Side scatter versus CD45 flow cytometric plot can distinguish acute leukaemia subtypes

Area of Science:

• Hematology
• Immunophenotyping
• Diagnostic Cytometry

Background:

• Flow cytometry is crucial for diagnosing acute leukaemia.
• Minimizing antibody panels for leukaemia subtyping is an ongoing research area.
• Differentiating acute myeloid leukaemia (AML) from acute lymphoblastic leukaemia (ALL) is critical for treatment.

Purpose of the Study:

• To evaluate the diagnostic utility of side scatter (SSC) versus CD45 flow dot plots.
• To determine if minimal immunological markers can differentiate AML from ALL.
• To assess the morphometric analysis of blast clusters for leukaemia subtyping.

Main Methods:

• Analyzed 100 acute leukaemia cases using SSC vs. CD45 plots.
• Evaluated blast cluster parameters: shape, CD45/SSC expression, continuity, and width-to-height (w/h) ratio.
• Utilized morphology, cytochemistry, and immunophenotyping for definitive diagnosis.
• Applied statistical tests and Receiver Operating Characteristic (ROC) curves to determine the optimal w/h ratio cut-off.

Main Results:

• Diagnosed 57 ALL and 43 AML cases.
• Median w/h ratio was 3.8 for ALL and 1 for AML (P<0.001).
• ROC analysis yielded an area under the curve of 0.9772.
• Optimal w/h ratio cut-off for distinguishing ALL from AML was 1.6.

Conclusions:

• A w/h ratio < 1.6 on SSC vs. CD45 plots suggests AML.
• A w/h ratio > 1.6 on SSC vs. CD45 plots suggests ALL.
• Morphometric analysis of blast clusters on SSC vs. CD45 plots effectively distinguishes ALL from AML and their subtypes.