Carina Levin

Red blood cells, platelets and polymorphonuclear neutrophils of patients with sickle cell disease exhibit oxidative stress that can be ameliorated by antioxidants

Sickle cell disease (SCD) is basically a red blood cell (RBC) disorder characterised by sickling and haemolysis, but platelets and polymorphonuclear neutrophils (PMN) are also involved. Oxidative damage may play a role in the pathogenesis of SCD. Using flow cytometry, we measured oxidative‐state markers simultaneously in RBC, platelets and PMN obtained from 25 normal donors, nine homozygous (SS) patients and six SS/beta‐thalassaemia patients. Reactive oxygen species (ROS) and reduced glutathione (GSH) were measured following staining of blood samples with fluorescence probes and gating on specific subpopulations based on size and granularity. Ten‐ to 30‐fold higher ROS production and 20–50% lower GSH content were found in RBC, platelets and PMN from SCD patients versus those of their normal counterparts. This could in part account for the clinical manifestations, such as haemolysis, a hypercoagulable state, recurrent bacterial infections and vaso‐occlusive incidences, in SCD. We further showed that exposure of SCD samples to antioxidants, such as N‐acetyl‐cysteine, vitamin C and vitamin E, decreased their oxidative stress. These results suggest that antioxidant treatment of patients with SCD could reduce oxidative damage to RBC, PMN and platelets, thereby alleviating symptoms associated with their pathology. The flow cytometry techniques presented herein could assist in monitoring the efficacy of such treatment.

Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia.

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.

Non-transferrin bound labile plasma iron and iron overload in Sickle Cell Disease: a comparative study between Sickle Cell Disease and β thalassemic patients

Background:u2002 Blood transfusions are the standard of care in β thalassemia and transfusions are also indicated in sickle cell disease (SCD) patients with hypersplenism, recurrent vaso‐occlusive crises and for stroke prevention. Iron overload caused by blood transfusions in thalassemia and in SCD may affect morbidity and mortality. Recent studies of iron overload in SCD suggest that the biologic features of SCD and the chronic inflammatory state may protect SCD patients from iron damage.

Pylephlebitis due to perforated appendicitis in a teenager

Pylephlebitis, a septic thrombophlebitis of the portal vein, is a life-threatening complication of intraabdominal infections, commonly associated with acute appendicitis in children, and diverticulitis in adults. A 13-year-old boy was admitted for high fever and jaundice. On the fifth day of hospitalization, ultrasound Doppler flow and Computer Tomography scan studies showed thrombosis of the portal vein and acute appendicitis. The patient was treated with antibiotics, anticoagulation and laparotomy with appendectomy. No thrombophilic risk factors were diagnosed. Our aim is to improve physicians’ awareness of this complication and emphasize the importance of early diagnosis and appropriate therapy in children in order to reduce serious complications and long-term sequels.

No evidence for myocardial iron overload and free iron species in multitransfused patients with sickle/β0-thalassaemia

Iron overload (IO) in the heart is a life‐threatening complication in transfusion‐dependent patients with thalassaemia major (TM) and to a lesser extent in sickle cell disease (SCD), while no data are available in patients with sickle/β0‐thalassaemia. Iron deposition in the heart, liver and pancreas was assessed using T2* MRI sequences, as well as free iron species assays – non‐transferrin bound iron (NTBI) and labile plasma iron (LPI), in addition to serum ferritin, percentage transferrin saturation and serum hepcidin, in 10 multitransfused patients (>30u2003yr) with sickle/β0‐thalassaemia. None of the patients had iron deposition in the heart. Three patients had mild, one had moderate, and two had severe liver IO. Two patients had mild iron deposition in the pancreas. In all the patients, serum hepcidin levels were normal – NTBI and LPI were not detected. Possible explanations of these findings are discussed.

Migraine and hypercoagulability, are they related? A clinical study of thrombophilia in children with migraine

neurological recovery in both cases. This approach allowed definitive neuraxis radiation therapy to be deferred until transplant conditioning for Case 1, and this was the planned therapy for Case 2. The role of haematopoietic stem cell transplantation in the management of Ph+ ALL is likely to evolve, but patients with unfavourable features, such as the cases presented, are likely to benefit from allogeneic transplantation following intensive induction therapy combined with a tyrosine kinase inhibitor. An excellent response measured by MRD detection may identify a subgroup with a good survival following transplantation (Cazzaniga et al, 2002; Lee et al, 2009). Additional post-transplant tyrosine kinase inhibitor therapy is well tolerated and may be an important factor in maintaining remission (Carpenter et al, 2007). In summary, we conclude that dasatinib and multi-agent chemotherapy are effective in controlling multiple childhood intracranial Ph+ ALL tumours and can be used as an alternative to emergent cranial radiation therapy. We suggest that this approach strikes a balance between maintaining the chance of cure whilst at the same time minimizing the potential for neurocognitive late effects. Acknowledgements

Thrombophilia in Infancy: Factor V Leiden and MTHFR or Factor II Double Heterozygocity as a Risk Factor

Thrombophilic risk factors are associated with thromboembolism in children but data in infants and neonates are not well established. The authors report a series of 9 infants with thrombotic events and the associated genetic risk factors. The clinical and laboratory records of newborns and infants with a history of thrombotic events were summarized, while patients with underlying diseases were excluded. The frequency of the genetic mutations was compared to a control group of 80 children from the same ethnic origin. In 6 patients a cerebrovascular accident was diagnosed and in 3 newborns, CT scan could diagnose antenatal brain infarct. In another 2 patients deep-vein thrombosis associated with femoral catheterization was diagnosed. Seven infants were factor V Leiden heterozygous and another one homozygous. Methylenetetrahydrofolate reductase genotype was found in 5 infants. Five cases were found to be double heterozygous for those two mutations, and another one double heterozygous for FVL and factor II. The results of this small series of patients indicate that cerebrovascular accident is the major thrombotic event in infants and the combination of more than one prothrombotic factors may be the cause of those events. The correct management, including anticoagulant therapy, is still under discussion and waiting for larger series and long-term follow-up results until accurate recommendations can be made.

Small-platelet thrombocytopenia in a family with autosomal recessive inheritance pattern

We describe the clinical and laboratory features of a family of Arab ancestry and consanguinity. Five affected individuals were diagnosed in two sibships. All affected members have small platelets, severe to moderate thrombocytopenia of neonatal onset, increased bleeding tendency and bleeding complications such as: life‐threatening massive hemoperitoneum due to corpus luteum rupture during ovulation and severe mucosal bleeding. The familial involvement and early onset of the disease support the presence of a congenital genetic disorder with an autosomal recessive inheritance pattern. This does not fit the clinical spectrum of any of the currently known thrombocytopenia disorders. Pediatr Blood Cancer 2013;60:E128–E130.

Hb Taybe: clinical and morphological findings in 43 patients

Hereditary sequence variants in globin genes are usually silent and are rarer in α‐globin chains than β‐globin chains. Some may lead to an unstable protein with a hemolytic or thalassemic phenotype. Hb Taybe is an unstable α‐chain hemoglobin variant caused by the deletion of a threonine residue at codon 38 or 39 of the α1 globin gene. This deletion results in a structural abnormality that affects the α1β2 contact and the α1β1 interface, producing a highly unstable Hb.

Immune-mediated mechanism for thrombocytopenia after Loxosceles spider bite.

Loxoscelism, characterized by high fever, vomiting, malaise, a dermonecrotic lesion, and thrombocytopenia, was diagnosed in a 3‐year‐old female. Clinical laboratory and dermatological signs are described. Blood test showed a transient hypercoagulable state and the presence of IgG antibodies against platelets, suggesting an immune‐mediated mechanism for platelet destruction, in addition to the direct toxic effect of the spider venom. The finding of platelet antibodies after a Loxosceles spider bite has not been previously reported. Pediatr Blood Cancer 2014; 61:1466–1468.