Chronic lymphocytic leukemia and infection risk in the era of targeted therapies: Linking mechanisms with infections

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in the world. Patient with CLL are at particular risk for infections due to inherent disease-related immune dysfunction in addition to the effect of certain systemic therapies on the immune system. The advent of B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib has led to a practice change that utilizes these targeted agents in the treatment of CLL, either in place of chemoimmunotherapy (CIT) or in later line settings. In this paper, we review the pathophysiology of immune dysfunction in CLL, the spectrum of immunodeficiency with the various therapeutic agents along with prevention strategies with a focus on targeted therapies.