Classifying acute leukemia by immunophenotyping: a combined FAB-immunologic classification of AML

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• Accurate classification of acute leukemia is crucial for effective treatment.
• Traditional French-American-British (FAB) classification relies on morphology and cytochemistry, which can be inconclusive in some cases.

Purpose of the Study:

• To evaluate the utility of immunophenotyping in distinguishing and subtyping acute leukemia.
• To compare immunophenotypic findings with the FAB classification.

Main Methods:

• A panel of monoclonal antibodies and heteroantisera was used to immunophenotype 138 cases of acute leukemia.
• Immunophenotypes were correlated with FAB classification based on morphology and cytochemistry.

Main Results:

• Immunophenotyping successfully differentiated AML from ALL.
• It identified cases (22%) indeterminate by cytochemistry and mixed lineage phenotypes (13%).
• Over 80% of AML cases showed correspondence to FAB subtypes M1, M2, M4, and M5.

Conclusions:

• Immunophenotyping is valuable for acute leukemia classification, especially when cytochemistry is negative or inconclusive.
• A combined approach using morphology, cytochemistry, and immunophenotyping is recommended for optimal acute leukemia subtyping.