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A high red cell distribution width (RDW) and low hemoglobin level increase the risk of arterial ischemic stroke (AIS), mostly in adults. The mechanisms related to AIS remain unknown. A total of 233 subjects (90 patients and 143 healthy controls [HC]) were enrolled. The mean(SD) age in patients and HC was 9.5(3.8) and 11.4(1.8) years, respectively. We found increased odds ratios (ORs) for large vessel and small vessel subtypes in patients without underlying diseases with a mean corpuscular volume (MCV) <80 fL (OR: 5.4, 95%CI 1.8-16.3 and 2.8, 95%CI 1.2-7.2), mean corpuscular hemoglobin levels <27 pg (OR: 2.9, 95%CI 1.0-6.7 and 2.6, 95%CI 1.0-6.7), and RDW >15% (OR: 5.5, 95%CI 1.3-24.5 and 2.7, 95%CI 1.0-7.3). RBC indices showed significant correlations with TM levels. Therefore, low MCV and MCH levels, and a high RDW were risk factors for AIS and associated with TM levels in this population., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Bone marrow transplantation (BMT) serves as the only curative treatment for patients with β-thalassemia major; however, hemostatic changes have been observed in these BMT patients. Aggregability of thalassemic red blood cells (RBCs) and increased red blood cell-derived microparticles (RMPs) expressing phosphatidylserine (PS) are thought to participate in thromboembolic events by initially triggering platelet activation. To our knowledge, there has been no report providing quantitation of these circulating PS-expressing RBCs and RMPs in young β-thalassemia patients after BMT. Whole blood from each subject was fluorescently labeled to detect RBC markers (CD235a) and annexin-V together with the known number TruCount™ beads. PS-expressing RBCs, RMPs, and activated platelets were identified by flow cytometry. In our randomized study, we found the decreased levels of three aforementioned factors compared to levels in patients receiving regular blood transfusion (RT). This study showed that BMT in β-thalassemia patients decreases the levels of circulating PS-expressing RBCs, their MPs, and procoagulant platelets when compared to patients who received RT. Normalized levels of these coagulation markers may provide the supportive evidence of the effectiveness of BMT for curing thalassemia.

Introduction: Hereditary pyropoikilocytosis (HPP) is the most common cause of non‐thalassemic severe inherited hemolytic anemia in Thai population. Up to 90% of affected patients harbor biallelic mutations of SPTB Providence (SPTB c.6055T>C), SPTB Buffalo (SPTB c.6074T>G), and SPTB Chiang Mai (SPTB c.6224A>G). This study aimed to develop a simple assay for mass screening of the three common SPTB mutations and to study their carrier frequencies in a healthy Thai population. Methods: We combined multiplex amplification refractory mutation system‐PCR (ARMS‐PCR) and high‐resolution melting (HRM) curve analysis to create a one‐step single‐tube assay. The primers were designed to generate products with different melting temperatures in the presence of 6055C, 6074G, and 6224G. Internal control primers were added for quality control. Residual samples from blood donors and healthy adolescents were collected and tested for the three common SPTB mutations using the newly developed assay. Results: Optimized multiplex ARMS‐PCR/HRM curve assay yielded well‐separated melt curves to detect the three SPTB mutations with 4‐h turnaround time. The assay was validated in screening of 2261 non‐repetitive blood donors and 89 adolescents, in which 10 (0.43%), 2 (0.09%), and 3 (0.13%) individuals were identified as carriers of SPTB Providence, SPTB Buffalo, and SPTB Chiang Mai, respectively. All mutated SPTB and 20 random wild‐type samples were confirmed using Sanger sequencing with 100% accuracy. Conclusion: The novel ARMS‐PCR/HRM curve assay is simple, accurate, and time‐effective for mass screening of the common SPTB mutations. This can be employed to prevent HPP birth in a Thai population. [ABSTRACT FROM AUTHOR]

Red blood cell (RBC) membrane disorders represent a significant category of hereditary hemolytic anemia; however, information from Southeast Asia is limited. We established a national registry aiming to characterize RBC membrane disorders and their molecular features in Thailand. A total of 100 patients (99 kindreds) diagnosed with RBC membrane disorders between 2011 and 2020 from seven university hospitals were enrolled. The most prevalent disorders observed were hereditary elliptocytosis (HE; n=33), hereditary pyropoikilocytosis (HPP; n=28), hereditary spherocytosis (HS; n=19), Southeast Asian ovalocytosis (SAO; n=10 of 9 kindreds), and two cases of homozygous SAO. The remaining cases were grouped as unclassified membrane disorder. Seventy-six patients (76%) were molecularly confirmed by PCR, direct DNA sequencing, or hi-throughput sequencing. The primary causative gene for HE and HPP was SPTB, accounting for 28 out of 29 studied alleles for HE and 56 of 56 studied alleles for HPP. In the case of HS, dominant sporadic mutations in the ANK1 gene (n=4) and SPTB gene (n=3) were identified as the underlying cause. Notably, the four most common variants causing HE and HPP were SPTB Providence (c.6055 T>C), SPTB Buffalo (c.6074 T>G), SPTB Chiang Mai (c.6224 A>G), and SPTB c.6171__82delins TGCCCAGCT. These recurrent SPTB mutations accounted for 79 out of 84 mutated SPTB alleles (94%). In summary, HE and hereditary HPP associated with recurrent SPTB mutations are the predominant types of RBC membrane disorders observed in Thailand. These findings have significant implications for the clinical management and future research of RBC membrane disorders in the region. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Molecular characteristics of hereditary red blood cell membrane disorders in Thailand: a multi-center registry" published in the Annals of Hematology. The correction states that one of the participating institutes was mistakenly omitted from the original article, and there was a typographical error in the years of data collection in the abstract section. The original article has been corrected. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. The authors of the article are listed at the end of the correction notice. [Extracted from the article]

One complication of thalassemia is thromboembolism (TE), which is caused by an abnormal red blood cell surface, as well as endothelial and platelet activation. These findings are commonly observed in severe β-thalassemia. However, limited information on α-thalassemia exists. This study enrolled subjects with deletional and non-deletional α-thalassemia and normal controls (NC). Plasma and serum of subjects were tested for endothelial activation markers including thrombomodulin (TM), vascular cell adhesion molecule-1 (VCAM-1), and von Willebrand factor antigen as well as platelet activation markers including thromboxane B2 and platelet factor 4. A total of 179 subjects were enrolled: 29 in the deletional group (mean age 13.3 ± 4.4 years), 31 in the non-deletional group (mean age 12.9 ± 4.8 years), and 119 in the NC group (mean age 13.6 ± 3.0 years). Twenty nine percent of subjects in the non-deletional group received regular red blood cell transfusion and iron chelator administration. Serum ferritin level was higher in the non-deletional group than that in the deletional group. Multivariate analysis demonstrated that VCAM-1 and TM levels were increased significantly in α-thalassemia compared with NC group (816.8 ± 131.0 vs 593.9 ± 49.0 ng/ml, and 4.9 ± 0.7 vs 4.0 ± 0.4 ng/ml, P < 0.001 respectively). VCAM-1 and TM levels in the non-deletional group were significantly higher than that in the deletional group. The present study demonstrated endothelial activation in children with α-thalassemia disease, especially those in the non-deletional group, which might be one risk factor for TE in α-thalassemia disease. [ABSTRACT FROM AUTHOR]

Highlights: [•] Nitric oxide bioavailability was determined in thalassemia. [•] Severe thalassemia patients have decreased erythrocytic nitrite levels. [•] Severe thalassemia patients have increased plasma hemoglobin and NO consumption. [•] The erythrocytic nitrite correlates with plasma hemoglobin and NO consumption. [•] Decreased NO availability may be associated with hemolysis. [Copyright &y& Elsevier]