Our findings show that virtually all cases of CLL (both with mutated genes and unmutated genes) are preceded by MBL. It is also interesting to note that both indolent disease (stage 0 or I) and more aggressive disease (stage II or III) showed evidence of a prediagnostic clone up to 3 years before the diagnosis of CLL. However, because the distribution of unmutated genes, as compared with mutated genes, was somewhat lower (23%) than distributions reported previously (35 to 40%),34 one might speculate that there are more aggressive CLL cases that present de novo without being preceded by MBL. Alternatively, our findings might reflect the ratio between unmutated and mutated genes in a nonclinic-based population of patients with CLL.
