Current opinion in hematology
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Curr. Opin. Hematol. · Nov 2003
ReviewRisk and prevention of transfusion-transmitted babesiosis and other tick-borne diseases.
Tick-borne diseases have increasingly been recognized in the United States as public health problems. The importance of tick-borne diseases has been accelerated by increases in animal populations, as well as increased human recreation in wooded environments that are conducive to tick bites. Babesiosis, usually caused by the intraerythrocytic parasite, Babesia microti and transmitted by the same tick as Lyme disease, has important transfusion implications. Although Lyme disease has not been reported from blood transfusion, newly identified tick-borne diseases such as ehrlichiosis raise additional questions about the role of the tick in transfusion-transmitted diseases. ⋯ In endemic areas transfusion-transmitted babesiosis is more prevalent than usually believed. The extension of the geographic range of various Babesia spp. and the movement of donors and blood products around the United States has resulted in the risk extending to non-endemic areas. Clinicians should maintain a high degree of clinical suspicion for transfusion-transmitted babesiosis.
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Curr. Opin. Hematol. · Sep 2003
ReviewThe association of pregnancy with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome.
Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome occurs more commonly in women and among women is commonly associated with pregnancy. Case series of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome from 1964 to 2002 were reviewed (1) to document the reports of occurrence of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome during pregnancy and (2) to search for reports of women with congenital or familial thrombotic thrombocytopenic purpura-hemolytic uremic syndrome who were initially diagnosed during their first pregnancy. ⋯ These other syndromes may also be associated with thrombocytopenia, microangiopathic hemolytic anemia, neurologic symptoms, and renal insufficiency, making their distinction from thrombotic thrombocytopenic purpura-hemolytic uremic syndrome difficult or impossible. The occurrence of preeclampsia and related syndromes, the hypercoaguable state that occurs in late pregnancy and postpartum, and the progressively decreasing concentration of ADAMTS13 that occurs during late pregnancy may combine to increase the risk for occurrence of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome.
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Thrombotic thrombocytopenic purpura (TTP) has been a mysterious and deadly disease that often could be treated effectively by plasma exchange, but without real understanding of the underlying pathophysiology. Recent advances now suggest that deficiency of a specific von Willebrand factor (VWF) cleaving protease promotes tissue injury in TTP. VWF multimers participate in the formation of platelet thrombi. ⋯ The VWF cleaving protease proves to be a new member of the ADAMTS family of metalloproteases, designated ADAMTS13. Autoantibodies that inhibit ADAMTS13 cause sporadic TTP, and mutations in the ADAMTS13 gene cause an autosomal recessive form of chronic relapsing TTP. Further studies of ADAMTS13 seem likely to change our approach to the diagnosis and treatment of TTP and other thrombotic microangiopathies.
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The ability to use an effective treatment constitutes a main concern in the management of acute ischemic stroke. Randomized trials have so far failed to demonstrate any beneficial effect of neuroprotective agents on neurologic outcome after an acute stroke. ⋯ Among them, a single randomized trial, the National Institute of Neurological Diseases and Stroke Trial, showed a beneficial effect of thrombolysis on outcome after an acute ischemic stroke with a significant increase in the number of patients with no or minimal disability at 3 months in the group receiving intravenous recombinant tissue plasminogen activator (rt-PA) compared with placebo. However, there was no reduction in mortality and there was, as in all other trials, a significant increase in the risk of symptomatic intracerebral hemorrhage (ICH).
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Curr. Opin. Hematol. · Jul 2002
ReviewMolecular mechanisms of resistance to STI571 in chronic myeloid leukemia.
Therapeutic use of the recently FDA-approved drug STI571 has been successful in the treatment of Philadelphia chromosome-positive leukemias. STI571 is a small molecule inhibitor with activity against BCR-ABL, the deregulated tyrosine kinase responsible for initiation and maintenance of the disease in the chronic phase of chronic myeloid leukemia (CML). ⋯ Studies investigating the molecular mechanisms of resistance to this novel compound have progressed rapidly and point to the continued importance of BCR-ABL in disease maintenance even at its latest stages. Here the authors review recent work aimed at elucidating the nature of STI51 resistance.