bims-conane 2025-10-19 papers

Blood. 2025 Oct 16. pii: blood.2025030958. [Epub ahead of print]

NMNAT3 deficiency: a novel red blood cell enzymopathy causing hemolysis by altering NAD levels and glycolysis.

Titine J J Ruiter, Brigitte A van Oirschot, Esme Waanders, Klaas Koop, Wouter W Van Solinge, Richard van Wijk, Judith J M Jans, Marije Bartels.

We describe the first case of NMNAT3 deficiency, a novel red cell enzymopathy leading to reduced NAD levels, causing mild hemolytic anemia which improved upon supplementation with NAD-precursors. We therefore propose testing for NMNAT3 variants in unexplained hereditary hemolytic anemia.

DOI: https://doi.org/10.1182/blood.2025030958

Clin Epigenetics. 2025 Oct 17. 17(1): 173

Comprehensive regulation of γ-globin expression by epigenetic modifications and protein post-translational modifications.

Dahang Ye, Meihuan Chen, Ying Zhu, XinYuan Feng, Liangpu Xu, Hailong Huang.

As a member of the hemoglobin family, γ-globin is usually persistently expressed at high levels to perform the oxygen-carrying function during fetal development. In recent years, related gene editing clinical trials have confirmed that reactivation of γ-globin expression is a promising therapeutic strategy for treating β-hemoglobinopathies, including β-thalassemia and sickle cell disease. Human γ-globin expression is finely regulated by multiple mechanisms, and a deeper understanding of the mechanisms will help develop drugs that target its activation. With the advancement of biotechnology, epigenetic modifications (EMs) and protein post-translational modifications (PPTMs) have shown irreplaceable roles in the regulation of γ-globin expression. Therefore, this review will comprehensively summarize the regulatory mechanisms of EMs and PPTMs on γ-globin to provide new ideas for the treatment of β-hemoglobinopathies.

Keywords: Epigenetic modifications; Protein post-translational modifications; Regulatory mechanisms; β-hemoglobinopathies; γ-globin

DOI: https://doi.org/10.1186/s13148-025-01962-5

Turk J Haematol. 2025 Oct 15.

Expression of Immune Checkpoints LAG-3, CTLA-4, TIM-3 and PD-1 in Beta Thalassemia patients Treated using HbF Augmentation Therapy and Regular Transfusions.

Komal Khan, Umaima Khan, Asma Shah, Syed Muhammad Ikram Shah, Yousaf Khan, Muhammad Tariq Masood Khan, Gulab Fatima Rani.

Introduction: Beta-thalassemia is an inherited hemoglobin disorder caused by mutations in HBB gene encoding beta globin chains. Severe anemia secondary to defective globin chains, chronic hemolysis and ineffective erythropoiesis requires transfusion support from early childhood. Recently used treatment options with promising results in resource limited countries includes drugs which augment HbF such as hydroxyurea and thalidomide. Although effective in alleviating anemia and related symptoms, these drugs particularly thalidomide has been known for its immunomodulatory role. Similarly, repeated transfusions with compromised immune system increases the risk of infections and weakened immunity. One of the key regulators of immune systems includes immune checkpoints, cell surface molecules on immune cells. Limited studies are available on immune checkpoints such as LAG-3, CTLA-4, TIM-3 and PD-1 expression in thalassemia and its treatment.
Objectives: This study aimed to compare LAG-3, CTLA-4, TIM-3, and PD-1 expression in patients treated using HbF augmenting drugs or transfusions and with iron overload. These findings will provide an insight into the immune regulation in betathalassemia in response to treatment.
Methods: In this study, the expression of LAG-3, CTLA-4, TIM-3 and PD-1 was quantified using real time PCR in patients managed on blood transfusions (n=33) or HbF augmenting drugs (n=140) and compared with healthy controls (n=27).
Results: Our results show an increased expression of LAG-3 in patients regardless of treatment whereas increased CTLA-4 in patients on regular transfusions. On the other hand, the expressions of TIM-3 and PD-1 were higher in patients taking HbF augmentation therapy compared to patients on blood transfusions or the healthy controls. A very weak to no correlation was found between serum ferritin and immune checkpoints.
Conclusions: These findings are suggestive of alterations in immune regulation in beta-thalassemia which could be attributed to thalassemia itself, repeated exposure to blood products, recurrent infections and the immunomodulatory drugs.

Keywords: Beta Thalassemia; HbF augmentation therapy; Hydroxyurea; Immune Checkpoints; Thalidomide

DOI: https://doi.org/10.4274/tjh.galenos.2025.2025.0278

Cytometry B Clin Cytom. 2025 Oct 14.

Comparison of flow cytometric osmotic fragility test between kinetic and endpoint assay principle.

Dong Il Won, Eui Yeol Jeong, Sang Mook Kim, Ye Ji Shim.

To screen hereditary spherocytosis (HS), we first introduced the novel flow cytometric osmotic fragility test (FC-OFT) based on the two-point kinetic assay principle (FC-OFTKinetic). With the introduction of FC systems with automatic tube loaders, we updated the FC-OFT protocol to follow the endpoint assay principle (FC-OFTEndpoint). This study aims to evaluate the updated FC-OFT protocol (FC-OFTEndpoint) and compare its assay performance with that of FC-OFTKinetic. We investigated factors influencing the FC-OFTEndpoint assay, optimized its protocol, and defined the cutoff index using 152 negative or artificially positive control samples. We then compared the assay performance with that of FC-OFTKinetic in 25 patients with anemia, including 14 with spherocytosis-8, 4, 1, and 1 with HS, autoimmune hemolytic anemia, burn injury, and liver cirrhosis, respectively. To optimize FC-OFTEndpoint, we adopted phosphate-buffered saline as the red cell suspension medium, 50% deionized water for hypotonic osmotic pressure in adults, and a 3-min standby time. This FC-OFTEndpoint was more accurate than FC-OFTKinetic in identifying spherocytosis in the 25 patients with anemia (p = 0.0313). FC-OFTEndpoint is a viable alternative to conventional OFT or FC-OFTKinetic for HS screening in clinical laboratories, as automatic FC enhances assay performance. These findings warrant validation in future multicenter studies with larger sample sizes.

Keywords: endpoint assay; flow cytometry; kinetic assay; osmotic fragility test

DOI: https://doi.org/10.1002/cyto.b.22254

Orphanet J Rare Dis. 2025 Oct 14. 20(1): 511

Ending diagnostic odyssey by reanalysis of whole exome sequencing data: reclassification of suspected Fanconi anemia cases to dyskeratosis congenita and Diamond-Blackfan anemia.

Eudald Tejero, María José Ramírez de Haro, Roser Pujol, Massimo Bogliolo, Benjamín Rodríguez-Santiago, Jordi Surrallés.

BACKGROUND: Initial Whole Exome Sequencing frequently fails to resolve rare disease cases. Bioinformatic reanalysis of existing genomic data utilizes advancing knowledge to enhance diagnosis without additional testing. This study investigated six patients with clinical features consistent with Fanconi Anemia but negative chromosomal breakage tests, whose initial genetic analyses were inconclusive.
RESULTS: Whole Exome Sequencing data from these patients (collected 2005-2009) underwent comprehensive reanalysis, including single nucleotide variants, insertions/deletions, and copy number variants across genes beyond those typically associated with Fanconi Anemia. Telomere length was assessed via monochrome multiplex quantitative PCR. Reanalysis identified clinically significant variants in two patients (33.3% yield): one harboured a heterozygous pathogenic loss-of-function variant in the Diamond-Blackfan anemia gene RPL5, while the second exhibited compound heterozygous variants in the TERT gene, indicative of dyskeratosis congenita.
CONCLUSIONS: This study underscores the clinical value of reanalyzing existing genomic data in unresolved suspected genetic disorders, even when phenotype-specific assays are negative. The 33.3% diagnostic yield aligns with gains from larger reanalysis studies (10-25%). Systematic reassessment after sufficient time (24 + months) for genomic advancements offers a cost-effective diagnostic approach for long-undiagnosed cases, highlighting the dynamic nature of genomic interpretation as gene-disease understanding evolves.

Keywords: Diamond-Blackfan Anemia; Dyskeratosis Congenita; Fanconi Anemia; RPL5; Rare Genetic Diseases; TERT; WES Reanalysis

DOI: https://doi.org/10.1186/s13023-025-03928-5

PeerJ. 2025 ;13 e20038

Genetic modifiers of response to thalidomide in transfusion-dependent beta-thalassemia patients: a whole-exome sequence analysis.

Waleed Mohammed Bawazir, Muhammad Ihtesham Khan, Mohannad Saeed Hazzazi, Ammar Abdullah Basabrain, Muhammad Tariq Masood Khan, Sami Siraj, Majed Naser Almashjary, Osman Radhwi, Steve Harakeh, Yasar Mehmood Yousafzai.

Background: Thalidomide induces fetal hemoglobin and renders most thalassemia patients transfusion-independent. Some patients, however, do not respond. Underlying genetic variations responsible for variable responses to thalidomide are unexplored.
Aims and objectives: To discover genetic variations that influence response to thalidomide in transfusion-dependent beta-thalassemia patients.
Methods: Twenty beta-thalassemia patients (14 excellent responders and six non-responders) who had received thalidomide were included in the study by a non-probability purposive sampling technique. Patients who showed a rise of >2 mg/dl in hemoglobin level and/or whose hemoglobin levels reached 9 gm/dl without blood transfusions were designated as excellent responders. Patients whose hemoglobin levels did not show an increment rise of >2 and/or whose hemoglobin levels did not rise above 5.9 gm/dl and needed blood transfusions to maintain optimal hemoglobin levels were designated as non-responders. DNA was extracted, and whole-exome sequencing was performed on an Illumina HiSeq System. Aligning and variant calling were done by the Sentieon software. Annotation was done by Annovar.
Results: The age of study participants ranged from 1-12 years, with a mean of 5.45 ± 3.81 years. There were 17 (85%) males and three (15%) females. A total of 222,180 germline variants were identified across 20 subjects, from which 24 candidate variants across 24 genes were identified. The three most common polymorphisms in the excellent responder group were found in the exon region of CHI3L1 (rs880633), NPNT (rs35132891), and ZNF 208 (rs10425763), which were found in 92%, 85%, and 71% cases, respectively. The commonest polymorphisms in the non-responder group were found in the PM20D1 gene (rs7518979), LGR6 (rs75658797), MYH15 (rs4299484), and RESF1 (rs3207618), each of which was found in 66.6% cases.
Conclusion: This study shows a significant association of single-nucleotide polymorphisms rs880633, rs35132891, and rs10425763 with excellent response status, while rs7518979, rs75658797, rs4299484, and rs3207618 are associated with non-response status.

Keywords: CHI3L1; LGR6; NPNT; Thalidomide; Transfusion dependent thalassemia; rs10425763; rs3207618; rs35132891; rs7518979; rs880633

DOI: https://doi.org/10.7717/peerj.20038