ABSTRACT
I. INTRODUCTION Infectious complications continue to be of great significance in the disease course of pa tients with chronic lymphocytic leukemia (CLL), being a major contributor to morbidity and mortality (1-6). These patients are predisposed to infections both because of the immune compromise, predominantly hypogammaglobulinemia, inherent to the primary disease process, and additional immunosuppression related to therapy with agents such as corticosteroids, purine analogs, and other cytotoxic drugs. It has been estimated that up to 80% of CLL patients will have their disease course complicated by infections, which range from moderate to life-threatening in severity (1-3). Infection is the leading cause of death in most series, accounting for mortality in 30% to 60% of CLL patients (1-4,7,8). Despite advances in therapeutics and antimicrobial support over the past five decades, the incidence of infection has nonetheless remained relatively constant (3,4,9). The introduc tion of purine analogs into the therapeutic armamentarium for this disease process in the past two decades had an impact on the spectrum of infectious complications seen in this population. Although bacterial infections, especially of the respiratory tract, remain most common (1-3), the occurrence of opportunistic infections, such as those caused by Can dida species and herpesviruses, has increased, related to the prolonged T-cell immunosup pression induced by this group of agents (10-14). In this chapter we will discuss the
pathogenesis of infection in this population, the spectrum of infections seen, risk factors for infection, and potential approaches for infection prophylaxis.
