Publications by authors named "Johanna Kremer Hovinga"
Article Synopsis
- The study evaluates the diagnostic significance of two immunoassay tests for heparin-induced thrombocytopenia (HIT) using data from 1393 patients, aiming to clarify the reliability of test results across their ranges.
- Findings reveal that while both assays correlate results to HIT diagnoses, the strength of this correlation differs, with the CLIA method showing a more pronounced increase in likelihood ratios compared to the ELISA method.
- A web-based calculator is provided to help clinicians estimate the probability of HIT based on individual test results, enhancing decision-making in patient care.
Article Synopsis
- The main treatment for immune-mediated thrombotic thrombocytopenic purpura (iTTP) in children includes therapeutic plasma exchange (TPE), corticosteroids, and rituximab, while caplacizumab is used for older children and adults, but its use for those under 12 is not officially approved.
- A case study of a 7-year-old girl with iTTP showed successful treatment with caplacizumab after adjusting the dose according to her ADAMTS13 activity, leading to significant clinical improvement and full recovery without major side effects.
- The review of existing literature revealed five cases of iTTP in children under 12 treated with caplacizumab, all showing success and safety,
Article Synopsis
- Immune-mediated thrombotic thrombocytopenic purpura (iTTP) can be life-threatening even with standard treatments, so caplacizumab was studied for its effect on preventing complications by inhibiting platelet interaction with von Willebrand factor.
- The study analyzed data from the phase 3 HERCULES trial, focusing on how caplacizumab performs in different patient subgroups based on their iTTP history, severity at the start of treatment, and initial immunosuppressive drugs.
- Results showed that caplacizumab led to quicker recovery of platelet counts, reduced complications, and improved outcomes for all patient subgroups, reinforcing its safety and effectiveness when used alongside other treatments.*
Article Synopsis
- Congenital thrombotic thrombocytopenic purpura (TTP) is caused by a severe deficiency of the ADAMTS13 enzyme, and the study compared the effectiveness of recombinant ADAMTS13 to standard therapies in preventing TTP events in patients.
- The phase 3 trial involved patients receiving either recombinant ADAMTS13 or standard therapy in alternating 6-month periods, measuring outcomes like acute TTP events, safety, and pharmacokinetics.
- Results showed no acute TTP events during recombinant ADAMTS13 prophylaxis, whereas standard therapy had one event; adverse events were lower with recombinant ADAMTS13, and no patients discontinued due to side effects from it, indicating it may be
Article Synopsis
- New analytical techniques allow for the simultaneous assessment of hundreds of proteins, helping to understand their roles in diseases like heparin-induced thrombocytopenia (HIT).
- Researchers used four panels of the Olink proximity extension assay on patients suspected of HIT to identify potential new biomarkers related to thrombus formation, inflammation, and the immune response.
- The study indicated that soluble P-selectin could serve as a significant marker for HIT, with future research planned to evaluate its diagnostic and prognostic value in patient care.
Introduction: Previous reports and meta-analyses derived from small case series reported a mortality rate of up to 40% in patients with coronavirus disease 2019 associated cerebral venous thrombosis (COVID-CVT). We assessed the clinical characteristics and outcomes in an international cohort of patients with COVID-CVT.
Patients And Methods: This was a registry study of consecutive COVID-CVT patients diagnosed between March 2020 and March 2023.
Importance: Heparin-induced thrombocytopenia (HIT) is a life-threatening condition that requires urgent diagnostic clarification. However, knowledge of the diagnostic utility of the recommended diagnostic tests is limited in clinical practice.
Objective: To evaluate the current diagnostic practice for managing the suspicion of HIT.
Article Synopsis
- The article commemorates the 100-year anniversary of Dr. Eli Moschcowitz's first description of thrombotic thrombocytopenic purpura (TTP) in 1924.
- It highlights significant advancements in understanding and treating TTP, including the introduction of plasma therapy and the discovery of the enzyme ADAMTS13.
- The review discusses the progression of treatments and diagnostic methods, illustrating how TTP has transformed from an incurable disease to a manageable condition.
Article Synopsis
- - The STASEY study assessed the safety and tolerability of emicizumab prophylaxis in hemophilia A patients with FVIII inhibitors, focusing on surgeries and postoperative bleeds in participants aged 12 and older.
- - A total of 46 participants had surgeries during the study; out of these, 37 had minor surgeries and 13 had major surgeries, with varying rates of treated postoperative bleeds associated with the surgeries and additional medications.
- - Overall, the study found that major surgeries were feasible for patients on emicizumab, with 59.1% of major surgeries resulting in postoperative bleeds, but no serious thrombotic complications were linked to the treatments used.
Article Synopsis
- * Caplacizumab, a new treatment that targets von Willebrand factor, isn't approved for use in pregnant or breastfeeding women but shows promise.
- * A case report demonstrates successful off-label use of caplacizumab during a patient's pregnancy, leading to positive outcomes without major complications.
Background: Current ADAMTS13 activity assays are important for diagnosing thrombotic thrombocytopenic purpura (TTP) but are unreliable to assay ADAMTS13 activity in animal models. The Cattle-FRETS71 assay is capable of detecting ADAMTS13 activity in plasma from multiple animal species, making it a potentially useful reagent at all stages of clinical research. The performance of Cattle-FRETS71 in TTP diagnosis is not yet known.
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- A study investigated sex differences in cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT), revealing that 77% of the patients were women.
- Women presented with more severe symptoms, such as coma and lower platelet counts, and more women underwent endovascular treatment compared to men.
- Despite these differences in presentation and treatment, the overall clinical outcomes, including complications and in-hospital mortality, were similar for both sexes.
Article Synopsis
- Adenovirus-based COVID-19 vaccines are widely used in low- and middle-income countries (LMICs), but cases of vaccine-induced cerebral venous sinus thrombosis (CVST) are rarely reported.
- A study of 228 CVST cases showed 63 from LMICs, with 51% meeting vaccine-induced immune thrombotic thrombocytopenia (VITT) criteria, compared to 62% from high-income countries (HICs).
- Although clinical manifestations were similar, in-hospital mortality was significantly lower in LMICs (23%) compared to HICs (43%), suggesting different outcomes despite similar treatment approaches.
Limited concordance of heparin/platelet factor 4 antibody assays for the diagnosis of heparin-induced thrombocytopenia: an analysis of the TORADI-HIT study.
Angelika Hammerer-Lercher Henning Nilius Jan-Dirk Studt Dimitrios A Tsakiris Andreas Greinacher Johanna A Kremer Hovinga
J Thromb Haemost
September 2023
Article Synopsis
- The study investigates the correlation between three different tests for diagnosing heparin-induced thrombocytopenia (HIT) in a cohort of 1393 patients, revealing weak correlations among the tests used.
- Only 8.5% (119 patients) were classified as HIT-positive, with notable differences in 4Ts scoring between HIT-positive and HIT-negative patients.
- The inconsistent results suggested a need for standardizing these antibody assays to improve their accuracy and comparability in clinical practice.
Aims Of The Study: Acquired haemophilia A is a rare disease with an annual incidence of 1.48 per million. Based on clinical observations, we suspect a higher incidence in southern Switzerland, and aimed at providing local epidemiological data, and clinical information regarding diagnosis, treatment and outcome in our region.
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- A 27-year-old woman with a history of severe pregnancy issues and blood clots was diagnosed with hereditary thrombotic thrombocytopenic purpura (TTP) due to a lack of the ADAMTS13 protein during her second pregnancy.
- She started receiving weekly injections of recombinant ADAMTS13 when her condition worsened and the fetus was at risk, which helped normalize her platelet count and stabilize fetal growth.
- At 37 weeks, she successfully delivered a small but healthy boy via cesarean section, and both continue to do well with ongoing treatment every two weeks.
Article Synopsis
- Diagnosing heparin-induced thrombocytopenia (HIT) is difficult at the bedside, leading to potential delays in diagnosis or overtreatment, and researchers aimed to improve this using machine-learning algorithms.
- A study with 1393 patients from multiple centers found high accuracy in diagnosing HIT using a machine-learning tool that considered various clinical and lab factors, outperforming the current methods.
- The machine-learning models significantly reduced false-negative and false-positive rates compared to the existing diagnostic algorithm, demonstrating their potential for better clinical outcomes in HIT diagnosis.
Article Synopsis
- Severe COVID-19 can increase von Willebrand factor levels and decrease ADAMTS13 activity, raising the risk of acute thrombotic thrombocytopenic purpura (TTP), especially during inflammation.
- A survey of 122 patients with hereditary TTP found that 70.5% participated, with most vaccinated; however, some faced health issues like ischemic events and myocarditis following vaccination.
- The findings suggest that the risk of acute hTTP episodes is higher with COVID-19 infection than with vaccination, indicating that hTTP patients can safely get vaccinated against SARS-CoV-2.
Article Synopsis
- Anticoagulation with heparin is commonly used for Covid-19 patients to prevent blood clots, but can lead to a serious condition called heparin-induced thrombocytopenia (HIT), characterized by low platelet counts due to specific antibodies.
- Diagnosing HIT involves assessing clinical signs and laboratory tests, but testing methods like the heparin-induced platelet activation (HIPA) test may yield false negatives, especially in Covid-19 cases.
- In a reported case, a Covid-19 patient on ECMO showed signs of HIT but initially had a negative HIPA test; reevaluation days later confirmed HIT, illustrating the need for careful clinical judgement and follow-up testing in similar situations.
Introduction: Caplacizumab demonstrated efficacy and safety in patients with immune-mediated thrombotic thrombocytopenic purpura (iTTP) in the phase 3 HERCULES trial. However, data on long-term outcomes following caplacizumab treatment are limited.
Objectives: The post-HERCULES trial (NCT02878603) evaluated long-term outcomes of patients with iTTP treated with caplacizumab in HERCULES and safety and efficacy of repeated caplacizumab use.
Article Synopsis
- Cerebral venous thrombosis (CVT) associated with vaccine-induced immune thrombotic thrombocytopenia (VITT) has high in-hospital mortality, but outcomes are better for those who survive hospitalization after SARS-CoV-2 vaccination.
- In a study of 107 CVT-VITT cases, 40% died during initial hospitalization, but of the 60 patients who survived, 88% achieved functional independence after a median follow-up of 150 days.
- No new thrombotic events were reported post-discharge, and only one case of major bleeding occurred, indicating a generally positive prognosis for survivors.
Article Synopsis
- - The study investigated how well physicians follow evidence-based guidelines for preventing recurrent venous thromboembolism (VTE) in a large group of patients, finding an adherence rate of only 36.1%.
- - Factors influencing adherence included patient age over 50, male sex, and certain clinical characteristics like unprovoked VTE and multiple incidents, but non-adherence was not linked to higher mortality or costs.
- - The research emphasizes the necessity of improving the implementation of evidence-based guidelines in clinical practice, as a low adherence rate could impact patient care quality.
Thrombophilia Impact on Treatment Decisions, Subsequent Venous or Arterial Thrombosis and Pregnancy-Related Morbidity: A Retrospective Single-Center Cohort Study.
Kristina Vrotniakaite-Bajerciene Tobias Tritschler Katarzyna Aleksandra Jalowiec Helen Broughton Justine Brodard Johanna Anna Kremer Hovinga
J Clin Med
July 2022
Article Synopsis
- - Thrombophilia testing's role in treatment decisions is unclear, leading to ongoing debates about its clinical usefulness.
- - A study involving 3550 patients at Bern University Hospital revealed that about 34% had thrombophilia, with only a small percentage influencing anticoagulation decisions.
- - Those with high-risk thrombophilia faced greater risks of venous thromboembolic events and pregnancy-related issues, highlighting limited benefits of testing in guiding treatments.
Article Synopsis
- The study investigates the treatment of cerebral venous thrombosis (CVT) caused by vaccine-induced immune thrombotic thrombocytopenia (VITT) following adenovirus-based COVID-19 vaccinations.
- Researchers analyzed data from 99 patients across 17 countries to assess adherence to recommended treatments, including immunomodulation and avoiding certain anticoagulants.
- While overall adherence to these treatment guidelines did not significantly impact mortality, patients who received immunomodulation showed lower mortality rates compared to those who did not.
Introduction: An increasing number of case reports have associated vaccinations against coronavirus disease 2019 (COVID-19) with immune-mediated thrombotic thrombocytopenic purpura (iTTP), a very rare but potentially life-threatening thrombotic microangiopathy, which leads to ischemic organ dysfunction. Thrombus formation in iTTP is related to a severe deficiency of the specific von Willebrand-factor-cleaving protease ADAMTS13 due to ADAMTS13 autoantibodies.
Methods: We present a case of iTTP following exposure to the mRNA-based COVID-19 vaccine BNT162b2 (Comirnaty, Pfizer-BioNTech).