ABSTRACT
Complex karyotypes have been associated with inferior outcomes in chronic lymphocytic leukemia (CLL) treated with chemoimmunotherapy (CIT), whereas their prognostic impact in the context of venetoclax-based treatments is still debated. In this prospective analysis on karyotype complexity in CLL, we evaluated the impact of complex (≥3 chromosomal aberrations [CAs], CKTs) and highly complex karyotypes (≥5 CAs; hCKTs) as well as specific aberrations in previously untreated patients without TP53 aberrations undergoing either CIT or time-limited venetoclax-based therapies in the phase 3 GAIA/CLL13 trial. Karyotype analyses were available for 895 of 926 patients (96.7%), of whom 153 (17%) had a CKT and 43 (5%) hCKT. In the CIT arm, CKT was associated with shorter progression-free survival (PFS) (hazard ratio [HR] 2.58; 95% confidence interval [95% CI], 1.54-4.32; P < .001) and overall survival (HR, 3.25; 95% CI, 1.03-10.26; P = .044). In the pooled venetoclax arms, a multivariable analysis identified hCKTs (HR, 1.96; 95% CI, 1.03-3.72; P = .041), but not CKTs, as independent adverse prognosticators for PFS. The presence of translocations (unbalanced and/or balanced) was also independently associated with shorter PFSs in the venetoclax arms. CIT led to the acquisition of additional CAs (mean CAs, 2.0-3.4; from baseline to CLL progression), whereas karyotype complexity remained stable after venetoclax-based treatments (2.0, both time points). This analysis establishes highly complex karyotypes and translocations as adverse prognostic factors in the context of venetoclax-based combination treatments. The findings of this study support the incorporation of karyotyping into the standard diagnostic workup of CLL, because it identifies patients at high risk of poor treatment outcomes and thereby improves prognostication. This trial was registered at www.clinicaltrials.gov as #NCT02950051.
Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell , Humans , Abnormal Karyotype , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Karyotype , Karyotyping , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , PrognosisABSTRACT
INTRODUCTION: Electronic patient-reported outcomes (ePRO) are increasingly recognized in health care, as they have been demonstrated to improve patient outcomes in cancer, but have been less studied in rare hematological diseases. The aim of this study was to develop and test the feasibility of an ePRO system specifically customized for aplastic anemia (AA) and paroxysmal nocturnal hemoglobinuria (PNH). METHODS: After performing a user-centered design evaluation an ePRO system for AA and PNH patients could be customized and the application was tested by patients and their medical teams for 6 months. Symptom-reporting triggered self-management advice for patients and prompts them to contact clinicians in case of severe symptoms, while the medical team received alerts of severe symptoms for patient care. RESULTS: All nine included patients showed a high adherence rate to the weekly symptom-reporting (72%) and reported high satisfaction. The system was rated high for usage, comprehensibility, and integration into daily life. Most patients (78%) would continue and all would recommend the application to other AA/PNH patients. Technical performance was rarely a barrier and healthcare providers saw ePRO-AA-PNH as a useful supplement, but the lacking integration into the hospital information system was identified as a major barrier to usage. CONCLUSION: An ePRO system customized for AA and PNH was feasible in terms of adherence, satisfaction, and performance, showing a high potential for these rare conditions in terms of data collection and patient guidance. However, the integration into clinical workflows is crucial for further routine use. TRIAL REGISTRATION: ClinicalTrials.gov NCT04128943.
Subject(s)
Anemia, Aplastic , Hemoglobinuria, Paroxysmal , Self-Management , Humans , Anemia, Aplastic/therapy , Hemoglobinuria, Paroxysmal/therapy , Hemoglobinuria, Paroxysmal/diagnosis , Pilot Projects , Feasibility Studies , Patient Reported Outcome Measures , ElectronicsABSTRACT
MDS with deletion 5q - a distinct subtype of myelodysplastic syndromes Abstract. Deletion of the long arm of chromosome 5 (del(5q)) is a recurrent anomaly in myelodysplastic syndromes associated with a distinct pathophysiology and specific treatment options. MDS with isolated del(5q) are associated with a favorable risk profile and can be treated with lenalidomide. MDS with isolated del(q) have to be distinguished from MDS with an anomaly on the long arm of chromosome 5 and more than one additional mutation turning these cases into high-risk forms of MDS.
Subject(s)
Myelodysplastic Syndromes , Thalidomide , Chromosome Deletion , Humans , Lenalidomide/therapeutic use , Myelodysplastic Syndromes/diagnosis , Myelodysplastic Syndromes/drug therapy , Myelodysplastic Syndromes/genetics , Thalidomide/therapeutic useABSTRACT
Although the molecular pathways that cause acute myeloid leukemia (AML) are increasingly well understood, the pathogenesis of peripheral blood cytopenia, a major cause of AML mortality, remains obscure. A prevailing assumption states that AML spatially displaces nonleukemic hematopoiesis from the bone marrow. However, examining an initial cohort of 223 AML patients, we found no correlation between bone marrow blast content and cytopenia, questioning the displacement theory. Measuring serum concentration of thrombopoietin (TPO), a key regulator of hematopoietic stem cells and megakaryocytes, revealed loss of physiologic negative correlation with platelet count in AML cases with blasts expressing MPL, the thrombopoietin (scavenging) receptor. Mechanistic studies demonstrated that MPLhi blasts could indeed clear TPO, likely therefore leading to insufficient cytokine levels for nonleukemic hematopoiesis. Microarray analysis in an independent multicenter study cohort of 437 AML cases validated MPL expression as a central predictor of thrombocytopenia and neutropenia in AML. Moreover, t(8;21) AML cases demonstrated the highest average MPL expression and lowest average platelet and absolute neutrophil counts among subgroups. Our work thus explains the pathophysiology of peripheral blood cytopenia in a relevant number of AML cases.
Subject(s)
Leukemia, Myeloid, Acute/pathology , Neutropenia/physiopathology , Receptors, Thrombopoietin/biosynthesis , Thrombocytopenia/physiopathology , Cohort Studies , Gene Knock-In Techniques , Hematopoiesis/physiology , Heterografts , Humans , Leukemia, Myeloid, Acute/complications , Leukemia, Myeloid, Acute/metabolism , Neutropenia/etiology , Thrombocytopenia/etiology , Thrombopoietin/blood , TranscriptomeABSTRACT
Favorable-risk human acute myeloid leukemia (AML) engrafts poorly in currently used immunodeficient mice, possibly because of insufficient environmental support of these leukemic entities. To address this limitation, we here transplanted primary human AML with isolated nucleophosmin (NPM1) mutation and AML with inv(16) in mice in which human versions of genes encoding cytokines important for myelopoiesis (macrophage colony-stimulating factor [M-CSF], interleukin-3, granulocyte-macrophage colony-stimulating factor, and thrombopoietin) were knocked into their respective mouse loci. NPM1mut AML engrafted with higher efficacy in cytokine knock-in (KI) mice and showed a trend toward higher bone marrow engraftment levels in comparison with NSG mice. inv(16) AML engrafted with high efficacy and was serially transplantable in cytokine KI mice but, in contrast, exhibited virtually no engraftment in NSG mice. Selected use of cytokine KI mice revealed that human M-CSF was required for inv(16) AML engraftment. Subsequent transcriptome profiling in an independent AML patient study cohort demonstrated high expression of M-CSF receptor and enrichment of M-CSF inducible genes in inv(16) AML cases. This study thus provides a first xenotransplantation mouse model for and informs on the disease biology of inv(16) AML.
Subject(s)
Disease Models, Animal , Leukemia, Myeloid, Acute , Neoplasm Transplantation/methods , Transplantation, Heterologous/methods , Animals , Chromosome Aberrations , Chromosomes, Human, Pair 16/genetics , Cytokines , Gene Knock-In Techniques , Heterografts , Humans , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/pathology , Mice , Mutation , Nuclear Proteins/genetics , NucleophosminABSTRACT
Standard of care for untreated mantle cell lymphoma (MCL) is still debated. At the University Hospital Zurich, advanced MCL in physically fit patients is treated either with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone induction followed by consolidating high-dose chemotherapy and autologous stem cell support (R-CHOP/HD-ASCT), or with rituximab plus fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone alternating with high-dose methotrexate-cytarabine (R-hyper-CVAD/MTX-AraC) without consolidating HD-ASCT upon physicians' and patients' choice. We retrospectively analysed the outcome and therapy tolerance in patients with MCL treated with R-CHOP/HD-ASCT or R-hyper-CVAD/MTX-AraC at the University Hospital Zurich between January 1996 and January 2016. Forty-three patients were included; 29 patients received R-CHOP/HD-ASCT and 14 patients R-hyper-CVAD/MTX-AraC. Mean age at diagnosis was 54.4 years (range 38-68 years). Thirty-five patients (81.4%) completed the entire first-line therapy (n = 24 in the R-CHOP/HD-ASCT group, n = 11 in the R-hyper-CVAD group). Of those, all patients responded and 97% achieved a complete remission (CR). With a mean follow-up of 5.7 years 10-year progression-free survival (PFS) for all patients was 32% and overall survival (OS) was 76%, with no difference between the two therapy groups. Complication-induced hospitalisation rate, haematological toxicity and economic burden were significantly higher in the R-hyper-CVAD therapy group. In contrast, quality of life and global health state were better in the R-hyper-CVAD therapy group. Both first-line therapies showed similar outcome with a median OS longer than 10 years. Due to significantly lower haematological toxicity and lower economic burden, we recommend R-CHOP/HD-ASCT as first-line therapy in fit adult patients with advanced MCL.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Cytarabine/administration & dosage , Hematopoietic Stem Cell Transplantation , Hospitalization/statistics & numerical data , Lymphoma, Mantle-Cell/therapy , Adult , Aged , Antibodies, Monoclonal, Murine-Derived/administration & dosage , Antibodies, Monoclonal, Murine-Derived/adverse effects , Antibodies, Monoclonal, Murine-Derived/economics , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/economics , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Cyclophosphamide/economics , Cytarabine/adverse effects , Cytarabine/economics , Dexamethasone/administration & dosage , Dexamethasone/adverse effects , Dexamethasone/economics , Doxorubicin/administration & dosage , Doxorubicin/adverse effects , Doxorubicin/economics , Drug Administration Schedule , Female , Hospitalization/economics , Humans , Lymphoma, Mantle-Cell/mortality , Lymphoma, Mantle-Cell/pathology , Lymphoma, Mantle-Cell/psychology , Male , Middle Aged , Prednisone/administration & dosage , Prednisone/adverse effects , Prednisone/economics , Quality of Life/psychology , Remission Induction , Retrospective Studies , Rituximab , Survival Analysis , Transplantation, Autologous , Vincristine/administration & dosage , Vincristine/adverse effects , Vincristine/economicsABSTRACT
This brief communication reports on a patient with an exceedingly rare "8p11 (eight-p-eleven) myeloproliferative syndrome" (EMS) with CEP110-FGFR1 rearrangement who responded to treatment with the multi-tyrosine kinase inhibitor (TKI) dasatinib. Dasatinib improved quality of life substantially by increasing blood counts and reducing the need for transfusions. This report demonstrates that the second-generation TKI may provide a therapeutic option for elderly and frail EMS patients who cannot be offered aggressive therapy, including allogeneic hematopoietic cell transplantation. The Oncologist 2017;22:480-483.
Subject(s)
Cell Cycle Proteins/genetics , Down Syndrome/drug therapy , Leukemoid Reaction/drug therapy , Neoplasms/drug therapy , Receptor, Fibroblast Growth Factor, Type 1/genetics , Chromosomes, Human, Pair 8/genetics , Dasatinib/administration & dosage , Down Syndrome/genetics , Down Syndrome/pathology , Female , Humans , Leukemoid Reaction/genetics , Leukemoid Reaction/pathology , Middle Aged , Neoplasms/genetics , Neoplasms/pathology , Oncogene Proteins, Fusion/genetics , Protein Kinase Inhibitors/administration & dosage , Quality of Life , Translocation, Genetic/geneticsABSTRACT
Iron supplements acutely increase hepcidin, but the duration and magnitude of the increase, its dose dependence, and its effects on subsequent iron absorption have not been characterized in humans. Better understanding of these phenomena might improve oral iron dosing schedules. We investigated whether the acute iron-induced increase in hepcidin influences iron absorption of successive daily iron doses and twice-daily iron doses. We recruited 54 nonanemic young women with plasma ferritin ≤20 µg/L and conducted: (1) a dose-finding investigation with 40-, 60-, 80-, 160-, and 240-mg labeled Fe as [(57)Fe]-, [(58)Fe]-, or [(54)Fe]-FeSO4 given at 8:00 am fasting on 1 or on 2 consecutive days (study 1, n = 25; study 2, n = 16); and (2) a study giving three 60-mg Fe doses (twice-daily dosing) within 24 hours (study 3, n = 13). In studies 1 and 2, 24 hours after doses ≥60 mg, serum hepcidin was increased (P < .01) and fractional iron absorption was decreased by 35% to 45% (P < .01). With increasing dose, fractional absorption decreased (P < .001), whereas absolute absorption increased (P < .001). A sixfold increase in iron dose (40-240 mg) resulted in only a threefold increase in iron absorbed (6.7-18.1 mg). In study 3, total iron absorbed from 3 doses (2 mornings and an afternoon) was not significantly greater than that from 2 morning doses. Providing lower dosages (40-80 mg Fe) and avoiding twice-daily dosing maximize fractional absorption. The duration of the hepcidin response supports alternate day supplementation, but longer-term effects of these schedules require further investigation. These clinical trials were registered at www.ClinicalTrials.gov as #NCT01785407 and #NCT02050932.
Subject(s)
Dietary Supplements , Ferritins/blood , Hepcidins/blood , Iron, Dietary/administration & dosage , Iron, Dietary/pharmacokinetics , Iron/metabolism , Administration, Oral , Adolescent , Adult , Biological Availability , Biomarkers/blood , Case-Control Studies , Cross-Over Studies , Drug Administration Schedule , Female , Follow-Up Studies , Humans , Intestinal Absorption , Iron/analysis , Male , Middle Aged , Prognosis , Young AdultABSTRACT
Interferon-α (IFNα) was the first effective drug therapy for hairy cell leukemia (HCL). Nowadays, it is used as an alternative treatment in selected patients. Due to unlimited treatment time, monitoring and early prediction of response are important. Moreover, IFNα is used in the therapy of chronic hepatitis C, where a single nucleotide polymorphism of interleukin-28B gene (IL28B) correlates with therapy response. The role of this polymorphism in therapy response of IFNα-treated patients with HCL is unknown. Thirty-seven HCL patients treated between 1978 and 2014 were included in this study. Treatment strategy and response parameters (blood cell counts, soluble interleukin-2 receptor (sIL2R), and bone marrow examination) have been assessed. Relative decrease of sIL2R was correlated with outcome parameters. Response parameters of IFNα-treated patients were correlated with IL28B polymorphism. Twenty-one patients were analyzed for the correlation of sIL2R ratio and outcome. After 1 and 3 months of therapy (IFNα or cladribine (CDA)), the median sIL2R level showed a relative decrease of 79 and 91%. These decreases significantly correlate with time to complete remission (CR, p = 0.029 and p = 0.018). Correlation analyses of IL28B genotype with outcome parameters are not significant. Six patients (16%) were diagnosed with secondary malignancies, and one death was registered (median follow-up time 14 years). IFNα is a safe, effective, and well-tolerated long-term treatment in HCL. Relative decreases of sIL2R levels correlate with time to CR and are useful as early predictor for response. There is no significant correlation between IL28B polymorphism and treatment response to IFNα. Graphical abstract.
Subject(s)
Genotype , Interleukins/genetics , Leukemia, Hairy Cell/blood , Leukemia, Hairy Cell/genetics , Receptors, Interleukin-2/blood , Adult , Alleles , Biomarkers , Drug Resistance, Neoplasm , Female , Follow-Up Studies , Humans , Interferon-alpha/therapeutic use , Interferons , Leukemia, Hairy Cell/drug therapy , Leukemia, Hairy Cell/mortality , Male , Middle Aged , Neoplasms, Second Primary/etiology , Polymorphism, Single Nucleotide , Prognosis , Recurrence , Treatment OutcomeABSTRACT
Calcium signaling is essential to support erythroid proliferation and differentiation. Precise control of the intracellular Ca(2+) levels in erythroid precursor cells (EPCs) is afforded by coordinated expression and function of several cation channels, including the recently identified N-methyl-d-aspartate receptor (NMDAR). Here, we characterized the changes in Ca(2+) uptake and electric currents mediated by the NMDARs occurring during EPC differentiation using flow cytometry and patch clamp. During erythropoietic maturation, subunit composition and properties of the receptor changed; in proerythroblasts and basophilic erythroblasts, fast deactivating currents with high amplitudes were mediated by the GluN2A subunit-dominated receptors, while at the polychromatic and orthochromatic erythroblast stages, the GluN2C subunit was getting more abundant, overriding the expression of GluN2A. At these stages, the currents mediated by the NMDARs carried the features characteristic of the GluN2C-containing receptors, such as prolonged decay time and lower conductance. Kinetics of this switch in NMDAR properties and abundance varied markedly from donor to donor. Despite this variability, NMDARs were essential for survival of EPCs in any subject tested. Our findings indicate that NMDARs have a dual role during erythropoiesis, supporting survival of polychromatic erythroblasts and contributing to the Ca(2+) homeostasis from the orthochromatic erythroblast stage to circulating red blood cells.
Subject(s)
Erythroid Precursor Cells/drug effects , Erythropoiesis , Receptors, N-Methyl-D-Aspartate/metabolism , Signal Transduction , Adolescent , Adult , Apoptosis , Calcium/metabolism , Cells, Cultured , Erythroid Precursor Cells/metabolism , Erythropoiesis/drug effects , Excitatory Amino Acid Agonists/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Female , Flow Cytometry , Glycine/pharmacology , Humans , Kinetics , Male , Membrane Potentials , Middle Aged , N-Methylaspartate/pharmacology , Patch-Clamp Techniques , RNA, Messenger/metabolism , Receptors, N-Methyl-D-Aspartate/agonists , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Receptors, N-Methyl-D-Aspartate/genetics , Signal Transduction/drug effects , Young AdultABSTRACT
Plasma sodium concentration is normally held within a narrow range. It may however vary greatly under pathophysiological conditions. Changes in osmolality lead to either swelling or shrinkage of red blood cells (RBCs). Here we investigated the influence of suspension osmolality on biophysical properties of RBCs and their ability to perfuse an artificial microvascular network (AMVN). Blood was drawn from healthy volunteers. RBC deformability was measured by osmotic gradient ektacytometry over a continuous range of osmolalities. Packed RBCs were suspended in NaCl solutions (0.45, 0.6, 0.9, 1.2, and 1.5 g/dL), resulting in supernatant osmolalities of 179 ± 4, 213 ± 1, 283 ± 2, 354 ± 3, and 423 ± 5 mOsm/kg H2O. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) were determined using centrifuged microhematocrit. RBC suspensions at constant cell numbers were used to measure viscosity at shear rates ranging from 0.11 to 69.5s(-1) and the perfusion rate of the AMVN. MCV was inversely and MCHC directly proportional to osmolality. RBC deformability was maximized at isosmotic conditions (290 mOsm/kg H2O) and markedly decreased by either hypo- or hyperosmolality. The optimum osmolality for RBC suspension viscosity was shifted toward hyperosmolality, while lower osmolalities increased suspension viscosity exponentially. However, the AMVN perfusion rate was maximized at 290 mOsm/kg H2O and changed by less than 10% over a wide range of osmolalities. These findings contribute to the basic understanding of blood flow in health and disease and may have significant implications for the management of osmotic homeostasis in clinical practice.
Subject(s)
Erythrocytes/cytology , Hemoglobins/chemistry , Microvessels , Rheology , Adult , Aged , Blood Viscosity , Erythrocyte Count , Erythrocyte Deformability/physiology , Erythrocyte Indices , Healthy Volunteers , Homeostasis , Humans , Microcirculation , Microfluidics , Middle Aged , Osmolar Concentration , Perfusion , Viscosity , Young AdultABSTRACT
BACKGROUND: Prolonged storage of red blood cells (RBCs) leads to storage lesions, which may impair clinical outcomes after transfusion. A hallmark of storage lesions is progressive echinocytic shape transformation, which can be partially reversed by washing in albumin solutions. Here we have investigated the impact of this shape recovery on biorheologic variables. STUDY DESIGN AND METHODS: RBCs stored hypothermically for 6 to 7 weeks were washed in a 1% human serum albumin (HSA) solution. RBC deformability was measured with osmotic gradient ektacytometry. The viscosity of RBC suspensions was measured with a Couette-type viscometer. The flow behavior of RBCs suspended at 40% hematocrit was tested with an artificial microvascular network (AMVN). RESULTS: Washing in 1% albumin reduced higher degrees of echinocytes and increased the frequency of discocytes, thereby shifting the morphologic index toward discocytosis. Washing also reduced RBC swelling. This shape recovery was not seen after washing in saline, buffer, or plasma. RBC shape normalization did not improve cell deformability measured by ektacytometry, but it tended to decrease suspension viscosities at low shear rates and improved the perfusion of an AMVN. CONCLUSIONS: Washing of stored RBCs in a 1% HSA solution specifically reduces echinocytosis, and this shape recovery has a beneficial effect on microvascular perfusion in vitro. Washing in 1% albumin may represent a new approach to improving the quality of stored RBCs and thus potentially reducing the likelihood of adverse clinical outcomes associated with transfusion of blood stored for longer periods of time.
Subject(s)
Blood Preservation/methods , Erythrocyte Transfusion , Erythrocytes/drug effects , Serum Albumin/pharmacology , Adenine/pharmacology , Adenosine Triphosphate/blood , Buffers , Cell Shape , Erythrocyte Indices , Erythrocytes/cytology , Erythrocytes, Abnormal/ultrastructure , Glucose/pharmacology , Glutathione/blood , Guanosine/pharmacology , Hemorheology , Humans , In Vitro Techniques , Mannitol/pharmacology , Models, Anatomic , Oxidation-Reduction , Perfusion , Plasma , Refrigeration , Sodium Chloride/pharmacology , SolutionsABSTRACT
Recently we showed that N-methyl D-aspartate receptors (NMDARs) are expressed in erythroid precursors (EPCs) and present in the circulating red blood cells (RBCs) of healthy humans, regulating intracellular Ca(2+) in these cells. This study focuses on investigating the possible role of NMDARs in abnormally high Ca(2+) permeability in the RBCs of patients with sickle cell disease (SCD). Protein levels of the NMDAR subunits in the EPCs of SCD patients did not differ from those in EPCs of healthy humans. However, the number and activity of the NMDARs in circulating SCD-RBCs was substantially up-regulated, being particularly high during haemolytic crises. The number of active NMDARs correlated negatively with haematocrit and haemoglobin levels in the blood of SCD patients. Calcium uptake via these non-selective cation channels was induced by RBC treatment with glycine, glutamate and homocysteine and was facilitated by de-oxygenation of SCD-RBCs. Oxidative stress and RBC dehydration followed receptor stimulation and Ca(2+) uptake. Inhibition of the NMDARs with an antagonist memantine caused re-hydration and largely prevented hypoxia-induced sickling. The EPCs of SCD patients showed higher tolerance to memantine than those of healthy subjects. Consequently, NMDARs in the RBCs of SCD patients appear to be an attractive target for pharmacological intervention.
Subject(s)
Anemia, Sickle Cell/blood , Calcium/blood , Erythrocytes/metabolism , Receptors, N-Methyl-D-Aspartate/blood , Adult , Case-Control Studies , Cell Hypoxia/physiology , Cells, Cultured , Erythrocyte Volume/drug effects , Erythrocyte Volume/physiology , Erythroid Precursor Cells/metabolism , Erythropoiesis/physiology , Glutathione/blood , Humans , Oxidation-Reduction , Receptors, N-Methyl-D-Aspartate/agonists , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Receptors, N-Methyl-D-Aspartate/physiology , Young AdultABSTRACT
We identified 11 human pedigrees with dominantly inherited hemolytic anemias in both the hereditary stomatocytosis and spherocytosis classes. Affected individuals in these families had an increase in membrane permeability to Na and K that is particularly marked at 0 degrees C. We found that disease in these pedigrees was associated with a series of single amino-acid substitutions in the intramembrane domain of the erythrocyte band 3 anion exchanger, AE1. Anion movements were reduced in the abnormal red cells. The 'leak' cation fluxes were inhibited by SITS, dipyridamole and NS1652, chemically diverse inhibitors of band 3. Expression of the mutated genes in Xenopus laevis oocytes induced abnormal Na and K fluxes in the oocytes, and the induced Cl transport was low. These data are consistent with the suggestion that the substitutions convert the protein from an anion exchanger into an unregulated cation channel.
Subject(s)
Anion Exchange Protein 1, Erythrocyte/genetics , Cations/metabolism , Chlorides/metabolism , Erythrocytes/metabolism , Potassium/metabolism , Sodium/metabolism , 4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid/pharmacology , Amino Acid Substitution , Anemia, Hemolytic/genetics , Anemia, Hemolytic/metabolism , Animals , Anion Exchange Protein 1, Erythrocyte/metabolism , Benzoates/pharmacology , Biological Transport , Cell Membrane Permeability , Dipyridamole/pharmacology , Humans , Molecular Sequence Data , Oocytes/cytology , Oocytes/metabolism , Pedigree , Phenylurea Compounds/pharmacology , Phosphodiesterase Inhibitors/pharmacology , Protein Structure, Tertiary , RNA/metabolism , Spherocytosis, Hereditary/genetics , Xenopus laevisABSTRACT
INTRODUCTION: A 27-year-old man presented due to unilateral leg pain. He had a history of diabetes insipidus and panhypopituitarism. Laboratory analysis revealed hormonal undersupply. MRI showed a large contrast medium-absorbing mass in the pituitary gland extending into the hypothalamus. FDG-PET/CT examination revealed a hypermetabolic soft tissue lesion around the left femoral shaft. After biopsy of the lesion, a diagnosis of multisystemic Langerhans cell histiocytosis was made.
Subject(s)
Diabetes Insipidus , Diabetes Mellitus , Hypopituitarism , Male , Humans , Adult , Positron Emission Tomography Computed Tomography , Hypopituitarism/diagnosis , Hypopituitarism/etiology , Diabetes Insipidus/diagnosis , Diabetes Insipidus/etiology , Pain/etiologyABSTRACT
The presence of N-methyl-d-aspartate receptor (NMDAR) was previously shown in rat red blood cells (RBCs) and in a UT-7/Epo human myeloid cell line differentiating into erythroid lineage. Here we have characterized the subunit composition of the NMDAR and monitored its function during human erythropoiesis and in circulating RBCs. Expression of the NMDARs subunits was assessed in erythroid progenitors during ex vivo erythropoiesis and in circulating human RBCs using quantitative PCR and flow cytometry. Receptor activity was monitored using a radiolabeled antagonist binding assay, live imaging of Ca(2+) uptake, patch clamp, and monitoring of cell volume changes. The receptor tetramers in erythroid precursor cells are composed of the NR1, NR2A, 2C, 2D, NR3A, and 3B subunits of which the glycine-binding NR3A and 3B and glutamate-binding NR2C and 2D subunits prevailed. Functional receptor is required for survival of erythroid precursors. Circulating RBCs retain a low number of the receptor copies that is higher in young cells compared with mature and senescent RBC populations. In circulating RBCs the receptor activity is controlled by plasma glutamate and glycine. Modulation of the NMDAR activity in RBCs by agonists or antagonists is associated with the alterations in whole cell ion currents. Activation of the receptor results in the transient Ca(2+) accumulation, cell shrinkage, and alteration in the intracellular pH, which is associated with the change in hemoglobin oxygen affinity. Thus functional NMDARs are present in erythroid precursor cells and in circulating RBCs. These receptors contribute to intracellular Ca(2+) homeostasis and modulate oxygen delivery to peripheral tissues.
Subject(s)
Calcium/physiology , Erythrocytes/physiology , Erythroid Precursor Cells/physiology , Intracellular Fluid/physiology , Receptors, N-Methyl-D-Aspartate/physiology , Adult , Animals , Cells, Cultured , Erythrocytes/drug effects , Erythroid Precursor Cells/drug effects , Excitatory Amino Acid Antagonists/pharmacology , Female , Humans , Intracellular Fluid/drug effects , Male , Middle Aged , Rats , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitorsABSTRACT
Alterations in hemoglobin oxygen affinity can be detected by exposing blood to different PO2 and recording oxygen saturation, a method termed tonometry. It is the gold standard to measure the PO2 associated with 50 % oxygen saturation, the index used to quantify oxygen affinity (P50Tono). P50Tono is used in the evaluation of patients with erythrocytosis suspected to have hemoglobin with abnormal oxygen affinity. Since tonometry is labor intensive and not generally available, we investigated whether accurate estimates of P50 could also be obtained by venous blood gas analysis, co-oximetry, and standard equations (P50Ven). In 50 patients referred for evaluation of erythrocytosis, pH, PO2, and oxygen saturation were measured in venous blood to estimate P50Ven; P50Tono was measured for comparison. Agreement among P50Ven and P50Tono was evaluated (Bland-Altman analysis). Mean P50Tono was 25.8 (range 17.4-34.1) mmHg. The mean difference (bias) of P50Tono-P50Ven was 0.5 mmHg; limits of agreement (95 % confidence limits) were -5.2 to +6.1 mmHg. The sensitivity and specificity of P50Ven to identify the 25 patients with P50Tono outside the normal range of 22.9-26.8 mmHg were 5 and 77 %, respectively. We conclude that estimates of P50 based on venous blood gas analysis and standard equations have a low bias compared to tonometry. However, the precision of P50Ven is not sufficiently high to replace P50Tono in the evaluation of individual patients with suspected disturbances of hemoglobin oxygen affinity.
Subject(s)
Hemoglobins/metabolism , Oximetry/methods , Oxygen/metabolism , Veins/chemistry , Adult , Aged , Blood Gas Analysis/methods , Female , Hemoglobins/analysis , Humans , Male , Middle Aged , Oxygen/analysis , Protein Binding , Sensitivity and Specificity , Substrate Specificity , Young AdultABSTRACT
Asplenia is found in a very heterogeneous group of patients with a wide range of age and comorbidities. These patients have an increased risk of overwhelming post-splenectomy infections (OPSI) even several decades after splenectomy. The mortality rate associated with OPSI is 30 - 60 %, which is why the immunisation against encapsulated bacteria is mandatory. In addition these patients show an increased risk of thrombosis of the portal venous system. In the present article all the necessary, during daily practice often neglected preventive measures and behavioural rules are discussed.
Subject(s)
Splenectomy/adverse effects , Surgical Wound Infection/etiology , Surgical Wound Infection/prevention & control , Venous Thrombosis/etiology , Venous Thrombosis/prevention & control , HumansABSTRACT
Hyperchromasia of the red blood cells (RBC), defined as an elevation of the hyperchromic subpopulation, has been described for various medical conditions. However, neither the association of hyperchromasia with an altered RBC membrane nor with other medical conditions has been investigated in a systematic way so far. Since the percentage of hyperchromic RBC is measured on a routine basis by many hematologic laboratories, we evaluated the predictive value of this parameter for the detection of RBC disorders. An extensive workup of all patients undergoing standard hematogram during a period of 6 months at our institution with a fraction of hyperchromic RBC larger than 10 % was collected by reviewing the medical history and performing osmotic gradient ektacytometry on RBC from a part of these patients. Thirty-two thousand two hundred twenty-six individuals were screened; of which, 162 (0.5 %) showed more than 10 % hyperchromic RBC. All of the patients examined by ektacytometry featured abnormal membrane deformability. Hereditary spherocytosis was found in 19 out of these 32 patients, in most cases unknown to the patient and currently asymptomatic. Another 17.9 % of the patients with an elevated subpopulation of hyperchromic RBC suffered from viral infection (human immunodeficiency virus, hepatitis). Our study shows that an elevated proportion of hyperchromic erythrocytes larger than 10 % is associated with both hereditary and acquired RBC membrane disorders and further follow-up should be considered.
Subject(s)
Erythrocyte Deformability , Erythrocytes, Abnormal/pathology , Spherocytosis, Hereditary/blood , Virus Diseases/blood , Adolescent , Adult , Aged , Aged, 80 and over , Anemia, Hemolytic, Autoimmune/blood , Anemia, Hemolytic, Autoimmune/diagnosis , Bilirubin/blood , Blood Cell Count , Erythrocyte Indices , Female , HIV Infections/blood , HIV Infections/diagnosis , Hemoglobins/analysis , Hepatitis, Viral, Human/blood , Hepatitis, Viral, Human/diagnosis , Humans , L-Lactate Dehydrogenase/blood , Male , Middle Aged , Osmotic Fragility , Sensitivity and Specificity , Spherocytosis, Hereditary/diagnosis , Staining and Labeling , Virus Diseases/diagnosis , Young AdultABSTRACT
Acquired Stomatocytosis in Hyperosmolar Hyperglycemic Derangement Abstract. In the context of a suicidally motivated suspension of insulin therapy, a massive hyperosmolar hyperglycemic derailment occurred in pancreoprivic diabetes mellitus most likely due to aethyltoxicity. In the blood picture differentiation stomatocytes could be detected, the development of which will be discussed in more detail below.