ERIC 2020 | Monoclonal B-cell lymphocytosis is on the road to CLL: always?

In my talk, I discuss a condition that was actually quite recently identified, called monoclonal B-cell lymphocytosis. And let’s say that in the last 15 years, we understood more about this condition that is defined by the presence of CLL like cells, so very close to the leukemic B cells in patients with chronic lymphocytic leukemia, but below the threshold used to define the diagnosis of chronic lymphocytic leukemia. And this condition can be actually identified in different contexts. In general population study, meaning healthy individuals who were recruited and donate blood to perform laboratory tests that we could identify this condition in up to 12% of the general population, but the clonal size was very, very low. The tiny clones can be identified and it is not clear if they carry a risk to progress to CLL at any time point during the observation, because it was never demonstrated.

While investigating individuals who were getting medical attention because of the presence of lymphocytosis that they blood test, we identify a so-called high-count monoclonal B-cell lymphocytosis, so high-count MBL, and this condition is actually a [inaudible 00:01:49] condition that carries a risk to progression of full-blown CLL, requiring treatment of about 1, 2%, per year. So individuals identified with high-count MBL should be monitor over time because there is a risk, though small, to develop full-blown disease requiring treatment. But this condition are also relevant to better understand the mechanism behind the occurrence of CLL and some clinical manifestations associated with CLL, like the increased risk of infections and the risk of other malignancies. So either say they are useful both to understand the CLL pathogenesis and to better identify individuals who would have the regular follow-up because they are at higher risk of progression and developing disease-related manifestation, and therefore require treatment.