| Abstract: | CD 49d is a surface integrin that is expressed on chronic lymphocytic leukaemia (CLL ) cells, and strongly correlates with more aggressive disease. Given its association with cell‐cell adhesion and leucocyte trafficking, we hypothesized that patients with high CD 49d expression would experience a clinical course dominated by lymphadenopathy. CD 49d expression was measured by flow cytometry and considered positive if expressed by ≥30% of CLL cells. The study included 797 newly diagnosed CLL /small lymphocytic leukaemia patients; 279 (35%) were CD 49d positive. CD 49d‐positive patients were more likely to present with lymphadenopathy (P < 0·001); a finding that persisted after adjusting for fluorescence in situ hybridisation (FISH ) and IGHV mutation status [odds ratio (OR ) 2·51; 95% confidence interval (CI ) 1·64–3·83; P < 0·001]. Among CLL Rai 0 patients, CD 49d positivity was associated with shorter time to development of lymphadenopathy (3·2 years vs not reached, P < 0·01). This association was maintained after adjusting for either FISH [hazard ratio (HR ) 2·18; 95% CI 1·25–3·81; P = 0·006) or IGHV status (HR 2·02; 95% CI 1·11–3·69; P = 0·02) individually, but was attenuated when adjusting by both (HR 1·72; 95% CI 0·88–3·38; P = 0·11).These data demonstrate that CD 49d‐positive CLL patients experience a disease course dominated by lymphadenopathy. These findings could have implications for therapy selection and disease monitoring. |
