A post-menopausal woman with anuria and uterus bulk: the spectrum of estrogen-induced TTP/HUS

Good practice statements (GPS) for the clinical care of patients with thrombotic thrombocytopenic purpura

BACKGROUND

Despite advances in treatment options for thrombotic thrombocytopenic purpura (TTP), there are still limited high quality data to inform clinicians regarding its management.

METHODS

In June 2018, the ISTH formed a multidisciplinary guideline panel to issue recommendations about treatment of TTP. The panel discussed 12 treatment questions related to both immune-mediated TTP (iTTP) and hereditary/congenital TTP (cTTP). The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including evidence-to-decision frameworks, to appraise evidence and formulate recommendations.

RESULTS

The panel agreed on eleven recommendations based on evidence ranging from very low to moderate certainty. For first episode and relapses of acute iTTP, the panel made a strong recommendation for the addition of corticosteroids to therapeutic plasma exchange (TPE), and a conditional recommendation for addition of rituximab and caplacizumab. For asymptomatic iTTP with low ADAMTS13, the panel made a conditional recommendation for rituximab outside of pregnancy, and for prophylactic TPE during pregnancy. For asymptomatic cTTP, the panel made a strong recommendation for prophylactic plasma infusion during pregnancy, but a conditional recommendation for plasma infusion or a wait and watch approach outside of pregnancy.

CONCLUSIONS

The panel's recommendations are based on all the available evidence for the treatment effects of various approaches including suppressing inflammation, blocking platelet clumping, replacing the missing and/or inhibited ADAMTS13, and suppressing ADAMTS13 antibody production. There was insufficient evidence for further comparison of different treatment approaches, for which future high-quality studies in iTTP (e.g., rituximab, corticosteroids, recombinant ADAMTS13, and caplacizumab) and in cTTP (eg, recombinant ADAMTS13) are needed.

Atypical aHUS: State of the art

Tremendous advances in our understanding of the thrombotic microangiopathies (TMAs) have revealed distinct disease mechanisms within this heterogeneous group of diseases. As a direct result of this knowledge, both children and adults with complement-mediated TMA now enjoy higher expectations for long-term health. In this update on atypical hemolytic uremic syndrome, we review the clinical characteristics; the genetic and acquired drivers of disease; the broad spectrum of environmental triggers; and current diagnosis and treatment options. Many questions remain to be addressed if additional improvements in patient care and outcome are to be achieved in the coming decade.

Atypical hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) is a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. The atypical form of HUS is a disease characterized by complement overactivation. Inherited defects in complement genes and acquired autoantibodies against complement regulatory proteins have been described. Incomplete penetrance of mutations in all predisposing genes is reported, suggesting that a precipitating event or trigger is required to unmask the complement regulatory deficiency. The underlying genetic defect predicts the prognosis both in native kidneys and after renal transplantation. The successful trials of the complement inhibitor eculizumab in the treatment of atypical HUS will revolutionize disease management.

Refractory thrombotic thrombocytopenic purpura associated with oral contraceptives and factor V Leiden: a case report

Introduction

Thrombotic microangiopathies constitute a heterogeneous group of diseases characterised by microangiopathic haemolytic anaemia and thrombocytopaenia associated with platelet aggregation in the microcirculation responsible for ischaemic manifestations. Classically, thrombotic microangiopathies are described as encompassing two main syndromes: thrombotic thrombocytopaenic purpura and the haemolytic-uraemic syndrome Many cases of idiopathic thrombotic thrombocytopaenic purpura have, to date, been associated with severe ADAMTS13 metalloprotease deficiency while haemolytic uraemic syndrome usually occurs in the context of normal protease activity. Oestrogens and factor V Leiden have rarely been implicated in the pathogenesis of thrombotic microangiopathy.

Case presentation

We describe the case of a 17-year-old female with refractory thrombotic thrombocytopaenic purpura. The patient was receiving a new generation of oral contraceptives for dysmenorrhoea and had factor V Leiden. After undergoing prolonged and intense plasma exchange therapy for 40 days and high dose oral corticosteroids therapy for 90 days, our patient recovered fully.

Conclusion

Patients with refractory thrombotic thrombocytopaenic purpura should likely be evaluated for congenital thrombophilic disorders and for ingestion of drugs that have been associated with this rare form of thrombotic microangiopathy. Identification of these and as yet other unknown genetic and/or acquired risk factors may lead to more judicious treatment approaches.

Drug-induced thrombotic thrombocytopenic purpura/hemolytic uremic syndrome: a concise review

An extensive variety of drugs have been associated with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP/HUS). Although a direct causal effect has usually not been proven, the cumulative evidence linking several drugs with TTP/HUS is strong. This paper reviews several categories of drugs including antineoplastics, immunotherapeutics and anti-platelet agents that have been reported to induce TTP/HUS. The pathogenesis of drug-induced TTP/HUS and the effectiveness of treatment regimens are also reviewed. A consensus on diagnostic criteria to accurately and consistently diagnose drug-induced TTP is needed.