Advances in Hematology最新文献

Background: Due to the sustained morbidity and mortality that malaria-associated anaemia imposes on patients, malaria is still a global threat, most especially, to residents in sub-Saharan Africa. Merozoite invasion and destruction of erythrocytes, a target for this study, have been necessary due to its unique nature and also since the erythrocytes suffer the most brunt of malarial infection leading to anaemia. The issue of malaria anaemia has to do with why uninfected RBCs get destroyed and even more so than infected ones. Studies have proposed that cytophilic anti-RSP2 (ring surface protein 2-merozoite rhoptry protein 2) antibodies present in sera enhance phagocytosis of RSP2-tagged RBCs by macrophages either directly or via complement, while others have proposed transfer of RSP2 to both infected and uninfected RBCs which may render them susceptible to phagocytosis. What is missing is the agent involved in the transfer of these parasite-induced surface proteins onto the uninfected RBCs, i.e., the mediator molecules. Considering the intracellular location of the parasite in the parasitophorous vacuolar membrane and the absence of a transport mechanism such as the Golgi apparatus within the mature RBC, since the latter has no nucleus, we propose that erythrocyte-derived microparticles (EMPs) may be the possible mediators.

Aim: This study aimed at examining the immunological interactions between EMPs released during malarial infections and host erythrocytes that may lead to their lysis possibly through complement mediation.

Methods: This was an experimental study during which malarial EMPs were isolated by differential centrifugation of malaria-positive plasma. This was followed by cell-based in vitro assays where malaria-positive EMPs were added to uninfected blood group "O" negative erythrocytes in the presence of complement and haemolysis checked for. Results and Conclusion. At a fixed volume of 50 μL complement, there were statistically significant (p < 0.01) increases in mean percentage haemolysis as the volume of EMPs increased. Similarly, at a fixed volume of 50 μL EMPs, there were statistically significant (p < 0.01) increases in mean percentage haemolysis with increasing volumes of complement. This was an indication that both complement and EMPs contribute significantly to uninfected erythrocyte haemolysis during malaria infection.

Rituximab hypersensitivity reactions are rare but are one of the main causes of rituximab elimination from antilymphoma immunochemotherapy treatments. While the clinical picture may be indistinguishable from other infusion-related reactions, hypersensitivity reactions (HSR) do not disappear and instead become more intense with subsequent administrations. Objective. To describe the use of the 12-step protocol for desensitization to intravenous rituximab in clinical practice and the complementary study of a possible IgE-mediated HSR in the context of B-cell lymphoma treatment. Methods. A 12-step rituximab desensitization protocol was performed prospectively within clinical practice in 10 patients with a history of severe infusion reactions or in patients who had a repeated reaction at subsequent doses despite taking more intense preventive measures. Skin prick tests were performed at the time of reaction and at a later time to eliminate false negatives due to possible drug interference. Results. Overall, with the desensitization protocol, 70% of patients were able to complete the scheduled immunochemotherapy. Two patients had to discontinue the therapy due to clinical persistence and the third due to lymphoma progression. Intradermal tests with 0.1% rituximab were positive in only 20% of cases, demonstrating a mechanism of hypersensitivity. Conclusions. The 12-step desensitization protocol is very effective and assumable within healthcare practice. There is a need to determine the mechanism underlying the infusion reaction in a large proportion of cases due to the risk of future drug exposure.

Background: The high prevalence of haemoglobin variants and glucose 6-phosphate dehydrogenase disorder (G6PDd) in sub-Saharan Africa means that substantial proportions of donor blood units carry these red cell abnormalities.

Aim: This study investigated the impact that inherited haemoglobin variants and/or G6PD status have on whole blood banked at 4-6°C for 35 days.

Method: This repeated-measure cohort study was undertaken on 103 donor blood units collected into blood bag containing CPDA-1 anticoagulant. On days 0, 7, 14, 21, and 35, full blood count, osmotic-induced haemolysis, and plasma K+ levels were estimated. Also, on day 0, G6PD status, haemoglobin variants, % foetal haemoglobin, and blood group of donor units were determined using methaemoglobin reductase, cellulose acetate electrophoresis, modified Bekte alkali denaturation assay, and slide haemagglutination test, respectively.

Result: Overall, although plasma K+ levels increased during storage, donor units from individuals ≥20 years, G6PD normal, Hb AC, or blood group B had comparatively higher percentage change in plasma K+ during storage. Osmotically induced haemolysis of donor units was significantly decreased in Hb AC (compared with Hb A or AS) donor units on days 7, 14, 21, and 35 (p < 0.0001 in each case). G6PDd donor units had comparatively reduced osmotic-induced lysis compared with G6PD normal units, reaching a statistical significance on day 35 (p = 0.043). Also, Hb AC units had comparatively nonstatistically higher plasma K+ at all time points (compared with Hb A or AS). Furthermore, whereas donor units from individuals ≥20 years showed significantly higher median free haemoglobin on day 21 (compared to donor <20 years), when donor units were stratified per Hb variants, only Hb AS units had median free haemoglobin below the 0.8% threshold after 35 days' storage.

Conclusion: Age of donor, blood group, Hb AC variant, and G6PD status may be important considerations in the storability of whole blood.

Obesity plays an essential role in the safety of pharmacologic drugs. There is paucity of data for direct oral anticoagulants (DOACs) in the obese, despite these agents becoming more widely used. The primary and secondary objectives of this study were to assess the safety and efficacy of DOACs in the overweight and obese populations when used for primary prophylaxis in the setting of non-valvular atrial fibrillation (NVAF) and for treatment of venous thromboembolisms (VTE). We conducted a retrospective cohort study in a large tertiary care center and obtained data through review of electronic health records. Among patients with NVAF and VTE on apixaban, there were no differences in rates of major bleeding (MB) and clinically relevant nonmajor bleeding (CRNMB) in the overweight and obese populations when compared to normal weight and underweight individuals. The multivariate adjusted analysis for rivaroxaban found that the odds of CRNMB for patients with BMI <25 was 5.37 (95% CI 1.50-19.32) times higher than that of BMI ≥25. Moreover, patients on medications that had known interactions with DOACs had 6.40 times higher odds of CRNMB than patients without such interactions (95% CI 1.49-27.57), which was not accounted for by the effects of aspirin and plavix alone. Efficacy was similar between all weight groups, for both apixaban and rivaroxaban. These results support previous analyses preformed in the large phase III trials and confirm that apixaban and rivaroxaban are safe in the overweight and obese.

This study aimed to determine the clinical impact of CD25⁺/CD123⁺ coexpression in adult B-cell acute lymphoblastic leukemia (B-ALL) cases. One hundred and twenty newly diagnosed B-ALL patients (≤60 years old) were included in this study. CD123 and CD25 expression on leukemic blast cells were assessed using flow cytometry. CD25⁺/CD123⁺ coexpression was detected in 40/120 B-ALL patients (33.3%). All B-ALL patients showed CD25⁺/CD123⁺ coexpression had lower induction of remission response and shorter overall survival as compared to B-ALL cases lacking coexpression. In conclusion, CD25⁺/CD123⁺ positive coexpression is a reliable flow cytometry marker for prediction of the outcome of adult B-ALL patients and could be used as a novel parameter for risk stratification of adult B-ALL cases.

Background: Imatinib mesylate is the gold standard for the treatment of all phases of Philadelphia-positive chronic myeloid leukemia. Patients on imatinib treatment may develop cytopenia due to drug toxicity. This study aimed to determine the types, grades, and time course of cytopenia in CML patients on imatinib at a Nairobi hospital.

Methods: This was a cross-sectional descriptive study of adult patients aged ≥18 years followed up at the Glivec International Patient Access Program (GIPAP) clinic from 2007 to 2015. Patients who developed cytopenia within 12 months of initiating imatinib were eligible. Clinical and hematologic data were retrieved from the patients' charts and entered into a study proforma. Measures of central tendency such as mean, median, mode, standard deviation, and variance were used for analysis.

Results: Sixty three percent (63.6%) of the 94 patients developed a monocytopenia, with anemia seen in 34%, neutropenia in 27.6%, and thrombocytopenia in 8% of the 94 patients. Anemia plus neutropenia was the most common bicytopenia at 12.7%. Pancytopenia was seen in only 5 of the 94 patients. Most of the cytopenia was grades 2 and 3. Anemia was present at baseline while neutropenia and thrombocytopenia developed within 12 months of imatinib initiation. Anemia resolved during the first 12 months of therapy while neutropenia and thrombocytopenia resolved within 24-36 months of treatment.

Conclusion: Monocytopenia, especially anemia, was the most common type of cytopenia. The cytopenia was predominantly grade 2, developed in majority of the patients within 6 months after imatinib initiation, and had resolved by 24-36 months after imatinib initiation.

Objectives: Evaluate the impact of a Quality and Safety Program (QSP) on the reduction of blood loss and transfusion needs in pediatric spinal deformity surgery, while defining risk factors for transfusion.

Background: Multimodal plan aiming to minimize transfusion needs has been shown to reduce transfusions and index rates in spinal deformity surgery. Anticipating blood loss and transfusion may help direct resources to patient needs or encourage reconsideration of the surgical plan.

Methods: This is a single-center retrospective study of prospectively collected data. Impact of this multimodal plan was studied on idiopathic deformities (Group A, 109 patients) and scoliosis associated with syndromic, neuromuscular, and muscular dystrophies (Group B, 100 patients), both before and after QSP.

Results: A decrease in total estimated blood loss was observed. In Group A, transfused patients decreased from 83.7% to 28% (p < 0.001, odds: 0.077), and, in Group B, from 98.7% to 66% (p < 0.01, odds: 0.038). Pearson's correlation identified patient body weight (r = 0.245, p=0.001) and Cobb angle (r = 0.175, p=0.017) as factors related to blood loss. A linear regression model to estimate hematic losses revealed that only body weight and transfusion showed predictive power, resulting in a low predictive model (R ² = 0.156; F(3,167) = 15.483, p < 0.001). A mediated model to explain blood loss was built based on a set of variables influencing transfusion which is, in turn, related to blood loss.

Conclusion: Transfusion needs in scoliosis surgery can be substantially reduced following a multimodal approach. The success of a program is strongly dependent on team effort, and the introduction of a risk assessment tool for transfusion needs indirectly assesses surgical risk, thus allowing relocation of resources to decrease blood loss.

This retrospective pilot study aimed to detect whether remaining dental/periodontal treatment need and periodontal inflammation after dental clearance would be associated with the initial therapy outcome of adult patients with acute leukemia undergoing induction chemotherapy. Different parameters were assessed from the patients' records: initial blood parameters, blood parameters during initial chemotherapy, leukemia/therapy related complaints, duration of fever, microbiological findings (blood and urine), as well as patients' survival. Dental treatment need was defined as the presence of at least one carious tooth; periodontal treatment need was determined by the presence of probing depth ≥3.5 mm in at least two sextants. To reflect periodontal inflammation, the periodontal inflamed surface area (PISA) was applied. Thirty-nine patients were included. A dental treatment need of 75% and periodontal treatment need of 76% as well as an average PISA of 153.18 ± 158.09 were found. Only two associations were detected: periodontal treatment need was associated with thrombocyte count after 7 days (p=0.03), and PISA was associated with erythrocyte count three days after induction of therapy (p=0.01). It can be concluded that remaining dental and periodontal treatment need as well as periodontal inflammation after dental clearance is not associated with the outcome of induction therapy in adult patients with acute leukemia.

Alpha-thalassemia is highly prevalent in the plural society of Brazil and is a public health problem. There is limited knowledge on its accurate frequency and distribution in the Amazon region. Knowing the frequency of thalassemia and the prevalence of responsible mutations is, therefore, an important step in the understanding and control program. Hematological and molecular data, in addition to serum iron and serum ferritin, from 989 unrelated first-time blood donors from Amazonas Hemotherapy and Hematology Foundation (FHEMOAM) were collected. In this study, the subjects were screened for -α ^3.7/4.2/^20.5, -^SEA, -^FIL, and -^MED deletions. Alpha-thalassemia screening was carried out between 2016 and 2017 among 714 (72.1%) male and 275 (27.9%) female donors. The aims of this analysis were to describe the distribution of various alpha-thalassemia alleles by gender, along with their genotypic interactions, and to illustrate the hematological changes associated with each phenotype. Amongst the patients, 5.35% (n = 53) were diagnosed with deletion -α ^-3.7 and only one donor with α ^-4.2 deletion. From the individuals with -α ^-3.7, 85.8% (n = 46) were heterozygous and 14.20% (n = 7) were homozygous. The frequency of the -α ^-3.7 deletion was higher in male (5.89%) than in female (4.0%). There is no significant difference in the distribution of -α ^-3.7 by gender (p = 0.217). The -α ^20.5, -^SEA, and -^MED deletions were not found. All subjects were analyzed for serum iron and serum ferritin, with 1.04% being iron deficient (n = 5) and none with very high levels of stored iron (>220 µg/dL). Alpha-thalassemia-2^3.7kb deletion was the most common allele detected in Manaus blood donors, which is a consistent result, once it is the most common type of α-thalassemia found throughout the world. As expected, the mean of hematological data was significantly lower in alpha-thalassemia carriers (p < 0.001), mainly homozygous genotype. Leukocytes and platelet count did not differ significantly. Due to the small number of individuals with iron deficiency found among blood donors, the differential diagnosis between the two types of anemia was not possible, even because minor changes were found among hematological parameters with iron deficiency and α-thalassemia. Despite this, the study showed the values of hematological parameters, especially MCV and MCH, are lower in donors with iron deficiency, especially when associated with α-thalassemia, and therefore, it may be useful to discriminate different types of microcytic anaemia. In conclusion, we believed screening for thalassemia trait should be included as part of a standard blood testing before blood donation. It should be noted that this was the f

Objectives: Essential thrombocythemia (ET) is one of the myeloproliferative neoplasms characterized by a sustained elevation of platelet numbers with a tendency for thrombosis and hemorrhage. The aim of this work is to establish the relation between calreticulin, factor V Leiden, prothrombin G20210A, and MTHFR mutations in ET patients and the thrombotic risk of these patients.

Methods: This study was carried out on 120 ET patients and 40 apparently healthy individuals as a control group.

Results: There were increases in WBCs, PLT counts, PT, fibrinogen concentration factor V Leiden, and MTHFR mutation in ET patients as compared to the control group (P < 0.05). Also, there were increases in WBCs, PLT counts, and hematocrit value in thrombosed ET patients as compared to the nonthrombosed ones (P < 0.05). On the contrary, there was no significantly statistical difference in ET patients with JAK2 V617F positive mutation versus the JAK2 negative group (P > 0.05) and in patients with cardiovascular risk factors versus patients with noncardiovascular risk factors (P > 0.05). ET patients with factor V Leiden, prothrombin gene, and CALR mutations were more prone to thrombosis (odds ratio 5.6, 5.7 and 4.7, respectively). On the contrary, JAk2V 617F and MTHFR mutations have no effect on the thrombotic state of those patients.

Conclusion: There is a significant increase risk of thrombosis in ET patients with CALR mutation, thrombophilic mutations, as well as factor V Leiden and prothrombin gene mutation with a risk of developing leukemic transformation.