Ektacytometry Analysis of Post-splenectomy Red Blood Cell Properties Identifies Cell Membrane Stability Test as a Novel Biomarker of Membrane Health in Hereditary Spherocytosis.

Hereditary spherocytosis (HS) is the most common form of hereditary chronic hemolytic anemia. It is caused by mutations in red blood cell (RBC) membrane and cytoskeletal proteins, which compromise membrane integrity, leading to vesiculation. Eventually, this leads to entrapment of poorly deformable spherocytes in the spleen. Splenectomy is a procedure often performed in HS. The clinical benefit results from removing the primary site of destruction, thereby improving RBC survival. But whether changes in RBC properties contribute to the clinical benefit of splenectomy is unknown. In this study we used ektacytometry to investigate the longitudinal effects of splenectomy on RBC properties in five well-characterized HS patients at four different time points and in a case-control cohort of 26 HS patients. Osmotic gradient ektacytometry showed that splenectomy resulted in improved intracellular viscosity (hydration state) whereas total surface area and surface-to-volume ratio remained essentially unchanged. The cell membrane stability test (CMST), which assesses the in vitro response to shear stress, showed that after splenectomy, HS RBCs had partly regained the ability to shed membrane, a property of healthy RBCs, which was confirmed in the case-control cohort. In particular the CMST holds promise as a novel biomarker in HS that reflects RBC membrane health and may be used to asses treatment response in HS.

Sickle cell disease: Clinical presentation and management of a global health challenge.

Sickle cell disease is an autosomal recessive, multisystem disorder, characterised by chronic haemolytic anaemia, painful episodes of vaso-occlusion, progressive organ failure and a reduced life expectancy. Sickle cell disease is the most common monogenetic disease, with millions affected worldwide. In well-resourced countries, comprehensive care programs have increased life expectancy of sickle cell disease patients, with almost all infants surviving into adulthood. Therapeutic options for sickle cell disease patients are however, still scarce. Predictors of sickle cell disease severity and a better understanding of pathophysiology and (epi)genetic modifiers are warranted and could lead to more precise management and treatment. This review provides an extensive summary of the pathophysiology and management of sickle cell disease and encompasses the characteristics, complications and current and future treatment options of the disease.

Predictors of short-term and long-term mortality in critically ill patients admitted to the intensive care unit following allogeneic stem cell transplantation.

Historically, the mortality of patients admitted to the ICU after allogeneic stem cell transplantation (alloSCT) is high. Advancements in transplantation procedures, infectious monitoring and supportive care may have improved the outcome. This study aimed to determine short-term and long-term mortality after ICU admission of patients after alloSCT and to identify prognostic clinical and transplantation-related determinants present at ICU admission for long-term outcome. A multicenter cohort study was performed to determine 30-day and 1-year mortality within 2 years following alloSCT. A total of 251 patients were included. The 30-day and 1-year mortality was 55% and 80%, respectively. Platelet count <25 × 109/L (OR: 2.26, CI: 1.02-5.01) and serum bilirubin >19 µmol/L (OR: 2.47 CI: 1.08-5.65) at admission, other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 4.59, CI: 1.49-14.1) and vasoactive medication within 24 h (OR: 2.35, CI: 1.28-4.31) were associated with increased 30-day mortality. Other donor than a HLA-matched-related or HLA-matched-unrelated donor (OR: 1.9, CI: 1.13-3.19), serum bilirubin >77 (OR: 2.05, CI: 1.28-3.30) and vasoactive medication within 24 h (OR: 1.65, CI: 1.12-2.43) were associated with increased 1-year mortality. Neutropenia was associated with decreased 30-day and 1-year mortality (OR: 0.29, CI: 0.14-0.59 and OR: 0.70, CI: 0.48-0.98). Myeloablative conditioning and T cell-depleted transplantation were not associated with increased mortality.

Acute sinusitis and blindness as the first presentation of chronic lymphocytic leukaemia.

Chronic lymphocytic leukaemia (CLL) is the most frequent form of leukaemia among adults in the Western world, presenting at a median age of 65 years. The diagnosis is usually made incidentally during routine blood examination while the disease is still in its early phase. We report a case of blindness of 24 hours due to acute sinusitis based on CLL localisation in a patient with undiagnosed CLL. Emergency endoscopic sinus surgery and intra- and extra-ocular orbital decompression were performed. The sinusitis resolved after surgery and intravenous antibiotics. Her vision improved within 24 hours and eventually recovered completely after six months. Her CLL remained in an indolent state, needing no active treatment. This case illustrates that blindness from a lymphoproliferative disorder may be treated with emergency endoscopic sinus surgery instead of conventional chemotherapy in order to salvage the vision first, even if the vision is lost for more than 24 hours.

Venous thromboembolism and prothrombotic parameters in Klippel-Trenaunay syndrome.

BACKGROUND: In Klippel-Trenaunay syndrome (KTS), a congenital combined vascular (capillary, venous and lymphatic) malformation with localised disturbed growth, venous thromboembolisms (VTEs) are frequently reported in small cohorts. DESIGN AND METHODS: We quantified the frequency of VTE by screening a large KTS-patient cohort with duplex compression ultrasonography. Additionally, we performed a case-control study to evaluate whether coagulation alterations were related to VTE and magnitude of vascular malformations as quantified by magnetic resonance imaging (MRI). RESULTS: Twenty-nine (39%) of 75 patients had signs of current or previous VTE, including superficial venous thrombosis, six (8%) of whom had a deep venous thrombosis or a pulmonary embolism. Compared with 105 controls, 54 adult patients (both: median age 33 years) had higher plasma levels of D-dimer, medians 266 (IQR 195-366) versus 457 (IQR 270-3840) mg÷l (p.

[Pathophysiology and treatment of sickle-cell disease]. / Pathofysiologie en behandeling van sikkelcelziekte.

Sickle-cell disease is a hereditary haemoglobinopathy caused by a mutation in the beta-globin gene. The disease is characterised by recurrent vaso-occlusive crises resulting in severe organ damage and a sharply reduced life expectancy. The formation of haemoglobin-S polymers in hypoxic conditions plays a pivotal role in sickle-cell disease and produces the characteristic phenotype of sickle-shaped erythrocytes that promote vasoocclusion. Endothelial cell activation, enhanced erythrocyte and leukocyte adhesion, vasoconstriction and coagulation activation play an important role in vaso-occlusive crises. Treatment of pain and hydration remain the main interventions in the management ofvaso-occlusive crises. Hydroxyurea has been shown to prevent vaso-occlusive crises by increasing the amount of foetal haemoglobin. Allogeneic stem-cell transplantation is the only curative therapy. However, transplantation-related mortality, graft-versus-host disease and the limited availability of HLA-identical donors restrict this therapeutic option.