Telomere length identifies two different prognostic subgroups among VH-unmutated B-cell chronic lymphocytic leukemia patients.

ABSTRACT

Some evidences suggest that telomere restriction fragment length (TRF-L) is an effective indicator of histopathogenesis in B-cell tumors. As histopathogenesis is relevant for B-cell chronic lymphocytic leukemia (B-CLL) prognosis, TRF-L was assessed by Southern blot in 201 patients and compared to variable immunoglobulin heave chain gene mutational status (VH-MS) and to other known prognostic features. Overall survival (OS), time to first treatment (TTFT) and progression-free survival (PFS) were evaluated. Our results indicate the following (1) TRF-L is heterogeneous among B-CLL patients (median 6014 bp, range 1465-16 762); (2) TRF-L correlates to VH-MS (r(2)=0.1994, P<0.0001) with VH-mutated patients showing long and VH-unmutated short telomeres; however, 41% of VH-unmutated and 5% of VH-mutated patients did not show this correlation and were thus defined as 'discordant'; (3) TRF-L effectively predicts outcome in terms of TTFT, PFS and OS; (4) VH-unmutated discordant patients have a better clinical outcome than VH-unmutated concordant patients (OS P<0.01, PFS P<0.05) and similar to that of VH-mutated patients (OS, PFS P=NS). Compared to VH-unmutated concordant patients, VH-unmutated discordant patients showed no peculiarity in their immunoglobulin rearrangement nor in their flow cytometry or fluorescence in situ hybridization profile. In conclusion, TRF-L can be helpful to refine prognostication of B-CLL patients, particularly those with a VH-unmutated immunoglobulin sequence.