Dr Sharman on Monoclonal B Lymphocytosis (MBL), a sometimes precursor to CLL

[AussieNeil]

In another informative and easy to understand blog, Dr Sharman discusses MBL, what it means to have it and how it is differentiated from CLL. This requires an explanation of cluster of differentiation (CD) markers and how Flow Cytometry is used to tell apart the different lymphomas and leukaemias by looking for tell tale CD marker patterns.

Anyone that has been recently diagnosed with a high lymphocyte count and is awaiting further testing will find this blog by Dr Sharman extremely relevant and helpful. At the end of his blog, he discusses his reasoning behind follow-up times for patients with abnormal lymphocyte blood counts.

cll-nhl.com/2013/07/monoclo...

A mechanism by which CLL develops via MBL is presented in this 2018 paper here:

haematologica.org/content/h...

There are some good references in this blog too, including:

- A guideline paper for MBL (Dr Sharman says that such papers are uncommon)

- How to read a flow cytometry or FISH report (50 minute video)

- How to understand your complete blood count (CBC), which I've added below

National Institutes of Health Education Paper on understanding your CBC

cc.nih.gov/ccc/patient_educ...

This paper also includes helpful information on how to live with neutropenia (low neutrophils), anaemia (low blood iron) and thrombocytopenia (low platelets).

Neil

[Cllcanada Top Poster CURE Hero]

Just wanted to mention, that the late Dr. Terry Hamblin was fairly involved in the early days of MBL, and his blog has a number of articles on this topic. May be of interest...

mutated-unmuated.blogspot.c...

[AussieNeil Administrator]

Dr Brian Koffman asked Dr. John Seymour of the Peter Mac in Melbourne, Australia to explain the basic concepts of MBL.

Takeaways:

- All cancer including CLL is clonal, in other worlds it is made up of identical cells.

- If one has ≥5,000 monoclonal B-cells that are typical of CLL, then chronic lymphocytic leukemia can be diagnosed.

- If one has < 5,000 the diagnosis is MBL or Monoclonal B-cell Lymphocytosis. (Or it could be the lymphoma form of CLL/SLL, Small Lymphocytic Lymphoma if there is nodal involvement - Neil)

- The clonal cells in both diagnoses are the same and the 5,000 value is admittedly arbitrary.

- MBL consist of two groups:

-- Low-count MBL has bloodB-cell counts <0.5x9 cells/liter.

-- High-count MBL has bloodB-cell counts ≥0.5x9/L but <5×109/L.

-- Low-count MBL does not progress to a malignant disease.

- - High-count MBL does at a rate of 1-2% per year.

- Both MBL and CLL patients have impaired immunity that puts us at a higher risk for infections and cancer.

- Even when diagnosed with CLL, many of us can have a normal life expectancy

Video interview can be viewed here: cllsociety.org/2019/10/e-r-...

Neil

[AnneeNor]

Thank you very clear explanation as so little is said about MBL