Clinical Monoclonal B lymphocytosis versus Rai 0 Chronic Lymphocytic Leukemia: a comparison of the cellular, molecular, cytogenetic features and clinical course in a prospective multicenter study [mRNA]

Prospective series of 136 clinical monoclonal B lymphocytosis (cMBL) and 216 chronic lymphocytic leukemia (CLL) Rai 0 patients, were investigated in this study. While the distribution of CD38 and ZAP-70 positivity was similar, IGHV-mutated cases were more frequent among cMBL (P = 0.005). A Cox multivariate analysis on the whole patient cohort showed that cMBL condition was predictive of longer PFS, while CD38 expression and IGHV-unmutated status and CD38 expression correlated significantly with a shorter PFS in cMBL and Rai0-CLL, respectively. Trisomy 12, 11q- and 17p- abnormalities were scanty and of no predictive value in both conditions. Notably, gene and miRNA expression profiling showed no significant differences between cMBL and Rai0-CLL. Furthermore, similar gene and miRNA expression signatures were found in cMBL and Rai0-CLL according to the IGHV gene mutational status: that is, unmutated cases had different signatures from mutated cases, irrespectively of the cMBL or CLL condition. Overall, our study based on a prospective series of patients indicates that no major biological differences exist in cMBL compared to Rai0-CLL, suggesting that this two entities mainly differ for the initial size of the monoclonal cell population which may reflect in the longer time for clonal expansion.

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Morabito F, Mosca L, Cutrona G, Agnelli L, Tuana G, Ferracin M, Zagatti B, Lionetti M, Fabris S, Maura F, Matis S, Gentile M, Vigna E, Colombo M, Massucco C, Recchia AG, Bossio S, De Stefano L, Ilariucci F, Musolino C, Molica S, Di Raimondo F, Cortelezzi A, Tassone P, Negrini M, Monti S, Rossi D, Gaidano G, Ferrarini M, Neri A