Intensity of antigen expression reflects IGHV mutational status and Dohner-defined prognostic categories in chronic lymphocytic leukemia, monoclonal B-cell lymphocytosis, and small lymphocytic lymphoma

We demonstrate the prognostic utility of antigen quantitation in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and monoclonal B-cell lymphocytosis (MBL). Median antibody-bound-per-cell (ABC) of CD20, CD22, CD25, CD19, and %CD38(+) was determined in CLL (185/208), SLL (8/208) and MBL (15/208) cases by flow cytometry, then compared to Dohner-classification, immunoglobulin status (mutated, IGHV-M; unmutated, IGHV-U), CLL-IPI risk and time to first treatment (TTFT). Trisomy 12 cases showed increased %CD38-expression (p =.0379). Higher %CD38 was observed in IGHV-U versus IGHV-M (p =.0003). CD20ABC was increased in IGHV-U versus IGHV-M (p =.006). Del13q cases demonstrated lower CD22ABC (p =.0198). Cases without cytogenetic abnormality exhibited higher CD19ABC (p =.0295) and CD22ABC (p =.0078). Del17p cases demonstrated lower CD25ABC (p =.0097). High and very-high CLL-IPI risk groups were associated with high CD38-expression (p =.02) and low CD25ABC (p =.0004). Shortened TTFT was associated with high CD38-expression (p <.0001). Interestingly, high CD25ABC trended toward shortened TTFT (p =.07). Quantitative antigen expression reflects CLL-IPI risk groups and Dohner-classification.