1. ¹Department of Hematology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
2. ²Department of Hematology, University Hospital, Bern, Switzerland
3. ³Department of Clinical Research, University Hospital, Bern, Switzerland
4. ⁴Institute of Human Genetics, Christian-Albrechts-University Hospital Schleswig-Holstein, Kiel, Germany
5. ⁵Terry Fox Laboratory, BC Cancer Research Centre, Vancouver, Canada
6. ⁶Department of Medicine, University of British Columbia, Vancouver, Canada

Correspondence: Dr A Röth, Department of Hematology, University Hospital Essen, Hufelandstr. 55, Essen D-45122, Germany. E-mail: alexander.roeth@uni-due.de; Dr G Baerlocher, Department of Hematology and Department of Clinical Research, University Hospital Bern, Freiburgstrasse 4, Bern CH-3010, Switzerland. E-mail: gabriela.baerlocher@insel.ch

Received 31 May 2007; Revised 20 August 2007; Accepted 29 August 2007; Published online 27 September 2007.

Abstract

To test the role of telomere biology in T-cell prolymphocytic leukemia (T-PLL), a rare aggressive disease characterized by the expansion of a T-cell clone derived from immuno-competent post-thymic T-lymphocytes, we analyzed telomere length and telomerase activity in subsets of peripheral blood leukocytes from 11 newly diagnosed or relapsed patients with sporadic T-PLL. Telomere length values of the leukemic T cells (means.d.: 1.530.65 kb) were all below the 1st percentile of telomere length values observed in T cells from healthy age-matched controls whereas telomere length of normal T- and B cells fell between the 1st and 99th percentile of the normal distribution. Leukemic T cells exhibited high levels of telomerase and were sensitive to the telomerase inhibitor BIBR1532 at doses that showed no effect on normal, unstimulated T cells. Targeting the short telomeres and telomerase activity in T-PLL seems an attractive strategy for the future treatment of this devastating disease.