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Monoclonal B-cell lymphocytosis: recommendations from the Dutch Working Group on CLL for daily practice
G D te Raa1, M H van Oers, A P Kater
1Department of Haematology, Academic Medical Centre Amsterdam, the Netherlands.
Insights
Monoclonal B-cell lymphocytosis (MBL) affects 3-5% of individuals over 40. While often asymptomatic, MBL can progress to chronic lymphocytic leukemia (CLL), necessitating careful monitoring and management strategies.
Area of Science:
- Hematology
- Oncology
- Immunology
Background:
- Monoclonal B-cell lymphocytosis (MBL) is characterized by small B-cell clones in asymptomatic individuals.
- MBL can present with a chronic lymphocytic leukemia (CLL) phenotype, atypical-CLL phenotype, or non-Hodgkin lymphoma phenotype.
- The prevalence of MBL in individuals over 40 is 3-5%, with a 1-2% annual risk of progression to CLL requiring treatment.
Purpose of the Study:
- To define Monoclonal B-cell lymphocytosis (MBL).
- To highlight the clinical consequences of MBL.
- To offer recommendations for the daily practice and management of MBL.
Main Methods:
- Literature review on MBL definitions, prevalence, and progression.
- Analysis of clinical data for MBL patients.
- Development of management guidelines based on available evidence.
Main Results:
- MBL is defined by the presence of B-cell clones, commonly with a CLL phenotype.
- A significant percentage of MBL cases may progress to CLL requiring treatment.
- Current official guidelines for MBL management are lacking in the Netherlands.
Conclusions:
- Individuals with suspected MBL require hematologist evaluation.
- CLL phenotype MBL may be managed with annual follow-up by general practitioners, with referral if progression occurs.
- Clear management recommendations are crucial for MBL patients to ensure timely intervention and prevent complications.
Abstract:
Monoclonal B-cell lymphocytosis (MBL) is defined by the presence of small B-cell clones in asymptomatic individuals. Usually, MBL cells are characterised by a chronic lymphocytic leukaemia (CLL) phenotype ('CLL phenotype MBL'); however, an atypical phenotype ('atypical-CLL phenotype MBL') or non-Hodgkin lymphoma phenotype ('non-CLL phenotype MBL') can be found as well. The prevalence of MBL in the general population with an age over 40 years is 3 to 5%. Subjects with MBL develop CLL requiring treatment at a rate of 1 to 2% per year. At the moment official guidelines with respect to MBL are not available in the Netherlands. On the basis of the available data, we will discuss the definitions of MBL , highlight clinical consequences and offer recommendations for daily practice. Individuals with clinically suspected MBL should undergo a complete evaluation by a haematologist. In case of CLL phenotype MBL , further annual follow-up can take place by the general practitioner. If signs of progression occur patients should be referred to a haematologist.
