INFECTIOUS AND IMMUNOSUPPRESSIVE COMPLICATIONS OF PURINE ANALOG THERAPY

Purpose: The purine analogs fludarabine, cladribine, and pentostatin a re active agents in the treatment of indolent lymphoid malignancies. T his report reviews the pattern, severity, and consequences of the immu nosuppression and myelotoxicity associated with these agents. Methods: The literature was searched using MedLine and Cancerline, as well as the bibliographies of published reports through the winter of 1994 and 1995. Results: Each of these drugs induces profound lymphocytopenia. A marked decrease in CD4 cells may persist for several years, while ot her mononuclear-cell populations recover more rapidly. The spectrum of infections encountered in these patients appears to be altered to inc lude a wide range of opportunistic organisms. Factors that increase th e risk of these infections include concurrent corticosteroids, extensi ve prior therapy, particularly with another purine analog, and poor re sponse to purine analog treatment. Conclusion: Because of the frequenc y of life-threatening infections with unusual pathogens that may occur in patients treated with purine analogs, aggressive and early diagnos tic evaluation and appropriate use of myeloid growth factors may be ne cessary to ensure appropriate antimicrobial therapy.