Immune Background Profiles Across B-cell Lymphoproliferative Disorders

IntroductionFlow cytometry is essential for the diagnosis and classification of B-cell chronic lymphoproliferative disorders (B-CLPDs), but routine assessment usually focuses on the clonal B-cell population.Background Tcell and natural killer (NK)-cell populations may also vary between subtypes and provide supportive immunological information.Peripheral blood and bone marrow samples should be analyzed separately because they represent biologically distinct compartments.This study compares the percentages and absolute counts of B cells, T cells, CD4-positive T cells, CD8-positive T cells, and NK cells across B-CLPD subtypes, with analyses stratified by sample type where appropriate. MethodsThe study included 210 newly diagnosed B-CLPD cases evaluated at the Department of Hematology, Sri Jayewardenepura General Hospital, Colombo, Sri Lanka, from July 2023 to December 2025.Diagnoses were based on morphology and multiparameter flow cytometric immunophenotyping.CD19+ B cells, CD3+ T cells, CD3+CD4+ T cells, CD3+CD8+ T cells, CD56+ NK cells, and the CD4/CD8 ratio were analyzed.Results were summarized using medians and interquartile ranges, and subtype differences were assessed using the Kruskal-Wallis test. ResultsOf the 210 cases, 181 were peripheral blood samples and 29 were bone marrow samples.In peripheral blood, B-cell, T-cell, and NK-cell measures differed significantly across B-CLPD subtypes.Significant differences were also observed in CD4+ T-cell count, CD4+ T-cell percentage, CD8+ T-cell count, and the CD4/CD8 ratio, whereas CD8+ T-cell percentage did not differ significantly.In the bone marrow, no significant subtyperelated differences were observed in the CD4/CD8-related measures examined. ConclusionB-CLPD subtypes show distinct immune profiles, particularly in peripheral blood.Routine lymphocyte subset data may provide useful supportive information during flow-cytometric assessment, although they should not replace established lineage-and subtype-specific diagnostic markers.