emergency classically associated with heparin therapy. This review focuses on type II HIT, characterized by the development of antibodies against platelet-factor 4 (PF4) bound to heparin after exposure, causing life-threatening thrombocytopenia, arterial thrombosis, and/or venous thrombosis. The high morbidity and mortality rates emphasize the need for early recognition and urgent intervention with discontinuation of heparin and initiation of non-heparin anticoagulation. We discuss the management of HIT with an emphasis on recent developments: (i) incorporating the phases of HIT (i.e., suspected, acute, subacute A and B, and remote) into its management, categorized according to platelet count, immunoassay, and functional assay results and (ii) direct-acting oral anticoagulants (DOACs), which are increasingly used in appropriate cases of acute HIT (off-label). In comparison to parenteral options (e.g., bivalirudin and danaparoid), they are easier to administer, are more cost-effective, and obviate the need for transition to an oral anticoagulant after platelet recovery. We also identify the knowledge gaps and suggest areas for future research.

Haemorrhagic intracranial complications associated with vaccine-induced thrombocytopenia or central venous thrombosis after COVID-19 vaccination: postulated underlying mechanisms with literature and case review.

Despite the unequivocal medical and social advantages of introducing vaccines against the novel coronavirus SARS-CoV-2, there were also some concerns regarding possible post-vaccination adverse events. Most of these are mild. But in rare cases, severe neurological symptoms including ischaemic stroke, intracranial haemorrhage (ICH), cerebral venous and sinus thrombosis (CVT), and thrombosis with thrombocytopenia (TTS) have been observed. Literature data suggests that thrombosis with thrombocytopenia was the major underlying cause of the ICH; dural venous sinuses/cerebral veins were indicated as the primarily affected sites of thrombosis. Our review confirms the previously documented suspicion that CVT and TTS are most likely to occur following vector-type, rather than mRNA, vaccine administration. The postulated mechanism of TTS is similar to heparin-induced thrombocytopenia (HIT) both clinically and serologically. Although ICH and VITT are very rare side effects of the COVID-19 vaccine, for patients with risk factors for thrombosis (e.g. pregnancy), physicians should carefully consider the benefit/risk ratio of vaccination.

Severe and Prolonged Thrombocytopenia Following Heparin and Apixaban Use: A Case Report and Literature Review

Abstract: Drug-induced thrombocytopenia can occur in hospitalized patients and complicate their antithrombotic treatment. Several medications can associate thrombocytopenia with immune and nonimmune mechanisms. Thrombocytopenia can occur at any time from a few hours to months after a new medication initiation. In this study, we have described the case of a female patient with acute-onchronic kidney injury following a non-steroidal anti-inflammatory agent use, who developed catheterrelated thrombosis and was treated with heparin without any complication for 5 days. She was discharged after 5 days and prescribed to use apixaban 2.5 mg twice daily. However, she was readmitted after 24 hours with fatigue, petechiae, and severe thrombocytopenia (7000/mm3). The workup was negative for other reasons of thrombocytopenia. With a possible diagnosis of drug-related thrombocytopenia, apixaban was discontinued. Following the treatment with the intravenous immunoglobulin, her platelet counts increased and stabilized around 40-50,000/mm3. Anticoagulation was thus continued with adjusted doses of rivaroxaban (10-15 mg/day). 17 days after apixaban discontinuation and treatment with prednisolone, her platelet count increased to 108,000/mm3. With reference to this case, a brief review on refractory heparin-induced thrombocytopenia and the association of direct oral anticoagulants with thrombocytopenia is presented.

Electronic consultation to improve care outcomes in patients with suspected and confirmed heparin-induced thrombocytopenia

BackgroundHeparin-induced thrombocytopenia (HIT) is a complication of heparin exposure associated with high risk for morbidity and mortality. Diagnosis and management are complex due to limitations of laboratory testing and the need for nonheparin anticoagulation. ObjectivesTo increase the delivery of evidence-based care of patients with suspected and confirmed HIT via electronic consultation (e-consult). MethodsWe describe the creation and implementation of an e-consult service for patients with concern for HIT at a large academic medical center. Hematology physicians with HIT expertise performed real-time chart review of all patients with a positive screening immunoassay result and provided written recommendations in their electronic health record. ResultsComparison of outcomes for 1 year before and the year after the e-consult service implementation identified improvements in direct thrombin inhibitor stewardship, increased diagnostic accuracy, and decreased length of stay of patients with confirmed HIT. ConclusionThe e-consult platform is a novel method for rapid, targeted consultative guidance, and this single-institution pilot demonstrates its feasibility and effectiveness to improve the care of patients with suspected and confirmed HIT.

Heparin-Induced Thrombocytopenia in Patients Suffering Cardiogenic Shock.

Cardiogenic shock (CS) is associated with high mortality. Patients treated for CS mostly require heparin therapy, which may be associated with complications such as heparin-induced thrombocytopenia (HIT). HIT represents a serious condition associated with platelet decline and increased hypercoagulability and remains a poorly researched field in intensive care medicine. Primary purpose of this study was to: 1) determine HIT prevalence in CS, 2) assess the performance of common diagnostic tests for the workup of HIT, and 3) compare outcomes in CS patients with excluded and confirmed HIT. Retrospective dual-center study including adult patients 18 years old or older with diagnosed CS and suspected HIT from January 2010 to November 2022. Cardiac ICU at the Ludwig-Maximilians University hospital in Munich and the university hospital of Bonn. In this retrospective analysis, adult patients with diagnosed CS and suspected HIT were included. Differences in baseline characteristics, mortality, neurologic and safety outcomes between patients with excluded and confirmed HIT were evaluated. In cases of suspected HIT, positive screening antibodies were detected in 159 of 2808 patients (5.7%). HIT was confirmed via positive functional assay in 57 of 2808 patients, corresponding to a prevalence rate of 2.0%. The positive predictive value for anti-platelet factor 4/heparin screening antibodies was 35.8%. Total in-hospital mortality (58.8% vs. 57.9%; p > 0.999), 1-month mortality (47.1% vs. 43.9%; p = 0.781), and 12-month mortality (58.8% vs. 59.6%; p > 0.999) were similar between patients with excluded and confirmed HIT, respectively. Furthermore, no significant difference in neurologic outcome among survivors was found between groups (Cerebral Performance Category [CPC] score 1: 8.8% vs. 8.8%; p > 0.999 and CPC 2: 7.8% vs. 12.3%; p = 0.485). HIT was a rare complication in CS patients treated with unfractionated heparin and was not associated with increased mortality. Also, HIT confirmation was not associated with worse neurologic outcome in survivors. Future studies should aim at developing more precise, standardized, and cost-effective strategies to diagnose HIT and prevent complications.

Association of Metal Cations with the Anti-PF4/Heparin Antibody Response in Heparin-Induced Thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is an antibody-mediated immune response against complexes of heparin and platelet factor 4 (PF4). The electrostatic interaction between heparin and PF4 is critical for the anti-PF4/heparin antibody response seen in HIT. The binding of metal cations to heparin induces conformational changes and charge neutralization of the heparin molecule, and cation-heparin binding can modulate the specificity and affinity for heparin-binding partners. However, the effects of metal cation binding to heparin in the context of anti-PF4/heparin antibody response have not been determined. Here, we utilized inductively coupled plasma mass spectrometry (ICP-MS) to quantify 16 metal cations in patient plasma and tested for correlation with anti-PF4/heparin IgG levels and platelet count after clinical suspicion of HIT in a cohort of heparin-treated patients. The average age of the cohort (n = 32) was 60.53 (SD = 14.31) years old, had a mean anti-PF4/heparin antibody optical density [OD405] of 0.93 (SD = 1.21) units, and was primarily female (n = 23). Patients with positive anti-PF4/heparin antibody test results (OD405 ≥ 0.5 units) were younger, had increased weight and BMI, and were more likely to have a positive serotonin release assay (SRA) result compared to antibody-negative patients. We observed statistical differences between antibody-positive and -negative groups for sodium and aluminum and significant correlations of anti-PF4/heparin antibody levels with sodium and silver. While differences in sodium concentrations were associated with antibody-positive status and correlated with antibody levels, no replication was performed. Additional studies are warranted to confirm our observed association, including in vitro binding studies and larger observational cohorts.

Combination of 2 Quantitative Immunoassays and Clinical Score Algorithm to Reduce False-Negative Results in Heparin-Induced Thrombocytopenia: Prevalence Study of Mauriziano Hospital in Turin, Italy.

Heparin-induced thrombocytopenia (HIT) is a serious adverse effect of heparin treatment caused by platelet-activating anti-platelet factor 4 (PF4)/heparin antibodies. Accurate diagnosis of HIT is essential but remains challenging. The aim of our study was to explore the performance of our optimized diagnostic laboratory algorithm, based on Chemiluminescence (CliA) and ELISA immunoassays, on suspected HIT patients. The study compared the prevalence of HIT diagnosis in A.O. Mauriziano with the literature. 163 consecutive patients were investigated for suspected HIT with CliA HemosIL Acustar HIT-IgG, Werfen. HIT was ruled out in all patients with CliA <0.13 U/mL. All patients with CliA >0.13 U/mL were further investigated with Zymutest-HIA anti-PF4 IgG ELISA immunoassay. In these patients, HIT was ruled out on the combination of CliA between 0.13 and 1.0 U/mL followed by ELISA assay <0.300 OD. HIT was ruled in patients whose plasma tested positive or doubtful with CliA and positive with ELISA immunoassay and confirmed positive with a platelet aggregation test (PAT). Suspicion of HIT was revealed with clinical 4Ts score or recent suggestive anamnestic history. Our diagnostic algorithm ruled out HIT diagnosis in 144/163 patients (88%) and predicted a positive PAT in 5/19 (26%) of CliA positive (4/5) or ELISA positive and CliA doubtful (1/5) patients. Our prevalence was 3.1%, comparable with the literature. The approach combining 2 quantitative immunoassays' (CliA and ELISA) results and 4Ts score probability was able to rule out the diagnosis within 1 h in 66% of patients with suspected HIT and within 24 h in 88% of patients. In the remaining 12% of cases, management decisions have to be based on individualized judgment while awaiting functional confirming results (48-72 h).

Heparin-induced thrombocytopenia with very high antibody titer is associated with slower platelet recovery and higher risk of thrombosis.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic disorder mediated by platelet-activating antibodies targeting platelet factor 4 (PF4) and heparin complex. A higher antibody titer is reflected in a higher optical density (OD) by enzyme-linked immunosorbent assay for heparin-PF4 antibodies. This single-institution retrospective study of 116 HIT patients examined the effect of heparin-PF4 OD on time to platelet recovery, vascular thrombosis, and in-hospital mortality. Patients were divided into 3 cohorts based on heparin-PF4 OD: cohort 1 had an OD ≥ 2 and ≤ 2.4, cohort 2 had an OD > 2.4 and ≤ 2.8, and cohort 3 had an OD > 2.8. A higher OD titer was associated with significantly increased time to platelet recovery when compared between cohorts 1 versus 2 (HR = 0.599, p = 0.0221) and 1 versus 3 (HR = 0.515, p = 0.0014), as well as an increased risk of thrombosis (79.4%-cohort 3 vs 53.8%-cohort 2 vs 46.1%-cohort 1, p = 0.04), but had no impact on mortality (2.62-alive vs 2.65-deceased, p = 0.7432). A higher OD titer can inform risk assessment and support decision-making in HIT patients; however, prospective studies are needed to further clarify the impact of heparin-PF4 OD on outcomes.

Clinical and economic implications of false-positive heparin-induced thrombocytopenia immunoassays: utility of the 4T score.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic condition induced by platelet-activating IgG antibodies that recognize PF4/heparin complexes. Diagnosis of HIT relies on enzyme immunologic assays (EIAs) and functional assays [serotonin release assay (SRA)]. Our institution uses a latex immunoturbidimetric assay (LIA), which has shown a positive-predictive value (PPV) of 55.6%, and a negative-predictive value (NPV) of 99.7%. The low PPV of EIAs/LIAs, in combination with the clinical delay in obtaining results of a SRA, commonly leads to a false-positive diagnosis of HIT and inappropriate treatment. We performed a single-institution retrospective study at a large tertiary center to assess patient management decisions and economic costs following a false-positive HIT (LIA) test. This study found an 89.5% incidence of false-positive HIT (LIA) tests. 97.4% of patients underwent anticoagulation changes. 69.6% of patients were switched to argatroban. Of patients with a false-positive HIT immunoassay (LIA), 42 (40.7%) patients were on a prophylactic dose of anticoagulation at the time of HIT (LIA) positivity, of which 22 (52.4%) were switched to full anticoagulation with either argatroban or fondaparinux. Of the 22 patients switched to full anticoagulation, 15 (68%) had low-probability 4T scores. Seven (8.8%) of patients had bleeding events after HIT (LIA) positivity. All seven patients were switched to argatroban from a full-dose heparin anticoagulation. Five of the seven patients were considered major bleeds. Utilization of argatroban incurred substantial costs, estimated at approximately $73 000 for false-positive HIT cases. False-positive HIT (LIA) tests contribute to unwarranted anticoagulation changes, increased bleeding risks, and substantial healthcare costs. Incorporating the 4T score into diagnostic algorithms may help mitigate these risks by guiding appropriate clinical decisions. Future research should focus on refining diagnostic approaches and standardizing management strategies to improve patient outcomes and cost-effectiveness in HIT diagnosis and management.

Heparin-induced thrombocytopenia in extracorporeal membrane oxygenation-supported patients: a systematic review and meta-analysis

BackgroundIn recent years, extracorporeal membrane oxygenation (ECMO) has been increasingly used in critically ill patients with respiratory or cardiac failure. Heparin is usually used as anticoagulation therapy during ECMO support. However, heparin-induced thrombocytopenia (HIT) in ECMO-supported patients, which results in considerable morbidity and mortality, has not yet been well described. This meta-analysis and systematic review aimed to thoroughly report the incidence of HIT on ECMO, as well as the characteristics and outcomes of HIT patients.MethodsWe searched the PubMed, Embase, Cochrane Library, and Scopus databases for studies investigating HIT in adult patients supported by ECMO. All studies conforming to the inclusion criteria were screened from 1975 to August 2023. Nineteen studies from a total of 1,625 abstracts were selected. The primary outcomes were the incidence of HIT and suspected HIT.ResultsThe pooled incidence of HIT in ECMO-supported patients was 4.2% (95% CI: 2.7–5.6; 18 studies). A total of 15.9% (95% CI: 9.0-22.8; 12 studies) of patients on ECMO were suspected of having HIT. Enzyme-linked immunosorbent assay (ELISA) is the most commonly used immunoassay. The median optical density (OD) of the ELISA in HIT-confirmed patients ranged from 1.08 to 2.10. In most studies, the serotonin release assay (SRA) was performed as a HIT-confirming test. According to the subgroup analysis, the pooled incidence of HIT in ECMO patients was 2.7% in studies whose diagnostic mode was functional assays, which is significantly lower than the incidence in studies in which the patients were diagnosed by immunoassay (14.5%). Argatroban was most commonly used as an alternative anticoagulation agent after the withdrawal of heparin. Among confirmed HIT patients, 45.5% (95% CI: 28.8–62.6) experienced thrombotic events, while 50.1% (95% CI: 24.9–75.4) experienced bleeding events. Overall, 46.6% (95% CI: 30.4–63.1) of patients on ECMO with HIT died.ConclusionAccording to our study, the pooled incidence of HIT in ECMO-supported patients is 4.2%, and it contributes to adverse outcomes. Inappropriate diagnostic methods can easily lead to misdiagnosis of HIT. Further research and development of diagnostic algorithms and laboratory assays are warranted.

Modern methods of laboratory diagnostics of heparin-induced thrombocytopenia

Modern methods of laboratory diagnostics of heparin-induced thrombocytopenia

Heparin-Induced Thrombocytopenia (HIT) in the Direct Oral Anticoagulants (DOAC) Era

Heparin-induced thrombocytopenia (HIT) is an uncommon complication of heparin therapy with significant risk for severe morbidity and mortality. We investigated the role and outcome of direct oral anticoagulants (DOACs) for the management of HIT. After institutional review board (IRB) approval, a retrospective review was performed identifying all patients with positive HIT serotonin-release assays between 2020 and 2022 at two hospitals. The demographic and clinical variables were collected as follows: initial anticoagulant, dosing and indication, interval before onset of HIT, thrombotic complications, platelet nadir and recovery, direct thrombin inhibitor (DTI) and DOAC usage, and clinical outcomes. 15 patients were included in the study. 8 underwent a vascular procedure, 3 had cardiac surgery, 1 patient had both and was included in both groups, and 5 patients had either noncardiac, nonvascular surgery, or no surgery. 14 patients received unfractionated heparin (93% with therapeutic dosing), and 1 received prophylactic enoxaparin prior to diagnosis of HIT. The average time to diagnosis of HIT was 10.77days after initial anticoagulation. In-hospital mortality was 27%, related to Covid-19 infection (3/4) and intracranial hemorrhage (1/4). 40% developed thrombosis (67% venous, 33% arterial) after the diagnosis of HIT. 8/11 survivors were discharged on a DOAC. With DOAC therapy, platelet counts rebounded to an average of 265K (±104.6K) within an average of 2.3days and 364K (±273.9K) within 30days after initiation of a DOAC. No recurrent thrombosis occurred after DOAC administration and only one patient had persistent thrombocytopenia within 30days. Mortality and thrombosis (arterial and venous) are common complications in patients diagnosed with HIT. In patients who survive to discharge, DOACs are the most common discharge antithrombotic agent, with low rates of recurrent thrombosis and thrombocytopenia.

Recent advances in classic heparin-induced thrombocytopenia (HIT), autoimmune HIT, spontaneous HIT, and vaccine-induced immune thrombotic thrombocytopenia

Recent advances in classic heparin-induced thrombocytopenia (HIT), autoimmune HIT, spontaneous HIT, and vaccine-induced immune thrombotic thrombocytopenia

HEMA-Lysine-Based Cryogels for Highly Selective Heparin Neutralization.

Unfractionated heparin (UFH) and its low-molecular-weight fragments (LMWH) are widely used as anticoagulants for surgical procedures and extracorporeal blood purification therapies such as cardiovascular surgery and dialysis. The anticoagulant effect of heparin is essential for the optimal execution of extracorporeal blood circulation. However, at the end of these procedures, to avoid the risk of bleeding, it is necessary to neutralize it. Currently, the only antidote for heparin neutralization is protamine sulphate, a highly basic protein which constitutes a further source of serious side events and is ineffective in neutralizing LMWH. Furthermore, dialysis patients, due to the routine administration of heparin, often experience serious adverse effects, among which HIT (heparin-induced thrombocytopenia) is one of the most severe. For this reason, the finding of new heparin antagonists or alternative methods for heparin removal from blood is of great interest. Here, we describe the synthesis and characterization of a set of biocompatible macroporous cryogels based on poly(2-hydroxyethyl methacrylate) (pHEMA) and L-lysine with strong filtering capability and remarkable neutralization performance with regard to UFH and LMWH. These properties could enable the design and creation of a filtering device to rapidly reverse heparin, protecting patients from the harmful consequences of the anticoagulant.

Usefulness of bicarbonate-based Impella purge solution in a patient with heparin-induced thrombocytopenia: the first case report of long-term management in Japan.

Percutaneous mechanical circulatory support utilizing micro-axial flow pumps, such as the Impella group of devices, has become a life-saving technique in the treatment of refractory cardiogenic shock, with ever-increasing success rates. A 30-year-old man presented with acute decompensated heart failure and a severely reduced left ventricular ejection fraction (17%). Despite initial treatment with inotropic drugs and intra-aortic balloon pump support, his hemodynamic status remained unstable. Transition to Impella CP mechanical circulatory support was made on day 6 owing to persistently low systolic blood pressure. A significant decline in platelet count prompted suspicion of heparin-induced thrombocytopenia (HIT), later confirmed by positive platelet-activated anti-platelet factor 4/heparin antibody and a 4Ts score of 6 points. Argatroban was initially used as the purge solution, but owing to complications, a switch to Impella 5.0 and a bicarbonate-based purge solution (BBPS) was performed. Despite additional veno-arterial extracorporeal membrane oxygenation support on day 24, the patient, aiming for ventricular assist device treatment and heart transplantation, died from infection and multiple organ failure. Remarkably, the Impella CP continued functioning normally until the patient's demise, indicating stable Impella pump performance using BBPS. This case highlights the usefulness of BBPS as an alternative to conventional Impella heparin purge solution when HIT occurs.

Chemokine Oligomers and the Impact of Fondaparinux Binding.

Heparin, a widely used clinical anticoagulant, is generally well-tolerated; however, approximately 1% of patients develop heparin-induced thrombocytopenia (HIT), a serious side effect. While efforts to understand the role of chemokines in HIT development are ongoing, certain aspects remain less studied, such as the stabilization of chemokine oligomers by heparin. Here, we conducted a combined ion mobility-native mass spectrometry study to investigate the stability of chemokine oligomers and their complexes with fondaparinux, a synthetic heparin analog. Collision-induced dissociation and unfolding experiments provided clarity on the specificity and relevance of chemokine oligomers and their fondaparinux complexes with varying stoichiometries, as well as the stabilizing effects of fondaparinux binding.

Deep vein thrombosis: Implications of thromboprophylaxis after lower limb cast immobilisation.

Deep vein thrombosis is a recognised complication of lower limb cast immobilisation and post operative state immobilisation. A national survey revealed that low molecular weight heparin (LMWH) is the favoured strategy for thromboprophylaxis in the latter context. However, clinicians need to be aware of the fact that the use of LMWH might incur the risk of subsequent development of heparin-induced thrombocytopenia, with its attendant life-threatening thrombotic complications. Some of the patients who develop those complications might be admitted under the care of general physicians, hence the importance of raising awareness of this issue.

Heparin-Induced Thrombocytopenia

The extensive use of therapeutic doses of heparin to prevent thrombosis in critically ill patients with COVID-19 during the pandemic has led to an increased incidence of bleeding and heparin-induced thrombocytopenia (HIT). In addition, the introduction of the AstraZeneca and Johnson&amp;Johnson vaccines against COVID-19 into clinical practice was associated with the development of a rare but very severe, adverse thrombotic complication, vaccine-induced immune thrombotic thrombocytopenia (VITT). Thrombotic complications of VITT turned out to be similar to HIT both clinically and pathophysiologically. HIT is a potentially fatal immune-mediated adverse drug response that results in emergence of antibodies that activate platelets in the presence of heparin. HIT is characterized by a high incidence of venous and arterial thromboses, often with fatal outcomes. Currently, there are clearly defined international guidelines for the diagnosis, treatment and prevention of HIT. In case of thrombotic complications, non-heparin anticoagulants should be used.