Precursor B-cell acute lymphoblastic leukaemia-a global view

Evaluation of Acute Leukaemias by Flow Cytometry and Its Correlation With Diagnosis Using Morphological and Special Staining Techniques

BACKGROUND

Leukaemia can be reliably diagnosed and classified by the simultaneous application of multiple techniques. Cytochemical stains that are cheap and do not require any special instruments are very important in developing countries for the diagnosis of acute leukaemia (AL).

AIM

To diagnose AL in all suspected cases by flow cytometry and to correlate the diagnosis with morphological and special staining like myeloperoxidase (MPO) and periodic acid-Sciff (PAS) techniques.  Methods and materials: The study participants' peripheral blood smear details and bone marrow aspirate smear morphologic findings, as well as socio-demographic information, were taken from the patients' medical files. In total, 57 newly diagnosed instances of acute leukaemia confirmed by flow cytometry were incorporated into the study, which underwent cytochemical labeling and morphological diagnosis. All patients who gave previous consent had their bone marrow aspirated, and a Wright-stained smear was produced for microscopic inspection, cytochemical staining, and immunophenotyping. In an ethylenediaminetetraacetic acid (EDTA) container, peripheral blood was also drawn for the same purpose. During the entire bone marrow smear examination, we used both MPO and PAS staining techniques.

RESULTS

 The study was carried out between July 2019 and June 2020. Out of 57 cases in the study, 29 (50.9%) cases on cytochemical analysis of leukaemia using PAS and MPO were diagnosed with acute myeloid leukaemia (AML) and 28 (49.1%) were diagnosed as acute lymphoid leukaemia (ALL). Cytochemical analysis of leukaemia using PAS and MPO rendered the diagnosis in 92.9% of acute leukaemia cases in our study. A total of 25 out of 25 AML cases and 28 out of 32 cases of ALL were correctly diagnosed based on morphology and cytochemical staining. Morphology and cytochemical analysis alone were unable to correctly diagnose a total of four ALL cases. All AML cases that were wrongly diagnosed as ALL were mostly M0 and M1-AML.

CONCLUSION

Morphological staining diagnosis by itself is capable of correctly identifying a large proportion of cases of AL, which comprised 92.98% of total cases. There was also a favorable relationship between findings of diagnosis by flow cytometry and findings of diagnosis by morphology assessment in determining acute leukaemias.

Rounding off our Global View series

In this issue, we publish the last instalment in our series 'Global View' within the 'Wider Perspective' umbrella. In it we query experts from a variety of countries-deliberately trying to encompass both those with strained economies as well as more affluent ones-as to how patients are handled within such widely varying health systems. Commentary on: Hokland et al. AML in the elderly-A global view. Br J Haematol 2023;203:760-773.

Single-cell transcriptome analysis profiles the expression features of TMEM173 in BM cells of high-risk B-cell acute lymphoblastic leukemia

BACKGROUND

As an essential regulator of type I interferon (IFN) response, TMEM173 participates in immune regulation and cell death induction. In recent studies, activation of TMEM173 has been regarded as a promising strategy for cancer immunotherapy. However, transcriptomic features of TMEM173 in B-cell acute lymphoblastic leukemia (B-ALL) remain elusive.

METHODS

Quantitative real-time PCR (qRT-PCR) and western blotting (WB) were applied to determine the mRNA and protein levels of TMEM173 in peripheral blood mononuclear cells (PBMCs). TMEM173 mutation status was assessed by Sanger sequencing. Single-cell RNA sequencing (scRNA-seq) analysis was performed to explore the expression of TMEM173 in different types of bone marrow (BM) cells.

RESULTS

The mRNA and protein levels of TMEM173 were increased in PBMCs from B-ALL patients. Besides, frameshift mutation was presented in TMEM173 sequences of 2 B-ALL patients. ScRNA-seq analysis identified the specific transcriptome profiles of TMEM173 in the BM of high-risk B-ALL patients. Specifically, expression levels of TMEM173 in granulocytes, progenitor cells, mast cells, and plasmacytoid dendritic cells (pDCs) were higher than that in B cells, T cells, natural killer (NK) cells, and dendritic cells (DCs). Subset analysis further revealed that TMEM173 and pyroptosis effector gasdermin D (GSDMD) restrained in precursor-B (pre-B) cells with proliferative features, which expressed nuclear factor kappa-B (NF-κB), CD19, and Bruton's tyrosine kinase (BTK) during the progression of B-ALL. In addition, TMEM173 was associated with the functional activation of NK cells and DCs in B-ALL.

CONCLUSIONS

Our findings provide insights into the transcriptomic features of TMEM173 in the BM of high-risk B-ALL patients. Targeted activation of TMEM173 in specific cells might provide new therapeutic strategies for B-ALL patients.

Treatment of Ph-Negative Acute Lymphoblastic Leukemia in Adolescents and Young Adults with an Affordable Outpatient Pediatric Regimen

BACKGROUND

B-cell acute lymphoblastic leukemia is frequent in Hispanic adolescents and young adults. Outcomes of implementation of pediatric-inspired regimens in low-and middle-income countries are not well known.

METHODS

In this study we treated 94 adolescents and young adults with a local BFM regimen designed to be affordable with the use of native L-asparaginase and mitoxantrone administered in an outpatient fashion, and the of BCR/ABL and measurable residual disease (MRD) determined by high sensitivity flow cytometry for risk stratification.

RESULTS

Induction mortality was 11%; 25% of patients had to abandon treatment or be transferred to another health system. Two-year overall (OS) and event free survival (EFS) were 61.5% and 49.8%, MRD-negative patients had a 24-month OS of 85.6% vs. 69.6% (p = .024) and EFS of 76% vs. 45.5% (p = .004). Patients older than 40 years and those who abandoned treatment had worse EFS. Overall drug costs in our regimen were 52% lower than those of CALGB10403.

CONCLUSION

The treatment of AYAs with ALL with an outpatient focus was implemented successfully at a reduced cost. Genetic risk assessment, treatment abandonment and lack of access to novel therapies remain major barriers for improving outcomes.

Diagnosis and treatment of acute lymphoblastic leukemia in Latin America

OBJECTIVE

to discuss the status and challenges associated with the management of acute lymphoblastic leukemia (ALL) in Latin America.

METHODS

This review summarizes various insights gained from information regarding diagnostic approaches and treatment strategies in adult patients with ALL in Latin American Countries.

RESULTS

Information regarding ALL in Latin America is scarce; however, many efforts have been made to overcomes these barriers. Nevertheless, major obstacles to successful treatment in Latin America and LMIC remain poor adherence, abandonment of treatment, and lack of supportive therapy and new therapeutic agents.

CONCLUSION

Further improvements in survival should be pursued by developing more Latin American registries, forming cooperative groups, developing educational models to facilitate earlier diagnosis and prevention of complications, better support therapy and management of infections, and adapting treatment strategies.