Immunologic issues

Patients with cancer frequently develop immunologic impairment as a result of the underlying malignancy and its treatment. Each immunologic deficit is associated with a specific spectrum of infection, although there is some overlap. Multiple risk factors may be present in the same patient, increasing the risk of and widening the spectrum of infection. Some nonimmunologic factors also play a role in the predisposition to infection. Increased survival durations among patients with solid tumors and hematologic malignancies and those who have undergone hematopoietic stem cell transplantation have resulted in a growing population of patients who remain at risk for the development of serious infections for sustained periods of time. This chapter discusses the immunologic defects commonly encountered in subgroups of cancer patients, focusing on the risk factors, infectious complications, and other features unique to each subgroup. A brief discussion of immune reconstitution in hematopoietic stem cell transplantation recipients is included. The stem cell transplantation specialists at MD Anderson perform more hematopoietic stem cell transplantations than at any other institution in the United States. Finally, the chapter concludes with a brief discussion of antimicrobial stewardship, which has become an important and (in the opinion of the author) mandatory strategy in the overall management of infection in cancer patients, particularly long-term survivors.