Evaluation framework for monoclonal B-cell lymphocytosis.

Abstract

e22571 Background: Monoclonal B cell lymphocytosis (MBL) is recognized as a precursor to chronic lymphocytic leukemia (CLL). There is an ongoing debate over whether MBL represents a benign, senescent condition or warrants further investigation and monitoring for potential progression. The natural history of MBL remains under scrutiny, and the need for surveillance in patients with incidental findings or familial risk factors is also being evaluated. Methods: We performed a systematic literature search using Web of Science and Science Direct databases to identify relevant studies. Our search using the term 'monoclonal B-cell lymphocytosis progression and monitoring' identified 844 documents. We selected articles if they were written in English and addressed monitoring or disease progression. Articles were excluded if published in other languages, were opinion pieces, or focused on treatment. Results: Our literature review identified 18 articles for qualitative analysis. These articles highlighted the importance of monitoring and assessing disease progression in MBL. Six articles examined the natural history of MBL, including its temporal behavior and progression to CLL requiring treatment. Four articles reported outcomes from patient cohorts monitored for 5 to 10 years. Five articles evaluated biomarkers, including genetic markers, imaging modalities, and cell counts, for their predictive value for disease progression and timing. Three articles provided specific monitoring recommendations, indicating that surveillance strategies should be based on whether MBL cell counts are classified as low or high. High MBL counts are associated with a 1-2% annual risk of progression, and annual clinical follow-up is recommended, including laboratory tests such as complete blood count (CBC), Fluorescence in situ hybridization (FISH), and assessment of markers such as immunoglobulin heavy-chain variable region (IGHV). The presence of IGHV was associated with a shorter time to first treatment. Emergence of new genetic mutations and deletions on chromosomes 17p or 11q were identified as potential indicators of progression. Physical examination remains essential for detecting B symptoms and increased infection frequency, which serve as indicators for further diagnostic evaluation. Conclusions: The literature review and qualitative analysis provide a comprehensive understanding of MBL indicating that high-risk MBL requires more extensive monitoring given progression risk. Progression occurs in approximately 1-2% of patients with high-count MBL. Longitudinal studies recommend monitoring these patients every 6 to 12 months, with baseline assessments including CBC, immunophenotyping, and a physical examination based on the 18 articles analyzed. Future research into timing and frequency of testing prognostic markers such as IGHV status and FISH is desired and would better define this condition and patients at higher risk of progression.