Monoclonal B-Cell Lymphocytosis Among Egyptian Elderly Healthy Adults

Background: Monoclonal B-cell lymphocytosis (MBL) is a benign expansion of clonal B lymphocytes that can be found in the blood of healthy adults, and it has the potential for evolution to chronic lymphocytic leukemia (CLL). MBL is commonly found among elderly population. We aimed to study the frequency among 200 healthy elderly adults who were chosen from general practice, ophthalmology, gynecology, cardiology, dermatology, and orthopedic preoperative patients. The selected individuals had normal hematologic parameters with no evident history of malignant disease. Methods: Blood samples were collected on EDTA, the leukocytes were stained by CD5/CD19 and kappa/lambda/CD19, and then MBL cells were searched for using flow cytometry to detect CD19-positive B-cell population with abnormal kappa/lambda immunoglobulin light chain ratio (> 3 or < 0.3) or disease-specific immunophenotype (IPT), i.e., co-expression of CD5/CD19. Results: The frequency of MBL among the studied samples was 5.5% without significant difference between males and females. The detected frequency found may be related to the sensitivity of the method used. Higher frequencies may be detected if more colors were used to detect more antigens. Conclusion: The study suggested that MBL can be identified through routine hospital investigations among elderly subjects and that monoclonal proliferation of B lymphocytes can be detected in an increasing number depending on the progressive improvements in the flow cytometric techniques. J Hematol. 2016;5(2):54-59 doi: http://dx.doi.org/10.14740/jh269w