BLOOD CULTURE FINDINGS DURING NEUTROPENIA IN ADULT PATIENTS WITH ACUTE MYELOID LEUKAEMIA, ACTA UNIVERSITATIS OULUENSIS D Medica 1075
|Kustantaja:||Oulun yliopisto|| |
|Sijainti:||Print Tietotalo|| |
|Tekijät:||KINNUNEN URPO|| |
In Oulu University Hospital Haematological Ward during the years 1990–1991, a manualblood culture system was able to detect bloodstream infection (BSI) in 23% of febrile episodes ofpatients with acute myeloid leukaemia (AML), whereas during the years 1992–1993 an automatedcontinuous-monitoring blood culture system (CMBCS) BacT/Alert® detected BSI in 40% offebrile episodes (p=0.043). During the years 1997–2003, regimens containing high-dosecytarabine predisposed patients to laboratory-confirmed BSI (LCBI) with an odds ratio (OR) of2.3 (with 95% confidence interval (CI) from 1.2 to 4.2). The LCBI risk was lowest afterthioguanine-containing regimens (OR 0.26, 95% CI; 0.12–0.58). In the register data (years1992–2006) from the prospective multi-centre AML -92 trial, when compared to cycle I, the ORfor LCBI was significantly higher (from 4.8 to 5.8) in subsequent cycles (p <0.001). In all, 67%of mortality due to BSI occurred in patients with active leukaemia.
An inoculum of microorganisms to produce 10 colony-forming units (cfu)/ml of 10 gram-positive coccal strains, 10 gram-negative bacillar strains and 8 Candida yeast strains was culturedin BacT/Alert® blood culture bottles in the presence of several chemotherapeutic drugs. Of thechemotherapeutic drugs tested, the anthracyclines exhibited inhibitory effects on the growth ofmicroorganisms in concentrations corresponding to the therapeutic levels. In the standard bottles,doxorubicin increased the incubation time of gram-positive cocci and idarubicin increased theincubation time of Candida glabrata. However, no increase in the incubation time of any microbeswas detected in the antimicrobial-neutralizing FAN bottles.
In conclusion, the use of CMBCSs has resulted in an increased LCBI rate in neutropenic AMLpatients. In general, chemotherapeutic agents have no significant inhibitory effects on the growthof common microbial pathogens in blood culture. The detection of some difficult-to-culturemicrobial strains – C. glabrata for example – in blood cultures may be impaired by the presenceof chemotherapeutics in blood. The chemotherapeutics may also affect the LCBI rate in otherways. As a predictor of adverse outcome of infection, the presence of active leukaemia is moreimportant than the type of chemotherapy being administered.