Clinical and molecular predictors of disease severity and survival in chronic lymphocytic leukemia

Several parameters may predict disease severity and overall survival in chronic lymphocytic leukemia (CLL). The purpose of our study of 190 CLL patients was to compare immunoglobulin heavy chain variable region (IgV_H) mutation status, cytogenetic abnormalities, and leukemia cell CD38 and Zap-70 to older, traditional parameters. We also wanted to construct a simple, inexpensive prognosis score that would significantly predict TTT and survival in patients at the time of diagnosis and help practicing clinicians. In univariate analyses, patients with higher clinical stage, higher leukocyte count at diagnosis, shorter leukocyte doubling time, elevated serum lactate dehydrogenase (LDH), unmutated immunoglobulin heavy chain variable region (IgV_H) genes, and higher CD38 had a shorter overall survival and time-to-treatment (TTT). CLL cell Zap-70 expression was higher in patients with unmutated IgV _H, and those with higher Zap-70 tended to have shorter survival. IgV_H4-34 or IgV_H1-69 was the most common IgV_H genes used (16 and 12%, respectively). Of those with IgV_H1-69, 86% had unmutated IgV_H and had a significantly shorter TTT. A cytogenetic abnormality was noted in 71% of the patients tested. Patients with 11q22 del and 17p13 del or complex abnormalities were significantly more likely to have unmutated IgV_H. We found that a prognostic score constructed using modified Rai stage, cellular CD38, and serum LDH (parameters easily obtained clinically) significantly predicted TTT and survival in patients at the time of diagnosis and performed as well or better than models using the newer markers.