Role of Piezo1 in Terminal Density Reversal of Red Blood Cells.

Density reversal of senescent red blood cells has been known for a long time, yet the identity of the candidate ion transporter(s) causing the senescent cells to swell is still elusive. While performing fractionation of RBCs from healthy individuals in Percoll density gradient and characterization of the separated fractions, we identified a subpopulation of cells in low-density fraction (1.02% ± 0.47) showing signs of senescence such as loss of membrane surface area associated with a reduction in band 3 protein abundance, and Phosphatidylserine (PS) exposure to the outer membrane. In addition, we found that these cells are overloaded with Na+ and Ca2+. Using a combination of blockers and activators of ion pumps and channels, we revealed reduced activity of Plasma membrane Ca2+ ATPase and an increase in Ca2+ and Na+ leaks through ion channels in senescent-like cells. Our data revealed that Ca2+ overload in these cells is a result of reduced PMCA activity and facilitated Ca2+ uptake via a hyperactive Piezo1 channel. However, we could not exclude the contribution of other Ca2+-permeable ion channels in this scenario. In addition, we found, as a universal mechanism, that an increase in intracellular Ca2+ reduced the initially high selectivity of Piezo1 channel for Ca2+ and allowed higher Na+ uptake, Na+ accumulation, and swelling.

[Panhypopituitarism, Diabetes Insipidus and Bone Pain - Is There a Systemic Disease Behind it?]

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.

High karyotypic complexity is an independent prognostic factor in patients with CLL treated with venetoclax combinations.

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.

Feasibility of electronic patient-reported outcome monitoring and self-management program in aplastic anemia and paroxysmal nocturnal hemoglobinuria-a pilot study (ePRO-AA-PNH).

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.

Hemoglobin is an oxygen-dependent glutathione buffer adapting the intracellular reduced glutathione levels to oxygen availability.

Fast changes in environmental oxygen availability translate into shifts in mitochondrial free radical production. An increase in intraerythrocytic reduced glutathione (GSH) during deoxygenation would support the detoxification of exogenous oxidants released into the circulation from hypoxic peripheral tissues. Although reported, the mechanism behind this acute oxygen-dependent regulation of GSH in red blood cells remains unknown. This study explores the role of hemoglobin (Hb) in the oxygen-dependent modulation of GSH levels in red blood cells. We have demonstrated that a decrease in Hb O2 saturation to 50% or less observed in healthy humans while at high altitude, or in red blood cell suspensions results in rising of the intraerythrocytic GSH level that is proportional to the reduction in Hb O2 saturation. This effect was not caused by the stimulation of GSH de novo synthesis or its release during deglutathionylation of Hb's cysteines. Using isothermal titration calorimetry and in silico modeling, we observed the non-covalent binding of four molecules of GSH to oxy-Hb and the release of two of them upon deoxygenation. Localization of the GSH binding sites within the Hb molecule was identified. Oxygen-dependent binding of GSH to oxy-Hb and its release upon deoxygenation occurred reciprocally to the binding and release of 2,3-bisphosphoglycerate. Furthermore, noncovalent binding of GSH to Hb moderately increased Hb oxygen affinity. Taken together, our findings have identified an adaptive mechanism by which red blood cells may provide an advanced antioxidant defense to respond to oxidative challenges immediately upon deoxygenation.

[Acquired Stomatocytosis in Hyperosmolar Hyperglycemic Derangement]. / Erworbene Stomatozytose beihyperosmolarer, hyperglykämer Entgleisung.

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.

[MDS with deletion 5q - a distinct subtype of myelodysplastic syndromes]. / MDS mit Deletion 5q.

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.

Donor Age and Red Cell Age Contribute to the Variance in Lorrca Indices in Healthy Donors for Next Generation Ektacytometry: A Pilot Study.

The ability of red blood cells (RBCs) to transport gases, their lifespan as well as their rheological properties invariably depend on the deformability, hydration, and membrane stability of these cells, which can be measured by Laser optical rotational red cell analyser (Lorrca® Maxsis, RR Mechatronics). The osmoscan mode of Lorrca is currently used in diagnosis of rare anemias in clinical laboratories. However, a broad range of normal values for healthy subjects reduces the sensitivity of this method for diagnosis of mild disease phenotype. In this pilot study, we explored the impact of age and gender of 45 healthy donors, as well as RBC age on the Lorrca indices. Whereas gender did not affect the Lorrca indices in our study, the age donors had a profound effect on the O_hyper parameter. To study the impact of RBC age on the osmoscan parameters, we have isolated low (L)-, medium (M)-, or high (H)- density fractions enriched with young, mature, and senescent RBCs, respectively, and evaluated the influence of RBC age-related properties, such as density, morphology, and redox state, on the osmoscan indices. As before, O_hyper was the most sensitive parameter, dropping markedly with an increase in RBC density and age. Senescence was associated with a decrease in deformability (EI_max) and tolerability to low and high osmolatites (Area). L-fraction was enriched with reticulocytes and cells with high projected area and EMA staining, but also contained a small number of cells small in projected area and most likely, terminally senescent. L-fraction was on average slightly less deformable than mature cells. The cells from the L-fraction produced more oxidants and NO than all other fractions. However, RBCs from the L-fraction contained maximal levels of reduced thiols compared to other fractions. Our study suggests that reference values for O_hyper should be age-stratified, and, most probably, corrected for the average RBC age. Further multi-center study is required to validate these suggestions before implementing them into clinical practice.

Lysophosphatidic Acid-Activated Calcium Signaling Is Elevated in Red Cells from Sickle Cell Disease Patients.

(1) Background: It is known that sickle cells contain a higher amount of Ca2+ compared to healthy red blood cells (RBCs). The increased Ca2+ is associated with the most severe symptom of sickle cell disease (SCD), the vaso-occlusive crisis (VOC). The Ca2+ entry pathway received the name of Psickle but its molecular identity remains only partly resolved. We aimed to map the involved Ca2+ signaling to provide putative pharmacological targets for treatment. (2) Methods: The main technique applied was Ca2+ imaging of RBCs from healthy donors, SCD patients and a number of transgenic mouse models in comparison to wild-type mice. Life-cell Ca2+ imaging was applied to monitor responses to pharmacological targeting of the elements of signaling cascades. Infection as a trigger of VOC was imitated by stimulation of RBCs with lysophosphatidic acid (LPA). These measurements were complemented with biochemical assays. (3) Results: Ca2+ entry into SCD RBCs in response to LPA stimulation exceeded that of healthy donors. LPA receptor 4 levels were increased in SCD RBCs. Their activation was followed by the activation of Gi protein, which in turn triggered opening of TRPC6 and CaV2.1 channels via a protein kinase Cα and a MAP kinase pathway, respectively. (4) Conclusions: We found a new Ca2+ signaling cascade that is increased in SCD patients and identified new pharmacological targets that might be promising in addressing the most severe symptom of SCD, the VOC.

A pilot clinical phase II trial MemSID: Acute and durable changes of red blood cells of sickle cell disease patients on memantine treatment.

An increase in abundance and activity of N-methyl D-aspartate receptors (NMDAR) was previously reported for red blood cells (RBCs) of sickle cell disease (SCD) patients. Increased Ca2+ uptake through the receptor supported dehydration and RBC damage. In a pilot phase IIa-b clinical trial MemSID, memantine, a blocker of NMDAR, was used for treatment of four patients for 12 months. Two more patients that have enrolled into the study did not finish it. One of them had psychotic event following the involuntary overdose of the drug, whereas the other had vertigo and could not comply to the trial visits schedule. Acute and durable responses of RBCs of SCD patients to daily oral administration of memantine were monitored. Markers of RBC turnover, changes in cell density, and alterations in ion handling and RBC morphology were assessed. Acute transient shifts in intracellular Ca2+, volume and density, and reduction in plasma lactate dehydrogenate activity were observed already within the first month of treatment. Durable effects of memantine included (a) decrease in reticulocyte counts, (b) reduction in reticulocyte hemoglobinization, (c) advanced membrane maturation and its stabilization as follows from reduction in the number of NMDAR per cell and reduction in hemolysis, and (iv) rehydration and decrease in K+ leakage from patients' RBC. Memantine therapy resulted in reduction in number of cells with sickle morphology that was sustained at least over 2 months after therapy was stopped indicating an improvement in RBC longevity.

[CME: Polycythemia vera]. / CME: Polycythaemia vera CME-Fragen.

CME: Polycythemia vera Abstract. Polycythemia vera is a myeloprolifere disease which is characterized by proliferation of all three (erythroid, megakaryocytic and granulocytic) cell lines. The causative mutation is in the JAK2-tyrosine kinase gene. The symptoms are related to the increased red blood cells. Common signs are itching (pruritus) and pain in the hands or feet. The most common complications are thrombotic events. Risk factors are age over 60 years and a thrombotic event in the patient's history. The treatment consists of phlebotomy combined with acetylsalicylic acid 100 mg a day. The goal of the therapy is the prevention of the common thrombotic events. During the course of the disease, cytoreductive treatment is indicated in most of the patients.

Diagnosis and treatment of follicular lymphoma: an update.

Over the last few years, there have been many changes in the management of patients with follicular lymphoma, resulting in improvements in progression-free survival and quality of life. In addition to established regimens such as radiotherapy and immunochemotherapy, new treatment options are on the horizon. Furthermore, even the use of established chemotherapy agents has evolved, with new combinations moving to the forefront of the current treatment strategy. Nevertheless, there remains an unmet need for patients who have early relapses, those who are not responsive to anti-CD20 treatment regimens and for those in whom minimal residual disease persists even after immunochemotherapy. This review provides a summary of current developments in the diagnosis, treatment and management of follicular lymphoma, focusing on the clinical issues from a Swiss perspective.

R-hyper-CVAD versus R-CHOP/cytarabine with high-dose therapy and autologous haematopoietic stem cell support in fit patients with mantle cell lymphoma: 20 years of single-center experience.

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.

Influence of Standard Laboratory Procedures on Measures of Erythrocyte Damage.

The ability to characterize the mechanical properties of erythrocytes is important in clinical and research contexts: to diagnose and monitor hematologic disorders, as well as to optimize the design of cardiovascular implants and blood circulating devices with respect to blood damage. However, investigation of red blood cell (RBC) properties generally involves preparatory and processing steps. Even though these impose mechanical stresses on cells, little is known about their impact on the final measurement results. In this study, we investigated the effect of centrifuging, vortexing, pipetting, and high pressures on several markers of mechanical blood damage and RBC membrane properties. Using human venous blood, we analyzed erythrocyte damage by measuring free hemoglobin, phosphatidylserine exposure by flow cytometry, RBC deformability by ektacytometry and the parameters of a complete blood count. We observed increased levels of free hemoglobin for all tested procedures. The release of hemoglobin into plasma depended significantly on the level of stress. Elevated pressures and centrifuging also altered mean cell volume (MCV) and mean corpuscular hemoglobin (MCH), suggesting changes in erythrocyte population, and membrane properties. Our results show that the effects of blood handling can significantly influence erythrocyte damage metrics. Careful quantification of this influence as well as other unwanted secondary effects should thus be included in experimental protocols and accounted for in clinical laboratories.