Infections Associated With Conventional Chemotherapy

The most frequently used agents for initial therapy of CLL have been the alkylating agents chlorambucil and cyclosphosphamide, alone or in combination with prednisone ± vincristine (CVP). Alkylating agents are both myelosuppressive and immunosuppressive, but neutropenia is the single most important factor predisposing to infection in patients receiving these drugs.

With the extensive use of these regimens, Gram-negative bacilli, including Enterobacteraceae and Pseudomonas aeruginosa, emerged as the predominant pathogens (40).

Adrenal corticosteroids (prednisone) have multiple effects on host defenses. Especially important is their effect on macrophages and monocytes. These cells are an important defense against mold infection such as aspergillosis since they ingest and kill spores. Steroids interfere with the sporicidal activity of these cells, although phagocytosis remains intact (5). Steroids also interfere with neutrophil function and inhibit release of vasoactive factors, chemoattractants, and pro-teolytic enzymes (44). Shaw et al. (45) randomly assigned half of a group of patients to 1 mg/kg prednisone daily for 3 mo followed by a 3-mo washout period vs the opposite sequence for the other half. During the administration of prednisone, patients experienced more frequent and more severe infections, especially infections caused by S. aureus.

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