Pregnancy outcomes after recovery from thrombotic thrombocytopenic purpura-hemolytic uremic syndrome

Pregnancy and the eye: What do we need to watch out for? A review

Pregnancy causes changes in all body systems, including the eye. The eye can undergo physiological and pathological changes in pregnancy. Some changes exacerbate pre-existing eye conditions while other conditions manifest for the first-time during pregnancy. Early recognition and management are essential to prevent sight threatening complications. In addition, some obstetric complications can be associated with ophthalmic signs. Prompt recognition of these eye findings may be life saving for both the mother and the foetus. The aim of this article is to present potential ocular complications in pregnancy and outline the appropriate management to preserve sight and maintain maternal and foetal safety. The safety of the use of common ophthalmological medications will also be discussed.

Maternal and fetal outcomes of pregnancy occurring after a diagnosis of immune-mediated thrombotic thrombocytopenic purpura

Pregnancy is a well-established trigger for a first episode or relapse of immune thrombotic thrombocytopenic purpura (iTTP). Other outcomes of subsequent pregnancy after a diagnosis of iTTP are less well described. We conducted this retrospective cohort study to evaluate maternal and fetal outcomes of pregnancy in women with prior iTTP from the Johns Hopkins Thrombotic Microangiopathy Cohort. Of 168 women in the cohort, 102 were of reproductive age at diagnosis. Fourteen pregnancies (in 9 women) that occurred after the initial iTTP episode were included in the analysis. iTTP relapse occurred in 9 (64%) pregnancies. Out of the 9 instances of relapse, 5 relapses occurred in 2 women. Seven pregnancies (50%) ended in fetal death or miscarriage in the setting of iTTP relapse and three were electively terminated due to fear of relapse. Four pregnancies (50% of the 8 that progressed beyond 20 weeks) were complicated by preeclampsia or HELLP syndrome, which is over ten-fold higher than that of the general population. No maternal deaths occurred. Only 4 pregnancies resulted in live births, of which, 2 were pre-term. Pregnancy in women with prior iTTP is associated with a substantial risk of iTTP relapse and fetal loss. Preeclampsia and HELLP syndrome is also more common than that in the general population. ADAMTS13 monitoring and preemptive therapy may improve pregnancy outcomes, which needs to be evaluated prospectively.

Diagnosis and management of thrombocytopenia in pregnancy

Thrombocytopenia, defined as platelet count <150×10⁹/L, is frequently observed by physicians during pregnancy, with an incidence of approximately 10% of all pregnancies. Most of the cases of thrombocytopenia in pregnancy are due to gestational thrombocytopenia, which does not confer an increased risk of maternal bleeding. However, because other causes can be associated with life-threatening events, such as severe bleeding, that can affect to maternal and fetal outcomes, differentiating other cause of thrombocytopenia, which includes preeclampsia, HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome, acute fatty liver of pregnancy, immune thrombocytopenia, hereditary thrombocytopenia, antiphospholipid syndrome, thrombotic thrombocytopenic purpura, and atypical hemolytic uremic syndrome, is important. Understanding the mechanisms and recognition of symptoms and signs are important to decide an adequate line of investigation. In this review, the approach to diagnosis and the management of the thrombocytopenia commonly observed in pregnancy are presented.

Pregnancy-associated thrombotic thrombocytopenic purpura complicated by Sjögren's syndrome and non-neutralising antibodies to ADAMTS13: a case report

Background

Thrombotic thrombocytopenic purpura (TTP) is a severe and life-threatening disease. Given its heterogeneous clinical presentation, the phenotype of TTP during pregnancy and its management have not been well documented.

Case presentation

We report here a 25-year-old woman, G1P0 at 36 weeks gestation, who developed severe thrombocytopenia and anemia. She was performed an emergent caesarean section 1 day after admission because of multiple organ failure. As ADAMTS 13 enzyme activity of the patient was 0% and antibodies were identified by enzyme-linked immunosorbent assay, she was diagnosed as acquired thrombotic thrombocytopenic purpura (aTTP). Furthermore, asymptomatic primary Sjögren’s syndrome was incidentally diagnosed on screening. After treatment with rituximab in addition to PEX and steroids, the activity of the ADAMTS 13 enzyme increased significantly from 0 to 100%.

Conclusions

To the best of our knowledge, this is the first case report of concomitant TTP and asymptomatic Sjögren’s syndrome in a pregnant woman. It highlights the association between pregnancy, autoimmune disease, and TTP. It also emphasizes the importance of an enzyme-linked immunosorbent assay in the diagnosis and rituximab in the treatment of patients with acquired TTP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04167-9.

Management of thrombotic microangiopathy in pregnancy and postpartum: report from an international working group

Pregnancy and postpartum are high-risk periods for different forms of thrombotic microangiopathy (TMA). However, the management of pregnancy-associated TMA remains ill defined. This report, by an international multidisciplinary working group of obstetricians, nephrologists, hematologists, intensivists, neonatologists, and complement biologists, summarizes the current knowledge of these potentially severe disorders and proposes a practical clinical approach to diagnose and manage an episode of pregnancy-associated TMA. This approach takes into account the timing of TMA in pregnancy or postpartum, coexisting symptoms, first-line laboratory workup, and probability-based assessment of possible causes of pregnancy-associated TMA. Its aims are: to rule thrombotic thrombocytopenic purpura (TTP) in or out, with urgency, using ADAMTS13 activity testing; to consider alternative disorders with features of TMA (preeclampsia/eclampsia; hemolysis elevated liver enzymes low platelets syndrome; antiphospholipid syndrome); or, ultimately, to diagnose complement-mediated atypical hemolytic uremic syndrome (aHUS; a diagnosis of exclusion). Although they are rare, diagnosing TTP and aHUS associated with pregnancy, and postpartum, is paramount as both require urgent specific treatment.

How I treat thrombotic thrombocytopenic purpura in pregnancy

Thrombotic thrombocytopenic purpura (TTP) is an acute, life-threatening thrombotic microangiopathy (TMA) caused by acquired or congenital severe deficiency of ADAMTS13. Pregnancy is a recognized risk factor for precipitating acute (first or recurrent) episodes of TTP. Differential diagnosis with other TMAs is particularly difficult when the first TTP event occurs during pregnancy; a high index of suspicion and prompt recognition of TTP are essential for achieving a good maternal and fetal outcome. An accurate distinction between congenital and acquired cases of pregnancy-related TTP is mandatory for safe subsequent pregnancy planning. In this article, we summarize the current knowledge on pregnancy-associated TTP and describe how we manage TTP during pregnancy in our clinical practice.

Complement-Mediated Disorders in Pregnancy

Complement-mediated disorders in pregnancy span a large spectrum and have been implicated in all three complement pathways: classical, lectin, and alternative. Our understanding of these disorders in recent years has advanced due to a better understanding of complement regulatory proteins, such as complement factor H, complement factor I, membrane cofactor protein, and thrombomodulin that particularly affect the alternative complement pathway. Enthusiasm in genotyping for mutations that encode these proteins has allowed us to study the presence of genetic variants which may predispose women to develop conditions such as pregnancy-associated hemolytic uremic syndrome (P-aHUS), thrombotic thrombocytopenic purpura, preeclampsia/hemolysis, elevated liver enzymes, low platelets (HELLP), systemic lupus erythematosus/antiphospholipid syndrome, and peripartum cardiomyopathy. The advent of the anti-C5-antibody eculizumab to quench the complement cascade has already proven in small case series to improve maternal kidney outcomes in complement-mediated obstetric catastrophes such as P-aHUS and HELLP. In this review, we will detail the pathogenesis behind these complement-mediated pregnancy disorders, the role of complement variants in disease phenotype, and the most up-to-date experience with eculizumab in this population.

Managing pregnancy-associated clinical emergencies in systemic lupus erythematosus: a case-based approach

Introduction: Systemic lupus erythematosus (SLE)-related thrombocytopenia during pregnancy and the postpartum period have been associated with adverse pregnancy outcomes and perinatal complications. In this case report, we present two SLE patients with thrombocytopenia emergencies secondary to HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome and thrombotic thrombocytopenic purpura (TTP).Areas covered: The first case involved a 26-year-old woman, G1P0 at 26 weeks gestation (GA), with high-titer antiphospholipid antibodies (aPL) (positive lupus anticoagulant, anti-beta 2 glycoprotein-1 (aβ2GP1), anti-cardiolipin) and non-criteria aPL to phosphatidylserine/prothrombin complex and anti-domain 1 β2GP1. This case highlights the risks associated with aPL in pregnancy, considers management issues relating to anticoagulation during pregnancy and highlights the importance of maintaining a high index of suspicion for diagnosis of HELLP in SLE patients. The second case was a 36-year-old female, G3P2 at 32 weeks GA, with class III lupus nephritis (LN) who developed severe pre-eclampsia, which included mild thrombocytopenia. This case illustrates the challenges in identifying and differentiating between three pregnancy emergencies that can be seen in SLE patients (pre-eclampsia, LN, and TTP) and presents the management of TTP in peripartum SLE.Expert opinion: These two cases remind us of the importance of timely diagnosis and management of thrombocytopenia in this population.

ADAMTS13: origins, applications, and prospects

ADAMTS13 is an enzyme that acts by cleaving prothrombotic von Willebrand factor (VWF) multimers from the vasculature in a highly regulated manner. In pathologic states such as thrombotic thrombocytopenic purpura (TTP) and other thrombotic microangiopathies (TMAs), VWF can bind to the endothelium and form large multimers. As the anchored VWF chains grow, they provide a greater surface area to bind circulating platelets (PLTs), generating unique thrombi that characterize TTP. This results in microvasculature thrombosis, obstruction of blood flow, and ultimately end-organ damage. Initial presentations of TTP usually occur in an acute manner, typically developing due to an autoimmune response toward, or less commonly a congenital deficiency of, ADAMTS13. Triggers for TMAs that can be associated with ADAMTS13 deficiency, including TTP, have been linked to events that place a burden on hemostatic regulation, such as major trauma and pregnancy. The treatment plan for cases of suspected TTP consists of emergent therapeutic plasma exchange that is continued on a daily basis until normalization of PLT counts. However, a subset of these patients does not respond favorably to standard therapies. These patients necessitate a better understanding of their diseases for the advancement of future therapeutic options. Given ADAMTS13's key role in the cleavage of VWF and the prevention of PLT-rich thrombi within the microvasculature, future treatments may include anti-VWF therapeutics, recombinant ADAMTS13 infusions, and ADAMTS13 expression via gene therapy.

Thrombocytopenia in pregnancy

Thrombocytopenia develops in 5% to 10% of women during pregnancy or in the immediate postpartum period. A low platelet count is often an incidental feature, but it might also provide a biomarker of a coexisting systemic or gestational disorder and a potential reason for a maternal intervention or treatment that might pose harm to the fetus. This chapter reflects our approach to these issues with an emphasis on advances made over the past 5 to 10 years in understanding and managing the more common causes of thrombocytopenia in pregnancy. Recent trends in the management of immune thrombocytopenia translate into more women contemplating pregnancy while on treatment with thrombopoietin receptor agonists, rituximab, or mycophenylate, which pose known or unknown risks to the fetus. New criteria to diagnose preeclampsia, judicious reliance on measurement of ADAMTS13 to make management decisions in suspected thrombotic thrombocytopenic purpura, new evidence supporting the efficacy and safety of anticomplement therapy for atypical hemolytic uremic syndrome during pregnancy, and implications of thrombotic microangiopathies for subsequent pregnancies are evolving rapidly. The goals of the chapter are to help the hematology consultant work through the differential diagnosis of thrombocytopenia in pregnancy based on trimester of presentation, severity of thrombocytopenia, and coincident clinical and laboratory manifestations, and to provide guidance for dealing with some of the more common and difficult diagnostic and management decisions.

Thrombocytopenia in pregnancy

Thrombocytopenia develops in 5% to 10% of women during pregnancy or in the immediate postpartum period. A low platelet count is often an incidental feature, but it might also provide a biomarker of a coexisting systemic or gestational disorder and a potential reason for a maternal intervention or treatment that might pose harm to the fetus. This chapter reflects our approach to these issues with an emphasis on advances made over the past 5 to 10 years in understanding and managing the more common causes of thrombocytopenia in pregnancy. Recent trends in the management of immune thrombocytopenia translate into more women contemplating pregnancy while on treatment with thrombopoietin receptor agonists, rituximab, or mycophenylate, which pose known or unknown risks to the fetus. New criteria to diagnose preeclampsia, judicious reliance on measurement of ADAMTS13 to make management decisions in suspected thrombotic thrombocytopenic purpura, new evidence supporting the efficacy and safety of anticomplement therapy for atypical hemolytic uremic syndrome during pregnancy, and implications of thrombotic microangiopathies for subsequent pregnancies are evolving rapidly. The goals of the chapter are to help the hematology consultant work through the differential diagnosis of thrombocytopenia in pregnancy based on trimester of presentation, severity of thrombocytopenia, and coincident clinical and laboratory manifestations, and to provide guidance for dealing with some of the more common and difficult diagnostic and management decisions.

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.

Pregnancy shortly after an acute episode of severe acquired thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a rare but potentially fatal condition. In women with a previous history of TTP there is increased risk of recurrence during pregnancy and the puerperium. There is some evidence that the risk of relapse during pregnancy is increased if the interval between the event and conception is short. We present a case in which pregnancy was achieved a few days after full recovery from an acute episode of severe acquired TTP (ADAMTS13 activity <0.1%) which was successfully treated with four courses of plasma exchange. There was no relapse of TTP during pregnancy and a healthy baby was delivered at term; the puerperium was uneventful.

Long-term outcomes of thrombotic microangiopathy treated with plasma exchange: A systematic review

With the adoption of plasma exchange as standard treatment for thrombotic microangiopathy (TMA), more patients are surviving and long-term outcomes have greater relevance. We conducted a systematic review to synthesize and evaluate the quality of evidence on long-term outcomes of TMA among adults treated with plasma exchange and to identify factors that may be associated with a worse long-term prognosis. We searched databases from 1980 to 2013 for eligible articles published in any language. We included studies that reported outcomes in at least ten adults with a history of TMA treated with plasma exchange and at least 6 months of follow-up. We abstracted data in duplicate and assessed the methodological quality of each study using an assessment tool developed based on recommended validity criteria. We screened 6672 articles, reviewed 213, and included 34 studies totaling 1182 patients (study median [range], 24 [10-118]). The mean (or median) follow-up ranged from 6 months to 13 years. The cumulative incidence of relapse and mortality was highly variable and ranged from 3 to 84 and 0 to 61%, respectively. The incidence of other outcomes across 10 studies also varied (outcomes included hypertension, kidney disease, preeclampsia, stroke, seizure, severe cognitive impairment, and depression); in three other studies, long-term neurocognitive function and health-related quality of life were significantly lower than in the general population. Patients who survive an episode of TMA may be susceptible to long-term vascular complications, but the magnitude of this risk and how to mitigate it remains unclear. Am. J. Hematol. 91:623-630, 2016. © 2016 Wiley Periodicals, Inc.

Dengue Virus Infection Triggering Thrombotic Thrombocytopenic Purpura in Pregnancy

We report a case of thrombotic thrombocytopenic purpura (TTP) that immediately followed symptomatic dengue virus infection in a pregnant lady. The patient developed dengue fever at 16 weeks of gestation, resulting in spontaneous abortion. Subsequently, fever reappeared with persistent thrombocytopenia and jaundice. Investigations revealed microangiopathic hemolysis; there was no evidence of disseminated intravascular coagulation. The TTP episode resolved after six cycles of therapeutic plasma exchange with fresh-frozen plasma. An ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif 13 repeats) activity assay, done during convalescence, showed normal activity. The patient had an uneventful second pregnancy and has remained free of TTP recurrence for more than 2 years now. We review the pathophysiological basis of TTP in dengue infection, and suggest that jaundice with disproportionate elevation of serum aspartate aminotransferase level in a patient with dengue should arouse the suspicion of TTP.

Thrombotic thrombocytopenic purpura and pregnancy: presentation, management, and subsequent pregnancy outcomes

In women presenting with an initial diagnosis of TTP during pregnancy, cTTP was more common than acquired TTP. Active monitoring and management during pregnancy results in positive pregnancy outcomes.

[Thrombocytopenia]

Thrombocytopenia means low platelet count. This is the most frequent cause of bleeding abnormalities. Petechias, purpuras, mucosal bleeding are typical clinical findings. Severe, even life threatening gastrointestinal or intracranial bleeding may also occur. Diagnostic laboratory finding is the prolonged bleeding time. There are several causes of thrombocytopenia. The major mechanisms for a reduced platelet count are decreased production and increased destruction of platelets, or both. The major task is to reveal the underlying cause. Examination of the bone marrow and the peripheral blood smear can be helpful as well as special diagnostics of the assumed disease. Therapy targets the underlying disease, and also involves platelet transfusion. However, in case of diseases with increased platelet activation and consumption, platelet transfusion is contraindicated because it may lead to aggravation of the pathologic process.

TTP and pregnancy

In this issue of Blood, Jiang et al use the Oklahoma Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome (TTP-HUS) Registry to demonstrate that in women with a previous history of TTP, associated with severe ADAMTS13 deficiency, the frequency of TTP recurrence is low and pregnancy outcomes are positive.1

Pregnancy outcomes following recovery from acquired thrombotic thrombocytopenic purpura

Pregnancy may precipitate acute episodes of thrombotic thrombocytopenic purpura (TTP), but pregnancy outcomes in women who have recovered from acquired TTP are not well documented. We analyzed pregnancy outcomes following recovery from TTP associated with acquired, severe ADAMTS13 deficiency (ADAMTS13 activity <10%) in women enrolled in the Oklahoma TTP-HUS Registry from 1995 to 2012. We also systematically searched for published reports on outcomes of pregnancies following recovery from TTP associated with acquired, severe ADAMTS13 deficiency. Ten women in the Oklahoma Registry had 16 subsequent pregnancies from 1999 to 2013. Two women had recurrent TTP, which occurred 9 and 29 days postpartum. Five of 16 pregnancies (31%, 95% confidence interval, 11%-59%) in 3 women were complicated by preeclampsia, a frequency greater than US population estimates (2.1%-3.2%). Thirteen (81%) pregnancies resulted in normal children. The literature search identified 382 articles. Only 6 articles reported pregnancies in women who had recovered from TTP associated with acquired, severe ADAMTS13 deficiency, describing 10 pregnancies in 8 women. TTP recurred in 6 pregnancies.

CONCLUSIONS

With prospective complete follow-up, recurrent TTP complicating subsequent pregnancies in Oklahoma patients is uncommon, but the occurrence of preeclampsia may be increased. Most pregnancies following recovery from TTP in Oklahoma patients result in normal children.

Acute kidney injury in pregnancy-current status

Pregnancy-related acute kidney injury (PR-AKI) causes significant maternal and fetal morbidity and mortality. Management of PR-AKI warrants a thorough understanding of the physiologic adaptations in the kidney and the urinary tract. Categorization of etiologies of PR-AKI is similar to that of acute kidney injury (AKI) in the nonpregnant population. The causes differ between developed and developing countries, with thrombotic microangiopathies (TMAs) being common in the former and septic abortion and puerperal sepsis in the latter. The incidence of PR-AKI is reported to be on a decline, but there is no consensus on the exact definition of the condition. The physiologic changes in pregnancy make diagnosis of PR-AKI difficult. Newer biomarkers are being studied extensively but are not yet available for clinical use. Early and accurate diagnosis is necessary to improve maternal and fetal outcomes. Timely identification of "at-risk" individuals and treatment of underlying conditions such as sepsis, preeclampsia, and TMAs remain the cornerstone of management. Questions regarding renal replacement therapy such as modality, optimal prescription, and timing of initiation in PR-AKI remain unclear. There is a need to systematically explore these variables to improve care of women with PR-AKI.

Management of pregnancy-associated thrombotic thrombocytopenia purpura

Thrombotic thrombocytopenia purpura (TTP) is an infrequent but serious disease. Pregnancy is a known risk factor for presentation or relapse of TTP. Difficulties in differentiating TTP from preeclampsia/HELLP (hemolysis, elevated liver enzymes and low platelets) syndrome, and current treatment recommendations are discussed in this case report. A woman with previously treated and stable TTP had a relapse at 36 weeks' gestation. Careful surveillance led to an early diagnosis. Severe disease in the peripartum period was treated successfully with cryosupernatant plasma-based plasmapheresis and platelet transfusion, with good maternal and neonatal outcomes. Cryosupernatant plasma is a viable alternative to fresh frozen plasma for plasmapheresis for TTP and may offer some therapeutic and logistical advantages. Platelet transfusion can be undertaken safely if needed to prevent or treat significant hemorrhage.

The Oklahoma Thrombotic Thrombocytopenic Purpura-haemolytic Uraemic Syndrome Registry. A model for clinical research, education and patient care

The Oklahoma Thrombotic Thrombocytopenic Purpura-Haemolytic Uraemic Syndrome (TTP-HUS) Registry has a 24 year record of success for collaborative clinical research, education, and patient care. This article tells the story of how the Registry began and it describes the Registry's structure and function. The Registry provides a model for using a cohort of consecutive patients to investigate a rare disorder. Collaboration between Oklahoma, United States and Bern, Switzerland has been the basis for successful interpretation of Registry data. Registry data have provided new insights into the evaluation and management of TTP. Because recovery from acute episodes of TTP has been assumed to be complete, the increased prevalence of hypertension, diabetes, depression, and death documented by long-term follow-up was unexpected. Registry data have provided opportunities for projects for students and trainees, education of physicians and nurses, and also for patients themselves. During our follow-up, patients have also educated Registry investigators about problems that persist after recovery from an acute episode of TTP. Most important, Registry data have resulted in important improvements for patient care.

How I treat thrombocytopenia in pregnancy

A mild thrombocytopenia is relatively frequent during pregnancy and has generally no consequences for either the mother or the fetus. Although representing no threat in the majority of patients, thrombocytopenia may result from a range of pathologic conditions requiring closer monitoring and possible therapy. Two clinical scenarios are particularly relevant for their prevalence and the issues relating to their management. The first is the presence of isolated thrombocytopenia and the differential diagnosis between primary immune thrombocytopenia and gestational thrombocytopenia. The second is thrombocytopenia associated with preeclampsia and its look-alikes and their distinction from thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome. In this review, we describe a systematic approach to the diagnosis and treatment of these disease entities using a case presentation format. Our discussion includes the antenatal and perinatal management of both the mother and fetus.

Diagnostic and therapeutic challenges in the thrombotic thrombocytopenic purpura and hemolytic uremic syndromes

Evaluation and management of patients with suspected thrombotic thrombocytopenic purpura (TTP) continue to be a critical challenge for hematologists. The diagnostic criteria are not precise, often causing uncertainty about whether it is appropriate to initiate plasma exchange (PEX), the essential treatment for TTP. Initiation of PEX remains a clinical decision; severe ADAMTS13 (< 10% activity) deficiency alone is neither sufficiently sensitive nor specific for the diagnosis of TTP. However, patients who do have severe acquired ADAMTS13 deficiency define the characteristic clinical features of TTP, the response to treatment, and the long-term outcomes. Patients with severe acquired ADAMTS13 deficiency are predominantly young women and the relative frequency of blacks is increased. Patients may present with only microangiopathic hemolytic anemia and thrombocytopenia, neurologic and renal abnormalities are often not present, fever rarely occurs; the complete “pentad” of these clinical features almost never occurs in current practice. Response to PEX is typically rapid but may not be sustained when PEX is stopped. Use of corticosteroids and rituximab has decreased the number of PEX treatments required to achieve a remission and has resulted in fewer PEX-related major complications. Relapse (in approximately 40% of patients) may be the most apparent risk after recovery, but long-term health outcomes are also very important. Minor cognitive abnormalities are common, the frequency of depression is increased, and the frequency of hypertension is increased. Careful long-term follow-up of TTP patients is essential.

Obstetric nephrology: AKI and thrombotic microangiopathies in pregnancy

AKI in pregnancy remains a cause of significant fetomaternal mortality and morbidity, particularly in developing countries. Hypertensive complications of pregnancy (preeclampsia/eclampsia or hemolysis, elevated liver enzymes, and low platelets count syndrome) are the leading cause of AKI in pregnancy worldwide. Thrombotic microangiopathy is another peculiar and devastating cause of AKI in pregnancy. During the last decade, our understanding, and in some cases, our management, of these causes of AKI in pregnancy has dramatically improved. For instance, convincing data have linked pre-eclampsia/eclampsia to an increase in circulating antiangiogenic factors soluble Flt 1 and endoglin, which induce endothelial cell dysfunction, hypertension, and proteinuria. Several distinct pathogenic mechanisms underlying thrombotic microangiopathy, including thrombotic microangiopathy occurring during pregnancy, have been established. Thrombotic microangiopathy, which can present as hemolytic uremic syndrome or thrombotic thrombocytopenic purpura, can be reclassified in four potentially overlapping subtypes: disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 deficiency-related thrombotic microangiopathy, complement alternative pathway dysregulation-related thrombotic microangiopathy, secondary thrombotic microangiopathy (verotoxin and antiangiogenic drugs), and thrombotic microangiopathy of undetermined mechanism. In most cases, pregnancy is only a precipitating factor for thrombotic microangiopathy. Treatment of thrombotic microangiopathy occurring during pregnancy should be tailored to the underlying pathogenic mechanism: (1) restoration of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 serum activity in the setting of thrombotic thrombocytopenic purpura through plasma exchanges and in some cases, B cell-depleting therapy and (2) inhibition of complement alternative pathway activation in atypical hemolytic uremic syndrome using antiC5 blocking antibody (eculizumab).

Unexpected frequency of Upshaw-Schulman syndrome in pregnancy-onset thrombotic thrombocytopenic purpura

Pregnancy may be complicated by a rare but life-threatening disease called thrombotic thrombocytopenic purpura (TTP). Most cases of TTP are due to an acquired autoimmune or hereditary (Upshaw-Schulman syndrome [USS]) severe deficiency of a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13). In the present study, we performed a cross-sectional analysis of the national registry of the French Reference Center for Thrombotic Microangiopathies from 2000-2010 to identify all women who were pregnant at their initial TTP presentation. Among 592 adulthood-onset TTP patients with a severe ADAMTS13 deficiency, 42 patients with a pregnancy-onset TTP were included. Surprisingly, the proportion of USS patients (n = 10 of 42 patients [24%]; confidence interval, 13%-39%) with pregnancy-onset TTP was much higher than that in adulthood-onset TTP in general (less than 5%) and was mostly related to a cluster of ADAMTS13 variants. In the present study, subsequent pregnancies in USS patients not given prophylaxis were associated with very high TTP relapse and abortion rates, whereas prophylactic plasmatherapy was beneficial for both the mother and the baby. Pregnancy-onset TTP defines a specific subgroup of patients with a strong genetic background. This study was registered at www.clinicaltrials.gov as number NCT00426686 and at the Health Authority, French Ministry of Health, as number P051064.

Diagnosis and management of maternal thrombocytopenia in pregnancy

Thrombocytopenia is a common finding in pregnancy, occurring in approximately 7-10% of pregnancies. It may be a diagnostic and management problem, and has many causes, some of which are specific to pregnancy. Although most cases of thrombocytopenia in pregnancy are mild, and have no adverse outcome for either mother or baby, occasionally a low platelet count may be part of a more complex disorder with significant morbidity and may be life-threatening. Overall, about 75% of cases are due to gestational thrombocytopenia, 15-20% secondary to hypertensive disorders; 3-4% due to an immune process, and the remaining 1-2% made up of rare constitutional thrombocytopenias, infections and malignancies. In this review, a diagnostic approach to investigating thrombocytopenia in pregnancy is presented, together with antenatal, anaesthetic and peri-natal management issues for mother and baby, followed by a detailed discussion on the specific causes of thrombocytopenia and the management options in each case.

The kidney in pregnancy: A journey of three decades

The spectrum of kidney disease occurring during pregnancy includes preeclampsia, hypertensive disorders of pregnancy, urinary tract infection, acute kidney injury, and renal cortical necrosis (RCN). Preeclampsia affects approximately 3-5% of pregnancies. We observed preeclampsia in 5.8% of pregnancies, and 2.38% of our preeclamptic women developed eclampsia. Severe preeclampsia and the eclampsia or hemolysis, elevated liver enzymes levels, and low platelets count (HELLP) syndrome accounted for about 40% of cases of acute kidney injury (AKI) in pregnancy. Preeclampsia/eclampsia was the cause of acute renal failure (ARF) in 38.3% of the cases. Preeclampsia was the most common (91.7%) cause of hypertension during pregnancy, and chronic hypertension was present in 8.3% of patients. We observed urinary tract infection (UTI) in 9% of pregnancies. Sepsis resulting from pyelonephritis can progress to endotoxic shock, disseminated intravascular coagulation, and AKI. The incidence of premature delivery and low birth weight is higher in women with UTI. The incidence of AKI in pregnancy with respect to total ARF cases has decreased over the last 30 years from 25% in 1980s to 5% in 2000s. Septic abortion-related ARF decreased from 9% to 3%. Prevention of unwanted pregnancy and avoidance of septic abortion are key to eliminate abortion-associated ARF in early pregnancy. The two most common causes of ARF in third trimester and postpartum periods were puerperal sepsis and preeclampsia/HELLP syndrome. Pregnancy-associated thrombotic thrombocytopenic purpura/hemolytic uremic syndrome and acute fatty liver of pregnancy were rare causes of ARF. Despite decreasing incidence, AKI remains a serious complication during pregnancy.

Thrombotic thrombocytopenic purpura

A 34-year old primipara was admitted to hospital with dichorionic-diamniotic twins in 26+3 weeks of gestation. In suspicion of HELLP-syndrome, caesarean section was performed at 27+4 weeks of gestation, because of platelet count was reduced to 44000/µl. A re-laparotomy had to be performed because of intra-abdominal bleedings. The patient was given seven packed thrombocytes and five packed erythrocytes. The patient complained about blurred vision. The right corner of the mouth was slightly depressed in terms of a facial nerve paresis. Further platelet counts were about 50000/µl. Haemoglobin: 7.8 mg/l. D-Dimer: 1066 mg/l. LDH was elevated to 1610 U/l, reticulocytes were elevated to 13.19% and haptoglobin was reduced to <0.08 g/l. The Coombs' test was negative. The ADAMTS-13 test showed a reduced activity. Hereby, the diagnoses of thrombotic thrombocytopenic purpura was confirmed. Plasma exchange is the most effective option; application of platelet concentrate should be avoided, because of worsening microangiopathy and subsequent neurological situation. After the patient has received plasma exchange, platelet count normalized. An ophthalmic examination showed a dysfunction in choroid perfusion as a cause for the blurred vision. After discharge regular lab tests were planned, but no further treatment was necessary at that point of time. The premature twins survived after ventricular haemorrhage, severe sepsis, bronchopulmonary dysplasia and other complications of neonates.

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.

Pregnancy-associated atypical haemolytic uraemic syndrome in the postpartum period: a case report and review of the literature

Pregnancy has been reported to be a trigger in about 10% of all patients with atypical haemolytic uraemic syndrome (aHUS). However, in contrast to pregnancy-associated thrombotic thrombocytopaenic purpura, the presentation of pregnancy-associated aHUS remains ill defined and can therefore be difficult to diagnose and manage appropriately. Here we report a case of pregnancy-associated relapse of aHUS in a patient with a previous medical history of aHUS prior to pregnancy.

DIAGNOSIS AND MANAGEMENT OF THROMBOCYTOPENIA IN PREGNANCY

Platelets are an essential component of the first step in the process of haemostasis, plugging defects in the endothelium and providing a surface for secondary haemostasis to occur, via the coagulation pathway. Platelet aggregation and activation cause granule release of von Willebrand factor, ADP and serotonin, which, in turn, results in recruitment of more platelets to form the platelet plug. This serves to stop the bleeding, and also to activate the coagulation pathway on the surface of the activated platelets, leading to a firm fibrin clot.

How I treat patients with thrombotic thrombocytopenic purpura: 2010

Thrombotic thrombocytopenic purpura (TTP) is the common name for adults with microangiopathic hemolytic anemia, thrombocytopenia, with or without neurologic or renal abnormalities, and without another etiology; children without renal failure are also described as TTP. The diagnosis of TTP is an indication for plasma exchange treatment, but beginning treatment requires sufficient confidence in the diagnosis to justify the risk of plasma exchange complications. Documentation of a severe deficiency of plasma ADAMTS13 activity, defined as less than 10% of normal, is not essential for the diagnosis of TTP. Some patients without severe ADAMTS13 deficiency may benefit from plasma exchange treatment; in addition, some patients with severe ADAMTS13 deficiency may subsequently be diagnosed with another cause for their clinical features. However, severe acquired ADAMTS13 deficiency does define a subgroup of patients who appear to benefit from treatment with corticosteroids and other immunosuppressive agents in addition to plasma exchange but who have a high risk for relapse. Approximately 80% of patients survive their acute episode, a survival rate that has not changed since the introduction of plasma exchange treatment. Although recovery may appear to be complete, many patients have persistent minor cognitive abnormalities. More effective as well as safer treatment for TTP is needed.

Successful prevention of thrombotic thrombocytopenic purpura (TTP) relapse using monthly prophylactic plasma exchanges throughout pregnancy in a patient with systemic lupus erythematosus and a prior history of refractory TTP and recurrent fetal loss

BACKGROUND

The occurrence of thrombotic thrombocytopenic purpura (TTP) in the setting systemic lupus erythematosus (SLE) is rare. In women of childbearing age, TTP is associated with high rates of recurrence in pregnancy. Furthermore, both TTP and SLE are associated with a significant risk of adverse pregnancy outcomes.

CASE PRESENTATION

We describe the case of a 36 year old female in her first trimester of pregnancy with a prior history of SLE-associated severe refractory TTP who was treated with a combination of corticosteroids and prophylactic plasma exchanges (PLEX) throughout pregnancy to prevent TTP recurrence. She delivered a healthy infant at 33 weeks of gestation after the onset of preterm labor. There was no evidence of TTP recurrence in the antepartum or postpartum period in this high risk patient.

CONCLUSION

Prophylactic PLEX should be considered as a therapeutic option to prevent recurrent TTP during pregnancy in high risk patients, including patients with previous SLE-associated TTP.