Our results indicate differences in early B-cell differentiation in Caucasians compared to Asians. Whether the markedly expanded proB cell pool in the BM of healthy Caucasians compared to Asians might be related to the strikingly higher incidence of CLL in the Caucasian population remains to be elucidated.
We hypothesize that higher numbers of proB cells might provide a higher chance to acquire pre-CLL specific mutations thereby increasing the statistical chance to develop CLL. Such a hypothesis might be supported by a recent study by Shukla et al. who showed that IRF4 deficient mice developed CLL, but only when the B1 cell population was genetically expanded.