High CD49d protein and mRNA expression predicts poor outcome in chronic lymphocytic leukemia

Abstract CD49d plays a critical role in leucocyte trafficking, activation and survival, and facilitates interactions between leucocytes and stromal cells. Recent data give evidence for the prognostic relevance of CD49d protein expression in B-CLL. In our study we analyzed both the expression of CD49d protein and mRNA in a cohort of 101 CLL patients. The percentage of leukemic B-cells expressing CD49d determined by flow cytometry ranged from 0 to 100%. 37 patients with high CD49d protein expression ≥ 45% (according to ROC analysis) had a significantly shorter treatment-free survival (TFS) and overall survival (OS) than 64 patients with low CD49d expression (median TFS: 116 versus 43 months, p  = 0.015; median OS: not reached in both groups, p  = 0.018). CD49d protein expression was strongly associated with CD38 status ( p  = 0.0001) and ZAP-70 status ( p  = 0.03) but not with IGVH mutation. In multivariate analysis high CD49d expression was a significantly independent prognostic factor (HR 3.0; p  = 0.005). According to the strong correlation of CD49d protein expression with CD49d mRNA expression ( r  = 0.39; p