International journal of laboratory hematology最新文献

Introduction: Elevated vitamin B12 concentration can be caused by supplementation, liver disease, kidney disease, or myeloid malignancies. Persistent, unexplained elevations of vitamin B12 can raise concern among patients and may lead to invasive diagnostic procedures, including bone marrow biopsy. A potential benign cause of this elevation is macro-B12, a complex of vitamin B12, transcobalamin, and immunoglobulins. Although not bioactive, this complex can cause elevated plasma vitamin B12 concentrations due to reduced clearance.

Methods: Polyethylene glycol (PEG) precipitation is a laboratory technique that can be used to support the suspicion of macro-B12. Here, a case is described in which a PEG precipitation could potentially have prevented an unnecessary bone marrow biopsy. In addition, the presence of macro-B12 was studied in a group of patients with and without myeloid malignancies.

Results: Macro-B12 was identified in 24% of 72 individuals with vitamin B12 > 1476 pmol/L. In one of these patients, a functional vitamin B12 deficiency was confirmed by an elevated methylmalonic acid (MMA) concentration. Macro-B12 was not detected in 8 patients with a myeloid malignancy.

Conclusion: These findings suggest that, in patients with persistently elevated vitamin B12 concentrations and a low suspicion of a myeloid malignancy, PEG precipitation may help to explain the elevated vitamin B12 and prevent unnecessary diagnostic procedures including bone marrow punctures.

Vacuoles in hematopoietic cell precursors have garnered significant attention in recent years due to their association with a newly characterized clonal hematopoiesis with acquired mutations of ubiquitin like modifier activating enzyme 1 (ubiquitin-activating enzyme E1, UBA1) gene associated with clinical systemic autoinflammatory manifestations, known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. The cytomorphologic hallmark of this rare disorder is vacuolization involving the granulocytic and erythroid precursors. While affected vacuolated cells are seen in most patients, the mere presence of such is not entirely specific for VEXAS syndrome; therefore, an aggregate of clinicopathologic correlates is needed to help distinguish VEXAS syndrome from morphologic mimics and prompt appropriate confirmatory genetic testing. Vacuolated hematopoietic cells could be seen in varied reactive conditions and neoplastic and nonneoplastic hematologic disorders and affect different lineages and cell types. This article aims to review the spectrum of vacuolated hematopoietic cells and their disease-association including VEXAS syndrome, among others.

Background: Accurate classification of novel globin gene variants is critical for the diagnosis and management of thalassaemia. The adaptation of ACMG/AMP guidelines for globin genes represents an important step toward standardising variant interpretation and enhancing clinical utility in the field. This study reports the haematological and molecular characteristics of a novel α2-globin variant identified in a Malay family.

Methods: A Malay family from Taiping, Perak, Malaysia, with a history of α-thalassaemia, was recruited for this study. The proband's phenotype was assessed through comprehensive haematological analysis and clinical evaluation. Known α-thalassaemia deletions and non-deletional mutations were screened using gap-PCR and ARMS-PCR. Sanger sequencing of the HBA genes was conducted to characterise the proband's genotype in detail.

Results: A novel pathogenic HBA2 variant was identified, expanding the known mutational spectrum of α-thalassaemia. This variant introduces a premature stop codon, occurs in trans with a known pathogenic allele associated with a significant clinical phenotype, segregates with the disease in the family, and is absent from major population databases. Based on haematological data, molecular findings, in silico predictions, and protein modeling, the variant meets the ACMG/AMP criteria for pathogenicity adapted for α-globin genes. We have designated this variant Hb Taiping, named after the location of its discovery. Its accurate classification is vital for carrier screening, genetic counselling, and prenatal diagnosis, thereby supporting improved clinical management.

Conclusion: This study identifies and characterises a novel α-globin gene variant, Hb Taiping, in a Malay family with α-thalassaemia. The discovery contributes to the growing body of pathogenic mutations linked to α-thalassaemia and underscores the importance of precise variant classification for effective diagnosis, risk assessment, and genetic counselling.

Introduction: Minimal/measurable residual disease (MRD) is a key prognostic factor in B-lymphoblastic leukemia/lymphoma (B-ALL/LBL), commonly assessed via multiparametric flow cytometry (MFC). This study evaluated 12 leukemia-associated immunophenotype (LAIP) markers-CD81, CD86, CD123, CD58, CD9, CD73, CD13/CD33, CD44, CD97, CD66c, CD49f, and CD304-to determine their suitability for MRD detection.

Methods: Marker expression was analyzed in 103 B-ALL cases at diagnosis, and 54 post-therapy follow-up samples, including 16 MRD-positive cases. Additionally, 25 non-B-ALL bone marrow samples were examined for marker expression in hematogones. Clinical and genetic correlation was also performed.

Results: Median age of patients was 9 years (range: 0.3-89), with male: female ratio of 1:1. We found that CD97, CD73, CD86, and CD58 are excellent markers for MRD analysis in B-ALL, as they are expressed in more than 85% of cases at baseline, and their expression is preserved in more than 75% of cases post-therapy. Two other extremely promising markers are CD81 and CD49f, both of which are expressed as LAIP in more than 50% of B-ALL cases, with retention of expression in more than 85% of cases post-therapy, and importantly, expression as LAIP in some post-therapy samples despite their absence at baseline. Hyperdiploidy was significantly associated with expression of CD86, CD97, CD123, CD66c, and CD9; BCR::ABL1 fusion was associated with CD49f, CD81, and CD66c.

Conclusion: CD97, CD73, CD86, and CD58 are the best amongst newer markers in B-ALL MRD assessment. Our findings support integrating these into MRD panels to enhance post-therapy MRD detection, thus improving prognostication and guiding treatment decisions.

CBL syndrome is caused by a heterozygous germline mutation in the CBL gene. It is a rare RASopathy that shares many clinical features with mild forms of Noonan syndrome. These patients have a higher risk of developing juvenile myelomonocytic leukaemia (JMML) during early childhood. Here we report a case of an 11-month-old infant with JMML and CBL syndrome. It was caused by a heterozygous de novo germline mutation in the CBL gene and acquired biallelic inactivation of the gene through copy-neutral loss of heterozygosity (CN-LOH) in haematological cells. CBL mutation was not found in parents and siblings. CN-LOH was confirmed by single nucleotide polymorphism array. This patient presented with an aggressive clinical course and required an allogeneic stem cell transplant.

Background: Direct oral anticoagulants (DOACs) have simplified anticoagulant therapy, but plasma level testing (i.e., anti-Xa and anti-IIa activities) remains important in specific clinical situations (e.g., emergency surgery, bleeding, renal impairment, or suspected non-adherence). However, the impact of sample storage on assay reliability is not well defined. This study evaluated the stability and potential systematic errors in DOACs (apixaban, rivaroxaban, edoxaban, dabigatran) plasma levels after 24 h storage under different conditions.

Methods: We enrolled 182 patients on one of the four DOACs. Blood samples were collected in duplicate citrated tubes. The first tube was processed within 4 h to obtain baseline values, with plasma successively stored at room temperature, 4°C, and -20°C for 24 h. The second tube was stored as whole blood at room temperature before measuring DOACs concentrations. DOACs were measured using dedicated clotting or chromogenic assays. Stability was assessed using non-parametric statistics, Passing-Bablok regression, and Bland-Altman analysis, with Acceptable Change Limits based on assay variability.

Results: All DOACs showed good stability across conditions, with median recoveries ranging from 93% to 102%. No significant proportional errors were observed. Minor constant biases were observed for apixaban (at 4°C and -20°C), and more consistently for rivaroxaban and edoxaban. Dabigatran showed no significant bias. Variability was generally low (< 7%), and most measurements near clinical thresholds remained accurate.

Conclusion: DOACs plasma levels remain stable after 24 h storage under various conditions. While minor biases exist, particularly for rivaroxaban and edoxaban, they are unlikely to affect clinical interpretation in most cases. Whenever needed, DOACs measurement can be deferred after blood drawing without jeopardizing results interpretation.

Introduction: Erythrocyte sedimentation rate (ESR) is a widely used inflammation marker. VISION Pro (Shenzhen YHLO Biotech Co. LTD, Shenzhen, China) is a fully automated ESR analyzer. This study verified its analytical performance and comparability to the manual Westergren method.

Methods: Inter- and intra-run precision study was assessed using control and patient samples at low, medium, and high ESR levels. Accuracy was evaluated by comparing 240 K₂EDTA (ethylenediaminetetraacetic acid) whole blood samples with the Westergren method in citrate divided by ESR subgroups (< 40, 40-80, > 80 mm). Sample stability was tested in 8 samples at room temperature and 2°C-8°C over 24 h. Reference range verification included 40 healthy individuals (20 male, 20 female). The effects of testing order for ESR and complete blood count (CBC) (ESR/CBC/ESR vs. CBC/ESR/CBC) and analysis modes (Cycle, Random, Mixer+Random) were also explored.

Results: Inter- and intra-run precision were acceptable at medium and high ESR levels without temperature correction, while low levels exceeded acceptable criteria (e.g., CV = 24.4% vs. criterion 11.3%). Agreement with Westergren was excellent, with no significant differences (intercept = 1.1 [95% CI: 0.0-1.4]; slope = 1.0 [95% CI: 0.9-1.0]), while temperature-corrected results showed unsatisfactory agreement (intercept = -0.1 [95% CI: -0.7 to 0.4]; slope = 0.8 [95% CI: 0.7-0.8]). Sample stability was maintained for up to 3 h at room temperature and up to 10 h at 2°C-8°C. Reference range verification demonstrated all 20 samples within limits for men and 19/20 for women, while only 17/20 for temperature-corrected results for women. ESR/CBC/ESR order minimally affected the results (14/15 acceptable), while CBC/ESR/CBC order influenced CBC parameters (predominantly MPV). No significant differences occurred between measurement modes (p = 0.093).

Conclusion: VISION Pro analyzer demonstrated acceptable ESR measurement performance without temperature correction and is suitable for routine laboratory use. Temperature-corrected results showed inconsistent performance and require cautious interpretation.