Guidelines on the diagnosis and management of the thrombotic microangiopathic haemolytic anaemias

Thrombotic Microangiopathy in Pregnancy: Current Understanding and Management Strategies

Thrombotic microangiopathy (TMA) represents a heterogeneous group of disorders characterized by microvascular thrombosis and end-organ damage. Pregnancy-associated thrombotic microangiopathy (p-TMA) has emerged as a distinct clinical entity with unique diagnostic challenges. Identifying the specific form of p-TMA is critical for appropriate and timely management. This review offers a comprehensive overview of the various forms of thrombotic microangiopathies associated with pregnancy, highlighting our current understanding of their pathophysiology and the evolving landscape of diagnosis and treatment for each.

A Comprehensive and Practical Approach to the Management of Lupus Nephritis in the Current Era

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE) and is one of the leading causes of morbidity and mortality in patients with SLE. It is estimated that up to 60% of individuals with SLE will develop LN, which can manifest at any stage of a patient's life; however, it commonly emerges early in the course of SLE and tends to exhibit a more aggressive phenotype in men compared to women. Black and Hispanic patients are more likely to progress to kidney failure than white patients. LN is characterized by kidney inflammation and chronic parenchymal damage, leading to impaired kidney function and potential progression to kidney failure. This article provides a comprehensive overview of the epidemiology, pathogenesis, clinical presentation, diagnosis, and management of LN, highlighting the importance of early recognition and treatment of LN to prevent progressive, irreversible kidney damage and improve patient outcomes. Additionally, the article discusses current and emerging therapies for LN, including traditional immunosuppressive agents, biological agents, and novel therapies targeting specific pathways involved in LN pathogenesis, to provide a practical guide for clinicians in properly diagnosing LN and determining a patient-centered treatment plan.

Stress-induced hyperglycemia is associated with the mortality of thrombotic thrombocytopenic purpura patients

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy with a rapid progression and high mortality rate. We aimed to explore early risk factors for mortality in patients with TTP.

METHODS

We conducted a retrospective analysis of 42 TTP patients that were admitted to our hospital between 2000 and 2021, with a median age of 49 (29-63) years. Risk factors for mortality were evaluated using multivariate logistic regression. Receiver operating characteristic curve analysis was used to determine the cut-off value of glucose for predicting mortality in patients, which was validated by comparison to a similar cohort in the published literature.

RESULTS

Elevated glucose level and reduced red blood cells (RBC) counts were risk factors for mortality in patients with TTP (glucose, odds ratio and 95% confidence interval: 2.476 [1.368-4.484]; RBC, odds ratio and 95% confidence interval: 0.095 [0.011-0.799]). The area under the curve of glucose was 0.827, and the cut-off value was 9.2 mmol/L, with a sensitivity of 75.0% and specificity of 95.8%. A total of 26 cases from the validation cohort had a sensitivity of 71.0% and a specificity of 84.0%. The change trends of the TTP-related laboratory indices differed during hospitalization.

CONCLUSION

Hyperglycemia at admission and unstable blood glucose levels during hospitalization may be potential predictors of mortality for TTP patients. The improved prognosis was associated with the recovery of platelet counts and a significant decrease in serum lactate dehydrogenase after five days of treatment.

Dengue Infection Triggering Concurrent Thrombotic Thrombocytopenic Purpura in a Case of Chronic Idiopathic Thrombocytopenic Purpura

We present a case report detailing the medical history of a 53-year-old female who had a well-established 10-year history of idiopathic thrombocytopenic purpura (ITP). The patient presented with fever and gum bleeding, prompting a series of laboratory investigations. These examinations revealed concurrent thrombocytopenia and hemolytic anemia, alongside a positive test result for serum dengue IgM antibodies. Initial treatment for the patient involved intravenous administration of glucocorticoids and intravenous immunoglobulin. Regrettably, this therapeutic intervention did not yield a favorable response. Subsequent clinical developments, including the onset of generalized tonic-clonic seizures, raised suspicions of thrombotic thrombocytopenic purpura (TTP). A notable diagnostic indicator was the elevated PLASMIC score (platelet count; combined hemolysis variable; absence of active cancer; absence of stem-cell or solid-organ transplant; mean corpuscular volume; international normalized ratio; creatinine), reinforcing the consideration of TTP. To confirm the diagnosis, ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs 13) enzyme levels were assessed and found to be low. Consequently, the patient was diagnosed with TTP. Plasmapheresis was administered, resulting in a positive clinical response after two cycles. Notably, the patient experienced a resolution of thrombocytopenia and hemolytic anemia. Following successful treatment, the patient was discharged with a prescription for immunosuppressants. This case underscores the critical importance of including TTP as a potential differential diagnosis when encountering patients with chronic ITP. TTP is characterized by its acute and life-threatening nature, often deviating from the typical clinical presentation. The application of the PLASMIC score serves as a valuable tool in guiding decision-making processes when TTP is suspected.

Therapeutic plasma exchange-free treatment for first-episode TTP: A systematic review

OBJECTIVE

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy (TMA), and therapeutic plasma exchange (TPE) is currently the standard treatment. However, TPE sometimes cannot be implemented. The aim of this study was to systematically review patients with a first TTP episode who were treated without TPE.

METHOD

The PubMed, Embase, Web of Science and Cochrane Library databases were searched by two investigators independently to collect case reports and clinical studies on TTP patients treated without TPE. After removing duplicate records and records that did not meet the inclusion criteria, the patients' data of eligible studies, including the basic characteristics, treatment regimens, and outcomes were extracted for further analysis.

RESULTS

A total of 5338 potentially relevant original studies were identified, from which 21 studies, including 14 cases, 3 case series and 4 retrospective studies, met eligibility requirements and were included. Treatment regimens in the absence of TPE were found to vary based on individual information. Most patients recovered, with normal platelet counts and ADAMT13 activity at discharge. In the meta-analysis of retrospective studies, the TPE-free group had no higher mortality than the TPE-treated group.

CONCLUSION

Our study shows that TPE-free treatment may not increase the mortality of TTP patients, which provides a new treatment concept for patients with first episodes of TTP. However, the current evidence is not high due to the lack of randomized controlled trials, so more well-designed prospective clinical trials are warranted to investigate the safety and efficacy of TPE-free treatment regimens in TTP patients.

Coexistence of thrombotic thrombocytopenic purpura and immune thrombocytopenic purpura in an Asian woman: a case report

A 33-year-old Chinese woman with a history of immune thrombocytopenic purpura presented with heavy menstrual bleeding. She was found to have thrombocytopenia, plasma ADAMTS13 activity of 0%, and positivity for the plasma ADAMTS13 inhibitor. She was diagnosed with the coexistence of thrombotic thrombocytopenic purpura and immune thrombocytopenic purpura. The patient was treated by plasmapheresis, a glucocorticoid, and rituximab. Her platelet level returned to normal, and she was discharged 28 days after admission. The number of plasmapheresis sessions and the timing of rituximab administration may be the key aspects of management of patients with thrombotic thrombocytopenic purpura who have underlying immune dysfunction caused by diseases such as immune thrombocytopenic purpura.

Coexistence of thrombotic thrombocytopenic purpura and adult-onset Still's disease

The association of Thrombotic thrombocytopenic purpura (TTP) and adult-onset Still's disease (AOSD) is very uncommon. Hereby, we present a case of TTP occurring in patient with a known AOSD and the successful outcome after plasma exchanges.

Atypical hemolytic uremic syndrome: when pregnancy leads to lifelong dialysis: a case report and literature review

Atypical hemolytic uremic syndrome (aHUS), a challenging disorder, commonly caused by inherited defects or regulatory processes of the complement alternative pathway. There are multiple causes, including pregnancy. Pregnancy provokes life-threatening episodes, preeclampsia, hemolysis elevated liver enzymes low platelets, microangiopathic hemolytic anemia (MAHA) and end-stage renal disease. Additionally, complement dysregulation and, with aHUS, affects fetal and maternal outcomes. Pregnancy-associated aHUS results in a poor prognosis with irreversible renal damage. Likewise, it is imperative to know that MAHA can provoke endothelial disruption, destruction of red cells and thrombocytopenia. We present a case of a young 18-year-old woman with MAHA and aHUS, requiring emergent cesarean section at 34 weeks of gestation and hemodialysis, secondary to complications from a recent pregnancy. Elevated blood pressure readings, rising creatinine levels, as well as her mother being on dialysis after pregnancy raised suspicion for thrombotic microangiopathy and aHUS. She was subsequently managed with plasma exchange, steroids, eculizumab and hemodialysis. Thus, plasma exchange should be initiated, with pending additional workup. Upon a definitive diagnosis of aHUS, eculizumab would be warranted to mitigate immune dysregulation. Understanding thrombotic microangiopathies diagnosis, and recognizing concomitant consequences, is vital. Having better insights into endothelial injuries can prevent unfortunate outcomes.

Proteinuria Increases the PLASMIC and French Scores Performance to Predict Thrombotic Thrombocytopenic Purpura in Patients With Thrombotic Microangiopathy Syndrome

Introduction

PLASMIC and French scores have been developed to help clinicians in the early identification of patients with thrombotic thrombocytopenic purpura (TTP). Nevertheless, the validity of these scores in thrombotic microangiopathy (TMA) cohorts with low TTP prevalence remains uncertain. We aimed to evaluate their diagnostic value in routine clinical practice using an unselected cohort of patients with TMA. We also analyzed the value of adding proteinuria level to the scores.

Methods

We retrospectively included all patients presenting with a biological TMA syndrome between January 1, 2008, and December 31, 2019, in a tertiary hospital. TMA etiology was ascertained, and scores were evaluated. Modified scores, built by adding 1 point for low proteinuria (<1.2 g/g), were compared with original scores for TTP prediction.

Results

Among 273 patients presenting with a full biological TMA syndrome, 238 were classified with a TMA diagnosis. Complete scores and proteinuria level were available in 134 patients with a TTP prevalence of 7.5%. Area under the receiver operating characteristic curve (AUC) of PLASMIC and French scores for TTP diagnosis was 0.65 (0.46–0.84) and 0.72 (0.51–0.93), respectively. AUC of modified PLASMIC and French scores was 0.76 (0.59–0.92) (P = 0.003 vs. standard score) and 0.81 (0.67–0.95) (P = 0.069 vs. standard score), respectively. Specificity, positive predictive value (PPV), and positive likelihood ratio of high-risk scores were significantly improved by adding proteinuria level.

Conclusion

PLASMIC and French scores have low predictive values when applied to an unselected TMA cohort. Including proteinuria level in the original scores improves their performance for TTP prediction.

Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome With Severe Thrombocytopenia and Severe ADAMTS13 Activity Deficiency

BACKGROUND

Differentiating preeclampsia with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome from thrombotic thrombocytopenic purpura (TTP) can present a diagnostic dilemma.

CASE

We report the case of a 34-year-old woman, G1P0, with monochorionic diamniotic twins who presented with new-onset blurry vision, hypertension, and a platelet count of 4×109/L. After a multidisciplinary discussion, a diagnosis of atypical HELLP syndrome was made, despite overlapping features concerning for TTP. Her platelet count and ADAMTS13 activity testing showed appropriate recovery after delivery, without plasma exchange therapy, supporting the diagnosis of HELLP syndrome.

CONCLUSION

Hemolysis, elevated liver enzymes, and low platelet count syndrome may present with severe thrombocytopenia and severe ADAMTS13 activity deficiency in ranges otherwise known to be more common with TTP.

Unresponsive Thrombotic Thrombocytopenic Purpura (TTP): Challenges and Solutions

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy secondary to a severely decreased A Disintegrin And Metalloprotease with ThromboSpondin type 1 repeats 13 (ADAMTS13) activity, resulting in the formation of widespread von Willebrand factor - and platelet-rich microthrombi. ADAMTS13 deficiency is mainly acquired through anti-ADAMTS13 autoantibodies in adults. With modern standards of care, unresponsive TTP has become rarer with a frequency of refractory/relapsing forms dropping from >40% to <10%. As patients with unresponsive TTP are at increased risk of mortality, prompt recognition and early therapeutic intensification are mandatory. Therapeutic options at the disposal of clinicians caring for patients with refractory TTP consist of increased ADAMTS13 supplementation, increased immunosuppression, and inhibition of von Willebrand factor adhesion to platelets. In this work, we focus on possible therapies for the management of patients with unresponsive TTP, and propose an algorithm for the management of these difficult cases.

Salmonella osteomyelitis complicating aseptic osteonecrosis: Don't forget about the antiphospholipid syndrome

Osteonecrosis in antiphospholipid syndrome is a diagnostic challenge for clinicians. Early diagnosis and intervention are important for better prognosis.

Incidence, diagnosis, and outcome of immune-mediated thrombotic thrombocytopenic purpura: A nationwide survey by the Spanish registry of thrombotic thrombocytopenic purpura

BACKGROUND

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare disease characterized by the presence of anti-ADAMTS13 autoantibodies. Achieving accurate information on incidence and customary disease management is important to provide appropriate diagnostic and therapeutic resources. The aim of this study was to determine the incidence and outcomes of iTTP in Spain.

STUDY DESIGN AND METHODS

A cross-sectional survey was carried out among Spanish hospitals, focused on iTTP patients ≥16 years old attended between 2015 and 2017, and those at follow-up before that interval. Incidence, prevalence, mortality, refractoriness, exacerbations, treatment complications, relapses, and sequelae were estimated.

RESULTS

Forty-two hospitals covering roughly 20 million inhabitants answered the survey and reported 203 episodes (138 newly-diagnosed and 65 relapses), of which 193 (95.1%) were treated. Incidence was 2.67 (95% CI 1.90-3.45) patients per million inhabitants per year and prevalence 21.44 (95% CI% 19.10-23.73) patients per million inhabitants. At diagnosis, ADAMTS13 activity and anti-ADAMTS13 autoantibody were measured in 97% and 84.3% of reported episodes, respectively. Fifteen patients (7.4%) died as a direct consequence of iTTP, 6 of them before receiving any iTTP-specific treatment. Thirty-one (16.1%) of the 193 treated episodes were refractory to plasma exchange and corticosteroids, and 51 (26.4%) suffered at least one exacerbation.

CONCLUSION

iTTP incidence and prevalence were somewhat higher than those documented in neighboring countries. Together with data on treatments and outcomes, this information will allow us to better estimate what is needed to improve diagnosis and prognosis of iTTP patients in Spain.

Plasma exchange and thrombotic microangiopathies: From pathophysiology to clinical practice

Thrombotic microangiopathy (TMA) brings together many diseases that have a commonality in the apparition of mechanical hemolysis with consuming thrombopenia. In all cases, these diseases can be life threatening, thereby justifying the implementation of treatment as an emergency. First-line treatment represents plasma exchange. This treatment has proven efficiency in improving the vital patient's and functional prognosis. However, the administration methods of plasma exchange can be redefined in light of the understanding of the pathophysiology of TMA. The aim of this review is to try to define, from pathophysiology, the place of plasma exchanges in the modern therapeutic arsenal of TMA.

Nivolumab-Induced Thrombotic Thrombocytopenic Purpura in a Patient with Anal Squamous Cell Carcinoma: A Lesson on Hematologic Toxicity from Immunotherapy

Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening microangiopathic hemolytic anemia characterized by thrombocytopenia, hemolytic anemia, and ischemic organ damage. It is mainly caused by an autoreactive antibody directed at ADAMTS13. Immunotherapy is frequently associated with autoimmune complications in patients with cancer, but only three cases of TTP have been reported, none implicating single treatment with the anti-programmed cell death receptor 1 ligand antibody nivolumab. We present the first identified and reported case of nivolumab-associated TTP in a 51-year-old woman with stage IIIc anal carcinoma who achieved complete response following chemoradiation and received adjuvant nivolumab as part of a randomized clinical trial. Twelve weeks into treatment, she presented with dark urine, progressive fatigue, and headache. TTP diagnosis was based on laboratory evidence of hemolytic anemia, thrombocytopenia, and ADAMTS13 activity of 9% associated with an inhibitor. She was treated with daily plasma exchange and oral prednisone and responded well to treatment, with platelet counts over 100 K/cmm within 4 days. We reviewed and summarized data from all reported cases of TTP associated with cancer immunotherapy. We provide guidance on identification and management of this devastating hematologic complication, focusing on the importance of early recognition, as most patients achieve complete recovery with appropriate treatment. KEY POINTS: Thrombotic thrombocytopenic purpura (TTP) was originally excluded from previous reviews of hematologic immune-related adverse events; however, several cases have been reported in the past 2 years in patients treated with either single agent or combination of cytotoxic T-lymphocyte-associated antigen 4 and the programmed cell death receptor 1 (PD-1) or the PD-1 ligand inhibitors. Although rare, TTP is a life-threatening condition that could be challenging to diagnose, and early recognition is key as delayed treatment is associated with significant increase in mortality. The pathophysiology of immunotherapy-induced TTP is likely related to autoimmune inhibition of ADAMTS13; the addition of prednisone and rituximab to urgent plasmapheresis appears to be effective and should be part of the up-front management for these patients.

Successful treatment of refractory thrombotic thrombocytopenic purpura associated with systemic lupus erythematosus with combination of plasma exchange and low-dose rituximab

OBJECTIVES

Thrombotic thrombocytopenia purpura (TTP) associated with systemic lupus erythematous (SLE) (i.e., SLE-TTP) is a rare life-threatening disease often requiring intensive immunosuppressive agents, in addition to high-dose corticosteroids and plasma exchange (PEX). The optimal therapy of rituximab is unclear, but 375 mg/m² weekly for 4 weeks is the usual practice, adopted from regimens for non-Hodgkin's lymphoma. We reported two cases of refractory SLE-TTP that showed good efficacy and prognosis with combination of methylprednisolone (MP) pulse, plasma exchange and low-dose rituximab (100 mg weekly for 4 weeks) treatment.

METHODS

Clinical data and treatment outcomes were reviewed of two patients diagnosed with refractory SLE-TTP at Peking Union Medical College Hospital between July 2017 and July 2018.

RESULTS

Both patients had SLE and presented with microangiopathic anemia and thrombocytopenia. Laboratory assays revealed high anti-nuclear antibody titers, reduced complement 3 and 4 levels, proteinuria, significantly elevated lactate dehydrogenase, schistocytes on peripheral blood smear, low ADAMTS13 activity, and the presence of ADAMTS13 inhibitor. In both patients, platelet counts remained below 50 × 10⁹/L after MP pulse and 6 PEXs, confirming the diagnosis of refractory SLE-TTP. Low-dose rituximab (100 mg weekly for 4 weeks) was administered in both cases, resulting in normalization of platelet counts and significant reductions in B-lymphocyte counts. No TTP relapse or SLE flare occurred during 24 months of follow-up.

CONCLUSIONS

Our cases confirmed the efficacy and good follow-up outcomes of low-dose rituximab treatment (100 mg weekly for 4 weeks) for refractory SLE-TTP.

Role of plasma exchange in management of patients clinically diagnosed of postpartum thrombotic microangiopathies: A retrospective observation from a tertiary health-care center

Introduction:

Diagnosis of postpartum thrombotic microangiopathies in pregnancy is a challenge, but plasma exchange (PE) is life-saving in such cases. This study was conducted with the aim to find the result of the early start of PE in such patients.

MATERIALS AND METHODS:

There were a total of seven clinically diagnosed cases of post partum thrombotic microangiopathies (PP-TMA) where PE was done. The diagnosis of PP-HUS and decision to start PE in such cases were based on the classical triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. All the PE procedures were done using fully automatic COM.TEC (Fresenius Kabi, Germany).

RESULTS:

Immediately before the start of PE, the mean platelet count and serum lactate dehydrogenase (LDH) and hemoglobin (Hb) were 53.1 × 109/L, 10,943 IU/L, and 6.4 gm%, respectively. After seven sessions of PE, platelet count improved to 158 × 10⁹/L and LDH dropped to 609 IU/L, and Hb improved to 10.3 gm% (P < 0.05). We got a positive renal response in four patients in whom serum creatinine value reached within normal range while in the remaining three patients, no positive renal response was obtained and serum creatinine remained above normal range. Thus, the response of PE was shown to be inadequate in three patients. Compliance to PE was good. Patients were discharged after 20 days (mean) of hospital admission.

CONCLUSION:

PE is life-saving in PP-HUS. High degree of clinical suspicion to it and early start of PE were crucial for successful outcome in our patient population.

Successful treatment of plasma exchange-refractory thrombotic thrombocytopenic purpura with rituximab: A case report

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), a subtype of thrombotic microangiopathy, has a very high fatality rate if there is no timely diagnosis or treatment. Here, we report a case of TTP refractory to high displacement plasma exchange, which was later successfully treated with rituximab.

CASE SUMMARY

Here we report a case of refractory TTP in a 63-year-old woman with a low platelet count and decreased ADAMTS13 activity. Her platelet count was 9 × 10⁹/L, hemoglobin level was 81 g/L, and ADAMTS13 was < 5%. She was diagnosed with thrombotic thrombocytopenic purpura. After 8 d of daily plasma exchange (PEX), her platelet levels were still low. However, after 6 d of treatment with rituximab, her platelet count increased and ADAMTS13 activity returned to normal.

CONCLUSION

PEX can cure most patients, but the relapse rate can be up to 50%-60%. This case suggested that rituximab can improve the curative efficiency of PEX and prevent disease relapse in TTP.

Clinical presentation and management of acquired thrombotic thrombocytopenic purpura: A case series of 55 patients

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 <10% of the normal range. ADAMTS13 inhibitor was tested in 20 patients and was positive in 18 patients. Both ADAMTS13 activity and ADAMTS13 inhibitor were examined in 20 patients and 90% of the patients showed double positive results. The treatment methods included plasma exchange, glucocorticoids, rituximab, immunosuppressants, and intravenous immunoglobulin. Thirty-three patients survived, and 22 patients died. Plasma exchange improved the remission rate from 16.7% to 65.3% (P = .022). The combined immunosuppressive therapy based on plasma exchange and glucocorticoids raised the remission rate from 43.8% to 75.8%. Most of acquired TTP patients had the Triad syndrome or the Quinary syndrome. A high proportion of TTP patients had ADAMTS13 activity reduction and ADAMTS13 inhibitor positivity. Plasma exchange and immunosuppressive therapy may improve the prognosis of this disease.

An Autopsy Case of Mixed Connective Tissue Disease Complicated by Thrombotic Thrombocytopenic Purpura

We herein report a patient with mixed connective tissue disease (MCTD) who had been stable for years but suddenly developed thrombotic thrombocytopenic purpura (TTP). The patient showed a clinical pentad of signs of TTP, low activity of ADAMTS13, and positivity of anti-ADAMTS13 antibodies. She did not respond to plasma exchange or steroid therapy and died five days after admission. An autopsy revealed microthrombi in the brain, heart, kidney, adrenal glands, esophageal submucosa, and bone marrow as well as diffuse alveolar hemorrhaging. Physicians should bear in mind that TTP can occur in MCTD patients regardless of disease activity.

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.

Gastrointestinal infection-related disseminated intravascular coagulation mimicking Shiga toxin-mediated hemolytic uremic syndrome - implications of classical clinical indexes in making the diagnosis: A case report and literature review

BACKGROUND

Thrombocytopenia associated with acute kidney injury is a challenging disorder. Thrombotic microangiopathy (TMA) is a potentially life- or organ-threatening syndrome that can be induced by several disorders or medical interventions. There is overlap between the clinical presentation and pathophysiology of thrombotic thrombocytopenia purpura and hemolytic uremic syndrome (HUS), and to a lesser extent, disseminated intravascular coagulation (DIC). We describe a case to illustrate the potential diagnostic difficulty, especially at initial presentation.

CASE SUMMARY

We reported a case of a 44-year-old woman that presented with diarrhea, thrombocytopenia, schistocytes, elevated serum lactate dehydrogenase (LDH) level and acute kidney injury. While the clinical presentation resembled that of Shiga toxin–induced HUS, the disease course was more consistent with gastrointestinal infection-related DIC. To aid in the accurate diagnosis of TMA and other associated disorders, we have undertaken a review and provided a clear interpretation of some typical biomarkers including schistocytes, LDH and platelet count, coagulation profile and more specific indexes of ADAMTS13, complement profile, and the isolation of Shiga toxin-producing Escherichia coli (commonly referred to as STEC).

CONCLUSION

The use and correct interpretation of classical indexes of schistocyte, LDH, and platelet count is vital in diagnosing TMA and associated disorders. Understanding the characteristics of these biomarkers in the context of thrombocytopenia purpura, HUS and DIC will facilitate the accurate diagnosis and early initiation of appropriate treatment.

Clinical features and prognosis of patients with thrombotic thrombocytopenic purpura associated with systemic lupus erythematosus: a review of 25 cases

Objective

To report the clinical features of patients with systemic lupus erythematosus (SLE) associated with thrombotic thrombocytopenic purpura (TTP). Their diagnosis, treatment, and prognosis were also discussed.

Methods

A total of 25 TTP-SLE pediatric patients were included in this study. Their clinical symptoms, laboratory findings, disease activity, and renal biopsy were retrospectively reviewed.

Results

The median age of the patient cohort was 14 years old. Nine patients were first diagnosed with SLE, followed by the diagnosis of TTP-SLE, whereas 15 patients were diagnosed with TTP and SLE concurrently. All the 25 TTP-SLE patients had decreased platelet count and microangiopathic hemolytic anemia. Fever, rash, edema and neurological symptoms were the main clinical symptoms. Fragmentation of erythrocytes on blood smear and increased LDH were found in all patients. Nineteen patients (76%) had impaired renal function. Renal biopsy showed that most of the patients had lupus nephritis class IV (20%) and TMA (20%). 13 patients (52%) were treated with glucocorticoids in combination with immunosuppressive agent, and 10 patients (40%) were treated with plasma exchange combined with glucocorticoids plus immunosuppressive agent. One patient died due to lung infection; others had disease remission. Fifteen patients had follow-up regularly, and their conditions were stable.

Conclusion

Patients with TTP-SLE often had moderate to severe lupus disease activity. Testing of LDH level and blood smear should be performed when kidney and neurological symptoms arise in children with SLE. The use of combination therapy, glucocorticoids plus immunosuppressive agent, provided satisfactory clinical outcome. Patients with refractory TTP-SLE will also need plasma exchange therapy.

Cutaneous and Renal Glomerular Vasculopathy: What Do We Know so Far?

Cutaneous renal glomerular vasculopathy (CRGV), colloquially named "Alabama rot," is an emerging condition in the United Kingdom, previously reported from the United States and Germany. The cause of CRGV is not yet determined; no definitive link to an infectious agent has been made. Dogs diagnosed with CRGV initially develop cutaneous lesions, and a proportion of these dogs go on to manifest acute kidney injury, which may result in oligoanuric acute renal failure. Antemortem diagnosis is challenging given the lack of a specific diagnostic test, and confirmation of CRGV is therefore currently dependent on identification of thrombotic microangiopathy on renal histopathology.

Systemic Lupus Erythematosus Complicated by HELLP Syndrome

We describe a pregnant woman with systemic lupus erythematosus, complicated by severe pre-eclampsia (the HELLP syndrome) and adult respiratory distress syndrome, who died in the intensive care unit.

A 33-year-old multigravid woman was referred to our university hospital at 17 weeks’ gestation because of an exacerbation of systemic lupus erythematosus with elevated liver enzymes and thrombocytopenia. At the time of admission, on physical examination she had revealed a butterfly rash over the cheeks, purpura, acute synovitis and oedema of the legs. Her blood pressure was 180/100 mmHg. The initial laboratory tests and immunological evaluation confirmed active systemic lupus erythematosus complicated by severe pre-eclampsia. One week after admission, she became suddenly confused and had a convulsion with Glascow Coma Score 10 (3+3+4). Therapeutic abortion was induced in the Obstetric Department. She was transferred to the intensive care unit with a diagnosis of respiratory failure, probably due to acute respiratory distress syndrome, and was intubated and ventilated. Dialysis was instituted on two consecutive days from the eighth day. In total she received over 20 units of red blood cells and large quantities of fresh frozen plasma and platelets. On the 24th day her Glascow Coma Score was 2 (1+1+E) and severe hypotension developed. She died from worsening acute respiratory distress syndrome on the 25th day.

Women with systemic lupus erythematosus should be advised to become pregnant when the disease is inactive and should be observed at an appropriate centre using a multidisciplinary approach. Therapeutic abortion is an acceptable option if active nephropathy and severe pre-eclampsia are present in early pregnancy.

Thrombotic Microangiopathies (TTP, HUS, HELLP)

Thrombocytopenia, strictly defined as a platelet count less than 150,000, is common in the emergency department. Recognition, diagnostic investigation, and proper disposition of a thrombocytopenic patient are imperative. One group of disorders leading to thrombocytopenia is the thrombotic microangiopathies, hallmarked by platelet destruction. These thrombotic microangiopathies include thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS) and hemolysis, elevated liver enzyme levels, low platelet count (HELLP), which should be distinguished from similar disease processes such as immune thrombocytopenia (ITP), disseminated intravascular coagulation (DIC) and heparin induced thrombocytopenia (HIT). In this article, clinical presentations, pathophysiology, diagnostic workup, management plans, complications, and dispositions are addressed for this complex group of platelet disorders.

Changes in plasma von Willebrand factor and von Willebrand factor cleaving protease in thrombotic thrombocytopenic purpura: A case report

The present case report described a patient with thrombotic thrombocytopenic purpura (TTP), who presented to the China-Japan Union Hospital of Jilin University (Changchun, China), and the changes in plasma von Willebrand factor (vWF) and vWF cleaving protease (vWF-cp) observed during treatment. Computed tomography and diffusion-weighted magnetic resonance (MR) imaging of the brain, cerebral MR angiography and other experimental tests were performed and the patient was subsequently diagnosed with TTP. The patient underwent treatment with plasma exchange, glucocorticoids and supportive care. Hematologic and biochemical parameters began to gradually improve over the 12 days after admission; platelet count, serum creatinine and serum lactate dehydrogenase concentrations returned to their normal ranges, plasma vWF concentration decreased to normal levels over the 30 days after admission, and vWF-cp activity increased compared with the levels detected in healthy volunteers. Monthly rituximab treatment was administered 4 times following patient discharge to prevent relapse, and no recurrence was detected at the 20-month follow-up. Plasma exchange therapy is effective in patients with TTP. After low-dose rituximab treatment, recurrent TTP has not been detected found till now. In the present case, vWF concentration and vWF-cp activity were measured at 8, 10, 23 and 32 days after admission; compared with the control group, patient's vWF concentration gradually decreased and vWF-cp activity slowly increased, suggesting that the patient had a favorable prognosis and a low risk of recurrence.

Recombinant ADAMTS-13: first-in-human pharmacokinetics and safety in congenital thrombotic thrombocytopenic purpura

Safety, tolerability, and pharmacokinetics of recombinant ADAMTS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13; BAX 930; SHP655) were investigated in 15 patients diagnosed with severe congenital ADAMTS-13 deficiency (plasma ADAMTS-13 activity <6%) in a prospective phase 1, first-in-human, multicenter dose escalation study. BAX 930 was well tolerated, no serious adverse events occurred, and no anti-ADAMTS-13 antibodies were observed. After single-dose administration of BAX 930 at 5, 20, or 40 U/kg body weight to adolescents and adults, there was approximate dose proportionality with respect to maximum plasma concentration (C_max [U/mL]) and area under the concentration-time curve (AUC [h∙U/mL]). Dose-related increases of individual ADAMTS-13:Ag and activity were observed and reached a maximum within 1 hour. With escalating BAX 930 doses administered, a dose-dependent persistence of ADAMTS-13-mediated von Willebrand factor (VWF) cleavage products and reduced VWF multimeric size were observed. This study demonstrated that pharmacokinetic parameters of BAX 930 were comparable to those estimated in previous plasma infusion studies and provided evidence of pharmacodynamic activity. This study was registered at www.clinicaltrials.gov as #NCT02216084.

Relapse of congenital thrombotic thrombocytopenic purpura, after spontaneous remission, in a second-trimester primigravida: case report and review of the literature

CONTEXT

Thrombotic microangiopathy syndrome or thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) describes distinct diseases sharing common pathological features: microangiopathic hemolytic anemia and thrombocytopenia, without any other apparent cause.

CASE REPORT

An 18-year-old second-trimester primigravida presented with a history of fifteen days of intense weakness, followed by diarrhea over the past six days. She reported having had low platelets since childhood, but said that she had never had bleeding or menstrual abnormalities. Laboratory investigation showed anemia with schistocytes, thrombocytopenia and hypohaptoglobulinemia. Red blood cell concentrate and platelet transfusions were performed. The hypothesis of TTP or HUS was put forward and ADAMTS13 enzyme activity was investigated. The patient evolved with increasing platelet counts, even without specific treatment, and she was discharged. One month afterwards, she returned presenting weakness and swollen face and legs, which had developed one day earlier. The ADAMTS13 activity was less than 5%, without presence of autoantibodies. Regarding the two previous admissions (at 9 and 16 years of age), with similar clinical features, there was spontaneous remission on the first occasion and, on the second, the diagnosis of TTP was suspected and plasmapheresis was performed, but ADAMTS13 activity was not investigated.

CONCLUSION

To date, this is the only report of congenital TTP with two spontaneous remissions in the literature This report reveals the importance of suspicion of this condition in the presence of microangiopathic hemolytic anemia and thrombocytopenia without any other apparent cause.

Diagnostic dilemma: Severe thrombotic microangiopathy in pregnancy

A diagnostic dilemma occurred when thrombotic microangiopathy developed during pregnancy. The diagnostic criteria of thrombotic microangiopathy include thrombocytopenia (platelets <100) and microangiopathic haemolytic anaemia (including thrombotic thrombocytopenic purpura and haemolytic-uraemic syndrome). An urgent interdisciplinary approach is required to treat thrombotic microangiopathy in pregnancy to differentiate between thrombotic microangiopathy and HELLP syndrome (haemolysis, elevated liver enzymes, low platelets).¹ This case presented with the pentad of thrombotic thrombocytopenic purpura: severe thrombocytopenia (platelets 9 × 10⁹/L), microangiopathic haemolytic anaemia (reticular count 245 × 10⁹/L (20-110)), LDH >5000 U/L (<425)), neurological abnormalities (Glasgow Coma Scale 10/15), renal failure (creatinine 140 µmol/L (<97)), fever (37.7℃). A Disintegrin And Metalloproteinase with a Thrombospondin type 1 motif, member 13 (ADAMTS13) activity of less than 5% and anti-ADAMTS13 antibodies retrospectively confirmed the diagnosis of acquired idiopathic thrombotic thrombocytopenic purpura in pregnancy. The immediate management in the Emergency Department with an interdisciplinary team of Consultant Nephrologists, Intensivists, Haematologists and Obstetricians facilitated prompt diagnosis resulting in immediate plasma exchange (PEX) and coordination of semi-elective delivery of the foetus.

The clinical and laboratory features of Chinese Han anti-factor H autoantibody-associated hemolytic uremic syndrome

BACKGROUND

Anti-complement factor H (CFH) autoantibody-associated hemolytic uremic syndrome (HUS) is a severe sub-type of HUS.

METHODS

We assessed the clinical and renal pathological features, circulating complement levels, and genetic background of Chinese pediatric patients with this sub-type of HUS. Thirty-three consecutive patients with acute kidney injury who tested positive for serum anti-CFH autoantibodies were enrolled in this study.

RESULTS

All of the eight patients who underwent renal biopsies presented with changes typical of thrombotic microangiopathy, especially changes in chronic characteristics. Compared to patients in remission and normal control subjects, patients with acute disease had significantly lower plasma CFH levels and significantly higher plasma complement 3a (C3a), C5a, and terminal complement complex (SC5b-9) levels. The CFH-anti-CFH immunoglobin G (IgG) circulating immunocomplex (CFH-CIC) titers were more closely correlated with CFH plasma levels than anti-CFH IgG levels. Of the 22 patients, four (18%) were homozygous for CFHR3-1Δ and ten were heterozygous for CFHR1 or CFHR3 deletions. Most patients responded well to a combination of plasma and immunosuppressive therapies, with a remission rate of 87%. At the end of the follow-up, nine patients reached the combined end-points, including two with end-stage renal disease and seven with relapses.

CONCLUSION

Plasma C3a, C5a, and SC5b-9 levels predicted disease activity in anti-CFH autoantibody-associated HUS patients enrolled in this study. These patients responded well to plasma therapy combined with immunosuppression.

Thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP; also known as Moschcowitz disease) is characterized by the concomitant occurrence of often severe thrombocytopenia, microangiopathic haemolytic anaemia and a variable degree of ischaemic organ damage, particularly affecting the brain, heart and kidneys. Acute TTP was almost universally fatal until the introduction of plasma therapy, which improved survival from <10% to 80-90%. However, patients who survive an acute episode are at high risk of relapse and of long-term morbidity. A timely diagnosis is vital but challenging, as TTP shares symptoms and clinical presentation with numerous conditions, including, for example, haemolytic uraemic syndrome and other thrombotic microangiopathies. The underlying pathophysiology is a severe deficiency of the activity of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13), the protease that cleaves von Willebrand factor (vWF) multimeric strings. Ultra-large vWF strings remain uncleaved after endothelial cell secretion and anchorage, bind to platelets and form microthrombi, leading to the clinical manifestations of TTP. Congenital TTP (Upshaw-Schulman syndrome) is the result of homozygous or compound heterozygous mutations in ADAMTS13, whereas acquired TTP is an autoimmune disorder caused by circulating anti-ADAMTS13 autoantibodies, which inhibit the enzyme or increase its clearance. Consequently, immunosuppressive drugs, such as corticosteroids and often rituximab, supplement plasma exchange therapy in patients with acquired TTP.

Rituximab as first-line treatment for acquired thrombotic thrombocytopenic purpura

Objective To investigate the efficacy and safety of rituximab (RTX) as first-line treatment of acquired thrombotic thrombocytopenic purpura (aTTP). Methods Twenty-five patients with acute aTTP and/or severe a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) deficiency were admitted to our centre from April 2009 to March 2015. Fourteen patients received RTX plus standard therapy (plasma exchange and corticosteroids) at acute episodes. Haemoglobin, platelet count, schistocytes, lactate dehydrogenase levels, ADAMTS13 activity and its inhibitors, and the ratio of B lymphocytes in the peripheral blood, were monitored. The number of plasma exchange (PEXs), total plasma volume, remission time, relapse ratio, and adverse effects were recorded. Results The median number of PEXs was 5 (2-17) sessions and median total plasma volume was 168.43 ml/kg (62.86-469.52 ml/kg). Patients achieved haematological remission at a median of 15 days (5-22 days), and the median time of immunological remission was 2 weeks (2-8 weeks) with a median follow-up of 13 months (3-61 months). ADAMTS13 activity significantly increased after 2 weeks. The B lymphocyte percentage in peripheral blood was reduced 1 week after the first dose of RTX infusion compared with before treatment (2.21% ± 5.23% vs 18.47% ± 7.34%, P = 0.000 [the result of statistical software]), and began to gradually increase 9 months later. Severe adverse effects and relapsing TTP were not observed during therapy and follow-up. However, one patient who had sustained immunological remission died of severe pneumonia 7 months later. Conclusion Although our study was limited by its small sample number and it was a non-controlled, clinical trial, it showed potential benefits of RTX therapy for acute aTTP. RTX may be administered as a first-line therapy for lowering patients' relapse rate in the long term. Randomized, controlled trials of RTX for aTTP are required.

Syndromes of Thrombotic Microangiopathy

Thrombotic thrombocytopenia purpura (TTP) and the hemolytic uremic syndrome (HUS) are rare thrombotic microangiopathies that can be rapidly fatal. Although the acquired versions of TTP and HUS are generally highest on this broad differential, multiple rarer entities can produce a clinical picture similar to TTP/HUS, including microangiopathic hemolysis, renal failure, and neurologic compromise. More recent analysis has discovered a host of genetic factors that can produce microangiopathic hemolytic syndromes. This article discusses the current understanding of thrombotic microangiopathy and outlines the pathophysiology and causative agents associated with each distinct syndrome as well as the most accepted treatments.

Thrombotic thrombocytopenic purpura in a new onset lupus patient?

We are presenting a case of TTP with undetectable levels of ADAMTS 13 in a 39-year-old woman. Diagnosis of systemic lupus was evoked in the setting of thrombotic microangiopathy. The patient presented normal renal function but important neurological impairment. Treatment with daily plasmapheresis as well as Rituximab, cyclophosphamide as steroids was required to achieve clinical improvement.

Evaluation and Management of Patients With Thrombotic Thrombocytopenic Purpura

Thrombotic thrombocytopenic purpura (TTP) describes syndromes with multiple etiologies, some of which are rapidly fatal without plasma exchange treatment. Although there have been advances in understanding the pathogenesis of TTP, evaluation and management remain difficult because there are no specific diagnostic criteria, as TTP can be clinically similar to other acute disorders, such as sepsis, disseminated malignancy, malignant hypertension, and preeclampsia, and because urgent treatment is required. An unexpected observation of anemia and thrombocytopenia should trigger consideration of TTP; evidence that the anemia is due to microangiopathic hemolysis, suggested by the presence of red cell fragmentation on the blood smear, supports the diagnosis. When the diagnostic criteria of microangiopathic hemolytic anemia and thrombocytopenia without an apparent alternative etiology are fulfilled, plasma exchange treatment is appropriate. However, plasma exchange has risks for severe complications and death; therefore, this management decision must be balanced against the confidence in the diagnosis. With plasma exchange treatment, approximately 80% of patients survive, in contrast to only 10% in the era prior to the availability of plasma exchange. The continuing mortality from TTP, the risks of plasma exchange treatment, and the potential for recurrent episodes of TTP are clinical challenges that remain to be solved.

Thrombotic thrombocytopenic purpura (TPP) successfully rescued by plasma exchange in the ICU: A report of two cases

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening disorder, which is characterized by thrombus formation in small blood vessels. The present study retrospectively analyzed the clinical data from two patients with severe TTP, who were treated successfully in the intensive care unit (ICU) at the Liaocheng People's Hospital in 2013. Comprehensive therapies were administered to the patients, including plasma exchange (PE), mechanical ventilation (case 1 only), steroid therapy, blood transfusion and anti-inflammatory treatment (case 2 only). The two patients returned to a stable state and were transferred back to the hematology department following PE. The positive outcome achieved for these patients suggests that early intervention involving bedside PE in the ICU may reduce the mortality rate of patients with severe TTP who have concurrent respiratory or circulatory failure and cannot be treated in the dialysis unit.

Recombinant thrombomodulin for secondary thrombotic thrombocytopenic purpura

In the pathogenesis of thrombotic thrombocytopenic purpura (TTP), reductions in the enzyme activity of ADAMTS13, which cuts ultralarge von Willebrand multimers, generates shear stress on the microvascular endothelium, leading to platelet aggregation and the formation of a thrombus. ADAMTS13 activity is markedly decreased in typical TTP, but is only mildly reduced in secondary TTP, which concomitantly develops with primary disease. The latter develops with septic disseminated intravascular coagulation (DIC) and often causes organ failure. Recombinant thrombomodulin (rTM) is a drug that is used to treat DIC and may also remit TTP because it improves vascular endothelial dysfunction. Therefore, we herein investigated the efficacy of rTM in patients treated for the pathology of secondary TTP. Patients who were admitted to the Emergency and Critical Care Center of our hospital and met the following conditions were extracted and retrospectively analyzed: hemolytic anemia accompanied by fragmented red blood cells (Hb < 12 g/dL or lower); thrombocytopenia (<100 × 10/μL); and ADAMTS13 activity <50%. Sixteen patients were included and accompanied by Kidney Disease: Improving Global Outcomes (KDIGO) stage 2 or more severe nephropathy and DIC. Eleven and 5 patients treated with and without rTM (the rTM and non-rTM treatment groups, respectively) were compared, and no significant difference was noted in their basic characteristics, such as background disease and severity. No significant difference was observed in survival rates; however, the platelet count, which is an important outcome of treatments for TTP, significantly increased in the rTM treatment group: 3.3 ± 2.6→11.3 ± 14.6 versus 3.5 ± 3.7→5.7 ± 3.9 (×1000/μL) (P = 0.034). Thrombotic thrombocytopenic purpura originally requires invasive treatments and its prognosis is not favorable. Blood thrombomodulin levels also markedly increase due to vascular endothelial dysfunction, whereas rTM alleviates vascular endothelial dysfunction in TTP patients with high blood TM levels, suggesting the importance of administering rTM. Thus, rTM may be effective for secondary TTP and may be adopted as adjuvant therapy.