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TTP is a life-threatening disorder with limited pharmaceutical treatment options. Recently, the potential of streptokinase in the treatment of acquired TTP was demonstrated in humans in vitro, and in vivo in a mouse model. We aimed to determine the in vitro and in vivo effects of streptokinase in an established Papio ursinus model of acquired TTP. In vitro: VWF activities & multimer patterns and thromboelastograms were assessed with increasing concentrations of streptokinase. In vivo: After induction of TTP, escalating streptokinase doses (ranging from 50,000 to 900,000 IU) were administered, and the effects of streptokinase assessed on peripheral blood counts, fibrinolysis, VWF activities & multimer patterns and thromboelastograms. In an extension of the study, high-dose streptokinase (1,500,000–3,000,000 IU) was administered to another baboon. After spiking, fibrinolysis with loss of large VWF multimers was observed at [2200 IU/mL]—roughly equivalent to 1,500,000 IU. However, administration of escalating intravenous streptokinase doses had no in vivo effect on the TTP phenotype, and in vivo increases in plasmin activity were mild when compared with baseline, even at high doses. Minimal effect on VWF multimer patterns was observed but only at doses ≥ 1500,000 IU. Streptokinase is not effective in resolving TTP in a Papio ursinus model of TTP, possibly due to limited activation of the baboon fibrinolytic system. Modifications to this model, the use of alternative higher animal models, or alternative thrombolytics, should be considered to establish proof-of-concept.

The efficacy and safety of caplacizumab in individuals with acquired thrombotic thrombocytopenic purpura (aTTP) have been established in the phase 2 TITAN and phase 3 HERCULES trials. Integrated analysis of data from both trials was conducted to increase statistical power for assessing treatment differences in efficacy and safety outcomes. Caplacizumab was associated with a significant reduction in the number of deaths (0 vs 4; P < .05) and a significantly lower incidence of refractory TTP (0 vs 8; P < .05) vs placebo during the treatment period. Consistent with the individual trials, treatment with caplacizumab resulted in a faster time to platelet count response (hazard ratio, 1.65; P < .001), a 72.6% reduction in the proportion of patients with the composite end point of TTP-related death, TTP exacerbation, or occurrence of at least 1 treatment-emergent major thromboembolic event during the treatment period (13.0% vs 47.3%; P < .001), and a 33.3% reduction in the median number of therapeutic plasma exchange days (5.0 vs 7.5 days) vs placebo. No new safety signals were identified; mild mucocutaneous bleeding was the main safety finding. This integrated analysis provided new evidence that caplacizumab prevents mortality and refractory disease in acquired TTP and strengthened individual trial findings, with a confirmed favorable safety and tolerability profile. These trials were registered at www.clinicaltrials.gov as #NCT01151423 and #NCT02553317.

Background Idiopathic membranous nephropathy (MN) is one of the major glomerulonephritis that cause nephrotic syndrome. The phospholipase A2 receptor (PLA2R) has recently been identified as an endogenous antigen of idiopathic MN. Thrombotic thrombocytopenic purpura (TTP) is a disorder characterized by schistocytes, hemolytic anemia, thrombocytopenia, and organ dysfunction which occurs as a result of thrombi. Patients with acquired TTP have autoantibodies against a disintegrin and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13). These autoantibodies act as an inhibitor and cause ADAMTS13 deficiency. Idiopathic MN and acquired TTP are usually considered as independent autoimmune diseases. We experienced a patient who developed TTP during the conservative treatment of idiopathic MN, with the coexistence of ADAMTS13 inhibitor and anti-PLA2R antibody. Case presentation A 73-year-old man presented with thrombocytopenia, hemolytic anemia, disturbance of consciousness, and acute kidney injury after 4-year course of biopsy-proven idiopathic MN. ADAMTS13 activity was undetectable and the ADAMTS13 inhibitor was identified. Additionally, he was positive for anti-PLA2R antibody. The patient did not have any diseases that could cause secondary thrombotic microangiopathy, and he was diagnosed with acquired TTP. Steroid therapy and plasma exchange were initiated and the acquired TTP resolved. MN achieved remission 3 months after the anti-PLA2R antibody disappeared. Conclusions This is the first reported case of acquired TTP developed during conservative treatment of idiopathic MN, with both ADAMTS13 inhibitor and anti-PLA2R antibody positive at the onset of the TTP. The present case suggests that idiopathic MN might be associated with the development of some cases of acquired TTP.

Background Thrombotic thrombocytopenic purpura (TTP) is associated with more deleterious outcomes in patients with systemic lupus erythematosus (SLE). However, ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) levels and ADAMTS13 inhibitor were not routinely assayed in most previous studies. The objective of this study is to compare the characteristics and outcomes of immune-mediated TTP (iTTP) in patients with and without SLE. Methods The medical data of 28 patients with iTTP from Peking Union Medical College Hospital were analysed. ADAMTS13 activity and ADAMTS13 inhibitor were measured in all patients. Results All 28 patients had ADAMTS13 inhibitor and severe ADAMTS13 deficiency. iTTP was considered SLE-related (SLE-TTP) in 10 patients and primary (primary iTTP) in 18 patients. Renal involvement on presentation was more severe in patients with primary iTTP as determined by higher serum creatinine (162.7 ± 110.6 vs 73.3 ± 13.4 μmol/L, p p p p = 0.01) compared to patients with primary iTTP. After adjustments for age and treatment, including steroid pulse therapy and IVIG treatment, the likelihood of clinical remission of SLE-TTP was significantly increased compared to that of primary iTTP (HR 7.6 [1.2, 50.1], p = 0.03). Mortality was also lower among patients with SLE-TTP than among patients with primary iTTP (0 vs 38.9%, p = 0.03). Conclusions Renal involvement was less severe in patients with SLE-TTP than in patients with primary iTTP. The treatment responses and outcomes of SLE-TTP were no worse and perhaps even better than those of primary iTTP. When TTP is diagnosed in SLE patients, the ADAMTS13 level and ADAMTS13 inhibitor profile should be considered in addition to clinical features.

Purpose The pharmacology, pharmacokinetics, efficacy, safety, dosing and administration, and place in therapy of caplacizumab, a novel antibody fragment that inhibits von Willebrand factor, for the treatment of acquired thrombotic thrombocytopenic purpura (TTP) are summarized. Summary Caplacizumab is a humanized anti–von Willebrand factor monoclonal antibody fragment that inhibits the interaction between ultralarge von Willebrand factor multimers and platelets. Caplacizumab is indicated for use in combination with standard-of-care modalities such as plasma exchange and immunosuppressive therapy for the treatment of adults with acquired TTP. By inhibiting von Willebrand factor, caplacizumab offers a new approach to the management of TTP by preventing the development of potentially life-threatening microvascular thrombosis that can occur in the disease process. In a randomized, placebo-controlled phase 3 trial, patients with acquired TTP treated with caplacizumab had more rapid platelet level normalization than placebo users; caplacizumab use also resulted in lower rates of disease recurrence and TTP-related death. The most common adverse events associated with caplacizumab use are bleeding-related events. In a phase 3 trial, serious bleeding-related adverse events were reported in 8 patients (11%) in the caplacizumab group and 1 patient (1%) in the placebo group. Caplacizumab is administered as an 11-mg intravenous loading dose 15 minutes prior to plasma exchange, followed by administration of 11 mg subcutaneously daily after plasma exchange. Once-daily caplacizumab administration can be continued for 30 days after the last plasma exchange. The medication and supplies for administration are provided as a single-use kit; patients should be trained on proper reconstitution and self-administration technique prior to the use of caplacizumab in the ambulatory setting. Conclusion Caplacizumab is a first-in-class von Willebrand factor inhibitor approved for the treatment of adults with acquired TTP.

The aim of this study was to explore the clinical characteristics and treatment of acquired thrombotic thrombocytopenic purpura (TTP). The clinical manifestations, laboratory findings, differential diagnoses, therapeutic methods, and prognosis of 55 patients with acquired TTP were retrospectively analyzed. Among the 55 TTP patients, 17 were males and 38 were females, with a mean age of 40 ± 15 years. Twenty-one patients had the Triad syndrome, which included neurological syndromes, microangiopathic hemolytic anemia, and thrombocytopenia. Twenty-three patients had the Quinary syndrome, which included fever, microangiopathic hemolytic anemia, thrombocytopenia, renal insufficiency, and neurological symptoms. Twenty-eight patients received the measurement for a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity and 23 patients had

Upshaw-Schulman syndrome is a rare inherited form of thrombotic thrombocytopenic purpura disease caused by deficiency of ADAMTS13 and reversible by fresh frozen plasma infusions. Unlike the more common acquired thrombotic thrombocytopenic purpura, patient with Upshaw-Schulman syndrome generally presents early life with a repeated episodes of microangiopathic haemolytic anaemia, usually triggered by acute illness. There are few reported cases about congenital thrombotic thrombocytopenic purpura and long term prognosis. We describe a 16 months old Palestinian male patient with history of severe neonatal jaundice, microangiopathic haemolytic anaemia and thrombocytopenia triggered by febrile illness associated with facial palsy as neurological manifestation favoured congenital thrombotic thrombocytopenic purpura. Low ADAMTS13 level and improvement in platelet counts after fresh frozen plasma infusion with novel mutation of Leu209Pro in exon 6 of the ADAMTS13 gene confirmed the diagnosis of congenital thrombotic thrombocytopenic purpura in our patient who later on developed coarctation of aorta suggested thrombotic complication of ADAMTS13/VWF missing axis dysfunction.

A 47-year-old man was admitted to our hospital because of thrombocytopenia and consciousness disturbance. As his laboratory data showed undetectable activity of a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13 (ADAMTS13) and the presence of ADAMTS13 inhibitor, he was diagnosed with acquired thrombotic thrombocytopenic purpura (TTP). Asymptomatic primary Sjögren's syndrome (SS) and primary hypothyroidism were incidentally diagnosed on screening. After initial plasma exchange therapy and pulse corticosteroid therapy, the patient received rituximab therapy for refractory TTP with "inhibitor boosting" and recovered. TTP secondary to primary SS is rare but can trigger refractory TTP. Treatment with rituximab, which is considered "inhibitor boosting," should be considered when re-exacerbation occurs.

Patients with severe autoimmune thrombotic thrombocytopenic purpura (TTP) experience acute hematologic emergencies during disease flares and a lifelong threat for relapse. Rituximab, in addition to steroids and therapeutic plasma exchange (TPE), has been shown to mitigate relapse risk. A barrier to care in initiating rituximab in the inpatient setting has been the presumed excessive cost of medication to the hospital. Retrospectively reviewing TTP admissions from 2004 to 2018 at our academic center, we calculated the actual inpatient cost of care. We then calculated the theoretical cost to the hospital of initiating rituximab in the inpatient setting for both initial TTP and relapse TTP cohorts, with the hypothesis that preventing sufficient future TTP admissions offsets the cost of initiating rituximab in all patients with TTP. At a median follow-up of 55 months in the initial TTP cohort, rituximab use produced a projected cost savings of $905 906 and would have prevented 185 inpatient admission days and saved 137 TPE procedures. In the relapse TTP setting, rituximab use produced a projected cost savings of $425 736 and would have prevented 86 inpatient admission days and saved 64 TPE procedures. From a hospital cost standpoint, cost of rituximab should no longer be a barrier to initiating inpatient rituximab in both initial and relapse TTP settings.

Introductions: Patients with acquired thrombotic thrombocytopenic purpura (TTP) show no severe abnormalities in coagulation or fibrinolysis. However, the exact extent of the abnormalities is unclear. Materials and Methods: This study analyzed 138 patients with acquired TTP and 46 patients with septic disseminated intravascular coagulation (DIC) who were included in a Japanese registry. Complete blood cell counts and 8 coagulation or fibrinolysis parameters were compared between the 2 groups. Results: Platelet counts in the acquired TTP group were significantly lower than those in the septic DIC group (P < .001). The international normalized ratio of prothrombin time and the activated partial thromboplastin time in the septic DIC group were significantly higher and longer, respectively, than those in the acquired TTP group (P < .01). The antithrombin (AT) values were significantly lower in the septic DIC group than in the acquired TTP group (P < .001), the latter of which were almost normal. Although both groups revealed elevations of fibrinogen degradation product (FDP) and D-dimer, these levels were significantly higher in the septic DIC group than in the acquired TTP group (P < .001). Of 138 patients with acquired TTP, 25 (18.1%) were diagnosed with septic DIC by the diagnostic criteria of the Japanese Ministry Health, Labour and Welfare, and 78 (56.5%) by those of the Japanese Association of Acute Medicine. Receiver operating characteristic curve analysis showed that acquired TTP could be diagnosed based on severe thrombocytopenia (9/L), normal AT level (>87%), and mildly elevated FDP (Conclusions: Our results indicate that 3 routine laboratory tests could differentiate between acquired TTP and septic DIC.

Despite the effectiveness of plasma exchange (PEX) and immunosuppressants in the treatment of acquired thrombotic thrombocytopenic purpura (aTTP), a number of patients still die as a result of the disease. Whether caplacizumab could rescue these patients remains still unsettled. The objective of this study was to characterise mortality patterns and prognostic factors in the first episode of aTTP. We queried the Spanish TTP Registry for patients with a diagnosis of aTTP in their presenting episode who fulfilled complete clinical and follow-up data (n = 102). The patients were diagnosed between 2004 and 2018, and all were treated with daily PEX and corticosteroids. Clinical and laboratory data were analysed at diagnosis and during the treatment course. Eight patients (7.7%) died between 12 h and 36 days after presentation, and could be classified into three patterns: death before treatment, early death driven by acute cardiac or neurologic events, and late death due to unremitted aTTP. Stupor or coma at diagnosis and platelet count < 20 x 10(9) /L by the 6th treatment day were independently associated with increased risk of death. Stupor or coma at diagnosis and lack of response to PEX by the 6th day in patients experiencing the first episode of aTTP are strong predictors of mortality. These patients could be rescued by novel agents aimed at halting the microvascular thrombosis until adequate immunosuppression is achieved.

Key Clinical Message Acquired thrombotic thrombocytopenic purpura is a life‐threatening condition that rarely presents during pregnancy. Early diagnosis and treatment with plasma exchange is needed to achieve a good pregnancy outcome., Acquired thrombotic thrombocytopenic purpura is a life‐threatening condition that rarely presents during pregnancy. Early diagnosis and treatment with plasma exchange is needed to achieve a good pregnancy outcome.

Acquired thrombotic thrombocytopenic purpura (TTP) is an autoimmune disease that can be triggered by different events, including viral infections. It presents as thrombotic microangiopathy and can lead to severe complications that often require management in the intensive care unit (ICU). We report a patient who presented with acquired TTP following COVID-19 infection. A 44-year-old woman presented to the emergency department with severe anemia, acute kidney injury and respiratory failure due to COVID-19. Clinical and laboratory findings were suggestive for thrombotic microangiopathy. On day 8 laboratory tests confirmed the diagnosis of acquired TTP. The patient needed 14 plasma exchanges, treatment with steroids, rituximab and caplacizumab and 18 days of mechanical ventilation. She completely recovered and was discharged home on day 51. Acquired TTP can be triggered by different events leading to immune stimulation. COVID-19 has been associated with different inflammatory and auto-immune diseases. Considering the temporal sequence and the lack of other possible causes, we suggest that COVID-19 infection could have been the triggering factor in the development of TTP. Since other similar cases have already been described, possible association between COVID and TTP deserves further investigation.

There is limited data on the use of caplacizumab beyond the initial treatment course. We describe a patient case demonstrating the efficacy of a second course of caplacizumab in a patient with relapsed acquired thrombotic thrombocytopenic purpura (TTP). A 25-year-old female was treated for an initial event of TTP with steroids, plasma exchange, rituximab, and caplacizumab. Caplacizumab was continued 30 days post plasma exchange, which was on day 46 of treatment, at which time platelets had improved to 292 x 109/L. Two weeks after completion of the first caplacizumab course, on day 60, she was readmitted with platelets of 5 x 109/L. Daily plasma exchange and steroids were started on admission, with rituximab added on day 65. On day 67, the decision was made to re-initiate caplacizumab due to a platelet count of 21 x 109/L. By day 72, platelets improved to 273 x 109/L and the patient was able to be discharged and completed her second 30-day post plasma exchange course of caplacizumab without complications or further relapses.

Acquired thrombotic thrombocytopenic purpura (TTP) is an uncommon microangiopathic disorder that can have variable presentations and can be precipitated by a multitude of stressors to the body, most commonly sepsis. TTP is caused by a deficiency of ADAMTS13 leading to intravascular clotting causing thrombocytopenia and microangiopathic hemolytic anemia. TTP can be associated with various other pathologic conditions. One such rare association has been reported with diabetic ketoacidosis (DKA). Here, we present an even less appreciated presentation in association with DKA. A 62-year-old African American male with previously diagnosed prediabetes presented with DKA and developed hemodynamically significant bleeding. He was confirmed to have TTP that responded to plasmapheresis. TTP is a life-threatening illness if not treated urgently with plasmapheresis with or without rituximab. As acquired TTP most commonly occurs during stress on the body, it is important to treat the underlying stressor. Early identification and initiation of appropriate interventions are crucial to reducing mortality associated with TTP. Furthermore, we need to appreciate less commonly associated conditions such as DKA among patients.

Since COVID-19 has been declared a global pandemic, variable clinical presentations have been reported, most commonly with respiratory symptoms and less commonly gastrointestinal or neurological symptoms. Hematologic disorders in the form of thrombotic microangiopathies (TMA) such as immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), and microangiopathic hemolytic anemia (MAHA) were also linked to the COVID-19 positive population. Many studies have proposed several possible theories, including viral-mediated, endothelial related, immune triggered, and consumptive mechanisms. In most of the literature, the severity of the disease is associated with more severe thrombocytopenia, with lower levels being associated with higher mortality. We herein report a case of a patient who tested positive for COVID-19 and went on to develop severe thrombocytopenia. Workup of the thrombocytopenia revealed that he had developed acquired Thrombotic thrombocytopenic purpura (TTP). Our case report highlights the need for early recognition, prompt diagnosis, and the subsequent initiation of urgent treatment.

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 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.

Zusammenfassung Anamnese Eine 42-jährige Patientin stellte sich zunächst mit einer Pyelonephritis vor. Zwei Tage später traten Hämatome und punktuelle Einblutungen der Extremitäten auf. Diagnostik/Befunde Eine erworbene thrombotisch-thrombozytopenische Purpura wurde diagnostiziert. Der klinische Befund zeigte das Bild einer thrombotischen Mikroangiopathie mit einer Thrombopenie von 8 × 10E9/l. Es konnten eine erniedrigte ADAMTS13-Aktivität und Autoantikörper nachgewiesen werden. Therapie und Verlauf Bei positivem PLASMIC Score wurde vor Erhalt der ADAMTS13-Diagnostik eine Therapie mittels Plasmaseparation, Steroiden und Caplacizumab eingeleitet und im Verlauf um Rituximab ergänzt. Darunter kam es zu einer raschen klinischen Remission mit jedoch persistierenden ADAMTS13-Antikörpern und reduzierter -Aktivität, so dass Caplacizumab für insgesamt 58 Tage appliziert wurde. Diskussion Mit Caplacizumab steht eine wirkungsvolle neue Therapie der erworbenen thrombotisch-thrombozytopenischen Purpura zur Verfügung. Die Zeit bis zum klinischen Ansprechen und die Zahl der Rückfälle können deutlich reduziert werden. Liegt jedoch eine persistierende Autoimmunaktivität über den Therapiezeitraum hinaus vor, geht diese mit einem hohen Rückfallrisiko einher und erfordert engmaschige Kontrollen.

Acquired thrombotic thrombocytopenic purpura (aTTP) is a serious disorder with arteriolar and capillary thrombosis for which the treatment usually requires plasma exchange with plasma as the replacement fluid. Management of patients who do not accept blood products is a serious challenge. We present the case of a Jehovah's Witness patient who achieved clinical response after treatment with plasma exchange using human albumin solution as the replacing fluid, high dose corticosteroids, and rituximab. The patient also received ADAMTS13 containing plasma cryoprecipitate and von Willebrand factor VIII concentrates. She had an exacerbation of her TTP in less than 3 weeks. She was treated with further plasma exchange with human albumin solution as the replacement fluid, high dose steroids, and rituximab. Bortezomib and N-acetylcysteine were added. The patient eventually improved clinically and achieved remission that is ongoing for more than 7 months. A review of the literature shows that all five previously reported cases of aTTP in Jehovah's Witnesses survived although none received plasma. Two were not even treated with plasma exchange. The experience of this case and those in the literature demonstrates that remission of aTTP may be achieved without using plasma or plasma exchange.

Thrombotic thrombocytopenic purpura (TTP) is a rare disease with a mortality rate of over 90% if left untreated. Therapeutic plasma exchange (PEX) is the mainstay of treatment of acquired TTP (aTTP), and with the introduction of PEX, the mortality rate declined dramatically below 20%. Although PEX together with corticosteroids are the backbone of the upfront management of patients with aTTP with successful outcomes, patients may remain refractory and/or relapse following an initial response to this treatment. There are some therapeutic options, which can be used among these patients, helping in improving outcomes of aTTP. Caplacizumab (formerly ALX-0081 or ALX-0681) is a humanized single-variable domain immunoglobulin that recognizes the human von Willebrand factor (vWF) A1 domain and inhibits the vWF-platelet glycoprotein 1b-alpha (GP1b-α) interaction. The drug was first developed for the prevention of thrombosis in high-risk patients with acute coronary syndrome undergoing percutaneous coronary intervention; however, drug development for this indication has been discontinued. Recently, caplacizumab received its first approval following Phase II TITAN and Phase III HERCULES trials in the European Union (EU) for the treatment of acute episode of aTTP in adult patients, in addition to PEX and immunosuppression. This review focuses on the use of caplacizumab as an emerging treatment option in patients with aTTP.

Background: Prior reports have shown acquired thrombotic thrombocytopenic purpura (TTP) co-existing with connective tissue disorders (CTD). However, these are mainly limited to case reports and case-series reports, and the patient characteristics and clinical outcomes in these patients are not well known. Methods: We used National Inpatient Sample and Nationwide Inpatient Sample (NIS) database for the years 2009 to 2016 to identify all adult patients with TTP and searched for either the presence or absence of any co-existing CTD. These two cohorts of TTP patients were then compared using statistical methods for baseline patient characteristics and clinical outcomes. The primary outcome of interest was the all-cause in-hospital mortality and the secondary outcomes were in-hospital length of stay, in-hospital total charge and in-hospital complications. Results: Of the 14,400 cases of TTP diagnosed between 2009 and 2016, nearly 9% (n = 1,247) had one or more underlying CTD. Patients with TTP were more likely to be young, black, female, with more than one comorbidity and with private insurance if they had an underlying CTD than when they did not have any underlying CTD. There was no difference in regards to the size, location or type of the hospital, or the time taken to initiate plasmapheresis. Patients being managed for TTP had a longer mean length of hospital stay and a greater mean total inpatient stay charge if they had underlying CTD. There was however no difference in the risks of inpatient mortality, acute coronary syndrome, cardiac arrest, acute stroke, need for mechanical ventilation or hemodialysis. Conclusion: TTP and CTD frequently co-existed and contributed to a longer hospital stay and a greater hospital charge. J Clin Med Res. 2019;11(7):509-514 doi: https://doi.org/10.14740/jocmr3850

Background: Immune-related adverse events (irAEs) are secondary reactions related to treatment with immune checkpoint inhibitors (ICIs). There have been six cases published reporting on an association between patients undergoing treatment with ICIs and the occurrence of acquired thrombotic thrombocytopenic purpura (TTP). Case report: We report a 61-year-old male receiving treatment with chemoimmunotherapy followed by pembrolizumab maintenance therapy for advanced non-small-cell lung cancer, presenting with bleeding symptoms, anemia, and thrombocytopenia. The patient received pembrolizumab seven times in total, in three-week cycles. Laboratory testing demonstrated hemolytic anemia, which, in combination with other findings, suggested thrombotic microangiopathy (TMA). PLASMIC scoring and specialized testing with ADAMTS13 activity and inhibitor confirmed a diagnosis of TTP. The patient was started on therapy with plasmapheresis and glucocorticoids, resulting in clinical improvement. The patient chose to leave the hospital under the care of home hospice and died approximately one month after being discharged. Conclusions: Of the six cases of ICI-induced TTP, only one other was treated with pembrolizumab to our knowledge to date. Our patient experienced an adverse reaction marked by thrombocytopenia and hematuria after drug exposure. With symptom improvement after ICI discontinuation and recurrence on readministration, a presumptive diagnosis of ICI-associated TTP was made. This case report and literature review emphasize the need for close observation of patients undergoing ICI therapy for potential rare irAEs. The further investigation aimed at the study of risk factors, disease severity, and treatment response to this form of secondary TTP is needed to guide treatment decisions.

Thrombotic thrombocytopenic purpura (TTP) is a rare but a potentially fatal condition. Although the majority of TTP cases are of unknown etiology, certain viral infections, malignancies, and medications have been linked to the acquired form of the illness. Regardless of the underlying etiology, TTP remains a great challenge diagnostically and therapeutically. TTP remains a very uncommon complication of HIV. We reviewed the current literature to better understand the relationship between HIV and TTP and address some of the major obstacles that may impede or delay the correct diagnosis. Here, we present a case of a 28-year-old male with complaints of light-headedness, fatigue, and gingival bleeding. He was found to have severe anemia and thrombocytopenia. He tested positive for the HIV and was then diagnosed with TTP. Despite needing endotracheal intubation for airway protection, he clinically improved with packed red blood cells, plasmapheresis, and highly active antiretroviral therapy.

Patient: Female, 57-year-old Final Diagnosis: Acquired thrombocytopenic purpura • influenza A virus infection Symptoms: Hypoxemia Medication:— Clinical Procedure: Plasma exchange Specialty: Critical Care Medicine • Hematology Objective: Rare disease Background: Thrombotic microangiopathy, characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ damage by microvascular thrombosis, has a high mortality rate; therefore, early diagnosis and treatment are important. Thrombotic thrombocytopenic purpura is caused by a deficiency of a disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13 (ADAMTS13), and results in thrombotic microangiopathy. Influenza virus causes thrombotic thrombocytopenic purpura by inducing immunoglobulin G autoantibodies against ADAMTS13. We report a rare case of thrombotic thrombocytopenic purpura caused by influenza A without anti-ADAMTS13 antibody that was treated by plasma exchange. Case Report: A 57-year-old woman was admitted to our hospital because of hypoxemia. We diagnosed pneumonia and disseminated intravascular coagulation. Despite treatment, she developed thrombocytopenia, and we diagnosed thrombotic microangiopathy and started plasma exchange. With a PLASMIC score of 6 points and neuropsychiatric symptoms, we strongly suspected thrombotic thrombocytopenic purpura and started rituximab. However, ADAMTS13 activity by FRETS-VWF73 assay was 65%, and anti-ADAMTS13 antibody was negative. After 4 plasma exchanges and 2 rounds of rituximab, platelet numbers and lactate dehydrogenase and creati-nine concentrations normalized on the 16th day of hospitalization. Subsequently, influenza A (H1N1) was identified in a nasopharyngeal swab collected on admission. Plasma enzyme-linked immunosorbent assay testing for chromogenic ADAMTS13 activity showed a significant decrease (

Thrombotic thrombocytopenic purpura (TTP) is thrombotic microangiopathy that is universally fatal if not promptly recognized and treated. Standard treatment includes plasma exchange (PLEX) therapy and immunosuppression. We present a case of an 80 years old African American male with a past medical history significant for essential hypertension, chronic obstructive pulmonary disease, and a recent TTP diagnosis for which he was treated with PLEX, glucocorticoids, and rituximab. The patient presented with complaints of shortness of breath of four days duration. He was hypoxemic on presentation; other vital signs were within normal limits. The basic metabolic panel and complete blood count were unremarkable. A computed tomography (CT) of the chest with contrast showed right lower lobe segmental and subsegmental pulmonary emboli. He was initiated on intravenous heparin therapy. During hospitalization, he had progressive clinical deterioration with progressive hypoxemia. A repeat CT scan demonstrated bilateral pulmonary infiltrates. The patient underwent bronchoscopy due to concerns of opportunistic infections in view of his recent immunosuppressive treatment. Bronchoalveolar lavage revealed cytomegalovirus (CMV), and the patient was initiated on ganciclovir. CMV pneumonia has been reported after rituximab therapy in patients with lymphomas and lymphoproliferative disorders. To our knowledge, this is the first case of CMV pneumonia after rituximab therapy in a patient with TTP.

BACKGROUND Consensus guidelines recommend that therapeutic plasma exchange (TPE) should be started within 4 to 8 hours after the diagnosis of suspected acquired thrombotic thrombocytopenic purpura (aTTP). This study aimed to audit the steps from diagnosis to initiation of plasma exchange at a centralized apheresis service. METHODS A retrospective review of the electronic medical record and laboratory information systems from January 1, 2014 to August 31, 2017 was conducted to identify all patients with suspected aTTP undergoing TPE. Demographics, comorbidities, pertinent laboratory tests, and temporal TPE procedural data were collected. RESULTS The median (5th-95th percentile) time from request to initiation of TPE was 5.4 (3.2-10.6) hours. TPE was initiated within 8 hours in 94 of the 108 patients (87.0%). The median (5th-95th percentile) time from request to central venous access was 2.5 (0.5-6.9) hours and from request to plasma product issuance from the blood bank was 3.4 (1.6-8.1) hours. aTTP patients in whom TPE was initiated greater than 6 hours from request did not have worse outcomes compared to those with TPE initiation within 6 hours: in-hospital mortality (2/14 [14.3%] vs 2/21 [9.5%], P = 0.66), median length of stay (9.0 [4.7-44.1] vs 8.3 [3.9-27.0] days, P = 0.76), and median number of days to durable platelet count recovery (4.5 [2.0-9.0] vs 4.0 [2.0-18.0] days, P = 0.66). CONCLUSIONS The 4 to 8-hour target window from TPE request to initiation appears feasible for a centralized apheresis program servicing a large healthcare system.

BACKGROUND Thrombotic thrombocytopenic purpura (TTP) is a rare disease and a potentially life-threatening thrombotic microangiopathy. Although the diagnostic and therapeutic techniques have improved, it is still difficult for clinicians to identify early due to different initial clinical manifestations and the incidence and survival rate are reported inconsistently. This study investigated the clinical characteristics, treatment strategies, and treatment outcomes of adult patients with acquired TTP. METHODS A retrospective analysis of 55 patients (35 females and 20 males) treated for acquired TTP from January 1, 2013 to December 31, 2017 was conducted. The analysis included clinical manifestations at onset, treatment efficacy measures, survival, cause of death, and the APACHE II (Acute Physiology and Chronic Health Evaluation II) and SOFA (sequential organ failure assessment) scores. RESULTS At onset, in addition to thrombocytopenia and hemolysis, 50 patients (90.91%) presented with neurological abnormalities, but only 19 (34.55%) showed the classic TTP pentad of symptoms. The overall mortality rate was 34.55%. Plasma exchange (PEX) was performed in 49 patients. The most effective treatment was PEX with a normal dose of corticosteroid and rituximab which showed a response rate of 81.25%. The main cause of death was cerebral hemorrhage. The APACHE II and SOFA scores were higher in non-survivors compared to survivors (APACHE II: 20.12±7.83 vs. 11.50±4.49, P

Acquired thrombotic thrombocytopenic purpura (TTP) in children is a rare but severe disease, which is caused by Immunoglobulin G antibodies, which inactivate a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13). Daily high-volume plasma exchange (PEX) and immunosuppression with glucocorticoids and rituximab is the current standard of treatment for TTP. We report two females aged 5 and 12 years, with TTP, induced by anti-ADAMTS13 inhibitory antibodies who relapsed very shortly after PEX, rituximab and glucocorticoids, in whom long-term remission with disappearance of ADAMTS13 inhibitors was achieved after one course of bortezomib.

Microangiopathic hemolytic anemia (MAHA) can be observed as a paraneoplastic syndrome (PS) in certain tumors. MAHA-related signet ring cell carcinoma (SRCC) of an unknown origin is very infrequent. Herein we present a SRCC case presented with refractory acquired thrombotic thrombocytopenic purpura (TTP). A 35-year-old man applied to the emergency service with fatigue and headache. His laboratory tests resulted as white blood cell 9,020/µL, hemoglobin 3.5 g/dL, platelet 18,000/µL. Schistocytes, micro-spherocytes, and thrombocytopenia were observed in his blood smear. MAHA was present and he was considered as having TTP. Plasma exchange treatment was initiated; however, he was refractory to this treatment. Thorax and abdomen computerized tomography revealed thickening of minor curvature in stomach corpus with hepatogastric and paraceliac lymphadenopathy. Bone marrow (BM) investigation by our clinic resulted as the metastasis of adenocarcinoma. Ulceration and necrosis were observed by gastric endoscopy procedure. Biopsy was taken during endoscopic intervention, which resulted as SRCC. MAHA may be seen as a PS in some tumors, especially gastric cancers. Tumor-related MAHA is generally accompanied by BM metastases. As a result, BM investigation may be used as the main diagnostic method to find the underlying cancer. The clinical course of cases with tumor-related MAHA is usually poor, and these cases are usually refractory to plasma exchange treatment. In conclusion, physicians should suspect a malignancy and BM involvement when faced with a case of refractory TTP.

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Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare autoimmune disorder characterized by auto-antibodies to Willebrand factor (vWF) cleaving enzyme (ADAMTS13), resulting in unusually large vWF multimers that lead to platelet aggregation, microthrombi formation and microangiopathic hemolytic anemia. Hemolysis in aTTP is mechanical; thus, direct antiglobulin test (Coombs test) is usually negative. Multiple autoimmune conditions and various auto-antibodies have been described in the context of chronic myelomonocytic leukemia (CMML). In this paper, we describe the first case of CMML with auto-antibodies to ADAMTS13, presenting initially as plasmapheresis-refractory Coombs-positive aTTP. ----- Results: Although our patient was not treated for CMML, a complete remission of aTTP was eventually achieved with rituximab. Conclusion; We propose that aTTP should be in the differential diagnosis of CMML patients with thrombocytopenia and anemia (Coombs positive or not) who develop signs of thrombotic microangiopathy. Further studies are much needed to decipher the immune-mediated processes in CMML.

Introduction Acquired thrombotic thrombocytopenic purpura is a rare disease associated with the production of autoantibodies against the VWF-cleaving protease ADAMTS13. The detection of these antibodies is made difficult by the instability of ADAMTS13 in citrated plasma and the time-consuming ADAMTS13 assays. The aim of our study was to evaluate the optimal conditions for detecting anti-ADAMTS13 inhibitory antibodies with the novel automated chemiluminescent immunoassay HemosILR AcuStar ADAMTS13 Activity assay. Methods The parallelism between the AcuStar ADAMTS13 calibration curve and ADAMTS13 concentrations in serially diluted citrated plasma was evaluated after 2 hours incubation at 25°C, 37°C, or 37°C after addition of Ca2+ to preserve the activity of the metalloprotease. Using Bethesda assays based on the 3 incubation procedures and the HemosILR AcuStar ADAMTS13 Activity assay, the inhibitor titers were determined in patients' samples with ADAMTS13 antibodies and compared with those determined using the TechnozymR ADAMTS13 activity ELISA. Results The criterion of parallelism was respected for the 3 incubation methods over the range of ADAMTS13 concentrations relevant for the detection of ADAMTS13 inhibitor antibodies in a Bethesda assay. In agreement with this observation, all the incubation methods permitted the accurate detection and quantification of inhibitory anti-ADAMTS13 antibodies in the samples from patients with acquired thrombotic thrombocytopenic purpura. Conclusion Incubation of plasma samples with normal plasma at 25°C, 37°C, or 37°C after addition of Ca2+ can be used in a Bethesda assay for quantifying the inhibitory activity of antibodies interfering with ADAMTS13 in the chemiluminescent HemosILR AcuStar ADAMTS13 Activity assay.

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare but life-threatening condition. In 2018, the nanobody caplacizumab was approved for the treatment of adults experiencing an acute episode of aTTP, in conjunction with plasma exchange (PEX) and immunosuppression for a minimum of 30 days after stopping daily PEX. We performed a retrospective, observational analysis on the use of caplacizumab in 60 patients from 29 medical centers in Germany during acute disease management. Caplacizumab led to a rapid normalization of the platelet count (median, 3 days; mean 3.78 days). One patient died after late treatment initiation due to aTTP-associated complications. In 2 patients with initial disease presentation and in 4 additional patients with laboratory signs of an exacerbation or relapse after the initial therapy, PEX-free treatment regimens could be established with overall favorable outcome. Caplacizumab is efficacious in the treatment of aTTP independent of timing and ancillary treatment modalities. Based on this real-world experience and published literature, we propose to administer caplacizumab immediately to all patients with an acute episode of aTTP. Treatment decisions regarding the use of PEX should be based on the severity of the clinical presentation and known risk factors. PEX might be dispensable in some patients.

Acute acquired thrombotic thrombocytopenic purpura (TTP) requires prompt recognition and initiation of plasma exchange (PEX) therapy and immunosuppression. When PEX fails, mortality nears 100%, making finding an effective treatment crucial. Primary refractory TTP occurs when initial therapies fail or if exacerbations occur during PEX therapy, both signifying the need for treatment intensification to achieve clinical remission. Rituximab helps treat most of the refractory TTP cases, except those that are severely refractory. A paucity of studies guiding severely refractory TTP makes management arbitrary and individualised, highlighting the value of isolated reports. We present an extremely rare case of primary refractory TTP with an insufficient platelet response to numerous types of treatments, including emerging therapies such as caplacizumab, on the background of repeated PEX and immunosuppressive therapies.

Introduction: Acquired thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease characterized by thrombotic microangiopathy leading to end-organ damage. The standard of care (SOC) treatment is therapeutic plasma exchange (TPE) alongside immunomodulation with steroids, with increasing use of rituximab +/- other immunomodulatory agents. The addition of caplacizumab, a nanobody targeting von Willebrand factor, was shown to accelerate platelet count recovery, reduce TPE treatments and hospital length of stay, decrease exacerbations and increase relapses in TTP patients treated in the TITAN and HERCULES trials. Given the efficacy of caplacizumab in the TITAN and HERCULES trials, we conducted a cost effectiveness analysis (CEA) of caplacizumab in acquired TTP, representing the first-ever CEA in TTP. Methods: We built decision tree models to evaluate the cost effectiveness of SOC plus caplacizumab versus SOC in acquired TTP based on the results of each of the phase II TITAN trial at 12-month follow-up and the phase III HERCULES trial at 1-month follow-up. Costs were assessed from the health system perspective. For each trial, the SOC cost was calculated as the sum of TPE sessions, hospital length-of-stay (LOS), intensive care unit (ICU) stay, and rituximab use, while the cost of the SOC plus caplacizumab arm included the SOC cost plus the list price of caplacizumab (USD $270,000 per TTP episode). Effectiveness was calculated in quality-adjusted life years (QALY). Cost effectiveness of each treatment arm was calculated as the ratio of cost divided by QALYs. The incremental cost effectiveness ratio (ICER) of adding caplacizumab to SOC was calculated as the difference between the costs of the two treatment arms divided by the difference in QALYs; the ICER was then compared against the 2019 US willingness-to-pay (WTP) threshold of $195,300 USD as a measure of overall cost effectiveness. To avoid potential confounding factors that might inadvertently bias our analysis against the addition of caplacizumab, all values used in our models were selected to maximize cost in the SOC arm and minimize cost in the SOC plus caplacizumab arm in the two clinical trials. We also created a Markov model comparing cost effectiveness of SOC plus caplacizumab versus SOC in acquired TTP with a 5-year time horizon. We performed one-way sensitivity analyses for all models varying parameters including LOS, ICU stay, number of TPE sessions, rituximab use, utilities of the well and diseases states, and caplacizumab cost. Results: In the decision tree models, caplacizumab use yielded a higher cost of treatment compared to SOC alone in both trials (TITAN: $325,647 for caplacizumab plus SOC, versus $89,750 for SOC; HERCULES: $323,547 for caplacizumab plus SOC, versus $83,634 for SOC). An improvement in QALYs with the addition of caplacizumab was noted as compared to SOC in both trials (0.07 in TITAN and 0.26 in HERCULES). The ICER for adding caplacizumab to SOC versus SOC alone was $3.7 million in the TITAN trial and $0.9 million in the HERCULES trial, well above the US WTP threshold. The 5-year horizon Markov model yielded higher cost of caplacizumab treatment compared to SOC alone ($551,878 versus $151,947) and an improvement in QALYs (3.19 versus 2.92). The ICER for adding caplacizumab to SOC was $1.5 million (95% confidence interval $1.25-$1.72 million) with SOC favored in 100% of 10,000 Monte Carlo simulations in a probabilistic sensitivity analysis. Among all parameters, decreasing the cost of caplacizumab had the greatest impact on decreasing the ICERs in all models. The price of caplacizumab treatment for one TTP episode to meet the 2019 US WTP would have to be $46,424 and $80,848 in the TITAN and HERCULES decision tree models, respectively, and $65,106 in a Markov model with a 5-year horizon. Conclusion: The addition of caplacizumab to SOC treatment is not cost effective at its current drug pricing. As our models are designed to maximize the cost effectiveness of caplacizumab, it is very likely that the actual costs incurred by this medication will be much higher than what we report here. Compared to CEA studies of other orphan drugs that, unlike caplacizumab, alter long-term disease course, the costs incurred by caplacizumab treatment in acquired TTP are at the higher end of the spectrum. Additional studies utilizing longer-term follow-up data are warranted to assess the full impact of caplacizumab on the cost of treating TTP. Figure Disclosures No relevant conflicts of interest to declare.