17p deletion and atypical flow cytometry profiles in chronic lymphocytic leukemia: correlation to clinical outcomes, single-center Egyptian study

Introduction
Chronic lymphocytic leukemia (CLL), a prevalent B-cell malignancy in older adults, demonstrates heterogeneous progression patterns, ranging from indolent to aggressive disease. It originates from clonal B cells with CD5 and other B-cell markers. Cytogenetic and molecular traits of CLL can predict patient outcomes and guide initial treatment. This study used fluorescence in situ hybridization to detect chromosome 17p deletion and analyze its correlation with immunophenotypic markers and their impact on disease progression or treatment response.


Patients and methods
Using a BD FACSCanto II Flow Cytometer, we studied B-cell markers in B cells in peripheral blood obtained from 68 newly diagnosed adult CLL patients. The immunophenotyping profile classified patients into typical and atypical CLL groups. Interphase fluorescence in situ hybridization was performed on the samples.


Results
17p deleted CLL patients presented more with B symptoms, had higher total leukocyte count, higher absolute lymphocytic count, lower platelet count at diagnosis, presented more with diffuse bone marrow infiltration, and had shorter lymphocyte doubling time. Atypical CLL patients presented with advanced stage had a higher percentage of B symptoms, higher total leukocyte count, higher absolute lymphocytic count, elevated lactate dehydrogenase, and shorter lymphocyte doubling time.


Conclusion
Patients with a deletion of the short arm of chromosome 17 (17p deletion) face a high-risk clinical course and poor treatment response. Atypical CLL patients show specific immunophenotyping profiles and worse disease characteristics compared to typical CLL patients, but this distinction does not impact treatment prognosis, unlike the 17p deletion.