RESUMO
Hereditary antithrombin deficiency (ATD) is a rare autosomal dominant condition (estimated prevalence 1:500-1:5000). Most ATD patients have AT activity levels 40-60% of normal. We present treatments for venous thromboembolism (VTE) in five cases of hereditary ATD. Four patients had a family history of ATD, and one had a de novo mutation. The majority of patients had a VTE while on prophylactic anticoagulation. AT concentrate augmentation was added in these cases to treat the VTE and for prophylaxis against further episodes. Two patients had significant bleeding events, one had permanent physical sequelae. Two of the patients were pregnant. VTE is a common cause of morbidity and mortality during pregnancy. Although low molecular weight heparins are the drugs of choice during pregnancy, this treatment was inadequate in one patient (developed VTE on therapy). These cases emphasize the need to screen for ATD in young patients (<55 years) presenting with VTE. AT augmentation therapy may be necessary in patients inadequately treated with conventional anticoagulants. Careful monitoring and individualized care are needed in ATD patients, especially those with demonstrated bleeding tendencies.
RESUMO
The rollout of the SARS-CoV-2 vaccine is underway, and millions have already been vaccinated. At least 25 reports of "immune thrombocytopenia" (ITP) or "thrombocytopenia" following the Moderna or Pfizer vaccine have been added to the Vaccine Adverse Event Reporting System (VAERS) in the US. ITP is a rare but known complication of several vaccinations. SARS-CoV-2 vaccine is new, with a novel mechanism of action, and understanding the epidemiology, clinical manifestations, treatment success and natural history of post-vaccination thrombocytopenia is evolving. We report a 74-year-old man who developed refractory thrombocytopenia within one day of receiving the Moderna SARS-CoV-2 vaccine. Several hours after vaccination, he developed significant epistaxis and cutaneous purpura. Severe thrombocytopenia was documented the following day, and he developed extremity weakness and encephalopathy with facial muscle weakness. Over a 14-day period, thrombocytopenia was treated first with high dose dexamethasone, intravenous immunoglobulin, platelet transfusions, rituximab, plasma exchange (for presumed acute inflammatory demyelinating polyneuropathy (AIDP)), and four daily doses of the thrombopoietin receptor agonist (TPO-RA) eltrombopag (Promacta™), without a platelet response. Three days later, he received the TPO-RA romiplostim (Nplate™). Five days later, his platelet count began to rise and by post-vaccination day 25, his platelet count was in the normal range. Thrombocytopenia was refractory to frontline and second-line treatment. The eventual rise in his platelet count suggests that one or both TPO-RAs may have impacted platelet recovery. Possibly, but less likely given the temporality, the drug-induced thrombocytopenia was subsiding. The aggressive use of immunosuppressive treatment may jeopardize the intended purpose of the SARS-CoV-2 vaccine, and earlier use of non-immunosuppressive second-line treatment for vaccine-related severe thrombocytopenia, such as with TPO-RAs, should be considered. While it is imperative to continue the global vaccination program, vigilance to the occurrence of post-vaccination severe thrombocytopenia is warranted.
RESUMO
Chronic platelet disorders (CPD), including chronic immune thrombocytopenic purpura (cITP), thrombotic thrombocytopenic purpura (TTP) and platelet function disorders are among the most common bleeding disorders and are associated with morbidity and mortality. The clinical phenotype and complexity of cITP is much like that of hemophilia. In cITP and hemophilia, bleeding is problematic for many, complicating employability, insurability and overall quality-of-life (QoL). While myriad drug therapies are available for cITP and hemophilia, each are variable in their effectiveness, very few (except for clotting factor concentrates for hemophilia) alter the natural history of the disorder and sometimes contribute to specific morbidities and mortality. Like in hemophilia, the management of cITP is not solely based on access to effective treatment but also includes accurate diagnosis and comprehensive care by a multidisciplinary team of specialists trained in the management of bleeding disorders. The model of comprehensive care in Hemophilia Treatment Centers (HTCs) has been recognized as highly effective, improving life expectancy for persons with hemophilia. cITP, and other CPDs, are complex disorders requiring specialized care. However, an integrated care model with a systematic and reliable population-based surveillance program does not exist. Extending the Comprehensive Care model with all its related benefits to the community of persons with cITP is sorely needed. This review will focus on cITP as a prototype chronic platelet disorder that could benefit greatly from the Comprehensive Care model.