Differences in blast immunophenotypes among disease types in myelodysplastic syndromes: a multicenter validation...

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• Melodysplastic syndromes (MDS) are a group of clonal hematopoietic stem cell disorders.
• Understanding immunophenotypic differences is crucial for diagnosing and classifying MDS subtypes.
• Distinguishing between MDS and its transformation to acute leukemia (AL-MDS) requires precise diagnostic markers.

Purpose of the Study:

• To validate immunophenotypic differences in myelodysplastic syndromes (MDS) across disease grades using flow cytometry.
• To identify specific immunophenotypic markers associated with disease progression and transformation to acute leukemia transformed from MDS (AL-MDS).

Main Methods:

• A multicenter flow cytometry study involving 115 patients with MDS.
• Patients were categorized into three groups: low-grade MDS, refractory anemia with excess blasts, and AL-MDS.
• Analysis of immunophenotypes, including CD34(+) myeloblasts, CD7, CD15, CD34(+) B-progenitors, and granulocyte granularity.

Main Results:

• Immunophenotypes of CD34(+) myeloblasts showed increased immaturity with disease progression.
• CD7 expression increased, while CD15 expression decreased on myeloblasts as MDS progressed.
• Percentages of CD34(+) B-progenitors and granulocyte granularity decreased with advancing disease grade.
• Logistic regression identified myeloblast percentages, CD7, and B7-H1 expression on myeloblasts as independent predictors of AL-MDS.

Conclusions:

• Immunophenotypic analysis using flow cytometry can effectively track MDS disease progression.
• Specific changes in myeloblast immunophenotypes, including CD7 and CD15 expression, are associated with higher disease grades and transformation to AL-MDS.
• CD7 and B7-H1 expression on myeloblasts are significant independent markers for identifying AL-MDS patients.