Journal of hematology最新文献

Immunosuppressive therapy for acquired severe aplastic anemia improves pancytopenia but has a significant risk of relapse (40%) and clonal evolution to myeloid neoplasms (15%), especially in patients older than 40. Yet, current guidelines for newly diagnosed severe aplastic anemia patients over the age of 40 recommend immunosuppressive therapy instead of curative allogeneic stem cell transplantation. Upfront allogeneic stem cell transplants are restricted to the rare patient who is not only young but also has a matched sibling donor. This article will discuss practice-changing data on the recent advances in upfront alternative donor hematopoietic cell transplants that could rewrite current treatment algorithms.

Thalassemic diseases are characterized by a reduced (β⁺) or absent (β⁰) synthesis of the globin chains of hemoglobin (Hb) due to genetic mutations. β-thalassemia was more frequent in the Mediterranean area, but now it is diffused worldwide. Three possible genetic forms can be distinguished: β⁰/β⁰, the most severe (Cooley's disease); β⁰/β⁺ of intermediate severity; β⁺/β⁺ associated with β-thalassemia intermedia or minor. Recently, a clinical non-genetic classification has been proposed: transfusion-dependent thalassemia (TDT), requiring regular lifetime blood transfusions, and non-transfusion-dependent thalassemia (NTDT), requiring occasional transfusions to manage acute cases. In this report, we studied a patient whose blood count indicated a severe anemia but also showed thrombocytosis, leukocytosis, and an elevated number of nucleated red blood cells (NRBC). These altered blood parameters suggested initially a possible diagnosis of hemoglobinopathy or myeloproliferative syndrome. The molecular and genetic analyses demonstrated the presence of HbF (5.3%) and HbA2 (7.7%) and the presence of the homozygote mutation (IVS1.6T>C) in the β-globin gene. According to these data, a diagnosis of β-thalassemia intermedia form has been proposed. Nevertheless, the clinical condition, the presence of thrombocytosis, leukocytosis, an elevated number of NRBC, and the frequent blood transfusions lead to reclassification of the patient as TDT subject. Consequently, this result suggests that a unique genotype-phenotype correlation is not possible in the presence of β⁺mutations since other concomitant pathologies can exacerbate the disease.

Multiple myeloma (MM) is a plasma cell dyscrasia which is typically characterized by identifiable paraprotein in the blood or urine. However, the minority of patients in whom paraprotein cannot be identified are designated non-secretory MM (NSM). Evaluation of treatment response is more difficult in these patients as paraprotein levels cannot be followed. A dearth of clinical trials including these patients exists because of an inability to measure response by classical serum and urine measurement mechanisms as well as seemingly decreased overall survival compared to secretory MM. NSM is subdivided into four subgroups: "non-producers", "true non-secretors", "oligosecretors" and "false non-secretors". The "non-producers" phenotype is associated with more aggressive disease course. Translocations such as those involving the proto-oncogene c-MYC (chromosome 8) and the lambda light chain gene IGL (chromosome 22) - more commonly associated with Burkitt lymphoma - are rare in MM. We describe a 60-year-old male with NSM who was identified as having multiple high-risk features including complex cytogenetics and a non-producer phenotype, which are features not considered in conventional MM staging and risk stratification. This case highlights the need for awareness of phenotypes and cytogenetics associated with higher clinical risk that are not included in the revised International Staging System.

Hemoglobin A1c (HbA1c) refers to non-enzymatically glycated hemoglobin and reflects the patient's glycemic status over approximately 3 months. An elevated HbA1c over 6.5% National Glycohemoglobin Standardization Program (NGSP) (48 mmol/mol the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC)) can be used to diagnose diabetes mellitus. In our laboratory, HbA1c is determined by ion-exchange chromatography which has the advantage of detecting common Hb variants such as Hb S, C, E and D without adversely affecting the HbA1c determination. Certain homozygous or compound heterozygous hemoglobinopathies such as homozygous sickle disease and Hb SC disease can significantly lower the HbA1c by reducing red cell lifespan. Occasionally however, rare and mostly benign hemoglobinopathies can interfere with this technique resulting in an apparent elevation of HbA1c in an otherwise non-diabetic patient. In this report, we describe such a hemoglobinopathy termed Hb Wayne that resulted in a significant HbA1c elevation in a normoglycemic individual. HbA1c was determined by multiple methods including immunoassay, a modified capillary electrophoresis and an alternative ion-exchange system. These techniques yielded significantly lower A1c results, more in keeping with the patient's clinical background. The alternative ion-exchange system resulted in a low A1c that was qualified by warning flags on the chromatogram that indicated the result was not reportable. The hemoglobinopathy in question, Hb Wayne, is a frameshift mutation in the alpha globin gene that results in an extended alpha globin polypeptide that can form two variants Hb Wayne I and Wayne II. Hb Wayne is a clinically silent asymptomatic disorder with no hematologic consequences. The artifactual elevation of HbA1c is, in contrast, very significant because it may result in a misdiagnosis of diabetes mellitus leading to unnecessary treatment. In this report, we compare our findings with other descriptions of Hb Wayne in the literature and corroborate a number of previous observations and conclusions.

Thrombotic microangiopathies cause ischemic organ damage and require urgent management for a favorable prognosis. Fat embolism syndrome from bone marrow necrosis is a rare and unique pathology that carries a high mortality rate. It can mimic thrombotic microangiopathies such as thrombotic thrombocytopenic purpura (TTP). Herein, we present a patient with sickle cell-beta-thalassemia who initially presented with a vaso-occlusive crisis, lab evidence of hemolysis, schistocytes and thrombocytopenia who developed acute encephalopathy with respiratory distress, consistent with TTP. She was found to have multiple infarcts in the brain. She was intubated and underwent plasma and red cell exchange. Bone marrow biopsy confirmed marrow necrosis from her vaso-occlusive crisis and subsequently, fat embolism syndrome. Here, we discuss the complex presentation and the complications of fat embolism from bone marrow necrosis and how it can mimic TTP.

Hereditary protein S (PS) deficiency is a rare condition associated with increased risk of venous thromboembolism (VTE). In 2020, the coronavirus disease 2019 (COVID-19) pandemic prompted development of vaccinations to protect against the virus. PS deficiency is not a contraindication to COVID-19 vaccinations, but there are no studies regarding potential adverse effects in this population. We report two cases, a 43-year-old mother and her 18-year-old son, who developed VTE shortly after their first COVID-19 vaccines. Testing confirmed hereditary PS deficiency with a previously undescribed mutation in both cases. The temporal association between COVID-19 vaccination and VTE in these patients with hereditary PS deficiency suggests a potential causal relationship. However, it is unclear if this applies to all patients with hereditary PS deficiency. This highlights the importance of reporting adverse events following COVID-19 vaccinations in this population to evaluate the risks and benefits of vaccination.

Evans syndrome (ES) is a rare autoimmune condition of unknown etiology that occurs in a small subset of patients diagnosed, either sequentially or concomitantly, with immune thrombocytopenia (ITP) or warm autoimmune hemolytic anemia (AIHA). Neutropenia is present occasionally. Diagnosis is based on exclusion with a median age of 52 years of age. Here we have a case of a young patient with ES presenting with recurrent infection. ES should be included in differential diagnoses for patients presenting with AIHA, ITP, cytopenias or recurrent infection as the prognosis is more favorable when diagnosis is made early and symptoms are still mild.

In adults, the sickle cell solubility test (SCST) is the most common screening test to determine the presence of hemoglobin S (HbS) within a blood sample. The assay is inexpensive, rapid, highly sensitive and specific. However, the SCST cannot accurately quantify the level of HbS in a test sample and requires confirmatory testing to distinguish between sickle trait and sickle cell disease. Despite these limitations, it remains the standard screening tool for HbS in a variety of settings such as screening in the US military or by the National Collegiate Athletic Association. With an increased awareness of the importance of screening for sickle cell in adults, we herein describe the current sensitivity, specificity, positive predictive value, and negative predictive value of this test. We also review overall clinical utility of this laboratory measure and briefly discuss new point-of-care techniques designed to overcome the SCST's shortcomings.

Systemic mastocytosis (SM) is a rare type of myeloproliferative neoplasm characterized by abnormal proliferation and infiltration of different tissue by clonal mast cells. The uncontrolled proliferation and activation of mast cells trigger the release of vasoactive and inflammatory mediators, resulting in a cascade of systemic symptoms. Around 95% of SM arise from a gain-of-function mutation at the KIT gene, specifically at codon 816, which highlights its essential role in SM and makes it an attractive target for therapy. Although KIT-negative SM is exceptionally rare, the increased number of cases documented in the literature makes it an intriguing dimension of this disorder. The reported clinical manifestations of KIT-negative SM are widely variable, but many are similar to KIT-positive SM. KIT-targeted therapeutic options have been a game-changer in KIT-positive SM, however their role in KIT-negative SM remains controversial. This report aimed to further understand KIT-negative SM by presenting two cases of KIT-negative SM, one of which was responsive to KIT-targeted therapy, and analyzing reported cases in the existing literature.

Hemoglobin Korle-Bu (Hb KB) is a rare and likely under-reported hemoglobin (Hb) variant resulting from an unusual point mutation on the beta-globin chain. Hb KB is typically clinically silent, and there are limited reports of Hb KB heterozygosity compounded with other hemoglobinopathies that can present with varying clinical phenotypes. Here, we report a case of compound Hb KB heterozygosity with Hb S in an asymptomatic military trainee with a positive sickle cell screening test. Hb capillary and gel electrophoresis predicted a compound Hb S/D-Punjab overlap, which foretells a severe clinical phenotype. Sequencing of the Hb beta gene HBB demonstrated Hb KB, allowing for a diagnosis that fit his asymptomatic clinical phenotype and allowed for retention in the military.