Infectious complications in patients with acute promyelocytic leukaemia treated with the AIDA regimen

Infections represent a frequent complication of chemotherapy used for acute myelold leukaemia (AML) and are associated with important toxicity frequently leading to treatment discontinuation. Acute promyelocytic leukaemia (APL) is a unique AML subset requiring tailored therapy including all-trans retinoic acid and anthracycline-based chemotherapy. We analysed in this study the incidence and type of infections complicating the clinical course of 89 consecutive APL patients receiving the AIDA protocol at a single institution. A total of 179 febrile episodes were registered during induction and consolidation, 52% of which were of unknown origin. Infections were clinically and microbiologically documented in 10.6 and 37.4% of cases, respectively. Coagulase-negative staphylococci represented the major cause of septicaemia (28%) and were more frequently isolated during induction, whereas viridans group streptococci, the second pathogen most frequently isolated from blood (27%), represented the principal pathogen detected during consolidation and were significantly associated with mucositis. Gram-negative bacteria accounted for 33.3% of all blood isolates. Fungal infections were only occasionally observed. Bloodstream infections in APL patients were compared with those documented in 271 consecutive patients affected by other subtypes of AML. The incidence of total septicaemia episodes, of staphylococcal bacteraemias and of fungaemias was significantly higher in patients with other AMLs. Empirical antibiotic therapy with ceftriaxone plus amikacin was effective in 73% of APL cases, most of the remaining cases being successfully managed by the addition of teicoplanin. One single death apparently related to infectious complication was recorded. Overall, infections led to antileukaemic treatment withdrawal in six patients, five of whom currently remain in haematologic remission for 13-106 months. These results indicate that a particular pattern of infections is observed in APL patients receiving ATRA plus anthracycline-based chemotherapy and that these appear to be effectively counteracted by standard management.