The relative expression levels of CD148 and CD180 on clonal B cells and CD148/CD180 median fluorescence intensity ratios are useful in the characterization of mature B cell lymphoid neoplasms infiltrating blood and bone marrow – Results from a single centre pilot study

Introduction: The categorization of mature B cell neoplasms (MBN) infiltrating blood and bone marrow are met with difficulties. The inclusion of CD148 and CD180 in the routine flow cytometry/FCM panels has been suggested to refine the diagnosis. We studied the discriminatory ability of CD148 and CD180 median fluorescence intensity(MFI), CD148/CD180 ratio and their expression relative to T cells (CD148ab/T, CD180ab/T), neutrophils (CD148ab/gr, CD180ab/gr) and normal B cells (CD148ab/n, CD180ab/n) in the differentiation of mature B cell neoplasms (MBN) especially non‐chronic lymphocytic leukaemia (CLL). Methodology: The flow cytometric (FCM) expression of CD148 and CD180 was studied prospectively in 102 patients (non‐CLL; n = 72); diagnosed by a comprehensive panel of immunophenotypic and cytogenetic studies. The MFI and ratios were statistically compared across MBNs by Mann‐Whitney U test. Cut‐off values, sensitivity and specificity were calculated for significant parameters by receiver operator characteristic curve. Results: CD180MFI > 4.35 showed 100% sensitivity and 90.9% specificity for a diagnosis of marginal zone lymphoma (MZL) while, CD148/180 > 5.15 was 100% specific and 81.8% sensitive for lymphoplasmacytic lymphoma. CD148ab/T(>4.3; 100% specificity, 83.4% sensitivity) and CD148ab/gr(>1.1; 100% sensitivity, 90% sensitivity) were useful for differentiating blastoid‐mantle cell lymphoma/MCL from diffuse large B cell lymphoma; while CD148MFI (≥20.25), CD148ab/T(>3.35) and CD148ab/gr(>0.95) showed >90% specificity and sensitivity for distinguishing MCL from CLL. Pairwise analysis also showed a good discriminant function of various parameters for distinguishing SMZL from other MBNs like FL, MCL as well as CLL. Conclusions: The current study shows an excellent utility of CD148MFI, CD180MFI, their ratio and relative expression levels in the subcategorization of immunophenotypically related MBNs. [ABSTRACT FROM AUTHOR]