Highlights d COVID-19 vaccines lead to high rates of seroconversion among patients with cancer d Patients with hematologic malignancies show lower immunogenicity post vaccination d Prior immunosuppressive therapies lead to lower responsiveness to COVID-19 vaccines d Prior COVID infection leads to more robust antibody responses to COVID-19 vaccines

Patients with hypopigmented mycosis fungoides (HMF) present at a younger age than those with classic MF. Our goal was to describe the clinical presentation, histopathologic features and long-term outcome in patients who developed HMF before the age of 21. It was observed that among 69 pediatric patients diagnosed with MF between 1992 and 2010, 50 had HMF. Thirty-five patients had clinical follow-up. There were 37 males and 32 females with a mean age of 13.6 years. Most patients were African American or Hispanic and presented with multiple hypopigmented patches. All biopsies showed epidermotropism of T-lymphocytes, whereas fibroplasia and lichenoid infiltrate were variable. All specimens tested were CD8+. Treatment modalities included topical steroids, narrow band ultraviolet B and psoralen and ultraviolet A. HMF patients were followed for <1-12 years. Most children responded to treatment, but recurrence rates were high. One patient progressed to plaque/tumor stage. Others did not progress; however, many were lost to follow-up. We present a large cohort of children with HMF and report on the features of disease and progression. A major difference in histology of HMF was lack of fibroplasia and lichenoid infiltrate, probably because of presentation in the early patch stage. Most patients have a waxing-and-waning course and relapse after discontinuation of therapy, requiring repetitive treatment.

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b b-thalassemias are characterized by an imbalance of globin chains with an excess of a-chains which precipitates in erythroid precursors and red blood cells (RBCs) leading to inefficient erythropoiesis. The severity of the disease correlates with the amount of unpaired achains. Our goal was to develop a simple test for evaluation of the free a-hemoglobin pool present in RBC lysates. Alpha-Hemoglobin Stabilizing Protein (AHSP), the chaperone of a-Hb, was used to trap excess aHb. A recombinant GST-AHSP fusion protein was bound to an affinity micro-column and then incubated with hemolysates of patients. After washing, the a-Hb was quantified by spectrophotometry in the elution fraction. This assay was applied to 54 patients: 28 without apparent Hb disorder, 20 b-thalassemic and 6 a-thalassemic. The average value of free a-Hb pool was 93 ± 21 ppm (ng of free a-Hb per mg of Hb subunits) in patients without Hb disorder, while it varies from 119 to 1,756 ppm, in b-thalassemic patients and correlated with genotype. In contrast, the value of the free a-Hb pool was decreased in a-thalassemic patients (65 ± 26 ppm). This assay may help to characterize b-thalassemia phenotypes and to follow the evolution of the globin chain imbalance (a/b+c ratio) in response to treatment.b-thalassemias (b-thal) are inherited autosomal diseases characterized by a decreased or abolished b-globin chain biosynthesis [1]. During the transition of g to b globin expression in the first year of life, the clinical severity is mainly related to the ratio a/b1g which indicates the level of chain disequilibrium. b-thal are generally classified as minor, intermediate, or major phenotype, and encompass a wide clinical spectrum ranging from asymptomatic carriers to forms that can be lethal in the absence of extensive treatment. Different factors can modulate the severity of this disease [2] such as the magnitude of the decrease of the b globin synthesis, for example hemoglobin E (Hb E b26Glu?Lys) [3], or with the co-inheritance of (i) an a-thalassemia (a-thal) [4], (ii) a triplicated a-globin gene [5] or (iii) a low but variable residual capacity of g globin production which can have the phenotype of a hereditary persistence of fetal Hb (Hb F a 2 g 2 ) [6].The imbalance between a and non a-globin (g1d1b) synthesis was established by radioactive in vitro biosynthesis of globin chains from reticulocytes or of bone marrow of b-thalassemic patients [7][8][9][10]. This imbalance leads to an excess of highly unstable free a-hemoglobin (a-Hb), precipitating on the cell membrane and acting as active oxidants causing apoptosis and inefficient erythropoiesis [1,11]. The severity of b-thal is directly correlated with the degree of imbalance as quantified by the amount of unbound a-globin chain [12]. Many studies have shown that one observes a soluble a chain fraction present in the cytosolic RBC and an insoluble a chain fraction in the membrane of b-thalassemic erythrocytes [13,14]. Because of technical difficulties and the burden of using radioactive materials, ...

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Mastocytosis is primarily limited to the cutaneous variant in pediatric patients. Systemic mastocytosis (SM) has been associated with t(8;21) acute myeloid leukemia (AML) in adults. We provide the first report of a child with t(8;21) AML, diagnosed with asymptomatic SM following four cycles of chemotherapy. Unlike most adults with SM/AML, she was not found to have a c-KIT (D816V) mutation. SM persisted in the bone marrow after completion of chemotherapy, and her AML relapsed 9 months off-treatment. Although she achieved a second remission, mastocytosis persists in the marrow. Pediatric patients with t(8;21) AML/SM may represent a high-risk group despite favorable cytogenetics.

Antiphospholipid syndrome (APS) is an acquired autoimmune thrombotic tendency that is identified by the presence of abnormal antiphospholipid laboratory tests in patients who have a history of vascular thrombosis and/or pregnancy complications including recurrent spontaneous miscarriages and a group of other complications due to placental insufficiency. Diagnostic testing for APS is often problematic because of many misconceptions regarding these empirically derived assays. This chapter is intended to provide hematology-oncology consultants with practical information about the uses and limitations of assays used to diagnose APS.