Z. Saouli (1), C. Savopoulos (1), Z. Kontoninas (1), V. Garypidou (2), S. Vakalopoulou (2), A. Hatzitolios (1), A. Papadopoulos (1) , G. Kaiafa (1)
(1) 1st Propedeutic Dept of Internal Medicine, Aristotle University of Thessaloniki, AHEPA University Hospital, Thessaloniki, Greece
(2) 2nd Propedeutic Dept of Internal Medicine, Aristotle University of Thessaloniki, Hippokratio Hospital, Thessaloniki, Greece
The diagnostic term monoclonal B-cell lymphocytosis (MBL) is used to characterise individuals with a circulating population of clonal B-cells, a total B-cell count of 9/L, and no other features of a B-cell lymphoproliferative disorder. In the recent literature, it has been reported that circulating chronic lymphocytic leukemia (CLL) –like B cells can be detected using multicolor flow cytometry in 0,57%-12% of adults with normal lymphocyte counts.
As far as we know, this is the first study in Greek population, investigating the frequency of circulating monoclonal B cells in 815 healthy blood donors, aged 30-70 years, with no evident history of malignant disease and normal blood counts, who provided signed informed consent. We used flow cytometric analysis of CD19/CD5/CD79b/CD20/CD23/CD38 expression, while other parameters, such as LDH, beta-2 microglobulin and C reactive protein were measured. Monoclonality was demonstrated by immunoglobulin light-chain restriction in all cases with CLL phenotype cells.
The monoclonal CLL phenotype cells were detected in 1,6% of individuals, with a higher frequency in men (male-to-female ratio 1.2:1) and elderly individuals (1.9% of 40- to 59-year-old versus 4.0% of 60- to 89-year-old, P = 0.01), which is within the framework of international studies.
Our study shows that a healthy percentage of the population in Greece , equal to 1.6% is bearing cells with CLL immunophenotype. The use of more extensive immunophenotype-order control and control of clonality seems to be a valuable prognostic factor for the occurrence of monoclonal lymphocytosis, which may potentially evolve into B-CLL over time. Furthermore, it is of great importance monitoring of these patients over time.