Depression and cognitive impairment following recovery from thrombotic thrombocytopenic purpura

Multicenter Prospective Pilot Study Identifying Thrombomodulin as a Potential Biomarker for Neurocognitive Outcomes in Immune Thrombotic Thrombocytopenic Purpura

Background/Objectives: Immune thrombotic thrombocytopenic purpura (iTTP) is a rare, chronically relapsing disorder that causes life-threatening thrombotic microangiopathy. Many survivors in clinical remission show evidence of ongoing silent cerebral infarction and neurocognitive deficits. Prospective longitudinal studies of this population are needed to acquire a complete understanding of the mechanism behind this ongoing neurologic injury. We aimed to assess the feasibility of a multicenter prospective study of neuropsychological and cognitive function in iTTP survivors in remission and examine novel biomarkers. Methods: We aimed to enroll 50 iTTP patients across three USTMA consortium sites between 2019 and 2022 in a 24-month longitudinal study. Clinical, cognitive, and biomarker assessments, including ADAMTS13 activity, were performed. Results: Despite the COVID-19 pandemic, we enrolled 38 subjects, and 31 (81.6%) completed closeout evaluations at 24 months. Upon the participants' enrollment in the study, we confirmed previous findings, including high rates of moderate to severe neurocognitive and psychiatric sequelae (anxiety, 47%; depression, 45%; and headaches, 55%). Changes in cognitive function were measurable and included decreased immediate memory and visuospatial abilities. Over this two-year study, we did not see a significant change in neurocognitive findings. There was no association between cognitive function and ADAMTS13 activity; however, we found that the level of soluble thrombomodulin (CD141) was significantly correlated with cognitive impairment. Conclusions: We conclude that a more extensive study is feasible, and at least 5-10 years may be required to detect trends in neurocognitive function. Soluble thrombomodulin is a promising biomarker for cognitive impairment in survivors of iTTP, and it is worthy of additional study.

[Management of congenital thrombotic thrombocytopenic purpura in the era of recombinant ADAMTS13 protein: Recommendations from the Reference Center for Thrombotic Microangiopathies (CNR-MAT)]

Thrombotic Thrombocytopenic Purpura (TTP) is a rare disease characterized by a severe deficiency of ADAMTS13, the specific protease that cleaves von Willebrand factor. The congenital form of TTP (cTTP) results from pathogenic variants of the ADAMTS13 gene. cTTP has two peaks of incidence: one in childhood and the other in adulthood, mainly in an obstetric context. The treatment of cTTP relies on ADAMTS13 replacement therapy for prophylaxis or on-demand, depending on the evolving nature of the disease, along with the management of cardiovascular risk factors. The historical treatment for cTTP has been substitution plasma therapy. Since 2017, a recombinant human ADAMTS13 protein (rhADAMTS13) has been evaluated in cTTP in international clinical trials. The rhADAMTS13 protein, intravenous infusion used for prophylaxis or on-demand, has been granted early access or compassionate use in cTTP in France in 2024. The objective of this document is to establish academic recommendations for the use of rhADAMTS13 in cTTP.

Initial US tertiary health care system experience using caplacizumab in patients with immune thrombotic thrombocytopenic purpura

Several international registries have reported on the efficacy of caplacizumab for the treatment of immune thrombotic thrombocytopenic purpura (iTTP). Similar real-world data from the United States (US) are limited. In this single center retrospective study, we sought to describe caplacizumab prescribing patterns and review clinical outcomes for US patients with iTTP. Subjects were eligible for inclusion if they were diagnosed with acute iTTP and received care at University of Pittsburgh Medical Center-affiliated hospitals from 2012 to 2022. Subjects were divided into an historical cohort who received standard of care therapy alone, and early and late administration cohorts (EA and LA) who received caplacizumab within and greater than 72 h of admission, respectively, plus standard of care. Clinical data were collected from the electronic record. Thirty-two subjects were included: 16 historical, 12 EA, and 4 LA subjects. Refractoriness occurred more frequently in the LA and historical cohorts as compared to the EA cohort (4 (100%) vs. 6 (38%) vs. 3 (25%), p = 0.02). The LA cohort also experienced longer lengths of hospital stay, required more TPE procedures, and were exposed to the greatest amount of donor plasma (p < 0.05 for all) as compared to the other cohorts. Time to platelet count normalization was longest in the LA cohort (p = 0.013). There were no significant between-group differences in bleeding events. Because we are unable to predict which patients will develop refractoriness, we recommend frontline administration of caplacizumab to all patients with iTTP.

The hemostatic system in chronic brain diseases: A new challenging frontier?

Neurological diseases (ND), including neurodegenerative diseases (NDD) and psychiatric disorders (PD), present a significant public health challenge, ranking third in Europe for disability and premature death, following cardiovascular diseases and cancers. In 2017, approximately 540 million cases of ND were reported among Europe's 925 million people, with strokes, dementia, and headaches being most prevalent. Nowadays, more and more evidence highlight the hemostasis critical role in cerebral homeostasis and vascular events. Indeed, hemostasis, thrombosis, and brain abnormalities contributing to ND form a complex and poorly understood equilibrium. Alterations in vascular biology, particularly involving the blood-brain barrier, are implicated in ND, especially dementia, and PD. While the roles of key coagulation players such as thrombin and fibrinogen are established, the roles of other hemostasis components are less clear. Moreover, the involvement of these elements in psychiatric disease pathogenesis is virtually unstudied, except in specific pathological models such as antiphospholipid syndrome. Advanced imaging techniques, primarily functional magnetic resonance imaging and its derivatives like diffusion tensor imaging, have been developed to study brain areas affected by ND and to improve our understanding of the pathophysiology of these diseases. This literature review aims to clarify the current understanding of the connections between hemostasis, thrombosis, and neurological diseases, as well as explore potential future diagnostic and therapeutic strategies.

A Systematic Review of the Epidemiology and Disease Burden of Congenital and Immune-Mediated Thrombotic Thrombocytopenic Purpura

Congenital (cTTP) and immune-mediated (iTTP) thrombotic thrombocytopenic purpura are serious and rare clotting disorders resulting from a deficiency in the ADAMTS13 enzyme. A systematic review was conducted using the Ovid® MEDLINE & Embase databases to synthesize the epidemiology and burden of cTTP and iTTP worldwide (from January 1, 2010, to February 6, 2020, with an update that covered the period January 1, 2020-February 11, 2022). Outcomes of interest were incidence and prevalence of TTP, incidence of acute episodes, mortality, burden of illness (eg complications, healthcare utilization, patient-reported outcomes) and disease management. A total of 221 eligible observational studies were included. The incidence rate of acute episodes ranged from 0.19-0.35 person-years in adult patients with cTTP, and 1.81-3.93 per million persons per year for iTTP in the general population. Triggers of acute episodes were similar for cTTP and iTTP, with pregnancy and infection the most commonly observed. Exacerbation in patients with iTTP varied widely, ranging from 2.4-63.1%. All-cause mortality was observed in 0-13.4% of patients with cTTP, across studies and follow-up periods, and in 1.1% (median follow-up: 0.4 years) to 18.8% (1 year) of patients with iTTP during acute episodes. Cardiovascular, renal, and neurological disease were common complications. TTP also led to work disturbances, feelings of anxiety and depression, and general activity impairment. TTP treatment regimens used were generally reflective of current treatment guidelines. The evidence identified describes a high patient burden, highlighting the need for effective treatment regimens leading to improvements in outcomes. Considerable evidence gaps exist, particularly for disease epidemiology, patient-reported outcomes, costs of disease management, and associated healthcare resource utilization. This review may help increase disease awareness and highlights the need for additional real-world studies, particularly in geographical regions outside the United States and Western Europe.

Antiphospholipid Antibodies in Mental Disorders

Thrombotic events striking the central nervous system are clinical criteria for the antiphospholipid syndrome (APS). Besides these, neuropsychiatric non-APS criteria manifestations are increasingly described in patients with persistently positive antiphospholipid antibodies (aPL). Among these are psychiatric manifestations. Animal models mainly describe hyperactive behavior and anxiety associated with hippocampal abnormalities. Cases of associations with psychosis, mood disorders, bipolarity, anxiety, obsessive-compulsive behavior, and depression have been reported but are still rare. Systematic human clinical association studies are concordant with a risk of psychosis, depression (simple to major), and anxiety disorders, but these are limited and of inconstant methodological quality. Brain imaging in patients, also insufficiently investigated, shows early signs of hypoperfusion and of subtle diffuse white matter changes compatible with an alteration of the axonal structure and changes in the myelin sheath. Direct interactions of aPL with the brain cells, both on cell lines and on animal and human brain biopsies, targeting both glial cells, astrocytes, and neurons, can be demonstrated. These clusters of arguments make the association between psychiatric diseases and aPL increasingly plausible. However, a considerable amount of clinical research must still be performed in accordance with the highest standards of methodological quality. The therapeutic management of this association, in terms of both prevention and cure, currently remains unresolved.

Long-term health-related quality of life and mental health in patients with immune thrombotic thrombocytopenic purpura

Immune thrombotic thrombocytopenic purpura (iTTP) is a rare and potentially life-threatening disorder. Treatment advances have lowered morbidity rates, but past acute events can still cause long-term consequences, reducing health-related quality of life (HRQoL) and determining cognitive impairment, anxiety, and depression. We aimed to investigate these aspects and the role of caplacizumab and rituximab: 39 patients were evaluated using the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), the FACIT-Fatigue, the Hospital Anxiety and Depression Scale, and the Functional Assessment in Cancer Therapy-Cognitive Function questionnaires. The median age at study inclusion was 50 years (IQR 38-60), and the median follow-up from diagnosis was 97 months (IQR 14-182); 82% of patients were female, and 36% had one or more recurrences. Caplacizumab was administered in 16 patients (41%), as well as rituximab. ITTP patients reported lower physical and mental HRQoL scores than the general population. No differences in physical or mental domains were observed between patients treated or not with caplacizumab, while those who received rituximab reported lower scores in mental health. Neurological impairment at diagnosis correlated with worse fatigue. The majority of patients (72%) reported anxiety or depression (82%). ITTP had a significant impact on the long-term cognitive function, fatigue, depression, and anxiety levels of patients, with a negative effect on their HRQoL. Our findings underscore the need to pay special attention to patients' long-term physical and mental health, regardless of the medical treatments received.

The TTP specialist nurse: an advocate for patients and professionals

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening blood disorder with a mortality rate of over 90% if left untreated, multiple long-term complications for survivors, and a lifelong risk of relapse. There is a valuable role for the clinical nurse specialist in both the acute and long-term care of patients with TTP. Historically part of the team caring for patients with TTP, specialist nurses have played a vital role in co-ordinating and facilitating treatment for patients, promoting patient advocacy, supporting continuous service improvement, and delivering education to the wider clinical team to disseminate best practice. In 2021, the TTP specialist nurse role was commissioned within the NHS England National Service Framework for TTP Specialist Centres. This article aims to appraise the role of the TTP specialist nurse and share the multidimensional reach of the role in achieving better outcomes for patients with TTP.

Cognitive decline in thrombotic thrombocytopenic purpura survivors: The role of white matter health as assessed by MRI

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare condition caused by severe ADAMTS13 deficiency, leading to platelet aggregation and thrombosis. Despite treatment, patients are prone to cognitive impairment and depression. We investigated brain changes in iTTP patients during remission using advanced magnetic resonance imaging (MRI) techniques, correlating these changes with mood and neurocognitive tests. Twenty iTTP patients in remission (30 days post-haematological remission) were compared with six healthy controls. MRI scans, including standard and specialized sequences, were conducted to assess white matter health. Increased T1 relaxation times were found in the cingulate cortex (p < 0.05), and elevated T2 relaxation times were observed in the cingulate cortex, frontal, parietal and temporal lobes (p < 0.05). Pathological changes in these areas are correlated with impaired cognitive and depressive scores in concentration, short-term memory and verbal memory. This study highlights persistent white matter damage in iTTP patients, potentially contributing to depression and cognitive impairment. Key regions affected include the frontal lobe and cingulate cortex. These findings have significant implications for the acute and long-term management of iTTP, suggesting a need for re-evaluation of treatment approaches during both active phases and remission. Further research is warranted to enhance our understanding of these complexities.

A British Society for Haematology Guideline: Diagnosis and management of thrombotic thrombocytopenic purpura and thrombotic microangiopathies

The objective of this guideline is to provide healthcare professionals with clear, up-to-date and practical guidance on the management of thrombotic thrombocytopenic purpura (TTP) and related thrombotic microangiopathies (TMAs), including complement-mediated haemolytic uraemic syndrome (CM HUS); these are defined by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and small vessel thrombosis. Within England, all TTP cases should be managed within designated regional centres as per NHSE commissioning for highly specialised services.

Immune thrombotic thrombocytopenic purpura: pathogenesis and novel therapies: a narrative review

Background and Objectives

Immune thrombotic thrombocytopenic purpura (iTTP) is a rare, but potentially fatal blood disease, resulting from autoantibodies against A Disintegrin and Metalloprotease with ThromboSpondin Type 1 Repeats, 13 (ADAMTS13). While major progress has been made in past decades concerning early diagnosis and management of iTTP, the mechanisms underlying the formation and the mechanism of action of these autoantibodies against ADMATS13 are still unknown. This review will provide a narrative review of pathogenesis and novel therapeutics of iTTP.

Methods

We did PubMed literature search using a combination of thrombotic thrombocytopenic purpura and treatment or pathogenesis from 1955 to November 2022. A total of 4,767 articles with full text were found and only relevant articles in English were further reviewed and summarized.

Key Content and Findings

We found that the primary mechanism underlying severe ADAMTS13 deficiency in patients with iTTP is autoantibody-mediated inhibition and/or accelerated clearance of ADAMTS13 metalloprotease. Other factors including allosteric regulation and post-translational modifications (i.e., glycosylation and citrullination, and arginine methylation, etc.) may affect ADAMTS13 secretion and function and also contribute to the pathogenesis of iTTP. The standard of care for iTTP today consists of therapeutic plasma exchange, anti-von Willebrand factor (vWF) caplacizumab, and immunosuppressives (e.g., corticosteroids and rituximab), known as the triple therapy, which has significantly reduced exacerbation and mortality rates.

Conclusions

We hope that the information provided in the review article helps better understand the pathogenesis of iTTP, which may guide design novel and more effective therapeutics for this potentially fatal disorder.

Patient-Reported Outcome Measures in Patients with Thrombotic Thrombocytopenic Purpura: A Systematic Review of the Literature

Health-related quality of life (HRQoL) impacts of thrombotic thrombocytopenic purpura (TTP) have been captured in clinical studies using patient-reported outcome (PRO) measures (PROMs) that are validated for other diseases. However, the validity evidence to support the use of existing PROMs in patients with TTP is unknown. In a systematic review of the literature, including studies of adults and children with TTP, we assessed the validity evidence for use of PROMs in clinical research and clinical practice, characterized HRQoL, described the integration of PROMs in clinical practice and evaluated PRO scores for patients with TTP compared with reference populations. From an initial 4518 studies, we identified 14 studies using 16 PROMs to assess general HRQoL domains in patients in remission. No identified studies assessed the validity of PROMs for the context of use of TTP and no studies described PROM integration into TTP clinical practice or evaluated PROMs that were specific for patients with TTP. Moreover, PRO scores were worse in patients with TTP compared with reference populations and other chronic conditions. We conclude that, in patients with TTP, PROMs pick up on important patient experiences not captured by clinical outcomes at present. There is, therefore, a need for studies that assess the validity of existing PROMs in patients with TTP to determine if TTP-specific PROMs specific to patients with TTP should be developed.

Silent cerebral infarction during immune TTP remission: prevalence, predictors, and impact on cognition

Immune thrombotic thrombocytopenic purpura (iTTP) survivors have increased risk of cardiovascular disease, including strokes, and report persistent cognitive difficulties during remission. We conducted this prospective study involving iTTP survivors during clinical remission to determine the prevalence of silent cerebral infarction (SCI), defined as magnetic resonance imaging (MRI) evidence of brain infarction without corresponding overt neurodeficits. We also tested the hypothesis that SCI is associated with cognitive impairment, assessed using the National Institutes of Health ToolBox Cognition Battery. For cognitive assessments, we used fully corrected T scores adjusted for age, sex, race, and education. Based on the diagnostic and statistical manual 5 criteria, we defined mild and major cognitive impairment as T scores with a 1 or 2 standard deviation (SD) and >2 SD below the mean on at least 1 test, respectively. Forty-two patients were enrolled, with 36 completing MRIs. SCI was present in 50% of the patients (18), of which 8 (44.4%) had prior overt stroke including during acute iTTP. Patients with SCI had higher rates of cognitive impairment (66.7% vs 27.7%; P = .026), including major cognitive impairment (50% vs 5.6%; P = .010). In separate logistic regression models, SCI was associated with any (mild or major) cognitive impairment (odds ratio [OR] 10.5 [95% confidence interval (95% CI), 1.45-76.63]; P = .020) and major cognitive impairment (OR 7.98 [95% CI, 1.11-57.27]; P = .039) after adjusting for history of stroke and Beck depression inventory scores. MRI evidence of brain infarction is common in iTTP survivors; the strong association of SCI with impaired cognition suggests that these silent infarcts are neither silent nor innocuous.

Psychometric evaluation of a patient-reported outcomes instrument for congenital thrombotic thrombocytopenic purpura

BACKGROUND

Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra-rare, life-threatening hereditary disorder that causes patients to experience significant morbidity and decreased health-related quality of life (HRQoL). A cTTP disease-specific patient-reported outcome (PRO) instrument that is reflective of patients' experiences with the disorder does not currently exist. The objective of this study was to evaluate and validate the psychometric properties of the Congenital Thrombotic Thrombocytopenic Purpura-Patient Experience Questionnaire (cTTP-PEQ), developed using a literature review, interviews with expert clinicians, and qualitative concept elicitation and cognitive debriefing interviews.

METHODS

This prospective, observational study (NCT03519672) was conducted with patients diagnosed with cTTP currently receiving treatment. Patients were enrolled through investigator sites and direct-to-patient recruitment. Individuals completed electronic self-administered PRO measures, including the cTTP-PEQ, at baseline and Day 14 (+ up to 10 days). The cTTP-PEQ consisted of five multi-item domains (Pain/Bruising, Cognitive Impairment, Visual Impairment, Mood, Treatment Burden) and three single-item domains (Fatigue, Headache, Activity Limitation), and assessed symptoms and impact of cTTP in the previous 24 h, 7 days, and 2 weeks. Convergent and discriminant validity were evaluated using Spearman's rank correlation coefficients. Known-groups validity was assessed between patient groups separated by Patient Global Impression of Severity (PGI-S; normal vs. mild/moderate/severe). Internal reliability was assessed using Cronbach's alpha. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs).

RESULTS

Thirty-six patients participated in this study. Convergent validity was confirmed with high-to-moderate correlations (r ≥ 0.4) for 12/15 hypothesized relationships between pairs of domains and/or total scores. Discriminant validity was confirmed with low correlations (r < 0.3) observed for 5/7 hypothesized relationships. Known-groups validity was confirmed with significant differences (p ≤ 0.05) in mean cTTP-PEQ scores between the two PGI-S groups for most domains and items at both timepoints. Cronbach's alpha was 0.88 at baseline and 0.91 at Day 14, confirming internal consistency of the instrument. Test-retest reliability was also confirmed with a high ICC (0.96).

CONCLUSION

This study validates the psychometric properties of the novel cTTP-PEQ for use in research and clinical practice to assess HRQoL among patients with cTTP. This instrument will be particularly useful when assessing cTTP disease burden and the impact of new treatments.

The Specificities of Thrombotic Thrombocytopenic Purpura at Extreme Ages: A Narrative Review

Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic microangiopathy (TMA) related to a severe ADAMTS13 deficiency, the specific von Willebrand factor (VWF)-cleaving protease. This deficiency is often immune-mediated (iTTP) and related to the presence of anti-ADAMTS13 autoantibodies that enhance its clearance or inhibit its VWF processing activity. iTTP management may be challenging at extreme ages of life. International cohorts of people with TTP report delayed diagnoses and misdiagnoses in children and elderly people. Child-onset iTTP shares many features with adult-onset iTTP: a female predominance, an idiopathic presentation, and the presence of neurological disorders and therapeutic strategies. Long-term follow-ups and a transition from childhood to adulthood are crucial to preventing iTTP relapses, in order to identify the occurrence of other autoimmune disorders and psychosocial sequelae. In contrast, older iTTP patients have an atypical clinical presentation, with delirium, an atypical neurological presentation, and severe renal and cardiac damages. They also have a poorer response to treatment and prognosis. Long-term sequelae are highly prevalent in older patients. Prediction scores for iTTP diagnoses are not used for children and have a lower sensitivity and specificity in patients over 60 years old. ADAMTS13 remains the unique biological marker that is able to definitely confirm or rule out the diagnosis of iTTP and predict relapses during follow-ups.

Immune thrombotic thrombocytopenic purpura: Spotlight on long-term outcomes and survivorship

Advances in diagnosis and treatment have dramatically improved survival of acute immune thrombotic thrombocytopenic purpura (iTTP) and iTTP has evolved from an acute fatal condition to a chronic relapsing disorder. In addition to the risk of iTTP relapse, iTTP survivors are at risk of multiple adverse health outcomes including higher than expected rates of all-cause mortality, increased rates of stroke and other cardiovascular disease, and higher rates of morbidities such as obesity, hypertension, and autoimmune disorders. iTTP survivors also report neurocognitive impairment, depression, and reduced quality of life. Women with iTTP are at risk for recurrent iTTP, preeclampsia, and other maternal and fetal complications in subsequent pregnancies. ADAMTS13 activity during clinical remission has emerged as an important targetable risk factor for iTTP relapse and other outcomes including stroke and all-cause mortality. This review summarizes current literature regarding the epidemiology and potential mechanisms for adverse long-term sequelae of iTTP, outlines current best practices in iTTP survivorship care, and highlights a research agenda to improve long-term iTTP outcomes.

Thrombotic Thrombocytopenic Purpura: From 1972 to 2022 and Beyond

This review tells the story of my personal experience with thrombotic thrombocytopenic purpura (TTP). It begins with my first encounter with TTP 50 years ago when 2 sisters presented 2 years apart, both pregnant and both died. At that time, I knew nothing about hereditary TTP (hTTP), the risks of pregnancy, or effective treatments. In 1991, a year after I moved to Oklahoma, therapeutic plasma exchange (TPE) was established as an effective treatment. With the availability of effective treatment, the number of patients presenting with suspected TTP soared. The diagnosis of TTP was imprecise. I worked with the Oklahoma Blood Institute (OBI) to understand the management of TTP. Because the OBI provided all TPE procedures for most of Oklahoma, we saw all consecutive patients within a defined geographic area who were identified at a uniform time early in the course of their TTP, without selection or referral bias. It was an inception cohort; this became the Oklahoma TTP Registry. In 2001, we began a very successful collaboration with the University of Bern, Switzerland, to measure ADAMTS13 activity in all of our patients. From our patients, we learned that acquired, autoimmune TTP (iTTP) is a chronic disease with risks for cognitive impairment and depression. Recognition in 2012 of three sisters with hTTP was reminiscent of the beginning of my story. hTTP has risks for multiple severe morbidities, beginning at birth and especially during pregnancy. Future management of both iTTP and hTTP will be more effective and more convenient.

Prevalence of neuropsychiatric symptoms and stroke in patients with hereditary thrombotic thrombocytopenic purpura

In this article, Borogovac et al emphasized the burden of stroke and neuropsychiatric symptoms in patients with hereditary thrombotic thrombocytopenic purpura (hTTP) based on an analysis of the International hTTP Registry. Given the rarity of hTTP, patient numbers were small; nevertheless, the prevalence of stroke reached 100% in patients over the age of 50. Nearly all patients also had evidence of neuropsychiatric symptoms. These data confirm the need to diagnose hTTP as early as possible and support the use of prophylaxis to prevent future events.

How I treat immune-mediated thrombotic thrombocytopenic purpura after hospital discharge

Immune-mediated thrombocytopenic purpura (iTTP) is a thrombotic microangiopathy characterized by an acquired ADAMTS13 deficiency as a result of the presence of an antibody inhibitor of ADAMTS13 leading to the formation of ultralarge von Willebrand multimers. Treatment of iTTP includes plasma exchange, high-dose glucocorticoids, rituximab, and, more recently, caplacizumab, to prevent the development of exacerbations. There is the risk of both relapse and long-term complications that include neurocognitive deficits and cardiovascular events that occur in patients in remission after recovery from an acute iTTP episode. Data on the risk factors for the development of these complications, the appropriate screening, and treatment are limited due to the paucity of research. This article is a review of the current understanding on the risk factors for exacerbation, relapse, and long-term complications of iTTP and discusses an approach to observing patients with iTTP after hospital discharge and during the long-term follow-up in the outpatient setting.

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.

Severe Thrombotic Thrombocytopenic Purpura (TTP) with Organ Failure in Critically Ill Patients

Thrombotic thrombocytopenic purpura (TTP) is a multiorgan disorder. Organ dysfunction occurs as a consequence of widespread microvascular thrombosis, especially in the heart, brain and kidney, causing transient or partial occlusion of vessels, resulting in organ ischemia. Intensive care unit (ICU) admission varies between 40% and 100% of patients with TTP, either because of severe organ failure or in order to initiate emergency plasma exchange (PEx). Severe neurologic manifestations and cardiac involvement have been associated with higher mortality. Acute kidney injury, although usually less severe than that in hemolytic and uremic syndrome, is common during TTP. Initial management in the ICU should always be considered in TTP patients. The current treatment of TTP in the acute phase is based on urgent PEx, combined with corticosteroid therapy, B-cell-targeted immunotherapy, rituximab and inhibition of the interaction between ultra-large Von Willebrand factor multimers and platelets, using caplacizumab, a monoclonal antibody. ICU management permits close monitoring and the rapid introduction of life-sustaining therapies. This review details the epidemiology of TTP in the ICU, organ failures of critically ill patients with TTP, and the initial management of TTP patients in the ICU.

Management of acquired, immune thrombocytopenic purpura (iTTP): beyond the acute phase

Modern therapy for acute TTP has resulted in a dramatic improvement in outcomes, with the combination of plasma exchange, immunosuppression, and caplacizumab being associated with >90% survival rates following an acute episode. TTP is no longer associated with just the acute episode, but requires long-term follow-up. There remains significant morbidity associated with acute TTP, and many patients suffer marked neuropsychological sequelae, including impairment in cognitive functioning, affective disorders, and reduction in health-related quality of life measures. The focus of management beyond the acute phase centres on relapse prevention, via careful monitoring of patients and the use of either ad hoc or regular immunosuppressive therapies. The main therapy used is rituximab, but despite more limited evidence, other immunosuppressive therapies may be required to aim for normalisation of ADAMTS 13 activity. Follow-up with a reduction in ADAMTS 13 activity levels (ADAMTS 13 relapse), rituximab is central to normalisation of activity levels and prevention of a clinical relapse. Fundamental to elective therapy is the role of ADAMTS 13 activity monitoring, and impact of reduced ADAMTS13 activity on end organ damage. This review discusses monitoring and treatment strategy for long-term management of TTP, including the variety of therapies available to maintain remission, prevent relapse and a summary of a long-term treatment pathway.

Major adverse cardiovascular events in survivors of immune-mediated thrombotic thrombocytopenic purpura

Cardiovascular disease is a leading cause of death in survivors of immune-mediated thrombotic thrombocytopenic purpura (iTTP), but the epidemiology of major adverse cardiovascular events (MACE) in iTTP survivors is unknown. We evaluated the prevalence and risk factors for MACE, defined as the composite of non-fatal or fatal myocardial infarction (MI), stroke, and cardiac revascularization, during clinical remission in two large iTTP cohorts (Johns Hopkins University and Ohio State University). Of 181 patients followed for ≥ 3 months after recovery from acute iTTP, 28.6% had a MACE event over a median follow up of 7.6 years. Stroke was the most common type of MACE (18.2%), followed by non-fatal MI (6.6%), cardiac revascularization (4.9%) and fatal MI (0.6%). Compared to the general United States population, iTTP survivors were younger at first stroke in remission (males [56.5 years vs. 68.6 years, p = 0.031], females [49.7 years vs. 72.9 years, p <  0.001]) or MI in remission (males [56.5 years vs. 65.6 years, p <  0.001] and females [53.1 years vs. 72.0 years, p < 0.001]). Age (HR 1.03 [95% CI 1.002-1.054]), race (Black/Other vs. White) (HR 2.32 [95% CI 1.12-4.82]), and diabetes mellitus (HR 2.37 [95% CI 1.09-0.03]) were associated with MACE in a Cox regression model also adjusted for sex, hypertension, obesity, hyperlipidemia, chronic kidney disease, atrial fibrillation, autoimmune disease, and relapsing iTTP. Remission ADAMTS13 activity was not significantly associated with MACE. In conclusion, iTTP survivors experience high rates of MACE and may benefit from aggressively screening for and managing cardiovascular risk factors.

Predictors of relapse and preventative strategies in immune thrombotic thrombocytopenic purpura

INTRODUCTION

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare autoimmune blood disorder, which presents with microangiopathic hemolytic anemia, thrombocytopenia, and microvascular thrombosis and is caused by severe deficiency of ADAMTS13. iTTP may result in both acute and chronic complications and is rapidly fatal without expedient treatment. Life-time risk of relapse is approximately 40%.

AREAS COVERED

A number of predictors of relapse has been described in the literature. The most well-studied predictor of relapse is persistent ADAMTS13 deficiency; however, it is not a perfect marker. Relapse can be prevented by treatment with immunosuppressive medications, with rituximab being the most studied.

EXPERT OPINION

Patients who recover from iTTP should be regularly assessed, including with ADAMTS13 activity testing. The optimal frequency of assessments has not been established, but every 3 months is recommended. Considering the potential for significant organ damage and mortality associated with iTTP relapse, patients in remission and with persistent ADAMTS13 activity of 10-20% should be prophylactically treated with immunosuppression. Additional markers to precisely identify patients at higher risk of relapse are needed.

Deleterious neurological impact of diagnostic delay in immune-mediated thrombotic thrombocytopenic purpura

BACKGROUND

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare life-threatening thrombotic microangiopathy requiring urgent therapeutic plasma exchange (TPE). However, the exact impact of a slight delay in TPE initiation on the subsequent patients' outcome is still controversial.

AIM

We aimed to study the frequency, short-term neurological consequences, and determinants of diagnostic delay in iTTP.

METHODS

We conducted a retrospective monocentric study including patients with a first acute episode of iTTP (2005-2020) classified into 2 groups: delayed (>24h from first hospital visit, group 1) and immediate diagnosis (≤24h, group 2).

RESULTS

Among 42 evaluated patients, 38 were included. Eighteen cases (47%) had a delayed diagnosis (median: 5 days). The main misdiagnosis was immune thrombocytopenia (67%). The mortality rate was 5% (1 death in each group). Neurological events (stroke/TIA, seizure, altered mental status) occurred in 67% vs 30% patients in group 1 and 2, respectively (p = 0.04). Two patients in group 1 exhibited neurological sequelae. The hospital length of stay was longer in group 1 (p = 0.02). At the first hospital evaluation, potential alternative causes of thrombocytopenia were more prevalent in group 1 (33% vs 5%, p = 0.04). Anemia was less frequent in group 1 (67% vs 95%, p = 0.04). All patients had undetectable haptoglobin levels. By contrast, 26% of schistocytes counts were <1%, mostly in group 1 (62% vs 11%, p = 0.01).

CONCLUSION

Diagnostic delay is highly prevalent in iTTP, with a significant impact on short-term neurological outcome. In patients with profound thrombocytopenia, the thorough search for signs of incipient organ dysfunction, systematic hemolysis workup, and proper interpretation of schistocytes count are the key elements of early diagnosis of TTP.

Lawrence K, Théberge J, Mandzia J, Barth D, Licht C, Patriquin CJ. Blood-brain barrier permeability in survivors of immune-mediated thrombotic thrombocytopenic purpura: a pilot study

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening disorder of systemic microthrombosis and organ ischemia. The etiology of chronic cerebrovascular outcomes in iTTP survivors is largely unknown. In this pilot study, we measured blood-brain barrier (BBB) permeability in patients with iTTP at the start of remission and 6 months later. This prospective pilot study included 7 adult patients with incident iTTP. Eligibility criteria included ADAMTS13 activity < 10% and detectable inhibitor at diagnosis. Patients were recruited from London Health Sciences Centre in Canada (2017-2019) within 3 days of hospital admission and followed for 6 months after remission (defined as normalization of platelet count and lactate dehydrogenase with no clinical signs or symptoms of microvascular injury for more than 30 days after the last plasma exchange). All patients had cerebral computed tomography perfusion scans with BBB permeability surface product measurements. Patients (5 women, 2 men) had a mean age of 48 years (range, 21-77 years). At diagnosis, patients had a mean platelet count of 22 (standard deviation [SD], 25) × 109/L. At the start of remission, mean BBB permeability surface product was 0.91 (0.30) mL/min/100 g. Six months later, the mean permeability surface product was 0.56 (0.22) mL/min/100 g, with a mean difference of -0.312 mL/min/100 g (95% confidence interval: -0.4729 to -0.1510; P = .0032). In this pilot study of patients with iTTP, pathologically increased BBB permeability was evident, and although there was some improvement, this persisted 6 months after remission. Future work will explore the chronicity of these findings and their clinical implications.

The standard of care for immune thrombotic thrombocytopenic purpura today

Targeted therapy of immune thrombotic thrombocytopenic purpura (iTTP) requires acurate and prompt diagnosis and differentiation from complement-mediated hemolytic uremic syndrome and other causes of thrombotic microangiopathy. ADAMTS-13 (A Disintegrin And Metalloprotease with ThromboSpondin-1 Domain, member 13) evaluation (activity and inhibitors or anti-ADAMTS-13 IgG) is the key for diagnosis and further management of patients with suspected iTTP during acute episode and in clinical response or remission. Clinical trial results and real-world data have demonstrated the efficacy and safety of the triple therapy consisting of therapeutic plasma exchange, caplacizumab, and immunosuppressives (e.g., corticosteroids and rituximab) for acute iTTP. Such a therapeutic strategy has significantly accelerated the normalization of platelet counts, decreased the length of stays in the intensive care unit and the hospital, but most importantly reduced the mortality rate. The present review highlights some of the important advancements for the diagnosis and management of iTTP and proposes triple therapy as the standard of care for acute iTTP today.

Survival after acute episodes of immune-mediated thrombotic thrombocytopenic purpura (iTTP) - cognitive functioning and health-related quality of life impact: a descriptive cross-sectional survey of adults living with iTTP in the United Kingdom

OBJECTIVES

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is an ultra-rare life-threatening thrombotic microangiopathy affecting adults with unpredictable disease onset and acute presentation. This study aimed to describe the health-related quality of life (HRQoL), cognitive functioning and work productivity of survivors following acute episode(s) of iTTP in the United Kingdom (UK).

METHODS

An online survey was developed in collaboration with the TTP Network. Descriptive statistics were calculated for the health questionnaire Short Form Survey-36 Version 2 (SF-36v2), the Hospital Anxiety and Depression Score (HADS), the PROMIS Cognitive Function Abilities Subset - Short Form 6a (PROMIS CFAS - SF6a), and the Work Productivity and Activity Index: Specific Health Problem (WPAI-SHP), along with several iTTP-specific bespoke questions.

RESULTS

Fifty participants were recruited between July-November 2019. The mean (standard deviation [SD]) standardized SF-36v2 physical and mental component scores were 42.16 (9.59) and 33.61 (12.34), lower than population norms. The mean (SD) standardized PROMIS CFAS - SF6a score was 39.69 (7.86), lower than population norms. HADS mean (SD) scores of 12.18 (3.14) and 11.78 (2.36) indicated moderate levels of anxiety and depression, respectively. Of those employed (58%), approximately 42.73% of participants reported work productivity loss due to their iTTP. Participants also reported experiencing flashbacks, fatigue interference in family, social and intimate life, and fears of relapse.

DISCUSSION AND CONCLUSION

Regardless of recency of the last acute episode, participant scores signified impairments in all domains. Remission from an acute episode of disease does not signify the conclusion of care, but rather the requirement for long-term healthcare particularly focused on psychological support.

Pattern of Brain Injury in Patients With Thrombotic Thrombocytopenic Purpura in the Precaplacizumab Era

OBJECTIVES

To describe short- and long-term neurologic prognosis of patients with thrombotic thrombocytopenic purpura and to identify clusters associated with evolution.

DESIGN

Prospective French cohort.

SETTING

ICU in a reference center.

PATIENTS

All consecutive patients with newly diagnosed thrombocytopenic purpura.

INTERVENTION

Comprehensive clinical, biological, and radiological evaluation at admission. Neurocognitive recovery was assessed using Glasgow Outcome Scale (range 1-5, with 1 representing death and 5 representing no or minimal neurologic deficit).

MEASUREMENTS AND MAIN RESULTS

Among the 130 newly diagnosed patients with thrombocytopenic purpura, 108 (83%; age 43 [30-52]; 73% women) presented with neurologic signs, including headaches (51%), limb weakness, paresthesia, and/or aphasia (49%), pyramidal syndrome (30%), decreased consciousness (20%), seizure (19%), cognitive impairment (34%), cerebellar syndrome (18%), and visual symptoms (20%). A hierarchical cluster analysis identified three distinct groups of patients. Cluster 1 included younger patients (37 [27-48], 41 [32-52], and 48 [35-54], in clusters 1, 2 and 3, respectively; p = 0.045), with a predominance of headaches (75%, 27%, and 36%; p < 0.0001). Cluster 2 patients had ataxic gait and cerebellar syndrome (77%, 0%, and 0%; p < 0.0001) and dizziness (50%, 0%, and 0%; p < 0.0001). Cluster 3 included patients with delirium (36%, 0%, and 9%; p < 0.0001), obtundation (58%, 0%, and 24%; p < 0.0001), and seizure (36%, 0%, and 14%; p < 0.0001). Acute kidney injury was 32%, 68%, and 77%, in clusters 1, 2, and 3, respectively (p < 0.0001). The three clusters did not differ for other biological or brain imaging. After a median follow-up of 34 months (12-71 mo), 100 patients (93%) were alive with full neurocognitive recovery (i.e., Glasgow Outcome Scale score 5) in 89 patients (89%). Patients from cluster 1 more frequently exhibited full recovery (Glasgow Outcome Scale score of 5) compared with clusters 2 and 3, (44 [98%], 13 [65%], and 21 [60%] at 3 mo; p < 0.0001), (44 [100%], 15 [68%], and 23 [69%] at 6 mo; p < 0.0001), and (40 [100%], 15 [79%], and 20 [57%] at 1 yr; p < 0.0001).

CONCLUSIONS

Initial clinical neurologic evaluation in thrombocytopenic purpura patients distinguishes three groups of patients with different clinical and functional outcomes.

Recognizing and managing hereditary and acquired thrombotic thrombocytopenic purpura in infants and children

We describe how infants and children with hereditary and acquired autoimmune thrombotic thrombocytopenic purpura (TTP) initially present and how they can be promptly diagnosed and effectively managed. These are uncommon disorders that are commonly misdiagnosed and can be rapidly fatal. TTP is caused by a severe deficiency of the plasma protease, A disintegrin and Metalloprotease with a ThromboSpondin type 1 motif, member 13 (ADAMTS13). Measurement of ADAMTS13 activity is becoming easily accessible. A common presentation of hereditary TTP is neonatal severe hemolysis and hyperbilirubinemia. However, the median age of diagnosis is not until 5.5 years. Plasma is effective treatment for exacerbations and for prophylaxis. Plasma may be replaced by recombinant ADAMTS13 when it becomes available. Acquired TTP is more frequent in older children, in whom it is more common in girls and is commonly associated with systemic lupus erythematosus. For acquired TTP, plasma exchange and immunosuppression are the current treatment for acute episodes; caplacizumab is now commonly used in adults and may replace plasma exchange.

[Endothelial dysfunction in thrombotic thrombocytopenic purpura: therapeutic perspectives]

Immune Thrombotic Thrombocytopenic Purpura (iTTP) is a rare but severe disease with a mortality rate of almost 100 % in the absence of adequate treatment. iTTP is caused by a severe deficiency in ADAMTS13 activity due to the production of inhibitory antibodies. Age has been shown to be a major prognostic factor. iTTP patients in the elderly (60yo and over) have more frequent organ involvement, especially heart and kidney failures compared with younger patients. They also have non-specific neurologic symptoms leading to a delayed diagnosis. Factors influencing this impaired survival among older patients remain unknown so far. Alteration of the functional capacity of involved organs could be part of the explanation as could be the consequences of vascular aging. In fact, severe ADAMTS13 deficiency is necessary but likely not sufficient for iTTP physiopathology. A second hit leading to endothelial activation is thought to play a central role in iTTP. Interestingly, the mechanisms involved in endothelial activation may share common features with those involved in vascular aging, potentially leading to endothelial dysfunction. It could thus be interesting to better investigate the causes of mid- and long-term mortality among older iTTP patients to confirm whether inflammation and endothelial activation really impact vascular aging and long-term mortality in those patients, in addition to their presumed role at iTTP acute phase. If so, further insights into the mechanisms involved could lead to new therapeutic targets.

Influence of Personality, Resilience and Life Conditions on Depression and Anxiety in 104 Patients Having Survived Acute Autoimmune Thrombotic Thrombocytopenic Purpura

Autoimmune thrombotic thrombocytopenic purpura (iTTP) is a life-threatening, relapsing disease in which an acquired deficiency of the enzyme ADAMTS13 leads to generalised microvascular thrombosis. Survivors have a high prevalence of depression and impaired cognitive function. The aim of this study was to determine whether life circumstances and personality have an influence on the development and severity of depression and anxiety in iTTP patients and how they impact the quality of life. With validated questionnaires, we examined the prevalence of depression and anxiety symptoms in 104 iTTP patients, as well as parameters of subjective cognitive deficits, quality of life, attitude to life and resilience. iTTP patients had significantly more depressive symptoms (p < 0.001), a tendency to have anxiety disorders (p = 0.035) and a significantly worse cognitive performance (p = 0.008) compared to the controls. Sex, age, physical activity and partnership status had no significant influence on depression, whereas the number of comorbidities did. Lower scores of resilience, attitude to life and quality of life were reported by patients compared to controls. iTTP patients had a high prevalence of depression and anxiety, as well as a more negative attitude to life and low resilience. Resilience correlated negatively with the severity of the depression. Furthermore, quality of life and cognitive performance were significantly reduced.

Burden of illness among Medicare and non-Medicare US populations with acquired thrombotic thrombocytopenic purpura

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare hematologic disorder that can lead to serious life-threatening medical complications.

OBJECTIVE

The aim of this study was to describe aTTP-related hospital resource utilization, cost, complications, and overall survival among US Medicare and non-Medicare populations following aTTP episodes prior to the US approval of caplacizumab.

METHODS

This retrospective study utilized administrative claims data for Medicare Fee-for-Service (FFS) beneficiaries (100% sample) and a sample of commercial, managed Medicaid [MM], Medicare Advantage [MA] plan members from the Inovalon MORE² Registry. aTTP patients ages 18+ were identified between 2010 and 2018 using a published validated algorithm: ≥1 hospitalization for thrombotic microangiopathy + therapeutic plasma exchange (TPE). 2,279 patients were identified; 65.2% were enrolled in Medicare FFS, 13.6% in commercial, 15.7% in MM, and 5.4% in MA. Mean hospitalization days for aTTP index episode ranged between 12 and 17 days; ∼60% of patients required intensive care. Mean payments for index hospitalization varied by payer [Medicare FFS: $29,024; MA: $12,860; commercial: $9,996 and MM: $10,470]. Among FFS patients, 15.7% died during initial hospitalization and 21.0% died within first 30 days of the event. During follow-up, 11.6-19.6% experienced aTTP-related exacerbation. Incidence rate of relapse and complications per 100 person-years was 5.6 [Medicare FFS: 3.6; MA: 8.7; commercial: 10.4 and MM: 14.7] and 16.7 [FFS: 15.5; MA: 20.5; commercial: 21.7 and MM: 19.1], respectively. Among Medicare patients with and without aTTP, mortality risk was 2.9 (95 % CI: 2.4-3.4) times higher for aTTP vs. non-aTTP patients.

CONCLUSION

This is the first real-world study evaluating burden of illness among aTTP patients in the US across payer types. Despite being treated with TPE, patients with aTTP have lower survival rates in comparison to a matched cohort without aTTP. These findings highlight the need for more effective and novel therapies to reduce disease burden for this population.Key pointsIn US Medicare and managed care populations with aTTP between 2010 and 2018, aTTP can lead to significant utilization of ICU services due to clinical complications, and/or relapse following hospital discharge.Despite treatment with therapeutic plasma exchange, acute mortality remains high (15.7%) indicating the need for more effective and novel treatments.

Immune thrombotic thrombocytopenic purpura in older patients: prognosis and long-term survival

Older age is associated with increased mortality in immune thrombotic thrombocytopenic purpura (iTTP). Yet, data are scarce regarding iTTP occurring among older patients. To assess clinical features and long-term impact of iTTP on mortality in older patients (>60 years old), characteristics and prognoses of adult iTTP patients enrolled in the French Reference Center for Thrombotic Microangiopathies registry between 2000 and 2016 were described according to age (<60 years old or ≥60 years old). Long-term mortality of iTTP older survivors was compared with that of non-iTTP geriatric subjects. Comparing, respectively, older iTTP patients (N = 71) with younger patients (N = 340), time from hospital admission to diagnosis was longer (P < .0001); at diagnosis, delirium (P = .034), behavior impairment (P = .045), renal involvement (P < .0001), and elevated troponin level (P = .025) were more important whereas cytopenias were less profound (platelet count, 22 × 103/mm3 [9-57] vs 13 × 103/mm3 [9-21], respectively [P = .002]; hemoglobin level, 9 g/dL [8-11] vs 8 g/dL [7-10], respectively [P = .0007]). Short- and mid-term mortalities were higher (P < .0001) and increased for every 10 years of age range. Age ≥60 years, cardiac involvement, increased plasma creatinine level, and total plasma exchange volume were independently associated with 1-month mortality. Compared with a non-iTTP geriatric population, older survivors showed an increased long-term mortality (hazard ratio = 3.44; P < .001). In conclusion, older iTTP patients have atypical neurological presentation delaying the diagnosis. Age negatively impacts short-term but also long-term mortality.

Incidence of acquired thrombotic thrombocytopenic purpura in Germany: a hospital level study

Background

Acquired thrombotic thrombocytopenic Purpura (aTTP) is a life-threatening ultra-orphan disease with a reported annual incidence between 1.5 and 6.0 cases per million in Europe and mainly affecting otherwise young and healthy adults aged 40 years on average. The goal of this study was to assess the incidence of aTTP in Germany.

Methods

A systematic review was performed to determine the published evidence on the aTTP epidemiology in Germany. To obtain additional evidence on the proportion of aTTP cases within the national Thrombotic Microangiopathy (TMA) population a hospital-level study was performed, using a retrospective data collection approach. Diagnosis of aTTP was confirmed if ADAMTS13 level were < 10% and/or the medical records explicitly mentioned aTTP diagnosis. The aggregated hospital data were then projected to the national level using logistic regression techniques.

Results

The systematic literature search did not provide incidence estimates of aTTP in Germany. Eight centers (≈27% of the top 30 TMA hospitals) delivered data according to a predefined data collection form. On average (year 2014–2016) a total number of 172 aTTP episodes per year was projected (95% confidence interval [95%CI]: 132–212). The majority were newly diagnosed aTTP cases (n = 121; 95%CI: 105–129), and 51 were recurrent aTTP cases (95%CI: 27–84). The average annual projected incidence (year 2014–2016) of aTTP episodes was 2.10 per million inhabitants in Germany (95%CI: 1.60–2.58).

Conclusions

The determined annual incidence of newly diagnosed aTTP cases and the overall annual incidence of aTTP episodes in Germany confirm the ultra-orphan character of aTTP. An external validation against international registries (France, UK and USA) shows that our findings are quite comparable with those international incidence rates.

Thrombotic thrombocytopenic purpura patients' attitudes toward depression management: A qualitative study

BACKGROUND AND AIMS

Thrombotic thrombocytopenic purpura (TTP) is a rare disorder characterized by acute episodes of systemic microvascular thrombosis; TTP is more common in adults, women, and African-Americans (Blacks). Our Oklahoma TTP Registry documented that survivors have an increased prevalence of depression compared with the general population; however, many patients' depression remains untreated. Moreover, studies identifying attitudes toward depression management are lacking. The objective of this study was to identify TTP patients' attitudes towards pharmacotherapy. As a secondary question, we explored attitudes towards counseling.

METHODS

We interviewed TTP patients with major depression who had experience with different management strategies (previous/current pharmacotherapy treatment versus no pharmacotherapy treatment). Eligibility criteria included (a) age > 18 years, (b) ADAMTS13-deficient TTP, (c) enrolled in the Oklahoma Registry, and (d) moderate/major depression on either the Beck Depression Inventory II or Patient Health Questionnaire from 2004 to 2012. Qualitative purposive sampling was used to interview patients with a range of experiences with TTP and depression symptom management. Our study was based on the theoretical framework of the Theory of Reasoned Action. Patients were asked about their views on depression (attitudes), their family and friends' views (social norms), and ways they cope with depression.

RESULTS

Semi-structured interviews were conducted between June and October 2013. Data saturation was achieved after interviewing 16 patients (nine, pharmacotherapy and seven, no pharmacotherapy). The majority (88%) were women; 56% were Black, and the median age was 49 years. Patients in both groups believed TTP was life altering and traumatic and that counseling improved depressive symptoms. However, the pharmacologic group believed medication improved one's quality of life, whereas the no pharmacotherapy group was not sure pharmacotherapy was effective and expressed fears related to potential addiction and side effects. When asked about cultural views to depression management, many Black patients stated that in the Black community, a person is taught to deal with his/her emotional issues instead of asking strangers for help.

CONCLUSION

Ensuring effective depression management is a critical part of TTP care. Understanding attitudes toward management will assist in tailoring patient discussions.

Long-term neuropsychological sequelae, emotional wellbeing and quality of life in patients with acquired thrombotic thrombocytopenic purpura

Neurological symptoms related to microthrombosis are the hallmark of acute manifestations of acquired thrombotic thrombocytopenic purpura (TTP). Despite the achievement of hematological remission, patients may report persisting neurological impairment that affects their quality of life. To assess the long-term neuropsychological consequences of acute TTP, we recruited 35 acquired TTP patients (77% females, median age at onset 41 years, interquartile range: 35–48) regularly followed at our out-patient clinic of thrombotic microangiopathies in Milan (Italy) from December 2015 to October 2016. Patients underwent a psychological evaluation of memory and attentional functions, emotional wellbeing and health-related quality of life at least three months after their last acute TTP event (median 36 months, interquartile range: 17–54). During the psychological consultation, 17 patients (49%) referred persisting subjective neurological impairment in the frame of a remission phase, with at least one symptom as disorientation, loss of concentration, dizziness, lack of balance, headache and diplopia. Neuropsychological assessment revealed lower scores than the Italian general population pertaining to direct, indirect and deferred memory. A higher degree of impairment of memory domains was found in patients with neurological involvement at the time of presentation of the first acute TTP episode. Anxiety and depression were detected in seven (20%) and 15 (43%) patients, respectively. Health-related quality of life was lower than the Italian general population, with mental domains more impacted than physical domains (mean difference 58.43, 95% confidence interval: 71.49–45.37). Our study demonstrates compromised memory and attention functions, persisting anxiety/depression symptoms and a generally reduced quality of life in patients recovering from acute acquired TTP. New clinical strategies should be considered to improve these symptoms.

Clinical Efficacy and Safety Profile of Caplacizumab for Acquired Thrombotic Thrombocytopenic Purpura

Thrombotic thrombocytopenic purpura (TTP) is usually defined as microangiopathy characterized by low platelet count and low red blood cell count, i.e., hemolytic anemia. It can either be acquired or immune-mediated. TTP requires quick diagnostic identification and emergent management. According to the evidence-based guidelines, the recommended therapy is plasma exchange and immunosuppression. Caplacizumab is used alongside the standard recommended therapy. Caplacizumab is a monoclonal antibody (Mab) that binds to von Willebrand factor (VWF). This prevents A1 VWF to bind platelet glycoprotein 1b receptor. The recommended dosage for this drug is 10mg. At the start, 10mg intravenous (IV) dose is given before plasma exchange, followed by daily 10mg subcutaneous (SC) dose after plasma exchange. Moreover, the SC dose is continued even after the daily plasma exchange is stopped. This review aims to consolidate findings related to the efficacy of this recently approved drug.

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.

Thrombotic thrombocytopenic purpura: Toward targeted therapy and precision medicine

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy characterized by severe congenital or immune-mediated deficiency in ADAMTS13, the enzyme that cleaves von Willebrand factor multimers. This rare condition leads invariably and rapidly to a fatal outcome in the absence of treatment, and therefore raises multiple diagnostic and therapeutic challenges. The novel concepts and mechanisms identified in the laboratory for this disease have been rapidly and successfully translated into the clinic for the benefit of patients, making TTP an archetypal disease that has benefited from targeted therapies. After decades of empirical treatment with plasma exchange, identification of ADAMTS13 as the key enzyme involved in TTP pathophysiology provided an explanation for the remarkable efficacy of plasma administration, in which the missing enzyme is replenished, and paved the way for development of a recombinant form of the enzyme. Similarly, the demonstration of a major role of anti-ADAMTS13 antibodies through models of passive transfer of autoimmunity spurred development of immunomodulatory strategies based on B-cell depletion. More recently, an inhibitor of the platelet-von Willebrand factor interaction demonstrated efficacy in large clinical trials through prevention of formation of further microthrombi and protection of organs from ischemia. These translational breakthroughs in TTP are described in our review.

TTP: long-term outcomes following recovery

Although risk for relapse may be the greatest concern following recovery from acquired, autoimmune thrombotic thrombocytopenic purpura (TTP), there are multiple other major health issues that must be recognized and appropriately addressed. Depression may be the most common disorder following recovery from TTP and may be the most important issue for the patient's quality of life. Severe or moderate depression has occurred in 44% of Oklahoma Registry patients. Recognition of depression by routine screening evaluations is essential; treatment of depression is effective. Minor cognitive impairment is also common. The recognition that cognitive impairment is related to the preceding TTP can provide substantial emotional support for both the patient and her family. Because TTP commonly occurs in young black women, the frequency of systemic lupus erythematosus, as well as other autoimmune disorders, is increased. Because there is a recognized association of TTP with pregnancy, there is always concern for subsequent pregnancies. In the Oklahoma Registry experience, relapse has occurred in only 2 of 22 pregnancies (2 of 13 women). The frequency of new-onset hypertension is increased. The most striking evidence for the impact of morbidities following recovery from TTP is decreased survival. Among the 77 patients who survived their initial episode of TTP (1995-2017), 16 (21%) have subsequently died, all before their expected age of death (median difference, 22 years; range 4-55 years). The conclusion from these observations is clear. Following recovery from TTP, multiple health problems occur and survival is shortened. Therefore, careful continuing follow-up is essential.

The association between urinary Alzheimer-associated neuronal thread protein and cognitive impairment in late-life depression: a controlled pilot study

Accumulation of tau protein is associated with both Alzheimer's disease (AD) and late-life depression (LLD). Alzheimer-associated neuronal thread protein (AD7c-NTP), which is closely linked with the tau protein, is elevated in the cerebrospinal fluid and urine of AD patients. This study examined the association between urinary AD7c-NTP and late-life depression with cognitive impairment. One hundred and thirty-eight subjects were recruited into late-life depression with cognitive impairment (LLD-CI, n=52), late-life depression without cognitive impairment (LLD-NCI, n=29), AD (n=27), and healthy control (HC, n=30) groups. The level of urinary AD7c-NTP was measured using the enzyme-linked immunosorbent assay method. The Montreal Cognitive Assessment scale (MoCA), Hamilton Rating Scale for Depression (HRSD) and Hamilton Anxiety Rating Scale (HAMA) were used to assess cognitive functions and depressive and anxiety symptoms in the AD and LLD groups. Urinary levels of AD7c-NTP in the LLD-CI group (1.0±0.7ng/ml) were significantly higher than both the LLD-NCI (0.5±0.3ng/ml) and HC groups (0.5±0.3ng/ml), but lower than in the AD group (1.6±1.7 ng/ml). No significant associations were found in the level of urinary AD7c-NTP in relation to age, gender, education and MoCA in the LLD-CI group. The level of urinary AD7c-NTP appears to be associated with cognitive impairment in late-life depression and may be a potential biomarker for early identification of cognitive impairment in LLD.

Recent advances in understanding and management of acquired thrombocytopenia

There are numerous congenital and acquired causes of thrombocytopenia. Thrombocytopenia could be a result of decreased bone marrow production, increased consumption, increased destruction, splenic sequestration or a combination of these causes. In this review, we have focused on some of the serious acquired causes of thrombocytopenia. There have been some significant advances in our understanding of the pathophysiology, diagnostic testing, and treatment of immune thrombocytopenia, heparin-induced thrombocytopenia, thrombotic thrombocytopenic purpura, and atypical hemolytic uremic syndrome over the past five years. These advances have resulted in a significant decrease in mortality and morbidity of patients with these disorders. Despite these advances, we are still faced with numerous unanswered questions in the pathophysiology and management of these complex thrombocytopenic disorders.

Caplacizumab reduces the frequency of major thromboembolic events, exacerbations and death in patients with acquired thrombotic thrombocytopenic purpura

Essentials Acquired thrombotic thrombocytopenic purpura (aTTP) is linked with significant morbidity/mortality. Caplacizumab's effect on major thromboembolic (TE) events, exacerbations and death was studied. Fewer caplacizumab-treated patients had a major TE event, an exacerbation, or died versus placebo. Caplacizumab has the potential to reduce the acute morbidity and mortality associated with aTTP.

SUMMARY

Background Acquired thrombotic thrombocytopenic purpura (aTTP) is a life-threatening autoimmune thrombotic microangiopathy. In spite of treatment with plasma exchange and immunosuppression, patients remain at risk for thrombotic complications, exacerbations, and death. In the phase II TITAN study, treatment with caplacizumab, an anti-von Willebrand factor Nanobody® was shown to reduce the time to confirmed platelet count normalization and exacerbations during treatment. Objective The clinical benefit of caplacizumab was further investigated in a post hoc analysis of the incidence of major thromboembolic events and exacerbations during the study drug treatment period and thrombotic thrombocytopenic purpura-related death during the study. Methods The Standardized Medical Dictionary for Regulatory Activities (MedDRA) Query (SMQ) for 'embolic and thrombotic events' was run to investigate the occurrence of major thromboembolic events and exacerbations in the safety population of the TITAN study, which consisted of 72 patients, of whom 35 received caplacizumab and 37 received placebo. Results Four events (one pulmonary embolism and three aTTP exacerbations) were reported in four patients in the caplacizumab group, and 20 such events were reported in 14 patients in the placebo group (two acute myocardial infarctions, one ischemic stroke, one hemorrhagic stroke, one pulmonary embolism, one deep vein thrombosis, one venous thrombosis, and 13 aTTP exacerbations). Two of the placebo-treated patients died from aTTP during the study. Conclusion In total, 11.4% of caplacizumab-treated patients and 43.2% of placebo-treated patients experienced one or more major thromboembolic events, experienced an exacerbation, or died. This analysis shows the potential for caplacizumab to reduce the risk of major thromboembolic morbidities and mortality associated with aTTP.