1. ¹Institut Pasteur, Paris, France
2. ²DBIM Hôpital Saint-Louis, INSERM U 444, Paris, France
3. ³Hematology Department, Hôpital de la Pitié, Paris, France
4. ⁴Hematology Department Hotel-Dieu, APHP, Paris, France

Correspondence: F Ajchenbaum-Cymbalista, Hematology Department, Hotel-Dieu, 1 place du parvis Notre-Dame, 75004, Paris, France; Fax: +33-1-42 34 82 54

Received 16 May 2002; Accepted 19 August 2002.

Abstract

In B-CLL IgV_H genes mutational status is a major prognostic factor. Since sequencing of IgV_H genes is not available in most laboratories, an easily performed surrogate assay is desirable. To identify the best surrogate assay, and to better discriminate prognostic subgroups we analyzed clinical and biological data from 58 typical CLL cases. A higher serum thymidine kinase level (>15 U/l) proved to be a strong predictor of mutational status, and the only independent one among the studied parameters. To further identify prognostic subgroups, cluster analysis was employed on 38 cases on which all data were available, which segregated two groups including 25 and 13 patients, respectively. These two clusters differed by their proliferative potential and appeared to discriminate patients with very different clinical course and outcome. s-TK was strikingly different among these two clusters, suggesting that s-TK level could be used routinely to identify patients at risk of progression.