Rituximab treatment in vitro results in favorable changes in Mcl-1 and XIAP expression in a subset of patients with CLL.

CLL cells from the blood were obtained and exposed to media or rituximab for 4 hours. Following this, protein lysates were prepared, normalized for total protein content, and analyzed by SDS-PAGE/immunoblotting using antibodies specific for Mcl-1 and XIAP. Protein bands were quantified by laser densitometry. Mcl-1 and XIAP decreased in a proportion of patients and increased in others that generally are in concordance with each other.