Syndromes of thrombotic microangiopathy associated with pregnancy

A case-based narrative review of pregnancy-associated atypical hemolytic uremic syndrome/complement-mediated thrombotic microangiopathy

Atypical hemolytic uremic syndrome is a complement-mediated thrombotic microangiopathy caused by uncontrolled activation of the alternative complement pathway in the setting of autoantibodies to or rare pathogenic genetic variants in complement proteins. Pregnancy may serve as a trigger and unmask atypical hemolytic uremic syndrome/complement-mediated thrombotic microangiopathy (aHUS/CM-TMA), which has severe, life-threatening consequences. It can be difficult to diagnose aHUS/CM-TMA in pregnancy due to overlapping clinical features with other thrombotic microangiopathy syndromes including hypertensive disorders of pregnancy. However, the distinction among thrombotic microangiopathy etiologies in pregnancy is important because each syndrome has specific disease management and treatment. In this narrative review, we discuss 2 cases to illustrate the diagnostic challenges and evolving approach in the management of pregnancy-associated aHUS/CM-TMA. The first case involves a 30-year-old woman presenting in the first trimester who was diagnosed with aHUS/CM-TMA and treated with eculizumab from 19 weeks' gestation. Genetic testing revealed a likely pathogenic variant in CFI. She successfully delivered a healthy infant at 30 weeks' gestation. In the second case, a 22-year-old woman developed severe postpartum HELLP syndrome, requiring hemodialysis. Her condition improved with supportive management, yet investigations assessing for aHUS/CM-TMA remained abnormal 6 months postpartum consistent with persistent complement activation but negative genetic testing. Through detailed case discussion describing tests assessing for placental health, fetal anatomy, complement activation, autoantibodies to complement regulatory proteins, and genetic testing for aHUS/CM-TMA, we describe how these results aided in the clinical diagnosis of pregnancy-associated aHUS/CM-TMA and assisted in guiding patient management, including the use of anticomplement therapy.

Thrombotic microangiopathy - the importance of a multidisciplinary approach

PURPOSE OF REVIEW

The purpose of this review is to highlight the importance of a multidisciplinary thrombotic microangiopathies (TMA) Team. This goal will be accomplished through review of the complement system, discuss various causes of thrombotic microangiopathies (TMA), and aspects of their diagnosis and management. In so doing, readers will gain an appreciation for the complexity of this family of disorders and realize the benefit of a dedicated multidisciplinary TMA Team.

RECENT FINDINGS

TMA causes derive from multiple specialty areas, are difficult to timely recognize, pose complex challenges, and require multidisciplinary management. Hematopoietic stem cell transplant-associated TMA (TA-TMA) and TA-TMA related multiorgan dysfunction syndrome (TA-TMA MODS) are areas of burgeoning research; use of complement testing and eculizumab precision-dosing has been found to better suppress complement activity in TA-TMA than standard eculizumab dosing. Newer tests are available to risk-stratify obstetric patients at risk for severe pre-eclampsia, whose features resemble those of TA-TMA MODS. Numerous disorders may produce TMA-like findings, and a systematic approach aids in their identification. TMA Teams elevate institutional awareness of increasingly recognized TMAs, will help expedite diagnostic and therapeutic interventions, and create pathways to future TMA-related research and facilitate access to clinical trials.

SUMMARY

Establishment of a TMA-Team is valuable in developing the necessary institutional expertise needed to promptly recognize and appropriately manage patients with TMA.

Management and follow-up of pregnancy-onset thrombotic thrombocytopenic purpura: the French experience

ABSTRACT

Pregnancy-onset thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening disease of which diagnosis and management requires experienced multidisciplinary teams. The mechanisms responsible for a deficiency in the disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13) leading to pregnancy-onset TTP may be congenital or acquired, and studying ADAMTS13 conformation could be of interest. The differential diagnosis between TTP and other pregnancy-associated thrombotic microangiopathies (TMA) is often challenging. Our retrospective multicenter study highlights the significance and the challenges associated with pregnancy-onset TTP and childbirth in terms of diagnosis, obstetric management, and follow-up aspects. Among 1174 pregnancy-onset TMA enrolled in the French Registry for TMA from 2000 to 2020, we identified 108 pregnancy-onset TTP: 52 immune-mediated TTP (iTTP, 48.1%), 27 acquired TTP of unidentified mechanism (uTTP, 25%), and 29 congenital TTP (cTTP, 26.9%). Data show that maternal outcome is good (survival rate: 95%) and fetal outcome is linked to the gestational age at the onset of the disease (survival rate: 75.5%). Three distinct entities with different natural histories emerged: pregnancy-onset iTTP appears similar to idiopathic iTTP, with an open ADAMTS13 conformation, and is marked by a relapse risk independent of subsequent pregnancies; pregnancy-onset uTTP appears to have a different pathophysiology with an unexpected open ADAMTS13 conformation and a very low relapse risk independent of subsequent pregnancies; finally, pregnancy-onset cTTP is characterized by the necessity of pregnancy as a systematic and specific trigger and a need for prophylactic plasmatherapy for subsequent pregnancies. This trial was registered at www.clinicaltrials.gov as #NCT00426686, and at the Health Authority and the French Ministry of Health (P051064/PHRC AOM05012).

Labor and delivery: DIC, HELLP, preeclampsia

Hematologists are often needed to assist with the management of microangiopathic emergencies in pregnancy. A firm understanding of the diagnosis and management of preeclampsia with severe features, hemolysis elevated liver enzyme and low platelet syndrome, and disseminated intravascular coagulation, which are the most common causes of microangiopathic emergencies, is critical. However, being able to consider when other microangiopathic emergencies (acute fatty liver of pregnancy, congenital and acquired thrombotic thrombocytopenic purpura, complement mediated microangiopathy, antiphospholipid syndrome) should be considered is imperative. The hematologist and obstetric team should work together to optimize the care of common as well as rare hematologic emergencies.

Long-term survival and renal outcomes of thrombotic microangiopathy in pregnancy: A retrospective cohort study

OBJECTIVE

Thrombotic microangiopathy (TMA) in pregnancy can rapidly progress, leading to severe morbidities. This study aimed to compare baseline demographics and clinical outcomes between pregnant women with and without TMA.

METHODS

Using the National Health Insurance Research Database, 207 patients with pregnancy-related TMA from January 1, 2006 to December 31, 2015 were enrolled. Their data were compared with a 1:4 propensity score-matched cohort of 828 pregnant women without TMA to evaluate mortality and end-stage renal disease (ESRD) risks. Cox proportional hazards models were used to estimate the adjusted hazard ratio and 95% confidence intervals.

RESULTS

A total of 1035 participants were included. The risks of mortality and ESRD were 4.46 and 5.97 times higher for the TMA cohort, respectively. Subgroup analysis revealed higher mortality and ESRD risks in patients with TMA aged >40 years with a history of hypertension, stroke, cancer, concomitant stroke, malignant hypertension, or gastroenterocolitis than in the matched cohort.

CONCLUSION

Pregnant patients with TMA, especially those older and with comorbidities and organ involvement, faced increased mortality and ESRD risks. Physicians should collaborate with obstetricians throughout the prenatal and postpartum periods for these patients.

Atypical Hemolytic-Uremic Syndrome: Genetic Basis, Clinical Manifestations, and a Multidisciplinary Approach to Management

Hemolytic uremic syndrome (HUS) is a thrombotic microangiopathy (TMA) defined by the triad of hemolytic anemia, thrombocytopenia, and acute kidney injury. Microthrombi develop in the glomerular capillaries secondary to endothelial damage and exert shear stress on red blood cells, consume platelets, and contribute to renal dysfunction and failure. Per current understanding of pathophysiology, HUS is classified into infectious, secondary, and atypical disease. The most common etiology is infectious sequelae of Shiga toxin-producing Escherichia coli (STEC); other causative organisms include shigella and salmonella. Secondary HUS arises from cancer, chemotherapy, solid organ and hematopoietic stem cell transplant, pregnancy, or autoimmune disorders. Primary atypical hemolytic-uremic syndrome (aHUS) is associated with genetic mutations in complement and complement regulatory proteins. Under physiologic conditions, complement regulators keep the alternative complement system continuously active at low levels. In times of inflammation, mutations in complement-related proteins lead to uncontrolled complement activity. The hyperactive inflammatory state leads to glomerular endothelial damage, activation of the coagulation cascade, and TMA findings. Atypical hemolytic-uremic syndrome is a rare disorder with a prevalence of 2.21 to 9.4 per million people aged 20 years or younger; children between the ages of 0 and 4 are most affected. Multidisciplinary health care is necessary for timely management of its extra-renal manifestations. These include vascular disease of the heart, brain, and skin, pulmonary hypertension and hemorrhage, and pregnancy complications. Adequate screening is required to monitor for sequelae. First-line treatment is the monoclonal antibody eculizumab, but several organ systems may require specialized interventions and coordination of care with sub-specialists.

Challenges in the diagnosis of thrombotic thrombocytopenic purpura

INTRODUCTION

Immune-mediated TTP (iTTP) is a rare condition without pathognomonic signs and symptoms. For this reason, the diagnosis of iTTP may be delayed or even missed, with potentially catastrophic consequences.

AREAS COVERED

The authors performed an extensive literature review on the diagnosis of iTTP and its challenges combined with their own experience in a referral center for patients with iTTP.

EXPERT OPINION

Although a definitive diagnosis of iTTP depends on the ADAMTS13 activity result, timely testing is rarely available at many centers to which patients present. If less complex tests were to become available, they would decrease the chances of late and/or missed diagnoses of iTTP throughout the world. While clinical scores to estimate the likelihood of iTTP exist, they are not well known, and can be misleading if used in the wrong context. Furthermore, the three scoring systems (PLASMIC, Bentley, and French) only moderately correlate with each other, which further complicates the landscape. The existence of these scores and how they should be used in practice is but one opportunity that can be seized through more robust programs to educate nonspecialist clinicians on how to recognize and treat patients with iTTP.

Renal Thrombotic Microangiopathy: A Review

Thrombotic microangiopathy (TMA), a pathological lesion observed in a wide spectrum of diseases, is triggered by endothelial injury and/or dysfunction. Although TMA lesions are often accompanied by clinical features of microangiopathic hemolytic anemia, thrombocytopenia, and ischemic end-organ injury, renal-limited forms of TMA are not infrequently encountered in clinical practice. The presence of renal-limited manifestations can be diagnostically challenging, often delaying the initiation of targeted therapy. Prompt investigation and empirical treatment of TMA is warranted to reduce associated morbidity and mortality. Major advances have been made with respect to the pathophysiology of primary TMA entities, with the subsequent development of novel diagnostic tools and lifesaving therapies for diseases like thrombotic thrombocytopenic purpura and complement-mediated TMA. This article will review the clinical presentation and pathologic hallmarks of TMA involving the kidney, and the disease-specific mechanisms that contribute to the endothelial injury that characterizes TMA lesions. Diagnostic approach and both empirical and disease-specific treatment strategies will be discussed, along with the potential role for emerging targeted disease-specific therapies.

Maternal morbidity and mortality in pregnant/postpartum women with suspected HELLP syndrome identifiable as probable thrombotic thrombocytopenic purpura or atypical hemolytic uremic syndrome by high LDH to AST ratio

OBJECTIVE

To describe findings in 8 women initially diagnosed as presumptive HELLP Syndrome, eventually confirmed as TTP/aHUS as distinguished by elevated calculated LDH:AST ratio > 22:1.

METHODS

All medicolegal files of patients evaluated between 1986 and 2015 with presumptive HELLP syndrome but later determined to have TTP/aHUS had LDH:AST ratios evaluated throughout care.

RESULTS

Fifty-eight pregnant/postpartum women presented with a diagnosis of presumptive HELLP syndrome. In the final analysis, 8 women had TTP/aHUS characterized by severe thrombocytopenia (<20 000/μl) at admission, rare epigastric pain, and the consistent demonstration of a very high calculated total LDH to AST ratio. This calculation greatly exceeded 22:1 with TTP/aHUS (mean = 32:1) versus 2:1 with HELLP and could be consistently demonstrated throughout care. Six of 8 women with TTP/aHUS died.

CONCLUSION

Correctly distinguishing between HELLP syndrome versus an imitator disorder continues to challenge obstetric specialists. This medicolegal data supplements prior findings supporting the concept of the LDH:AST ratio as a useful screening tool for clinicians to differentiate TTP/aHUS apart from HELLP syndrome in order to facilitate earlier hematology consultation, patient referral to tertiary care and emergent hemotherapy for these mothers.

Hypercoagulability and Inflammatory Markers in a Case of Congenital Thrombotic Thrombocytopenic Purpura Complicated by Fetal Demise

BACKGROUND

Congenital thrombotic thrombocytopenic purpura (cTTP) is a rare disorder caused by an inherited genetic deficiency of ADAMTS13 and affects less than one per million individuals. Patients who are diagnosed with TTP during pregnancy are at increased risk of maternal and fetal complications including fetal demise. We present a case of a 32-year-old G3P0 (gravida 3, para 0) who presented at 20 weeks gestation with a new diagnosis of congenital TTP (cTTP) and fetal demise.

METHODS

We describe the pathophysiology of pregnancy complications in a patient with cTTP using platelet procoagulant membrane dynamics analysis and quantitative proteomic studies, compared to four pregnant patients with gestational hypertension, four pregnant patients with preeclampsia, and four healthy pregnant controls.

RESULTS

The cTTP patient had increased P-selectin, tissue factor expression, annexin-V binding on platelets and neutrophils, and localized thrombin generation, suggestive of hypercoagulability. Among 15 proteins that were upregulated, S100A8 and S100A9 were distinctly overexpressed.

CONCLUSIONS

There is platelet-neutrophil activation and interaction, platelet hypercoagulability, and proinflammation in our case of cTTP with fetal demise.

17β-Estradiol promotes angiogenesis of bone marrow mesenchymal stem cells by upregulating the PI3K-Akt signaling pathway

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The role and mechanism of 17β -estradiol in the regulation of BMSC promoting angiogenesis were analyzed by bioinformatics techniques for the first time.

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Combined with FN1, MCM2, XPO1, NTRK1 and other proteins, 17β-estradiol is able to activate PI3K-Akt, MAPK and other signaling pathways to regulate BMSCs to promote or remodel angiogenesis.

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17β-estradiol upregulates the PI3K-Akt signaling pathway to promote the BMSC angiogenesis process of differentiation.

Objective

Estrogen is an important hormone affecting angiogenesis in women and is important for female physical development. Menopausal women are prone to serious cardiovascular and cerebrovascular diseases when estrogen is significantly reduced. Bone marrow mesenchymal stem cells (BMSC) have potential roles in processes such as angiogenesis and remodeling. This study is to investigate the effect of 17β-estradiol on BMSC angiogenic differentiation and its underlying molecular mechanism, and to provide a basis for the treatment of microvascular diseases.

Methods

Enrichment analysis of apoptosis, migration or angiogenesis processes and molecular mechanisms of BMSC treated with 17β-estradiol was performed to screen core proteins and perform molecular docking validation. Human MSCs were cultured in vitro to examine the effect of 17β-estradiol on BMSC migration or angiogenic differentiation.

Results

17β-estradiol acted on 48 targets of BMSC and was involved in regulating 52 cell migration processes or 17 angiogenesis processes through 66 KEGG pathways such as PI3K-Akt, MAPK, etc. 17β-estradiol bound tightly to 10 core proteins including APP, NTRK1, EGFR, and HSP90AA1. 17β-estradiol promoted cell scratch area closure rate and CD31 expression in BMSCs, downregulated BMSC apoptosis rate, and promoted Akt and p-Akt protein expression in BMSC.

Conclusion

17β-estradiol binds to FN1, MCM2, XPO1, NTRK1 and other proteins to initiate PI3K-Akt, MAPK and other signaling pathways, so as to regulate BMSC to promote or remodel angiogenesis, verifying that 17β-estradiol up-regulates PI3K-Akt signaling pathway to promote BMSC angiogenic differentiation.

A new pathological perspective on thrombotic microangiopathy

Thrombotic microangiopathy (TMA) refers to a condition caused by microvascular injury that includes thrombosis, hemolytic anemia, and thrombocytopenia. There are two classic TMAs, hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura, as well as an atypical HUS (aHUS). aHUS includes a broad spectrum of disorders with diverse etiologies and shares clinical manifestations with classic TMA; however, it frequently lacks typical clinical and laboratory findings. These traits can confuse clinicians and pathologists in terms of renal pathologic diagnosis, especially in cases where TMA is associated with other glomerulopathies or hypertensive renal disease. In this review, new paradigms for classifying TMA and the diversity of histopathologic changes including associated renal diseases are discussed. Renal biopsy is an important and useful diagnostic tool for diagnosing TMA and identifying TMA changes in other renal diseases, including hypertension. Adopting the term “TMA features” for TMA-like changes in glomerulus or artery/arteriole in addition to the pathological diagnosis of glomerulopathy would be informative to clinicians for a prompt diagnosis and treatment of aHUS.

Diagnosis of thrombotic microangiopathy in preeclampsia in the common marmoset (Callithrix jacchus) and treatment by cesarean section

A pregnant common marmoset (Callithrix jacchus) showed tachypnea, hypothermia, and anorexia at close to the expected delivery date. Severe anemia and thrombocytopenia, schistocytes, and high levels of LDH and D-dimer were observed. Three days after the onset of clinical signs, a cesarean section was conducted due to stillbirth. Marmoset immediately recovered after surgery, and the abnormal CBC and blood chemistry parameters before surgery returned to the normal ranges. Diagnosis of pregnancy-associated thrombotic microangiopathy was made because removal of infant and placenta is curative. To the best of our knowledge, this is the first case report of thrombotic microangiopathy in a marmoset with preeclampsia.

Pr-AKI: Acute Kidney Injury in Pregnancy – Etiology, Diagnostic Workup, Management

Despite significant improvements in inpatient and outpatient management, pregnancy-related acute kidney injury (Pr-AKI) remains an important risk factor for early and late maternal and fetal morbidity and mortality. There is a discrepancy between the incidence of Pr-AKI in developing and in developed countries, with the former experiencing a decrease and the latter an increase in Pr-AKI in recent decades. Whereas septic and hemorrhagic complications predominated in the past, nowadays hypertensive disorders and thrombotic microangiopathy are the leading causes of Pr-AKI. Modern lifestyles and the availability and widespread use of in-vitro fertilization techniques in industrialized countries have allowed more women of advanced age to become pregnant. This has led to a rise in the percentage of high-risk pregnancies due to the disorders and comorbidities inherent to or accompanying aging, such as diabetes, arterial hypertension and preexisting chronic kidney disease. Last but not least, the heterogeneity of symptoms, the often overlapping clinical and laboratory characteristics and the pathophysiological changes related to pregnancy make the diagnosis and management of Pr-AKI a difficult and challenging task for the treating physician. In addition to general supportive management strategies such as volume substitution, blood pressure control, prevention of seizures or immediate delivery, each disease entity requires a specific therapy to reduce maternal and fetal complications. In this review, we used the current literature to provide a summary of the physiologic and pathophysiologic changes in renal physiology which occur during pregnancy. In the second part, we present common and rare disorders which lead to Pr-AKI and provide an overview of the available treatment options.

Severe thrombocytopenia and microangiopathic hemolytic anemia in pregnancy: A guide for the consulting hematologist

A hematologist receives a call from a maternal-fetal medicine (MFM) physician about a previously healthy patient who became ill at 25 weeks' gestation. Her mental status is deteriorating. There are signs of fetal distress. Platelet count and hemoglobin are falling. The MFM physician is considering the hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome. For the hematologist, everything seems unfamiliar. Our goal is to provide hematologists with the fundamental knowledge required for understanding and managing these patients who become suddenly and seriously ill during pregnancy and in whom thrombocytopenia and microangiopathic hemolytic anemia are part of their presentation.

Morbidities and Mortality in Patients with Hereditary Thrombotic Thrombocytopenic Purpura

More women (117) than men (85) were diagnosed with hTTP. The difference was caused by 34 women who were diagnosed during pregnancy.

Half of patients with hTTP who were older than age 40 years had had stroke, kidney injury requiring dialysis, and/or severe cardiac injury.

Hereditary thrombotic thrombocytopenic purpura (hTTP) is a rare disorder caused by severe ADAMTS13 deficiency. Major morbidities and death at a young age are common. Although replacement of ADAMTS13 can prevent morbidities and death, current regimens of plasma prophylaxis are insufficient. We identified 226 patients with hTTP in 96 reports published from 2001 through 2020. Age at diagnosis was reported for 202 patients; 117 were female and 85 were male. The difference was caused by diagnosis of 34 women during pregnancy, suggesting that many men and nulliparous women are not diagnosed. Eighty-three patients had severe jaundice at birth; hTTP was suspected and effectively treated in only 3 infants. Of the 217 patients who survived infancy, 73 (34%) had major morbidities defined as stroke, kidney injury, or cardiac injury that occurred at a median age of 21 years. Sixty-two patients had stroke; 13 strokes occurred in children age 10 years or younger. Of the 54 patients who survived their initial major morbidity and were subsequently observed, 37 (69%) had sustained or subsequent major morbidities. Of the 39 patients who were observed after age 40 years, 20 (51%) had experienced a major morbidity. Compared with an age- and sex-matched US population, probability of survival was lower at all ages beginning at birth. Prophylaxis was initiated in 45 patients with a major morbidity; in 11 (28%), a major morbidity recurred after prophylaxis had begun. Increased recognition of hTTP and more effective prophylaxis started at a younger age are required to improve health outcomes.

Thrombotic microangiopathy with renal injury: an approach for the general physician

Thrombotic microangiopathy with renal dysfunction is a haematological and renal emergency warranting urgent diagnosis and intervention. As the potential underlying causes may be complex, assessment and management can be challenging for treating clinicians, and a timely and collaborative approach between general physicians, haematologists and nephrologists may be extremely helpful in order to optimise clinical outcomes. This paper will aim to build an understanding of different potential presentations of thrombotic microangiopathies and provide a practical framework for diagnosis and management, using a case-based discussion format, for acute and general physicians. Some aspects of subsequent specialist management are also discussed.

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.

Thrombotic microangiopathy during pregnancy

Pregnancy is a high-risk time for the development of different kinds of thrombotic microangiopathy (TMA). Three major syndromes including TTP (thrombotic thrombocytopenic purpura), PE/HELLP (preeclampsia/hemolysis, elevated liver function tests, low platelets), and aHUS (atypical hemolytic- uremic syndrome) should be sought in pregnancy-TMA. These severe disorders share multiple clinical features and overlaps and even the coexistence of more than one pathologic mechanism. Each of these disorders finally ends in endothelial damage and fibrin thrombi formation within the microcirculation that fragments RBCs (schystocytes), aggregates platelets, and creates ischemic injury in the targeted organs i.e.; kidney and brain. Although the mechanisms of these severe disorders have been revealed, pregnancy-related TMA still interfaces with diagnostic and therapeutic challenges. Here, we highlight the current knowledge of diagnosis and management of these complications during pregnancy.

Post-cardiac surgery thrombotic thrombocytopenic purpura: presence of anti-ADAMTS13 autoantibodies at preoperative baseline

Thrombotic thrombocytopenic purpura (TTP) rarely complicates acute inflammatory conditions such as surgery, including post-cardiac surgery. Review of 32 previously-reported cases of post-cardiac surgery TTP indicates that this disorder often occurs as early as 2-3 days following surgery, which seems too soon to implicate new formation of anti-ADAMTS13 autoantibodies as a consequence of surgery itself. We diagnosed post-cardiac surgery TTP in a 60-year-old female that began approximately 3 days post-coronary artery bypass surgery in which anti-ADAMTS13 autoantibodies were implicated. We therefore investigated whether anti-ADAMTS13 autoantibodies were also present in a preoperative blood sample. Inhibitory (neutralizing) anti-ADAMTS13 autoantibodies were detectable in the preoperative blood sample, suggesting that the role of surgery in precipitating TTP might be due to effects such as abrupt increase in postoperative von Willebrand factor levels and associated proinflammatory factors, rather than effects of surgery itself leading to the formation of de novo anti-ADAMTS13 autoantibodies.

COVID-19 associated thrombotic thrombocytopenic purpura (TTP) ; A case series and mini-review

INTRODUCTION

Thrombotic microangiopathies are a group of disorders that are mainly related to endothelial dysfunction. This category of endothelial dysfunction results of several imbalances between platelets, endothelium and immune system, also cytokine production.

AIM OF THIS STUDY

To report cases with thrombotic thrombocytopenic purpura (TTP) and COVID-19 and review COVID-19 endothelial dysfunction literature.

METHODS

Primary laboratory data, peripheral blood smear, ADAMTS13 antigen activity level, and antibody ordered for each of these four patients. Treatments for COVID-19 administered for all patients. Traditional treatments for TTP also were administered.

RESULTS

There were numerous schistocytes (more than 5%) in peripheral blood smears for each patient. ADAMTS13 antigen activity level was below 10%, and ADAMTS13 antibody was elevated for each patient. COVID-19 PCR was positive for all patients, and CT-Scans were indicative of the involvement of COVID-19.

CONCLUSION

In this case series, we reported four COVID-19 patients who presented with signs and symptoms of anemia and thrombocytopenia, resulting in thrombotic thrombocytopenic purpura.

Post-partum occurrence of Wunderlich syndrome and microangiopathic haemolytic anaemia (MAHA): a case report

This is a case of a 27-year-old primigravida with monochorionic diamniotic twin gestation who was admitted to the hospital for induction of labour. Her postpartum course was complicated by microangiopathic haemolytic anemia (MAHA). The etiology for the MAHA was initially thought to be secondary to pre-eclampsia and vitamin B12/folate deficiency. However, she had persistent anemia and further workup demonstrated that she had a left renal cell carcinoma (RCC) with perinephric haemorrhage consistent with Wunderlich syndrome. This case was intriguing because of its unusual presentation and the several diagnostic and therapeutic challenges along the way. Abbreviations: MAHA: microangiopathic haemolytic anaemia; RCC: renal cell carcinoma; BP: blood pressure; WS: Wunderlich syndrome; CT: computed tomography; LFTs: liver function tests; LDH: lactate dehydrogenase; HELLP: haemolysis elevated liver enzymes, low platelets; DIC: disseminated intravascular coagulation; PLASMIC: score for TTP - includes platelet count <30 x 109/L, evidence of haemolysis (reticulocyte count >2.5%, haptoglobin undetectable, or indirect bilirubin >2mg/dL), active cancer, history of solid organ transplant, mean corpuscular volume (MCV) <90fL, INR <1.5, creatinine <2mg/dL. Each item is sored as being present (YES) or not (NO). Absence of active cancer and solid organ transplant gets scored with a point each. The total points are added up to categorize the severity and risk of TTP. Low risk <4, Intermediate 5, high risk >6; TTP: thrombotic thrombocytopenic purpura; APLA- anti-phophospholipid antibody; BMI: body mass index; TMAs: thrombotic microangiopathies; HUS: haemolytic uremic syndrome; vWF: von Willebrand factor.

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.

Therapeutic plasma exchange in pregnancy: A literature review

Therapeutic plasma exchange (TPE) is indicated as a treatment for a wide array of diseases, extensively addressed in the Guidelines of the American Society for Apheresis. In pregnancy, TPE is an uncommon event and application is largely based on extrapolation of efficacy and safety in a non-pregnant population. This review intends to describe the currently available experience of TPE in pregnancy to help clinicians recognise indications during pregnancy and to support current guideline recommendations with literature-based experiences. In order to identify the clinical indications for which TPE is applied in pregnant women, we performed a literature search including studies till November 2019, without a start date restriction. Data extraction included medical indication for TPE and safety of TPE in pregnant women. 279 studies were included for analysis. Nowadays, TPE is predominantly applied for thrombotic microangiopathies, lipid disorders and a variety of autoimmune diseases. The application of TPE during pregnancy remains largely empiric and relies on individual case reports in the absence of high-quality studies and definitive evidence-based guidelines. Safety profile of TPE during pregnancy appears to be comparable to application of TPE in non-pregnant patients. In conclusion, based on the limited evidence that we found in literature with a high risk of publication bias, TPE procedures can be used safely during pregnancy with the appropriate preparation and experience of a multidisciplinary team.

[Hypertensive Disorders in Pregnancy]

Hypertensive disorders occur in up to 10 % of pregnancies and increase both maternal and fetal morbidity and mortality. The most important differential diagnoses comprise pre-existing chronic hypertension, pregnancy-associated hypertension, and preeclampsia with simultaneous proteinuria. Antihypertensive therapy during pregnancy should be initiated when blood pressure is 150-160/100-110 mmHg. With regard to an earlier initiation of therapy, the data situation is not clear. Pre-eclampsia is defined as new or pre-existing elevated blood pressure ≥ 140/90 mmHg in pregnancy with at least one new organ manifestation, usually proteinuria ≥ 300 mg/day or ≥ 30 mg/mmol in the protein-creatinine ratio. Thrombotic microangiopathies TTP and aHUS are altogether rare but potentially life-threatening diseases that should be clarified in case of severe or atypical courses.

Covid-19 and Thrombotic Thrombocytopenic Purpura: A Case Report

Endothelial injury by toxins, drugs, immune complexes leads to activation of coagulation cascade and thrombosis, which result in platelet consumption and red blood cell injury. These thrombotic microangiopathies can potentially injure numerous organs and result in organ dysfunction. In this case, we present the fourth reported patient with thrombotic thrombocytopenic purpura associated with COVID-19.

HOW Collaborative position paper on the management of thrombocytopenia in pregnancy

Thrombocytopenia in pregnancy is a common occurrence, affecting up to 10% of women by the time of birth. These recommendations aim to provide pragmatic guidance on the investigation, diagnosis and management of thrombocytopenia in pregnancy; including safety of neuraxial anaesthesia and precautions required for birth. Management of neonatal thrombocytopenia is also addressed. The authors are clinicians representing haematology, obstetric medicine, maternal-fetal medicine, and anaesthesia. Each author conducted a detailed literature review then worked collaboratively to produce a series of unanimous recommendations. The recommendation strength is limited by the lack of high-quality clinical trial data, and represents level C evidence.

Oxidative Stress and Preeclampsia-Associated Prothrombotic State

Preeclampsia (PE) is a common obstetric disease characterized by hypertension, proteinuria, and multi-system dysfunction. It endangers both maternal and fetal health. Although hemostasis is critical for preventing bleeding complications during pregnancy, delivery, and post-partum, PE patients often develop a severe prothrombotic state, potentially resulting in life-threatening thrombosis and thromboembolism. The cause of this thrombotic complication is multi-factorial, involving endothelial cells, platelets, adhesive ligands, coagulation, and fibrinolysis. Increasing evidence has shown that hemostatic cells and factors undergo oxidative modifications during the systemic inflammation found in PE patients. However, it is largely unknown how these oxidative modifications of hemostasis contribute to development of the PE-associated prothrombotic state. This knowledge gap has significantly hindered the development of predictive markers, preventive measures, and therapeutic agents to protect women during pregnancy. Here we summarize reports in the literature regarding the effects of oxidative stress and antioxidants on systemic hemostasis, with emphasis on the condition of PE.

Diagnostic dilemma in postpartum associated hemolytic uremic syndrome in a 38th week pregnant 31-year-old Congolese: a case report

BACKGROUND

Thrombotic microangiopathy is associated with HELLP syndrome, thrombotic thrombocytopenic purpura, or atypical hemolytic uremic syndrome (aHUS) during pregnancy. Standard laboratory and physical examinations can help distinguish between these three diseases promptly and guide their management. This is critical because their managements and prognoses differ considerably. The ADAMTS13 test, complement tests, and biopsies can help ascertain the diagnosis; however, they take time, and are not widely available. In this case report, we present a case that highlights the diagnostic and therapeutic dilemmas associated with the aforementioned diseases.

CASE PRESENTATION

A 31-year old P3G3 patient presented at 38 weeks with high blood pressure, bilateral pitting edema, and a low fetal heart rate. A cesarean section was performed to extract the fetus. On postoperative day 2, the suites were marked by anemia, low platelet count, acute kidney injury, declining liver function, and the presence of schistocytes on the peripheral thin smear. The patient was lucid, coherent, and presented no neurological deficits. The ADAMTS13 test and anti-complement therapy were not readily available, so the team made a presumptive diagnosis of aHUS based on the history, clinical presentation, and standard laboratory results. Due to a lack of anticomplement therapy, the patient was prescribed four sessions of hemodialysis. The renal function and platelet count gradually increased, and the patient was discharged on postoperative day 18. The patient was followed for over a year and did not present relapses of thrombocytopenia or microangiopathic hemolytic anemia.

CONCLUSIONS

The prompt diagnosis and management of aHUS lead to favorable outcomes. Healthcare providers should be able to rapidly differentiate between pregnancy-associated thrombotic microangiopathies and prescribe appropriate management. Here, we highlighted the challenges of diagnosing and managing postpartum associated aHUS in a low-resource setting.

Thrombotic microangiopathy, DIC-syndrome and COVID-19: link with pregnancy prothrombotic state

For last months, humanity has faced a formidable unknown enemy, which is presented as a new coronavirus infection. Despite the fact that the causative agents of new diseases appear at a certain frequency and that the virus SARS-CoV-2 has certain common properties with its predecessors, at the moment we are dealing with a new unknown pathogenesis of the development of severe complications in patients with risk factors. A final understanding of pathological process mechanisms is the goal of the scientific community. Summarizing research data from different countries, it became obvious that in severe cases of viral infection, we are dealing with a combination of the systemic inflammatory response syndrome, disseminated intravascular coagulation and thrombotic microangiopathy (TMA). Thrombotic microangiopathy is represented by a group of different conditions in which thrombocytopenia, hemolytic anemia, and multiple organ failure occur. The article reflects the main types of TMA, pathogenesis and principles of therapy. The main participants in the process are described in detail, including the von Willebrand factor and ADAMTS-13. Based on the knowledge available, as well as new data obtained from patients with COVID-19, we proposed possible models for the implementation of conditions such as sepsis, TMA, and DIC in patients with severe new coronavirus infection. Through a deeper understanding of pathogenesis, it will be possible to develop more effective diagnosis and therapy.

Postpartum atypical hemolytic uremic syndrome: Evaluating thrombotic microangiopathy in the pregnant woman

Acute kidney injury in women during pregnancy and the puerperium is often ascribed to hypertensive complications of pregnancy, especially pre-eclampsia. However, rarer causes, including atypical hemolytic uremic syndrome (aHUS) can be triggered by pregnancy. We present a case of a woman with post-partum acute kidney injury due to aHUS, which was successfully treated with the C5a inhibitor eculizumab. We also present a summary of the evaluation and management of thrombotic microangiopathy in pregnancy.

Pregnancy and non-pregnancy related immune thrombotic thrombocytopenic purpura in women of reproductive age

Pregnancy is a precipitating factor for immune thrombotic thrombocytopenic purpura (iTTP). We compared the clinical course and outcomes of iTTP in women of reproductive age, between those with pregnancy- and non-pregnancy-related iTTP. A review of all reproductive-aged women diagnosed with iTTP during 2010-2019 in seven university hospitals in Israel. Of 42 cases of iTTP, 12 (28.6%) were pregnancy-related. At presentation, the laboratory profiles did not differ significantly between those with pregnancy- and non-pregnancy-related iTTP, including hemoglobin (median 8.4 vs 8.0 g/dL), platelet count (12.5 vs. 11.5 X 10⁹/L); and levels of bilirubin (1.23 vs. 1.82 mg/dL), lactate dehydrogenase (1615 vs. 1701 U/L), creatinine (0.61 vs. 0.79 mg/dL) and anti-ADAMTS13 antibodies titer (75 vs. 82 U/mL). The proportions of women with renal, neurologic, or hepatic involvement were similar between the groups. Cardiac involvement was more common among those with pregnancy-related disease (25.0% vs. 3.3%, P = 0.06). The median number of courses of plasma-exchange therapy was 11 for both groups. All the women were treated with parenteral corticosteroids and the rate of adjunctive treatments did not differ between the groups (P = 0.30). Four women (one-third) with pregnancy-related disease had preeclampsia. Two women (16.7%) with pregnancy-related iTTP died during the acute episode (P = 0.07); no deaths were observed in the non-pregnancy-related group. Among reproductive-aged women with iTTP, most clinical and laboratory profiles were similar between those with pregnancy- and non-pregnancy-related disease. However, the higher rates of cardiac involvement and mortality among women with pregnancy-related iTTP highlight its challenging management.

Correlations Between Interleukin-11 Expression and Hypertensive Kidney Injury in a Rat Model of Renovascular Hypertension

BACKGROUND

Interleukin-11 (IL-11) is a pleiotropic cytokine of the interleukin-6 family. Recent studies revealed its crucial role in the development of cardiovascular fibrosis. In this study we examined IL-11 expression levels in the heart and the kidney exposed to high blood pressure in renovascular hypertensive rats and their correlations to fibrotic markers and kidney injury.

METHODS

Two-kidney, one-clip renovascular hypertension (2K1C) was induced in rats. IL-11 expression was measured by real-time polymerase chain reaction in the left ventricle and the right kidney. The correlation of cardiac IL-11 expression with biomarkers of renal fibrosis was assessed. We further investigated IL-11 expression in 2K1C rats grouped into rats with malignant vs. nonmalignant hypertension (distinguishing criteria: weight loss, number of fibrinoid necrosis, and onion skin lesions).

RESULTS

Thirty-five days after clipping, mean arterial pressure was significantly increased in 2K1C. Renal IL-11 expression was elevated in 2K1C. In the heart there was only a trend toward higher IL-11 expression in 2K1C. IL-11 in the kidney in 2K1C correlated with the expression of transforming growth factor (TGF)-β1/2, collagens, fibronectin, osteopontin, as well as tissue inhibitors of metalloprotease 1/2. There were also correlations of IL-11 with tissue collagen expansion, number of activated fibroblasts and serum creatinine, but no correlation with mean arterial pressure. Renal expression of IL-11 was highest in rats with malignant hypertension.

CONCLUSIONS

Renal IL-11 expression of renovascular hypertensive rats is markedly increased and correlates with profibrotic markers and loss of function and might therefore serve as a biomarker for the severity of hypertensive nephrosclerosis.

Regulation of the complement system and immunological tolerance in pregnancy

Preeclampsia is a serious vascular complication of the human pregnancy, whose etiology is still poorly understood. In preeclampsia, exacerbated apoptosis and fragmentation of the placental tissue occurs due to developmental qualities of the placental trophoblast cells and/or mechanical and oxidative distress to the syncytiotrophoblast, which lines the placental villi. Dysregulation of the complement system is recognized as one of the mechanisms of the disease pathology. Complement has the ability to promote inflammation and facilitate phagocytosis of placenta-derived particles and apoptotic cells by macrophages. In preeclampsia, an overload of placental cell damage or dysregulated complement system may lead to insufficient clearance of apoptotic particles and placenta-derived debris. Excess placental damage may lead to sequestration of microparticles, such as placental vesicles, to capillaries in the glomeruli of the kidney and other vulnerable tissues. This phenomenon could contribute to the manifestations of typical diagnostic symptoms of preeclampsia: proteinuria and new-onset hypertension. In this review we propose that the complement system may serve as a regulator of the complex tolerance and clearance processes that are fundamental in healthy pregnancy. It is therefore recommended that further research be conducted to elucidate the interactions between components of the complement system and immune responses in the context of complicated and healthy pregnancy.

Combined Immature Platelet Fraction and Schistocyte Count to Differentiate Pregnancy-Associated Thrombotic Thrombocytopenic Purpura from Severe Preeclampsia/Haemolysis, Elevated Liver Enzymes, and Low Platelet Syndrome (SPE/HELLP)

The occurrence of thrombotic microangiopathy (TMA) in pregnancy is an unfortunate emergency condition. Proper diagnosis is mandatory which requires the consideration of two overlapping diagnoses: severe preeclampsia/haemolysis, elevated liver enzymes, and low platelet syndrome (SPE/HELLP) and thrombotic thrombocytopenic purpura (TTP). The long turn-around times of ADAMTS13 testing precludes the timely distinction between the two conditions. We aimed at evaluating schistocyte counts and immature platelet fraction (IPF%), as both increase in TMAs, to discriminate between TTP and SPE/HELLP of pregnancy. IPF% was measured using Sysmex XE-2100 automated hematology analyzer, and schistocyte counts were estimated microscopically as per the International Council for Standardization in Hematology-Schistocyte Working Group guidelines. The study included 30 pregnant patients with SPE/HELLP, 13 pregnant patients with TTP, and 30 women with normal pregnancy. The discrimination between the two patient categories was based on clinical judgment and TTP cases were identified using the PLASMIC score. TTP patients had higher values of IPF% than SPE/HELLP [19.5% (16.9-27.1) vs 13% (9.5-23.25); p < 0.001]; similar results were revealed regarding schistocyte counts [6.5% (3.9-8.6) vs 2.1% (1.6-3.5); p < 0.001]. IPF% and schistocyte counts were able to discriminate between TMA patients and normal pregnant women, and between and SPE/HELLP and TTP patients. Moreover, the discriminatory function of each was improved when the two parameters were used in combination. IPF% analysis should be used in conjunction with manual schistocyte counting in TMA cases to distinguish TTP pregnant patients from patients having SPE/HELLP.

Collapsing Lesions and Focal Segmental Glomerulosclerosis in Pregnancy: A Report of 3 Cases

The relationship between focal segmental glomerulosclerosis (FSGS) and pregnancy is complex and not completely elucidated. Pregnancy in patients with FSGS poses a high risk for complications, possibly due to hemodynamic factors, imbalance between angiogenic and antiangiogenic factors, and hormonal conditioning. Although poor clinical outcomes associated with collapsing FSGS are common outside of pregnancy, the prognosis during pregnancy is not well documented. We report 3 patients who developed collapsing FSGS during pregnancy, 2 of whom had presumed underlying FSGS. Two patients underwent biopsy during pregnancy, and 1, during the puerperium. None of the 3 patients improved spontaneously after delivery, and 1 experienced a rapid deterioration in kidney function and proteinuria after delivery. Aggressive immunosuppressive therapy led to a full response in 1 case (without chronic lesions) and to partial responses in the remaining 2 cases. These cases suggest that collapsing lesions should be considered in patients with FSGS who develop a rapid increase in serum creatinine level or proteinuria during pregnancy and that these lesions may at least partially respond to treatment.

The conundrum of postpartum thrombotic Microangiopathy: case report and considerations for management

Background

Microangiopathic hemolytic anemias and thrombocytopenias in pregnant or postpartum women constitute an interdisciplinary diagnostic and therapeutic challenge in the evaluation of thrombotic microangiopathies (TMA), where urgent care must be considered.

Case presentation

We here report the case of a 21-year-old Somali woman, who was delivered by emergency caesarean section at 35 weeks of gestational age with acute dyspnea, placental abruption and gross edema due to severe preeclampsia/HELLP syndrome. After delivery, she developed acute kidney failure and thrombotic microangiopathy as revealed by kidney biopsy. The lack of early response to plasma exchange prompted extensive laboratory workup. Ultimately, the patient completely recovered with negative fluid balance and control of severe hypertension.

Conclusions

This case report emphasizes the importance to differentiate between primary TMA syndromes and microangiopathic hemolytic anemias due to systemic disorders. Delayed recovery from preeclampsia/HELLP syndrome and malignant hypertension can clinically mimic primary TMA syndromes in the postpartum period.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1286-1) contains supplementary material, which is available to authorized users.

Thrombotic Microangiopathy and the Kidney

Thrombotic microangiopathy can manifest in a diverse range of diseases and is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and organ injury, including AKI. It can be associated with significant morbidity and mortality, but a systematic approach to investigation and prompt initiation of supportive management and, in some cases, effective specific treatment can result in good outcomes. This review considers the classification, pathology, epidemiology, characteristics, and pathogenesis of the thrombotic microangiopathies, and outlines a pragmatic approach to diagnosis and management.

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.

A retrospective study of pregnancy-associated atypical hemolytic uremic syndrome

Pregnancy-associated atypical hemolytic uremic syndrome (aHUS) refers to the thrombotic microangiopathy resulting from uncontrolled complement activation during pregnancy or the postpartum period. Pregnancy-associated aHUS is a devastating disease for which there is a limited clinical understanding and treatment experience. Here we report a retrospective study to analyze the clinical and prognostic data of 22 cases of pregnancy-associated aHUS from the Spanish aHUS Registry under different treatments. Sixteen patients presented during the first pregnancy and as many as nine patients required hemodialysis at diagnosis. Identification of inherited complement abnormalities explained nine of the 22 cases, with CFH mutations and CFH to CFHR1 gene conversion events being the most prevalent genetic alterations associated with this disorder (66%). In thirteen of the cases, pregnancy complications were sufficient to trigger a thrombotic microangiopathy in the absence of genetic or acquired complement alterations. The postpartum period was the time with highest risk to develop the disease and the group shows an association of cesarean section with pregnancy-associated aHUS. Seventeen patients underwent plasma treatments with a positive renal response in only three cases. In contrast, ten patients received eculizumab with an excellent renal response in all, independent of carrying or not inherited complement abnormalities. Although the cohort is relatively small, the data suggest that pregnancy-associated aHUS is not different from other types of aHUS and suggest the efficacy of eculizumab treatment over plasma therapies. This study may be useful to improve prognosis in this group of aHUS patients.

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.

Acute kidney injury during pregnancy and puerperium: a retrospective study in a single center

BACKGROUND

Acute kidney injury (AKI) is rare in women during pregnancy and puerperium, however, it is related to increased morbidity and mortality rates.

OBJECTIVE

The aim of this study was to investigate the incidence, characteristics, and outcomes of AKI during pregnancy and puerperium in a Chinese population.

METHODS

In this study, pregnant women discharged from hospital between January 2008 and June 2015 were screened. AKI was defined if the level of serum creatitine >70.72umol/l in pregnant women without chronic kidney disease (CKD). Acute-on-CKD was defined as a 50% increase in the level of serum creatinine vs baseline in patients with pre-existed CKD.

RESULTS

We reported a high incidence (0.81%) of AKI during pregnancy and puerperium. Three hundred and forty-three cases of AKI during pregnancy and puerperium included 21 severe AKI cases and 21 cases with acute-on-CKD. Pre-eclampsia/eclampsia, and postpartum hemorrhage were the most frequent causes of AKI during pregnancy and puerperium. About 17% women with pre-eclampsia/eclampsia and 60% women with HELLP syndrome complicated with AKI. The maternal outcome was good except in the setting of amniotic fluid embolism or hemorrhagic shock, whereas the prenatal outcome was relatively poor. Among the 14 death cases, 7 cases received renal replacement therapy. Amniotic fluid embolism and postpartum hemorrhage were the major causes of death in pregnant women with AKI.

CONCLUSION

AKI during pregnancy and puerperium is not as rare as we thought. Pre-eclampsia/eclampsia is the most common cause of AKI during pregnancy and puerperium, however, the outcome of pre-eclampsia-related AKI is good. Amniotic fluid embolism and postpartum hemorrhage are the leading causes of maternal mortality. Severe AKI may predict poor outcome.

Kidney Diseases Associated With Alternative Complement Pathway Dysregulation and Potential Treatment Options

Atypical hemolytic uremic syndrome and C3 glomerulopathy (dense deposit disease and C3 glomerulonephritis) are characterized as inappropriate activation of the alternative complement pathway. Genetic mutations affecting the alternative complement pathway regulating proteins (complement factor H, I, membrane cofactor protein and complement factor H-related proteins) and triggers (such as infection, surgery, pregnancy and autoimmune disease flares) result in the clinical manifestation of these diseases. A decade ago, prognosis of these disease states was quite poor, with most patients developing end-stage renal disease. Furthermore, renal transplantation in these conditions was associated with poor outcomes due to graft loss to recurrent disease. Recent advances in targeted complement inhibitor therapy resulted in significant improvement in disease remission, renal recovery, health-related quality of life and allograft survival.

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.

Pernicious Anemia Associated Cobalamin Deficiency and Thrombotic Microangiopathy: Case Report and Review of the Literature

A 43-year-old Hispanic male without significant previous medical history was brought to emergency department for syncope following a blood draw to investigate a 40 lbs weight loss during the past 6 months associated with decreased appetite and progressive fatigue. The patient also reported a 1-month history of jaundice. On examination, he was hemodynamically stable and afebrile with pallor and diffuse jaundice but without skin rash or palpable purpura. Normal sensations and power in all extremities were evident on neurological exam. Presence of hemolytic anemia, schistocytosis, thrombocytopenia, and elevated lactate dehydrogenase (LDH) was suggestive of thrombotic thrombocytopenic purpura (TTP). However, presence of leukopenia, macrocytes, and an inadequate reticulocyte response to the degree of anemia served as initial clues to an alternative diagnosis. Two and one units of packed red blood cells were transfused on day 1 and day 3, respectively. In addition, one unit of platelets was transfused on day 2. Daily therapeutic plasma exchange (TPE) was initiated and continued until ADAMTS-13 result ruled out TTP. A low cobalamin (vitamin B12) level was evident at initial laboratory work-up and subsequent testing revealed positive intrinsic factor-blocking antibodies supporting a diagnosis of pernicious anemia with severe cobalamin deficiency. Hematological improvement was observed following vitamin B12 supplementation. The patient was discharged and markedly improved on day 9 with outpatient follow-up for cobalamin supplementation.