Spontaneous regression of chronic lymphocytic leukemia: clinical and biological features of 9 cases

We describe 9 CLL patients who underwent a spontaneous clinical regression. CD38 and ZAP-70 were negative in all cases. Immunoglobulin heavy chain variable region (IgVH) genes, mutated in all 7 evaluable patients, were restricted to the VH3 family in 6, with the usage of VH3-30 gene in 2. The light chain variable region genes were mutated in 6/8 cases, with the usage of Vκ4-1 gene in 3. Microarray analysis of CLL cells revealed a distinctive genomic profile. The number of activated T lymphocytes expressing IFN-γ, TNF-α and IL-4 was similar between CLL in spontaneous regression and healthy individuals. We compared gene expression profiles obtained from 4 cases of CLL who underwent spontaneous regression with that of 3 B-cells from healthy donors and 18 CLL cases with either stable or progressive disease.