Somatic hypermutation (SHM) is an important step in antigen-driven B cell development creating B lymphocytes expressing high-affinity antibody receptors. It is known that the peripheral B lymphocyte compartments of healthy children and adults differ considerably. However, the development of SHM with age has not been studied in detail previously. Therefore, we used the immunoglobulin (Ig)κ-restriction enzyme hot-spot mutation assay (Igκ-REHMA) to gain an estimation of SHM levels in different age groups in order to relate this to the size of the memory B lymphocyte subpopulations. We show that the level of SHM increases rapidly during the first 2 years of life. This reflects the changes of the memory B cell subpopulations, but also changes in the SHM within memory B cell subsets, probably reflecting an increase of secondary memory B cell responses.
Schatorjé, E. J., Driessen, G. J., van Hout, R. M. W. M., van der Burg, M., & de Vries, E. (2014). Levels of somatic hypermutations in B cell receptors increase during childhood. Clinical and Experimental Immunology, 178(2), 394-398. https://doi.org/10.1111/cei.12419