Thrombotic thrombocytopenic purpura

Effectiveness and safety of caplacizumab in acquired thrombotic thrombocytopenic purpura: health technology assessment and classification according to the methodology established in Colombia

OBJECTIVES

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare hematological disease whose clinical management includes caplacizumab along with plasma exchange and immunosuppression, according to international guidelines. Caplacizumab has been available in Colombia since 2022. This study seeks to determine the therapeutic classification of caplacizumab according to the methodology of the Instituto de Evaluación Tecnológica en Salud.

METHODS

The classification was carried out through a deliberative process following the modified Delphi technique, with a panel of experts, made up of four hemato-oncologists, a pharmaceutical chemist, and a patient. The results of effectiveness and safety obtained through a systematic review, therapeutic thresholds (clinical significance), and degree of acceptability (willingness to use the technology) were used for the classification.

RESULTS

Fourteen effectiveness and safety outcomes were submitted for the classification process. Caplacizumab showed clinical significance for some effectiveness outcomes, was not considered inferior in terms of safety, and displayed acceptability of use. Through consensus, the panel determined that caplacizumab plus the standard regimen is superior to the standard regimen in terms of treatment response and composite outcome, and no different for the other effectiveness and safety outcomes. Likewise, in overall terms, the panel determined that caplacizumab together with the standard regimen is superior to the standard regimen.

CONCLUSION

Treatment with caplacizumab together with the standard regimen was considered superior to the standard regimen for the treatment of patients with aTTP, as it showed clinically significant benefits in critical outcomes for decision making, and a safety profile no different to its comparator.

Self-limited thrombotic thrombocytopenic purpura

Our team is presenting a patient who is a 57-year -old woman with a past medical history of cerebral vascular accident. The patient presented to the emergency department with symptoms of fever, right upper quadrant pain, and emesis. Initial diagnostic studies revealed thrombocytopenia with acute kidney injury, fever, and leukocytosis. After initiation of treatment for sepsis, the patient developed a hemolytic anemia, which resolved with administration of methylprednisolone. Labs subsequently revealed ADAMTS-13 activity of 4% with positive inhibitor, which confirmed the diagnosis of thrombotic thrombocytopenic purpura (TTP) after the patient's discharge. On retrospective analysis, the case represents a unique and rapid clinical recovery from TTP without administration of therapeutic plasma exchange, rituximab, or caplacizumab.

Assessing Biomarkers in Viral Infection

Current biomarkers to assess the risk of complications of both acute and chronic viral infection are suboptimal. Prevalent viral infections like human immunodeficiency virus (HIV), hepatitis B and C virus, herpes viruses, and, more recently, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may be associated with significant sequelae including the risk of cardiovascular disease, other end-organ diseases, and malignancies. This review considers some biomarkers which have been investigated in diagnosis and prognosis of key viral infections including inflammatory cytokines, markers of endothelial dysfunction and activation and coagulation, and the role that more conventional diagnostic markers, such as C-reactive protein and procalcitonin, can play in predicting these secondary complications, as markers of severity and to distinguish viral and bacterial infection. Although many of these are still only available in the research setting, these markers show promise for incorporation in diagnostic algorithms which may assist to predict adverse outcomes and to guide therapy.

HIV-associated thrombotic thrombocytopenic purpura (HIV-TTP): A practical guide and review of the literature

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), a serious thrombotic microangiopathy (TMA), is prevalent in the South African HIV-infected population. The exact pathogenesis of HIV-associated TTP (HIV-TTP) is however still unclear with diagnostic and therapeutic inconsistancies.

METHODS

A systematic review of the published literature regarding HIV-TTP was performed.

RESULTS

HIV-TTP is still associated with significant morbidity and mortality in Africa despite the availability of anti-retroviral therpy (ART). Diagnosis of HIV-TTP requires the presence of a micro-angiopathic haemolytic anaemia with significant red blood cell schistocytes and thrombocytopenia in the absence of another TMA but background activation of the coagulation system and inflammation in HIV infected people can result in diagnostic anbiguity. Plasma therapy in the form of infusion or exchange is successful but expensive, associated with side-effects and not widely available. Adjuvant immunosuppression therapy may of benefit in patients with HIV-TTP and ART must always be optimised. Endothelial dysfunction caused by chronic inflammation and complement activation most likely contributes to the development of HIV-TTP.

CONCLUSION

The role of adjuvant immunomodulating therpy, the therapeutic targets and pathogenic contribution from endothelial dysfunction in HIV-TTP requires further investigation.

Rituximab for acute plasma-refractory thrombotic thrombocytopenic purpura: A case report

Introduction and importance

Thrombotic thrombocytopenic purpura (TTP) is a rare disease due to deficiency of ADAMTS13 which can present with anemia and thrombocytopenia. The study highlights the role of PLASMIC score in diagnosis and rituximab in the treatment of this condition.

Case presentation

Herein, we report a case of 38 years old female who had presented with fever, irritability, and altered sensorium. On investigations, she had hemolytic anemia, and thrombocytopenia with peripheral blood smear showing occasional schistocytes and managed with steroids and plasma exchange. As her platelet, LDH, and a few other lab parameters failed to normalize and met the criteria of refractory TTP, hence she was started on 5 cycles of rituximab and her condition improved.

Clinical discussion

Thrombotic thrombocytopenic purpura can be presumed based upon PLASMIC score where if the score is 5 or more while ADAMTS13 assay is required for confirmation. It is a life-threatening condition where treatment options include therapeutic plasma exchange (PEX), glucocorticoids, Rituximab, and caplacizumab. Rituximab is considered particularly in refractory cases.

Conclusion

Thrombotic thrombocytopenic purpura can lead to complications due to low platelet counts. Hence, early diagnosis and intervention are crucial to prevent such complications.

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Thrombotic thrombocytopenic purpura is a rare disease due to deficiency of ADAMTS13 where patients can present with anemia and thrombocytopenia.

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PLASMIC score can be used for presumptive diagnosis of this condition while ADAMTS13 assay is required for confirmation.

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Steroids and plasma exchange are the preferred treatment.

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In case of refractory cases, Rituximab can play a role to treat as well as prevent recurrence.

Unmet needs in the management of immune-mediated thrombotic thrombocytopenic purpura and the potential role of caplacizumab in the UK-A modified-Delphi study

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is an ultra-rare, blood-clotting disorder. Management historically relies on plasma exchange and immunosuppression; however, a 10%-20% mortality rate is still observed. Caplacizumab binds to von Willebrand factor and directly inhibits platelet aggregation; addition of caplacizumab to historical treatment induced faster resolution of platelet count in clinical trials. In 2019, a modified-Delphi study was conducted with UK experts, to develop consensus statements on management of acute TTP and the potential role of caplacizumab. An unmet need was acknowledged, and areas requiring improvement included: time to diagnosis and treatment initiation; time to platelet normalisation (TTPN) during which patients remain at risk of persistent microvascular thrombosis and organ damage; and incidence of subsequent exacerbations and relapses. Caplacizumab addition to historical treatment within 24 h (after confirmatory ADAMTS13 [a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13] assay) would significantly reduce TTPN, which directly influences acute outcomes, with manageable bleeding risk and reduced burden on healthcare systems. Expert panellists agree that poor outcomes in iTTP largely result from failure to rapidly control microvascular thrombosis. Use of caplacizumab during a confirmed iTTP episode could offer better control and may plausibly improve long-term outcomes. However, this consensus must be validated with further clinical trials and robust real-world evidence.

Concurrent thrombotic thrombocytopenic purpura and Guillian Barre Syndrome post infectious diarrhea

Thrombotic thrombocytopenic purpura (TTP) characterized by microangiopathic hemolytic anemia, thrombocytopenia and signs of organ dysfunction, is due to either congenital or acquired deficiency of ADAMTS13 gene. Guillian Barre Syndrome (GBS) is a post infectious disorder, most commonly associated with C. jejuni infection. Both conditions have high mortality if untreated and have been reported with other comorbid conditions. We found only one case report of sequential TTP and GBS. However, we report the first case of concurrent TTP and GBS infection in a 22 years old female after bloody diarrhea, successfully managed by symptomatic treatment, sessions of plasmapheresis, and hemodialysis. TTP and GBS have both been associated with bacterial and viral infections, and antibodies formed against them may result in cross reactivity due to molecular mimicry. It is suggested although unproven that in such cases, patients likely developed cross-reactivity against both platelet and neurogenic glycoproteins (the linking antigen) following predisposing infection.

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TTP is due to deficiency of ADAMTS13, defined by microangiopathic hemolytic anemia, thrombocytopenia, and organ dysfunction.

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GBS is post-infectious disease, defined by progressive symmetric weakness of limbs, diminished or absent reflexes, and paresthesia.

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Both GBS and TTP have been reported with bacterial and viral infection including C. jejuni.

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In concurrent cases molecular mimicry and aberrant immune response is a plausible explanation.

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Such patients likely developed cross-reactivity against both platelet and neurogenic glycoproteins following an infection.

Acquired Thrombotic Thrombocytopenic Purpura Following Inactivated COVID-19 Vaccines: Two Case Reports and a Short Literature Review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in December 2019, causing millions of deaths all over the world, and the lack of specific treatment for severe forms of coronavirus disease 2019 (COVID-19) have led to the development of vaccines in record time, increasing the risk of vaccine safety issues. Recently, several cases of thrombotic thrombocytopenic purpura (TTP) have been reported following COVID-19 vaccination. TTP is a rare disease characterized by thrombocytopenia, microangiopathic hemolytic anemia and ischemic end-organ lesions. It can be either congenital or acquired. Various events such as viral infections, medication, pregnancy, malignancies, and vaccinations may cause TTP. Here, we report two cases of acquired TTP following Sinopharm COVID-19 vaccine (BBIBP-CorV) and Sinovac COVID-19 vaccine (CoronaVac). Diagnosis was based on clinical presentation and confirmed with a severe reduction in the activity of von Willebrand factor-cleaving protease ADAMTS-13 and the presence of inhibitory autoantibodies. The two patients were successfully treated with corticosteroids, plasma exchange therapy and rituximab in the acute phase. In the literature, the reported cases of TTP induced by COVID-19 vaccination occurred after Adenoviral Vector DNA- and SARS-CoV-2 mRNA-Based COVID-19 vaccines. To the best of our knowledge, this is the first report of acquired TTP after inactivated virus COVID-19 vaccination.

Case Report: Systemic lupus erythematous associated with thrombotic thrombocytopenic purpura, a diagnostic challenge

Thrombotic thrombocytopenic purpura (TTP) is an uncommon microangiopathic disease and sometimes is associated with systemic lupus erythematous (SLE). However, this probable causal relationship has not been completely proven. The diagnostic differentiation of both diseases is difficult in the first instance because they share similar characteristics that may overlap. We present a case of a 32-year-old woman with antecedents of epileptic seizures since she was 12 years old. The patient was admitted to the emergency room with a clinical picture of headaches, fever, paleness in the skin and mucosa, confused state, paresthesia, and transient spasticity of the extremities. The laboratory results revealed direct Coombs negative hemolytic anemia, severe thrombocytopenia, significant elevation of lactate dehydrogenase, and presence of schistocytes ++ in the peripheral film. In addition, positive antinuclear antibodies and positive anti-native DNA in titers of 1/320 and 1/160, respectively, were found. Urinalysis showed that serum creatinine was in normal range. Because of limited hospital resources, ADAMTS13 was not evaluated. However, based on clinical, hematological, and biochemical findings, we concluded that it was a case of TTP associated with SLE and indicated treatment with plasmapheresis and methylprednisolone pulses, obtaining a satisfactory response (normalization of biomarker levels, health condition) after the second session of plasmapheresis. Diagnosis of both SLE and TTP is often difficult to achieve; however, adequate correlation of clinical manifestations and laboratory tests, along with the help of partial therapeutic interventions, may lead to good clinical response.

Hypertensive Emergency as the Initial Presentation of Acquired Thrombotic Thrombocytopenic Purpura: A Case Report

Thrombotic thrombocytopenic purpura (TTP) is a type of thrombotic microangiopathy (TMA) related to a deficiency of ADAMTS13 protein, which could lead to fatal outcomes. TTP presents a vast array of symptoms, making its diagnosis a challenge to physicians. In this report, we discuss the case of an 80-year-old male who presented with abdominal pain and hypertension with underlying severe thrombocytopenia and hemolysis. Although his presentation could also be secondary to malignant hypertension, he was promptly diagnosed with TTP based on these findings. TTP is a hematologic emergency, and it should be kept in the differential diagnosis when a patient presents with thrombocytopenia and hemolysis with or without accompanying symptoms.

[Treatment of thrombotic thrombocytopenic purpura]

The review discusses approaches to treatment of congenital thrombotic thrombocytopenic purpura (TTP) or Upshaw-Schulman syndrome. In congenital TTP, plasma transfusions are sufficient. Such treatment options as plasma exchange, administration of clotting factor VIII concentrate, recombinant ADAMTS13, are also used. Separately discussed issues of management of patients with TTP during pregnancy, and pediatric patients with TTP.

An Imperfect Marker: SLE and TTP-Like MAHA Without Low ADAMTS13

Thrombotic thrombocytopenic purpura (TTP) is a potentially fatal condition that can be challenging for clinicians to identify in the setting of autoimmune diseases such as systemic lupus erythematosus (SLE). This difficulty is compounded when a patient presents with all of the clinical signs of a TTP-like microangiopathy, however, with near normal ADAMTS13. This case report describes a 44-year-old female with a history of SLE who was hospitalized with acute on chronic anemia, thrombocytopenia, and altered mental status. The patient's ADAMTS13 was mildly low; hence, she was initially treated for SLE-associated immune thrombocytopenic purpura without any clinical response. The patient then underwent plasmapheresis (plasma exchange [PLEX]) for treatment of a suspected TTP-like microangiopathy. She responded to PLEX with improvement in her platelet count and mental status. This case illustrates the importance of considering TTP-like microangiopathic hemolytic anemia in the differential for patients with a history of SLE presenting with clinical signs of TTP even in the setting of near-normal ADAMTS13, thus warranting prompt treatment with PLEX.

Parvovirus Infection and Thrombotic Thrombocytopenic Purpura in an Adult Patient With Sickle Cell Beta-Thalassemia

Parvovirus infection and thrombotic thrombocytopenic purpura (TTP) are rare manifestations in adults with sickle cell beta-thalassemia. Due to the lack of a clear demarcation between the complications related to sickle cell disease (SCD) and TTP, the diagnosis is often challenging. The treatment requirements for both these entities are divergent and complicated, thus necessitating a careful plan of action during atypical presentations. Here we present a case of a 22-year-old woman during the peripartum period with fever, generalized body aches, and large joint pains that soon evolved into labor. The patient’s history was suggestive of an undiagnosed and inherited blood disorder. The presentation of aplastic crisis-splenic sequestration during early adulthood is atypical for the SCD course in general populations. Moreover, as the patient’s clinical status deteriorated with blood transfusion, the diagnosis and management of a sickle cell crisis event and TTP added to the dilemma in the presence of non-classic parvovirus infection. Though the causation of TTP due to SCD-parvovirus infection is questionable, the treatment of the baseline sickle cell crisis with the novel supportive measures resolved the underlying complications in our patient, suggesting the causal effect. As a result of this, we emphasize the importance of being vigilant about such atypical presentations to avoid delays in diagnosis and treatment of such life-threatening emergencies like TTP.

[Treatment of thrombotic thrombocytopenic purpura]

The review discusses approaches to treatment of acquired thrombotic thrombocytopenic purpuгa (aTTP). In patients with aTTP plasma exchanges, glucocorticosteroids allow to stop an acute attack of TTP, and use of rituximab allows to achieve remission. In recent years, caplacizumab has been used. Treatment options such as cyclosporin A, bortezomib, splenectomy, N-acetylcysteine, recombinant ADAMTS13 are also described. Separately discussed issues of management of patients with TTP during pregnancy, and pediatric patients with TTP.

Clinical pharmacology of caplacizumab for the treatment of patients with acquired thrombotic thrombocytopenic purpura

Introduction: Caplacizumab is a humanized anti-von Willebrand Factor (vWF) Nanobody® for the treatment of acquired Thrombotic Thrombocytopenic Purpura (aTTP). Caplacizumab targets the A1-domain of vWF, inhibiting the interaction between vWF and platelets. Clinical studies conducted in aTTP patients confirmed the rapid and sustained complete suppression of the vWF activity using an initial intravenous dose of 10 mg, and a maintenance subcutaneous 10 mg daily dosing regimen, with corresponding favorable efficacy and safety profiles. Areas covered: The pharmacokinetics of caplacizumab are non-linear, characterized by a target-mediated disposition and the exposure is dependent upon drug and target concentration over time. The pharmacokinetics of caplacizumab are predictable when considering the turn-over of the circulating vWF and its modulation by the drug over time. Renal and hepatic impairment are not expected to influence the exposure to the drug, and no direct or indirect drug-drug pharmacokinetic interactions are anticipated based on the mechanism of action and the specificity of the pharmacodynamic effect of caplacizumab. Expert opinion: Caplacizumab prevents the interaction between vWF and platelets, offering a direct and rapid therapeutic intervention to stop microthrombosis. The combination of caplacizumab with plasma exchange and immunosuppression represents an important, potentially life-saving advance in the treatment of aTTP patients.

[Atypical intracerebral hemorrhage-etiology and acute management]

Acute management as well as establishing the etiology of an intracerebral hemorrhage is still a challenge for clinicians. The location of the intracerebral hemorrhage alone should not be used to determine the cause because atypically located hemorrhages can be caused by long-standing arterial hypertension and typically located hemorrhages can occur due to non-hypertensive causes. Besides discussing the classification of intracerebral hemorrhages, this article focuses on a diagnostic algorithm as well as the presentation of potential (rarer) causes of non-traumatic intracerebral hemorrhages. Furthermore, the acute treatment of intracerebral hemorrhage with respect to recent data on blood pressure management as well as the management of bleeding under oral anticoagulant treatment are described.