[Infection control in neutropenia induced by high-dose cytarabine chemotherapy]

A high-dose cytarabine (Cylocide; Ara-C: HDAC) chemotherapy has been successfully used as a postremission consolidation therapy for acute myeloid leukemia (AML). Although this chemotherapy has been estimated to cause severe myelosuppression, there has been no report about infection risk relating to HDAC chemotherapy. The purpose of this retrospective study is to evaluate the infection risk in AML patients treated with HDAC (n = 18) compared to those treated with standard-dose Ara-C (SDAC, n = 18). The mean duration of severe neutropenia (neutrophils < 500/microl) in HDAC group and SDAC was 14.8 days and 10.4 days, respectively, indicating a significant prolongation in the HDAC group (p < 0.05). The frequency of febrile neutropenia in the HDAC group tended to increase compared to that in the SDAC group (p = 0.093). The average days of usage of quinolone antimicrobial prophylaxis and aminoglycoside antibiotic injection in febrile neutropenia in the HDAC group were significantly longer than those of the SDAC group (quinolone; p < 0.01, aminoglycoside; p < 0.05). The frequency of Streptococcus infection isolated from pharyngeal mucus in the HDAC group was significantly higher than that in the SDAC group (100% versus 75%; p < 0.05). These results suggest that HDAC chemotherapy increased the infection risk compared to SDAC, and especially patients who received HDAC need a further prevention plan against gram-positive bacteria.