Evaluation of serum markers in the LRF CLL4 trial: β2-microglobulin but not serum free light chains, is an independent marker of overall survival.

Chronic lymphocytic leukemia (CLL) is characterized by heterogeneous clinical behavior and there is a need for improved biomarkers. The current study evaluated the prognostic significance of serum free light chains (sFLC, kappa, and lambda) and other serum markers (bar, serum thymidine kinase (sTK), soluble CD23, and LDH) together with established biomarkers in 289 patients enrolled into the LRF CLL4 trial. In a multivariable analysis of serum markers alone, higher big and kappa light chains were statistically significant in predicting disease progression and higher blg, and sTK in predicting mortality. In multivariable analysis for overall survival the following were independently significant: β2M levels, immunoglobulin gene (IGHV) mutational status (>98% homology), age, 17p13 deletions (>10%), and CD38 expression. β2M is the only serum marker that retained clear independent value as a biomarker in the LRF CLL4 trial and remains powerfully prognostic requiring evaluation in any future method of risk stratifying patients

CD38 expression and immunoglobulin variable region mutations are independent prognostic variables in chronic lymphocytic leukemia, but CD38 expression may vary during the course of the disease

Although the presence or absence of somatic mutations in the immunoglobulin variable region (IgVH) genes in chronic lymphocytic leukemia (B-CLL) identifies subtypes with very different prognoses, the assay is technically complex and unavailable to most laboratories. CD38 expression has been suggested as a surrogate marker for the 2 subtypes. IgVH mutations and CD38 expression in 145 patients with B-CLL with a long follow-up were compared. The 2 assays gave discordant results in 41 patients (28.3%). Multivariate analysis demonstrated that Binet stage, IgVH mutations and CD38 were independent prognostic indicators. Median survival time in patients whose cells had unmutated IgVH genes and expressed CD38 was 8 years; in those with mutated IgVH genes not expressing CD38, it was 26 years. For those with discordant results, median survival time was 15 years. Thus, although CD38 expression does not identify the same 2 subsets as IgVH mutations in CLL, it is an independent risk factor that can be used with IgVH mutations and clinical stage to select patients with B-CLL with the worst prognoses. Using cryopreserved cells taken at intervals during the course of the disease, however, changes of CD38 expression over time were demonstrated in 10 of 41 patients. Causes of the variation of CD38 expression require further study. Additional prospective studies are required for comparing CD38 expression with other prognostic factors and for taking sequential measurements during the course of the disease

Cell surface phenotype profiles distinguish stable and progressive chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is clinically heterogeneous. While some patients have indolent disease for many years, 20-30% will progress and ultimately die of their disease. CLL may be classified by the Rai or Binet staging system, mutational status of the immunoglobulin variable heavy-chain gene (IGVH), ZAP-70 overexpression, cytogenetic abnormalities (13q-, + 12, 11q-, 17p-) and expression of several cell surface antigens (CD38, CD49d) that correlate with risk of disease progression. However, none of these markers identify all cases of CLL at risk. In a recent review, we summarized those CD antigens known to correlate with the prognosis of CLL. The present study has identified surface profiles of CD antigens that distinguish clinically progressive CLL from slow-progressive and stable CLL. Using an extended DotScan? CLL antibody microarray (Version 3; 182 CD antibodies), and with refined analysis of purified CD19 + B-cells, the following 27 CD antigens were differentially abundant for progressive CLL: CD11a, CD11b, CD11c, CD18, CD19, CD20 (two epitopes), CD21, CD22, CD23, CD24, CD25, CD38, CD40, CD43, CD45, CD45RA, CD52, CD69, CD81, CD84, CD98, CD102, CD148, CD180, CD196 and CD270. The extensive surface profiles obtained provide disease signatures with an accuracy of 79.2%, a sensitivity of 83.9% and a specificity of 72.5% that could provide the basis for a rapid test to triage patients with CLL according to probability of clinical progression and potential earlier requirement for treatment.8 page(s

Multivariate analysis of prognostic factors in CLL: clinical stage, IGVH gene mutational status, and loss or mutation of the p53 gene are independent prognostic factors

This study evaluates the prognostic significance of genetic abnormalities (detected at or shortly after presentation), clinical stage, lymphocyte morphology, CD38 expression, and IGVH gene status in 205 patients with chronic lymphocytic leukemia (B-CLL). Deletion of chromosome 11q23, absence of a deletion of chromosome 13q14, atypical lymphocyte morphology, and more than 30% CD38 expression are significantly associated with the presence of unmutated IGVH genes. Advanced stage, male sex, atypical morphology, more than 30% CD38 expression, trisomy 12, deletion of chromosome 11q23, loss or mutation of the p53 gene, and unmutated IGVH genes are all poor prognostic factors in a univariate analysis. However, only 98% or more homology of IGVH genes to the germline sequence, loss or mutation of the p53 gene, and clinical stage retain prognostic significance in a multivariate analysis. The median survival of patients with mutated IGVH genes, unmutated IGVH genes, and loss or mutation of the p53 gene regardless of IGVH gene status is 310, 119, and 47 months, respectively. These data should facilitate the design of new trials for the management of patients presenting with advanced disease or poor prognosis early stage disease

ZAP-70 expression identifies a chronic lymphocytic leukemia subtype with unmutated immunoglobulin genes, inferior clinical outcome, and distinct gene expression profile

The presence or absence of somatic mutations in the expressed immunoglobulin heavy chain variable regions (IgVH) of chronic lymphocytic leukemia (CLL) cells provides prognostic information. Patients whose leukemic cells express unmutated IgVH regions (Ig-unmutated CLL) often have progressive disease, whereas patients whose leukemic cells express mutated IgVH regions (Ig-mutated CLL) more often have an indolent disease. Given the difficulty in performing IgVH sequencing in a routine diagnostic laboratory, this prognostic distinction is currently unavailable to most patients. Pilot gene expression profiling studies in patients with CLL identified genes that were differentially expressed between the Ig-unmutated and Ig-mutated CLL subtypes. Here, we have profiled an expanded cohort of 107 patients and show that ZAP-70 is the gene that best distinguishes the CLL subtypes. Ig-unmutated CLL expressed ZAP-70 5.54-fold more highly than Ig-mutated CLL (P < 10-21). ZAP-70 expression correctly predicted IgVH mutation status in 93% of patients. ZAP-70 expression and IgVH mutation status were comparable in their ability to predict time to treatment requirement following diagnosis. In 7 patients, ZAP-70 expression and IgVH mutation status were discordant: 4 Ig-mutated CLLs had high ZAP-70 expression and 3 Ig-unmutated CLLs had low ZAP-70 expression. Among these ZAP-70 "outliers," those with Ig-mutated CLL had clinical features that are uncharacteristic of this CLL subtype: 2 required early treatment and 2 used a mutated VH3-21 gene, an IgVH gene that has been associated with progressive disease. We developed reverse transcriptase–polymerase chain reaction and immunohistochemical assays for ZAP-70 expression that can be applied clinically and would yield important prognostic information for patients with CLL