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

[Clinical study on Rituximab in the treatment of idiopathic thrombotic thrombocytopenic purpura]

目的

观察利妥昔单抗（RTX）在特发性血栓性血小板减少性紫癜(ITTP)治疗中的价值。

方法

17例ITTP患者中9例采用RTX＋血浆置换＋糖皮质激素治疗（RTX组），8例采用血浆置换+糖皮质激素±免疫抑制剂（对照组）。RTX用法为375 mg/m²每周1次连续4次。监测患者血常规、LDH、ADAMTS13活性及抑制物、外周血B淋巴细胞百分比。观察两组患者的血浆置换次数/总量、缓解时间、复发率及不良反应发生情况。

结果

RTX组、对照组血浆置换次数中位数分别为5(2~8)、6(4~9）次，血浆置换总量中位数分别为9.6(4.0~15.4)、11.2(7.5~14.6)L。RTX组、对照组达到血液学缓解中位时间分别为15(5~20)d、22(7~36)d，达到免疫学缓解中位时间分别为2(2~8)、2(2~4）周。两组患者ADAMTS13活性均在2周后显著回升。RTX组随访期内无复发，对照组4例患者复发。RTX给药前及治疗后1周患者外周血B淋巴细胞百分比差异有统计学意义[(18.39±7.15)％对(2.19±5.11)%，P<0.001], 9个月后逐渐回升，治疗中未观察到RTX相关严重不良反应，但该组1例患者持续免疫学缓解7个月后死于肺部感染。

结论

RTX联合血浆置换和糖皮质激素治疗ITTP，能快速获得血液学甚至免疫学缓解，降低复发率，不良反应少，但需注意防治感染。

Ciprofloxacin-Induced Thrombotic Thrombocytopenic Purpura: A Case of Successful Treatment and Review of the Literature

A 49-year-old African American woman was admitted to our hospital with abdominal pain, nausea, vomiting, lethargy, and confusion. She was receiving ciprofloxacin for a urinary-tract infection prior to admission. Laboratory examination revealed anemia, thrombocytopenia, elevated lactate dehydrogenase, and serum creatinine. Peripheral smear showed numerous schistocytes, and the patient was diagnosed with thrombotic thrombocytopenic purpura (TTP). Ciprofloxacin was identified as the offending agent. The patient received treatment with steroids and plasmapheresis, which led to rapid clinical recovery. This is the first case to our knowledge of successfully treated ciprofloxacin-induced TTP; previously reported cases had fulminant outcomes. Quinolones are an important part of the antibiotic armamentarium, and this case can raise awareness of the association between quinolones and TTP. A high index of suspicion for detection and early and aggressive management are vitally important for a successful outcome.

Long-term remission induced by low-dose rituximab for relapsed and refractory thrombotic thrombocytopenic purpura: A report of two cases

Thrombotic thrombocytopenic purpura (TTP) is acquired in the majority of cases. Traditional therapy consists of plasma exchange (PEX), as well as the administration of certain immunosuppressive agents including steroids. A standard dose of rituximab (RTX) at 375 mg/m² weekly for 4 consecutive weeks was recently demonstrated to have significant activity in patients with acquired TTP. To date, clinicians have limited experience using low-dose RTX. In the present study, 2 patients were treated with low-dose RTX at 100 mg weekly for 4 consecutive weeks as a salvage therapy following failure to respond to PEX and other immunosuppressive agents. Prior to RTX therapy, the patients had severely deficient ADAMTS13 activity and detectable anti-ADAMTS13 inhibitors. The patients achieved complete remission and presented long-term stabilization during follow-up. Repeated detection during follow-up demonstrated that the patients had 100% ADAMTS13 activity and undetectable anti-ADAMTS13 antibodies. Although further investigation in a prospective clinical trial is required, the use of low-dose RTX seems to be as effective as a standard dose for patients with relapsing or refractory acquired TTP.

Spontaneous acute subdural hematoma and intracerebral hemorrhage in a patient with thrombotic microangiopathy during pregnancy

Preeclampsia, HELLP syndrome (hemolysis, elevated liver enzymes, and low-platelet count), and acute fatty liver of pregnancy are the main causes of thrombotic microangiopathy and severe liver dysfunction during pregnancy and represent different manifestations of the same pathological continuum. The case of a 35-week pregnant woman who was admitted to an intensive care unit immediately after a Cesarean section due to fetal death and the presence of nausea, vomiting, and jaundice is reported. Postpartum preeclampsia and acute fatty liver of pregnancy were diagnosed. The patient developed an acute subdural hematoma and an intracerebral hemorrhage, which were subjected to neurosurgical treatment. The patient died from refractory hemolytic anemia and spontaneous bleeding of multiple organs. Preeclampsia, HELLP syndrome, and acute fatty liver of pregnancy might overlap and be associated with potentially fatal complications, including intracranial hemorrhage, as in the present case. Early detection and diagnosis are crucial to ensure appropriate management and treatment success.

Platelet transfusions in platelet consumptive disorders are associated with arterial thrombosis and in-hospital mortality

While platelets are primary mediators of hemostasis, there is emerging evidence to show that they may also mediate pathologic thrombogenesis. Little data are available on risks and benefits associated with platelet transfusions in thrombotic thrombocytopenic purpura (TTP), heparin-induced thrombocytopenia (HIT) and immune thrombocytopenic purpura (ITP). This study utilized the Nationwide Inpatient Sample to evaluate the current in-hospital platelet transfusion practices and their association with arterial/venous thrombosis, acute myocardial infarction (AMI), stroke, and in-hospital mortality over 5 years (2007-2011). Age and gender-adjusted odds ratios (adjOR) associated with platelet transfusions were calculated. There were 10 624 hospitalizations with TTP; 6332 with HIT and 79 980 with ITP. Platelet transfusions were reported in 10.1% TTP, 7.1% HIT, and 25.8% ITP admissions. Platelet transfusions in TTP were associated with higher odds of arterial thrombosis (adjOR = 5.8, 95%CI = 1.3-26.6), AMI (adjOR = 2.0, 95%CI = 1.2-3.3) and mortality (adjOR = 2.0,95%CI = 1.3-3.0), but not venous thrombosis. Platelet transfusions in HIT were associated with higher odds of arterial thrombosis (adjOR = 3.4, 95%CI = 1.2-9.5) and mortality (adjOR = 5.2, 95%CI = 2.6-10.5) but not venous thrombosis. Except for AMI, all relationships remained significant after adjusting for clinical severity and acuity. No associations were significant for ITP. Platelet transfusions are associated with higher odds of arterial thrombosis and mortality among TTP and HIT patients.

Does corticosteroid treatment cause prolonged recovery and increased total bilirubin level in severe ADAMTS-13-deficient TTP patient?

A 41-year-old female patient complaining of fatigue, headache, mild confusion, and rush on her lower extremities was admitted to our emergency department. Laboratory tests revealed that he had anemia, thrombocytopenia, and increased levels of indirect bilirubin and lactic dehydrogenase (LDH) in blood tests. Direct and indirect Coombs tests were negative, and fragmented erythrocytes were observed in peripheral blood smears. The patient was diagnosed with thrombotic thrombocytopenic purpura (TTP). The best supportive care was provided. Therapeutic plasma exchange (TPE) and 1 mg/kg methylprednisolone treatments were administered. On the 10th day of treatment, LDH level and fragmented red blood cells in peripheral blood smear were decreased, but his direct and indirect bilirubin levels increased despite the fact that he was treated with 1 mg/kg methylprednisolone and TPE. The patient had severe ADAMTS-13 deficiency. After discontinued steroids treatment, his bilirubin level normalized within 4 days. On the 4th day after bilirubin level normalized, vincristine treatment was administered. TPE was also continued. There was no consensus about the optimal schedule for discontinuing plasmapheresis therapy, and also we observed total bilirubin level improvement with discontinued corticosteroid treatment. In this case, corticosteroid treatment was linked with the increase of total bilirubin level in severe ADAMTS-13-deficient TTP patient.

Von Willebrand factor-cleaving protease activity in thrombotic microangiopathy: first report from iran

BACKGROUND

Thrombotic microangiopathy (TMA) is a rare but devastating small vessels disorder that is characterized by intravascular platelet thrombi, thrombocytopenia, and various degrees of organ ischemia and anemia, which is due to erythrocyte fragmentation in microcirculation.

OBJECTIVES

The Aim of this study was to determine the von Willebrand factor-cleaving protease (ADAMTS13) activity during the acute phase of TMA. We also investigated inhibiting antibodies against ADAMTS13 in these patients.

PATIENTS AND METHODS

In a collaborative work with Mario-Negro institute of pharmacological research in Bergamo-Italy, we registered the clinical and laboratory data, collected the serum samples, and transferred the samples to the laboratories. Serum samples were taken before the start of plasmapheresis or at least 15 days after the final exchange.

RESULTS

We recruited 40 patients (14 males and 26 females) with the mean age of 46.12 ± 17.26 years. The mean activity of ADAMTS13 was 34.58% ± 21.83%. Two patients had inhibitory antibodies against ADAMTS13 with profound deficiency of ADAMTS13 activity (< 6%). Infectious diseases were the most common underlying condition, followed by systemic lupus erythematous.

CONCLUSIONS

Majority of patients had an underlying condition and had various ADAMTS13 activity. The presence of inhibiting antibodies and accompanied complete deficiency of ADAMTS13 activity is an indicator of severity.

Cryosupernatant and Immunosuppression as Effective Alternative Therapies for TTP in Three Pediatric SLE Patients

Thrombotic thrombocytopenic purpura (TTP) and systemic lupus erythematosus (SLE) very rarely present simultaneously and pose a diagnostic and therapeutic dilemma to the physician. Prompt diagnosis and management with plasma exchange and immunosuppression is life-saving. To describe the effectiveness of cryosupernatant and steroids in pediatric SLE with TTP. We describe three children aged 12-14 years with SLE who were diagnosed with TTP based on fever, CNS manifestations, ANA, anti-dsDNA, anti-sm positivity, hypocomplementemia, and microangiopathic anemia with thrombocytopenia. All three children were managed with cryosupernatant and steroids without plasmapheresis. All children improved with cryosupernatant and steroids. All attained remission within 10 days. They were doing well at last follow up without relapse or flare. Cryosupernatant and steroids may be an effective therapy for Thrombotic thrombocytopenic purpura with systemic lupus erythematosus.

Acute neurological symptoms of Moschcowitz disease - case report

Thrombotic thrombocytopenic purpura (TTP, Moschcowitz disease) is characterized by thrombotic microangiopathy leading to microvascular occlusion and ischemic dysfunction of various organs including the brain. In the course of the rare disease most patients develop neurological symptoms of varying severity and characteristics. The case presented is that of a 34-year-old female patient with profound thrombocytopenia, anemia and rapidly progressive neurological deterioration into coma with normal result of brain imaging. TTP was recognized on the basis of hematological analysis. The initiated steroid therapy and plasma exchange failed to prevent the turbulent course of disease in the patient, who died exhibiting symptoms of multiple organ failure caused by thrombotic microangiopathy. TTP remains to be a diagnostic challenge, particularly in the case of atypical symptoms or when neuroimaging and laboratory results are inconclusive. Before using the corticosteroids and plasma exchange, TTP had a case fatality rate of approx. 90% (Podolak-Dawidziak, 2013). Nowadays recovery is possible when vigorous treatment is introduced early in the course of this disease.

Clinical features of gestational thrombocytopenia difficult to differentiate from immune thrombocytopenia diagnosed during pregnancy

AIM

To investigate the clinical features of gestational thrombocytopenia (GT) difficult to differentiate from immune thrombocytopenia (ITP) during pregnancy.

METHODS

The January 2000-December 2012 hospital database was analyzed to identify women with ITP or GT (after excluding other possible causes of thrombocytopenia) among those first noted to have platelet counts of less than 100 000/μL during pregnancy. The maternal characteristics, platelet count fluctuations and pregnancy outcomes were compared between women with ITP and GT.

RESULTS

There were 23 pregnancies (22 women) with thrombocytopenia (GT, 13; ITP, 10). The GT group included five twin pregnancies (38.5%), whereas all pregnancies of the ITP group were singleton pregnancies, with significantly more twin pregnancies in the GT group (P = 0.046). Thrombocytopenia in the first trimester occurred in 70% (7/10) of ITP cases and 23.1% (3/13) of even GT cases. The nadir platelet count was less than 70 000/μL in 100% (10/10) of ITP cases and 30.8% (4/13) of GT cases (P < 0.001). Maternal treatment was required in 80% (8/10) of ITP cases, but in none of the GT cases. The pregnancy outcomes were favorable in both groups, and no case required fetal treatment.

CONCLUSION

Gestational thrombocytopenia with platelet counts of less than 10 0000/μL occurred more frequently in twin pregnancies. Although onset of thrombocytopenia in the first trimester and a platelet count of less than 70 000/μL is more common in ITP, these findings were not uncommon in GT. Differentiation between ITP and GT may be feasible only with post-partum changes in the platelet count.

Renal-limited thrombotic microangiopathy and acute interstitial nephritis with a single dose of quinine

Quinine has been reported to cause acute kidney injury by various mechanisms. The response to quinine can result in a spectrum of problems ranging from isolated thrombocytopenia to thrombotic microangiopathy (TMA) to disseminated intravascular coagulation. Quinine has also been reported to cause acute interstitial nephritis (AIN). We report an unusual presentation where both of these entities of renal-limited TMA and AIN were precipitated by a single dose of quinine.

Successful treatment of an elderly frail patient with acquired idiopathic thrombotic thrombocytopenic purpura under close monitoring of ADAMTS13 activity and anti-ADAMTS13 antibody titers

A 68-year-old woman was admitted to the regional hospital because of hemolytic anemia, thrombocytopenia, and neurological abnormalities including unconsciousness. One week before admission, she suffered from diarrhea and subsequently passed out and hit her face on the ground. She was suspected of having TTP and was transferred to our hospital. We performed the assays of ADAMTS13 activity and anti-ADAMTS13 antibody titers, and confirmed the diagnosis of acquired idiopathic TTP with total deficiency of ADAMTS13 activity with its inhibitor. She was initially treated with plasma exchange combined with corticosteroids, however, we were forced to substitute plasma exchange with fresh frozen plasma infusion due to procedure-associated complications. The infusion of fresh frozen plasma was known as less effective and more likely to boost inhibitor titers compared to plasma exchange. In this circumstance, we could successfully switch the plasma therapy under close monitoring of ADAMTS13 activity and anti-ADAMTS13 antibody titers which precisely revealed the disease status of TTP in our patient, and eventually she achieved complete remission with normal level of ADAMTS13 activity and no inhibitor. Our experience suggested that the measurement of ADAMTS13 activity and inhibitor titer might be valuable not only for making the diagnosis but also for guiding treatment decisions by precise evaluating of disease status in patients with the acquired form of TTP.

Low incidence of ADAMTS13 missense mutation R1060W in adult Egyptian patients with thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is an acute life-threatening disorder, characterized by thrombocytopenia, microangiopathic hemolytic anemia, widespread microvascular thrombi and consequent clinical sequelae due to ischemic organ damage. TTP is most commonly associated with deficiency or inhibition of von Willebrand factor-cleaving protease (ADAMTS13) activity. ADAMTS13 mutations and polymorphisms have been reported in childhood congenital TTP, but their significance in adult-onset TTP is still under investigation. Two mutations stand out: the single base insertion 4143insA in exon 29 and the missense mutation R1060W in exon 24 have both been observed in several unrelated families, mainly in adult-onset TTP, and over a wide geographic area. Our objective in this study is to identify the prevalence of R1060W missense mutation in exon 24 ADAMTS13 in a sample of adult Egyptian TTP patients. Thirty-one adult-onset TTP patients were included in this study, with a male/female ratio of 1:4. Twenty-six cases (84%) presented with acute idiopathic TTP, 2 cases were drug abusers and 3 cases were pregnant. None of the study cases provided a history of suspicious TTP symptoms during childhood (2 cases gave a history of episodes of thrombocytopenia during childhood). All cases showed statistically significant decreased ADAMTS13 activity compared to normal controls (p < 0.001). The study revealed a high statistical difference regarding the ADAMTS13 inhibitor level in primary versus secondary cases (p = 0.003). None of our Egyptian cases or of the healthy normal controls are positive for exon 24 missense mutation. Larger studies and regional and national TTP registries are recommended.

Reticulate dermatoses

The term "reticulate" is used for clinical description of skin lesions that are configured in a net-like pattern. Many primary and secondary dermatoses present in such patterns involving specific body sites. Certain cutaneous manifestations of systemic diseases or genodermatoses also present in such manner. This review classifies and describes such conditions with reticulate lesions and briefly, their associated features.

Long term outcome and sequelae in patients after acute thrombotic thrombocytopenic purpura episodes

We report on 21 patients with idiopathic thrombotic thrombocytopenic purpura (TTP) whose courses of disease have been followed from the respective diagnosis until now. They had a documented ADAMTS13 activity below 5%, a high autoantibody titer and detectable ultralarge von Willebrand factor (VWF) multimers during their episodes. The initial diagnosis was based on clinical symptoms and on laboratory parameters: thrombocytopenia, haemolytic anaemia, schistocytes and an increased LDH level. 103 acute clinical episodes of 21 TTP-patients during a time period of 30 years are described. Case histories, comorbidities and sequelae were retrospectively documented.

RESULTS, CONCLUSION

Although patients are consistently in a prothrombotic status, clinical acute manifestations only occur after triggering. Most common trigger factors are gastrointestinal infections and pregnancy. The relapse risk per month is 0.026; men have a higher risk for relapses (0.044) than women (0.021). Patients recover physically well, except for renal insufficiency in four cases. Nevertheless, major portion of patients suffers persistently from depression, anxiety disorders and persistent neurocognitive impairments.

Thrombotic thrombocytopenic purpura in the first trimester of pregnancy

Thrombotic thrombocytopenic purpura (TTP) occurs more commonly in women and so can be associated with pregnancy. The time during pregnancy with greatest risk for development of TTP is near term and during the post partum period. TTP occurring in early trimester is uncommon and is also associated with great maternal and fetal mortality. We report a successful outcome of pregnancy in a woman with TTP in early first trimester who was treated with therapeutic plasma exchange.

Unresponsive thrombotic thrombocytopenic purpura in critically ill adults

INTRODUCTION

The prognosis of thrombotic thrombocytopenic purpura (TTP) has considerably improved since the introduction of plasma exchange (PEX) therapy. However, unresponsive thrombotic thrombocytopenic purpura (Un-TTP) still carries high morbidity and mortality rates, indicating a need for early specific treatments.

PATIENTS AND METHODS

In a retrospective study including consecutive adults with TTP admitted between January 1997 and January 2011 in a teaching hospital intensive care unit (ICU), our objective here is to identify early clinical and laboratory features predicting Un-TTP. Patients who responded to plasma exchange and steroids (N = 49) were compared with patients with unresponsive TTP defined as requirement for other treatments, protracted course, or death (N = 37, 43 %).

RESULTS

Hospital mortality was 24.3 % in the Un-TTP group. Variables associated with Un-TTP on univariate logistic regression were older age, cardiac involvement, neurological involvement, higher anti-a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS13) immunoglobulin G (IgG) titer, lower platelet counts starting on day 2, higher Sequential Organ Failure Assessment (SOFA) scores starting on day 3, need for higher plasma volumes to obtain remission, and greater use of adjuvant treatments and life-sustaining interventions. Multivariate logistic regression identified four factors independently associated with Un-TTP: age over 60 years [odds ratio (OR) 7.90; 95 % confidence interval (95 % CI) 1.06-78.34], cardiac (OR 5.17; 95 % CI 1.63-16.39) or neurological (OR 8.04; 95 % CI 1.27-51.03) manifestations at diagnosis, and day 2 platelet count less than 15 G/l (OR 3.88; 95 % CI 1.30-11.62).

CONCLUSION

Therapeutic intensification starting on day 3 or even earlier in patients with the independent risk factors for unresponsive TTP identified in our study deserves evaluation in a multicenter prospective study.

Filter membrane-based automated therapeutic plasma exchange: a report of two cases from Nigeria

These case reports demonstrated the diagnostic dilemma encountered in patients with systemic lupus erythematosus and thrombotic thrombocytopenic purpura particularly in settings with limited diagnostic facilities and laboratory support. The similarities in the diagnostic criteria for both conditions make clear distinction as well as management decisions difficult. We present the difficulties encountered with both the diagnosis and the management of these two patients that were managed in our facility.

The emerging concept of residual ADAMTS13 activity in ADAMTS13-deficient thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening disease characterized by acute episodes of widespread microvascular thrombosis. The discovery that the plasmatic activity of the von Willebrand factor cleaving protease, ADAMTS13, is severely deficient in patients with TTP partially clarified the pathophysiology of the disease. However, the finding of severe deficiency of ADAMTS13 alone is unable to fully explain the clinical heterogeneity of the disease. The recent development of methods that measure ADAMTS13 activity with great analytical precision offers the opportunity to define the relationships between levels of ADAMTS13 activity below 10% (herein defined as "residual ADAMTS13 activity") and the clinical manifestations of the disease. Recent studies suggest that the amount of residual activity of ADAMTS13 may be a major determinant of the clinical heterogeneity of TTP. Herein, we review the recent findings on residual ADAMTS13 activity and their implications for research and clinical practice in the field.

Recurrent thrombotic thrombocytopenic purpura-like syndrome as a paraneoplastic phenomenon in malignant peritoneal mesothelioma: a case report and review of the literature

We report the case of an African American male with no significant past medical history presenting with recurrent, rapidly relapsing episodes of thrombotic thrombocytopenic purpura (TTP) despite aggressive treatment with several lines of treatment. Incidentally, these episodes were associated with severe abdominal pain which eventually developed into acute abdomen and prompted exploratory laparotomy, revealing diffuse carcinomatosis with a tumor located on the left pelvis that was encasing the distal sigmoid colon. Pathology made a final diagnosis of peritoneal mesothelioma. TTP-like syndrome (TTP-LS) has been described as a paraneoplastic phenomenon in several malignancies but never before in the setting of malignant mesothelioma. Paraneoplastic TTP-like syndrome has historically been associated with a dismal prognosis and particular clinical and laboratory abnormalities described in this paper. It is of utmost importance to make a prompt determination whether TTP is idiopathic or secondary to an underlying condition because of significant differences in their prognosis, treatment, and response. This paper also reviews the current literature regarding this challenging condition.

Evaluation of efficacy and safety of the anti-VWF Nanobody ALX-0681 in a preclinical baboon model of acquired thrombotic thrombocytopenic purpura

ALX-0681 is a therapeutic Nanobody targeting the A1-domain of VWF. It inhibits the interaction between ultra-large VWF and platelet GpIb-IX-V, which plays a crucial role in the pathogenesis of thrombotic thrombocytopenic purpura (TTP). In the present study, we report the efficacy and safety profile of ALX-0681 in a baboon model of acquired TTP. In this model, acute episodes of TTP are induced by administration of an ADAMTS13-inhibiting mAb. ALX-0681 completely prevented the rapid onset of severe thrombocytopenia and schistocytic hemolytic anemia. After induction of TTP, platelet counts also rapidly recovered on administration of ALX-0681. This effect was corroborated by the full neutralization of VWF activity. The schistocytic hemolytic anemia was also halted and partially reversed by ALX-0681 treatment. Brain CT scans and post mortem analysis did not reveal any sign of bleeding, suggesting that complete neutralization of VWF by ALX-0681 under conditions of thrombocytopenia was not linked with an excessive bleeding risk. The results obtained in this study demonstrate that ALX-0681 can successfully treat and prevent the most important hallmarks of acquired TTP without evidence of a severe bleeding risk. Therefore, ALX-0681 offers an attractive new therapeutic option for acquired TTP in the clinical setting.

ADAMTS-13 activity and autoantibodies classes and subclasses as prognostic predictors in acquired thrombotic thrombocytopenic purpura

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a rare life-threatening disease. Of surviving patients, 45% develops an exacerbation or a late recurrence. Severe ADAMTS-13 deficiency, both during the acute episode and remission, is a well-established predictor of recurrence. The predictive value of anti-ADAMTS-13 antibodies, their inhibitory activity and Ig class subtype for disease recurrence is still to be established.

OBJECTIVES

To analyze ADAMTS-13-related biomarkers (ADAMTS-13 and anti-ADAMTS-13 immunoglobulins, classes and subclasses) and their potential relationship with prognosis.

PATIENTS/METHODS

In 115 patients with TTP, we assessed the association between levels of these biomarkers and the severity of acute episodes; we analysed also the hazard ratio (HR) and 95% confidence interval (CI) of recurrence in association with biomarkers levels retrieved at the previous acute episode or during remission, using Cox regression models.

RESULTS

During the acute phase, higher IgA, IgG1 and IgG3 titers showed the strongest association with acute episode severity. In the survival analyzes, the only biomarker significantly associated with a high hazard of recurrence after an acute episode was the presence of IgG. Conversly, low ADAMTS-13 activity or antigen levels (<10%), the presence of ADAMTS-13 inhibitor or IgG during remission were all significantly associated with a higher hazard of recurrence.

CONCLUSIONS

Both the Ig class and subclass are of predictive value for acute episode severity in patients with TTP. Although markers that could predict the risk of recurrence in the acute phase are limited, a thorough assessment of ADAMTS-13-related parameters during remission is warranted.

Life-threatening hemorrhagic shock after laparoscopic surgery: a case of postoperative thrombotic thrombocytopenic purpura

We report the successful management of a female patient who developed postoperative thrombotic thrombocytopenic purpura (TTP) after an uneventful laparoscopic oophorocystectomy. The patient underwent uneventful laparoscopic surgery for ovarian cystoma. One hour after completion of surgery, the patient suddenly went into shock, with her blood pressure dropping to 60/40 mmHg. Hemorrhage into the abdominal cavity with an estimated blood loss of 2,000 ml was confirmed by exploratory laparotomy. Initially, anemia and thrombocytopenia were attributed to blood consumption or disseminated intravascular coagulation (DIC). However, blood tests revealed evidence of hemolytic anemia, with fragmented erythrocytes observed on peripheral blood smear examination. Serum levels of lactate dehydrogenase, blood urea nitrogen, and creatinine were elevated. Based on the findings, postoperative TTP was suspected. High-dose steroids and plasma infusions were administered but proved ineffective. Plasma exchange was performed three times, resulting in resolution of postoperative TTP. TTP is an idiopathic disorder, known to be triggered by surgical trauma. Postoperative TTP is difficult to distinguish clinically from DIC because of its close similarity with the latter and subtle differences from other postoperative hematological complications. It is important to bear in mind the possibility of postoperative TTP in patients with unexplained hemorrhagic shock after uneventful surgery.

The TITAN trial--assessing the efficacy and safety of an anti-von Willebrand factor Nanobody in patients with acquired thrombotic thrombocytopenic purpura

The Phase II TITAN trial is designed to assess the efficacy and safety of an anti-von Willebrand factor (vWF) Nanobody in patients with acquired thrombotic thrombocytopenic purpura (TTP). Nanobodies are a novel class of therapeutic proteins and are based on the smallest functional fragments of single-chain antibodies that occur naturally in the Camelidae family (Nanobody® and Nanobodies® are registered trademarks of Ablynx NV). With vWF implicated in the thrombotic process underlying TTP, an anti-vWF Nanobody may hold significant promise as adjunctive therapy to plasma exchange. Recruitment is currently ongoing, and aims to include a total of 110 patients from countries in Europe, the Middle East, Australia and Northern America.

A case of thrombotic thrombocytopenic purpura induced by acute pancreatitis

Thrombotic thrombocytopenic purpura (TTP) is a multisystemic microvascular disorder that may be caused by an imbalance between unusually large von Willebrand factor multimers and the cleaving protease ADAMTS13. In acquired TTP, especially in secondary TTP with various underlying diseases, the diagnosis is difficult because there are many cases that do not exhibit severe deficiency of ADAMTS13 or raised levels of ADAMST13 inhibitors. It is well known that collagen disease, malignancy, and hematopoietic stem cell transplantation can be underlying conditions that induce TTP. However, TTP induced by acute pancreatitis, as experienced by our patient, has rarely been reported. Our patient completely recovered with treatments using steroids and plasma exchange (PE) only. In cases where patients develop acute pancreatitis with no apparent causes for hemolytic anemia and thrombocytopenia, the possibility of TTP should be considered. Treatments for TTP including PE should be evaluated as soon as a diagnosis is made.

Treatment of enterohemorrhagic Escherichia coli (EHEC) infection and hemolytic uremic syndrome (HUS)

Verotoxigenic Escherichia coli (VTEC) are a specialized group of E. coli that can cause severe colonic disease and renal failure. Their pathogenicity derives from virulence factors that enable the bacteria to colonize the colon and deliver extremely powerful toxins known as verotoxins (VT) or Shiga toxins (Stx) to the systemic circulation. The recent devastating E. coli O104:H4 epidemic in Europe has shown how helpless medical professionals are in terms of offering effective therapies. By examining the sources and distribution of these bacteria, and how they cause disease, we will be in a better position to prevent and treat the inevitable future cases of sporadic disease and victims of common source outbreaks. Due to the complexity of pathogenesis, it is likely a multitargeted approach is warranted. Developments in terms of these treatments are discussed.

Attending rounds: microangiopathic hemolytic anemia with renal insufficiency

The classification of thrombotic microangiopathy has evolved and expanded due to treatment and advances in understanding of the diseases associated with this clinical presentation. The three clinical forms of thrombotic microangiopathy-thrombotic thrombocytopenic purpura (TTP), hemolytic uremic syndrome (HUS), and disseminated intravascular coagulation-encompass a wide range of disorders that can be classified as either primary (idiopathic) or secondary to another identifiable disease or clinical context. Identification of an inhibitor to a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) in the idiopathic and acute forms of TTP, recognition of the absence of ADAMTS13 inhibition in diarrheal HUS, identification of complement abnormalities in atypical HUS, and a better understanding of the role of plasma therapy, rituximab, and eculizumab therapy have all had a major effect on current understanding of the thrombotic microangiopathies. In this Attending Rounds, a patient with a thrombotic microangiopathy is presented, along with discussion highlighting the difficulty of differentiating TTP from HUS and disseminated intravascular coagulation, the need for a prompt diagnosis, and the role for plasma therapy in appropriately selected patients. The discussion attempts to provide a simple clinical approach to the diagnosis, treatment options, and future course of adults and children suffering from a thrombotic microangiopathy.