Congenital thrombotic thrombocytopenic purpura related to a novel mutation in ADAMTS13 gene and management during pregnancy

Differentiating and Managing Rare Thrombotic Microangiopathies During Pregnancy and Postpartum

The most common thrombotic microangiopathy (TMA) of pregnancy is the well-recognized syndrome of preeclampsia with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome. However, rare TMAs, including thrombotic thrombocytopenic purpura, complement-mediated hemolytic-uremic syndrome, and catastrophic antiphospholipid syndrome, may occur during pregnancy or postpartum and present with features similar to those of preeclampsia with severe features. Early recognition and treatment of these infrequently encountered conditions are key for avoiding serious maternal morbidities with long-term sequelae and possible maternal or fetal death. Differentiating between preeclampsia with severe features and these rare TMAs is diagnostically challenging as there is significant overlap in their clinical and laboratory presentation. Given the rarity of these TMAs, high-quality evidence-based recommendations on diagnosis and management during pregnancy are lacking. Using current objective information and recommendations from working groups, this report provides practical clinical approaches to diagnose and manage these rare TMAs. This report also discusses how to manage individuals with a history of these rare TMAs who are planning to conceive. To optimize favorable outcomes, a multidisciplinary approach including obstetricians, maternal-fetal medicine specialists, hematologists, and nephrologists alongside close clinical and laboratory monitoring is vital.

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.

Pregnancy-onset thrombotic thrombocytopenic purpura with nephrotic syndrome: a case report

Pregnancy-onset thrombotic thrombocytopenic purpura (TTP) was reported by many obstetricians and hematologists, but less by nephrologists, and the detailed clinical course of its renal complication is not known. Here, we report a case of a 33-year-old pregnant woman who suffered from pregnancy-onset TTP with nephrotic syndrome which was controlled by the termination of pregnancy. On admission, she had periorbital and lower leg edema at 32 weeks of gestation. Her serum albumin level was 2.8 g/dL and the urine protein/creatinine ratio was 4.1 g/g Cr. Besides those, she had thrombocytopenia, hemolytic anemia, and severe deficiency of A Disintegrin-like and Metalloproteinase with Thrombospondin type 1 motifs 13 (ADAMTS-13) activity. Thus, she was diagnosed with nephrotic syndrome due to pregnancy-onset TTP. A cesarean section was performed without complications for the patient and her baby. Then, all her symptoms improved shortly. She was suspected of congenital TTP because of no ADAMTS-13 inhibitor results and the persistent deficiency of ADAMTS-13 activity even after her condition improved. Pregnancy-onset TTP can cause nephrotic syndrome. Termination of pregnancy should be considered in cases with pregnancy-onset TTP to protect kidney function.

Success and limitations of plasma treatment in pregnant women with congenital thrombotic thrombocytopenic purpura

BACKGROUND

Congenital thrombotic thrombocytopenic purpura (cTTP), otherwise known as Upshaw-Schulman syndrome, is an extremely rare hereditary disease. Pregnancy is identified as a trigger for TTP episodes in patients with cTTP.

OBJECTIVES

To investigate the ideal management of pregnant patients with cTTP.

PATIENTS/METHODS

We identified 21 patients with a reproductive history (38 pregnancies) in a Japanese cTTP registry. Fetal outcomes were compared between two groups: group 1 (n = 12), pregnancy after diagnosis of confirmed cTTP by ADAMTS13 gene analysis; and group 2 (n = 26), pregnancy before diagnosis of confirmed cTTP.

RESULTS

In group 1, ADAMTS13 activity was closely monitored until delivery in most cases. Among 10 pregnancies in group 1, prophylactic fresh frozen plasma (FFP) infusions during pregnancy were performed to replenish ADAMTS13. In group 2, prophylactic FFP infusions were not administrated in 23 pregnancies and FFP test infusions were performed in only three pregnancies. The live birth rate of group 1 was significantly higher than that of group 2 (91.7% vs 50.0%, respectively, P = .027). The fetal survival rates of women without FFP infusions were dramatically decreased after 20 weeks of gestation. The FFP infusion dosage in group 1 was generally higher than 5 mL/kg/wk by 20 weeks of gestation.

CONCLUSIONS

Our results indicate that FFP infusions of more than 5 mL/kg/wk should be initiated as soon as patients become pregnant. However, even with these infusions, patients with repeated TTP episodes before pregnancy might have difficulty giving birth successfully. Recombinant ADAMTS13 products might be new treatment options for pregnant patients with cTTP.

Two novel mutations in ADAMTS13 in a Chinese boy with congenital thrombocytopenic purpura: a case report

BACKGROUND

Mutations in the ADAMTS13 gene family have been reported to cause congenital thrombotic thrombocytopenic purpura (cTTP), a rare disease characterized by thrombocytopenia and hemolytic anemia. Nearly 150 causative mutations in ADAMTS13 have been identified; however, only a few of them were detected in Chinese patients.

CASE PRESENTATION

A 5-year-old Chinese boy presented with history of thrombocytopenic purpura, hemolytic anemia, and renal injury since the neonatal period. Gene analysis revealed two novel mutations in ADAMTS13: a missense mutation 332G > A (p:Gly111Glu) in exon4 and a nonsense mutation 3121C > T (p:Gln1041stop) in exon 24. Genetic analysis of his parents confirmed the heterozygous nature of the mutations.

CONCLUSION

We report two novel mutations in ADAMTS13 (332G > A, 3121C > T) in a Chinese boy. These two mutations may lead to early onset of cTTP and severe symptoms.

Thrombocytopenia in pregnancy: Diagnosis and approach to management

Thrombocytopenia during pregnancy presents unique challenges for the hematologist. Obstetricians generally manage many of the pregnancy-specific etiologies, ranging from the benign (gestational thrombocytopenia) to the life-threatening (preeclampsia; hemolysis, elevated liver enzymes and low platelets syndrome; and acute fatty liver of pregnancy). However, hematologists may be consulted for atypical and severe presentations and to help manage non-pregnancy specific etiologies, including immune thrombocytopenia, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome and antiphospholipid syndrome, among others, in which maternal and fetal risks must be considered. This review provides a general approach to the diagnosis and management of thrombocytopenia in pregnancy for the consulting hematologist.

Complement activation associated with ADAMTS13 deficiency may contribute to the characteristic glomerular manifestations in Upshaw-Schulman syndrome

INTRODUCTION

Upshaw-Schulman syndrome (USS) is a congenital form of thrombotic thrombocytopenic purpura (TTP) associated with loss-of-function mutations in the ADAMTS13 gene, possibly leading to aberrant complement activation and vascular injury. However, USS is extremely rare, and there have been no systematic studies correlating histopathological severity with local ADAMTS13 expression and complement activation.

MATERIALS AND METHODS

Here, we compared histopathological features, ADAMTS13 immunoreactivity, and immunoreactivity of complement proteins C4d and C5b-9 among renal biopsy tissues from five USS cases, ten acquired TTP cases, and eleven controls.

RESULTS

Pathological analysis revealed chronic glomerular sclerotic changes in the majority of USS cases (4 of 5), with minor glomerular pathology in the remaining case. In two of these four severe cases, more than half of the glomerular segmental sclerosis area was localized in the perihilar region. The average number of ADAMTS13-positive cells per glomerulus was significantly lower in USS cases than controls (p < 0.05). Conversely, C4d staining was significantly more prevalent in the glomerular capillary walls of USS cases than controls (p < 0.05), while C5b-9 staining did not differ significantly among groups.

CONCLUSIONS

These findings suggest that the severity of glomerular injury in USS is associated with deficient ADAMTS13 expression and local complement activation, particularly in vascular regions with higher endothelial shear stress. We suggest that C4d immunostaining provides evidence for complement-mediated glomerular damage in USS.

ADAMTS13: more than a regulator of thrombosis

ADAMTS13, a plasma reprolysin-like metalloprotease, proteolyzes von Willebrand factor (VWF). ADAMTS13 is primarily synthesized by hepatic stellate cells (HSCs), and mainly regulates thrombogenesis by cleaving VWF. Recent studies demonstrate that ADAMTS13 also plays a role in the down-regulation of inflammation, regulation angiogenesis, and degradation of extracellular matrix. The purpose of this review is to introduce the state of progress with respect to some of the theorized roles of ADAMTS13.