Figure 1

Differential expression and prognostic impact of CXCR4 and CD49d in M-CLL. (a) We analyzed the expression of CXCR4 in a cohort of 124 serially collected M-CLL samples and used the median expression as a binary classifier based on receiver operating characteristic analysis. M-CLL patients showed a much more heterogeneous expression of CXCR4 than U-CLL cases. (b) M-CLL patients with a CXCR4^hi phenotype had a significantly inferior outcome when compared with CXCR4^lo patients. (c) The cohort was then categorized into CD49d^lo (<30% expression) and CD49d^hi (⩾30% expression) subsets. Again M-CLL cases showed much more heterogeneity in the expression of CD49d than U-CLL cases. (d) M-CLL patients with a CD49d^hi phenotype had a significantly inferior outcome when compared with CD49d^lo patients. (e) When assessed as continuous variables, CXCR4 and CD49d were strongly correlated. Similarly, using categorical cutoffs to define the cohort, the majority of M-CLL cases showed concordant expression for CXCR4 and CD49d: CXCR4^hi/CD49d^hi or CXCR4^lo/CD49d^lo. 27% of the cases were discordant for these markers. (f) The Kaplan–Meier curves for the discordant cases bisected the CXCR4^hi/CD49d^hi and CXCR4^lo/CD49d^lo curves highlighting the prognostic importance of both CXCR4 and CD49d and suggesting that the combined assessment of CXCR4 and CD49d has clinical utility.