Improved identification of clinically relevant Acute Leukemia subtypes using standardized EuroFlow panels versus...

Area of Science:

• Hematology
• Immunophenotyping
• Flow Cytometry

Background:

• Rare acute leukemia (AL) subtypes, such as blastic plasmacytoid dendritic cell neoplasm (BPDCN) and early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), present diagnostic challenges due to overlapping immunophenotypes with other poorly differentiated AL.
• Routine flow cytometry may misclassify or fail to detect these rare entities, leading to potential delays in appropriate treatment.
• Previous classifications of acute myeloid leukemia (AML)-M0, AML with minimal differentiation, and ambiguous lineage AL may obscure the presence of these distinct subtypes.

Purpose of the Study:

• To evaluate the efficacy of the standardized EuroFlow™ Consortium approach in accurately diagnosing rare AL subtypes, specifically BPDCN and ETP-ALL.
• To re-assess previously classified AL cases, including AML-M0 and ambiguous lineage AL, to identify potentially missed diagnoses of BPDCN and ETP-ALL.
• To determine if the EuroFlow™ method improves diagnostic accuracy and refines the classification of various acute leukemia entities.

Main Methods:

• Reanalysis of 49 banked cryopreserved AL samples using standardized EuroFlow™ Consortium flow cytometry panels.
• Application of target sequencing to identify common mutations within these rare AL subtypes.
• Comparative analysis of initial diagnoses versus diagnoses obtained through the standardized EuroFlow™ approach.

Main Results:

• Revised or refined diagnoses were established for 23 out of 49 cases (47%).
• Three cases of ETP-ALL and two cases of BPDCN were newly identified after reclassification.
• Additional findings included the identification of immature plasmacytoid dendritic cell/monocytic components in 12 AML cases, megakaryoblastic differentiation in one AML case, and precise maturation staging in five ALL cases.

Conclusions:

• The standardized EuroFlow™ Consortium approach significantly enhances diagnostic accuracy for acute leukemias, particularly for rare and challenging subtypes like BPDCN and ETP-ALL.
• This improved diagnostic capability can lead to more precise subtyping and potentially impact clinical treatment decisions for patients with acute leukemia.
• The study highlights the value of standardized protocols in overcoming limitations of routine flow cytometry for complex hematological malignancies.