Seminars in hematology
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Seminars in hematology · Oct 2009
ReviewPathogenesis and management of iron deficiency anemia: emerging role of celiac disease, helicobacter pylori, and autoimmune gastritis.
The causes of iron deficiency vary significantly during different stages of life, and according to gender and socioeconomic circumstances. Although dietary iron is important, iron deficiency anemia (IDA) is mostly attributed to blood loss and may be the presenting clinical feature of occult bleeding from the gastrointestinal (GI) tract heralding underlying malignancy. Conventional GI diagnostic workup fails to establish the cause of iron deficiency in about one third of patients. ⋯ Cure of previously refractory IDA by H pylori eradication provides strong evidence supporting a cause-and-effect relation. The intriguing recent observations of H pylori antibodies directed against epitopes on gastric mucosal cells in atrophic gastritis imply an autoimmune mechanism triggered by H pylori and directed against gastric parietal cells by means of antigenic mimicry. Improved understanding of the role of abnormal iron absorption in IDA has important implications for current concepts related to the pathogenesis and management of IDA.
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Seminars in hematology · Jul 2009
ReviewAdvances in antibacterial therapy against emerging bacterial pathogens.
During the last decade, both gram-positive and gram-negative bacteria that are resistant to most or all available antibacterial classes have become increasingly prevalent nosocomial pathogens, particularly among immunocompromised patients and those hospitalized in intensive care units. Among gram-positive bacteria, increasing concerns are posed for health care- and community-associated methicillin-resistant Staphylococcus aureus (MRSA), S aureus with reduced susceptibility to vancomycin, and vancomycin-resistant enterococci (VRE). A spectrum of newer antibacterial agents has been developed for the treatment of multi-resistant gram-positive bacteria, such as linezolid, tigecycline, daptomycin, and novel glycopeptides. ⋯ Currently, non-fermenting bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii are commonly resistant to all available antibiotics, including the newer agents. Colistin retains activity against most P aeruginosa and A baumannii, but its clinical use remains questionable, while newer carbapenems and tigecycline have limited additional advantages. Rational use of newer antibacterial agents coupled with enhanced infection control measures may be able to sufficiently control MDR organisms as to allow hematological patients to recover from serious infectious complications.
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Seminars in hematology · Jul 2009
ReviewNeutropenic fever syndromes in patients undergoing cytotoxic therapy for acute leukemia and myelodysplastic syndromes.
Fever represents the major surrogate of infection in neutropenic cancer patients. A number of neutropenic fever syndromes have been recognized, the causes and significance of which will vary depending upon the clinical context. First neutropenic fever syndromes are typically of bacterial origin, the character of which may be influenced by whether antibacterial chemoprophylaxis has been administered. ⋯ Recrudescent neutropenic fevers, defined by the appearance of a new fever after defervescence of the first fever, are often a function of invasive fungal infection or gram-positive infections outside the spectrum of the initial empirical antibacterial regimen. The myeloid reconstitution syndrome occurs in parallel with neutrophil recovery from aplasia and may not necessarily represent new infection. Recognition of these patterns can help the clinician make better clinical judgments and management plans.
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Seminars in hematology · Jul 2009
ReviewManagement of infections complicating allogeneic hematopoietic stem cell transplantation.
The use of allogeneic hematopoietic stem cell transplantation for the treatment of hematologic malignancies, as well as some benign hematologic disorders, has continued to grow over the last 10 years. The availability of this procedure to an increasing number of patients has been facilitated by the use of newer techniques, including reduced intensity conditioning (RIC) regimens, peripheral blood stem cells (PBSCs) and cord blood as donor sources, graft manipulation such as selective T-cell depletion, and other in vitro and in vivo attempts to reduce the risk and severity of graft-versus-host disease (GVHD) after transplantation without losing the potential benefits of a graft-versus-tumor effect for patients with hematologic malignancies. The underlying theme of many of these newer techniques has been to minimize the severity and duration of transplant-related immune suppression, thus reducing the risk of morbidity and mortality from infectious complications. This article reviews immune suppression and recovery that occur after allogeneic stem cell transplantation, with changes in the epidemiology, and some of the recent advances that have been made in management of infectious complications.
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Seminars in hematology · Apr 2008
ReviewSafety update on recombinant factor VIIa in the treatment of congenital and acquired hemophilia.
Recombinant activated factor VII (rFVIIa) appears to be safe when used for its licensed indication of congenital and acquired hemophilia A or B with inhibitors. One should carefully consider the clinical indication for which the agent is used when patient risk factors are present that might predispose the subject to a thromboembolic (TE) event, or when concomitant hemostatic agents are being used. ⋯ However, the incidence of serious TE events in hemophilia patients with inhibitors treated with rFVIIa appears to be much less than 1%. The role of rFVIIa in off-label indications should be assessed through rigorously controlled clinical trials or by analyzing carefully collected data from national and international registries.