Aspergillus susceptibility testing in patients with cancer and invasive aspergillosis: difficulties in establishing correlation between in vitro susceptibility data and the outcome of initial amphotericin B therapy.
OBJECTIVE
As the failure of amphotericin B therapy in patients with invasive aspergillosis often exceeds 50%, we sought to determine the relationship between in vitro amphotericin B resistance and clinical failure of amphotericin B against invasive aspergillosis.


METHODS
Retrospective study.


METHODS
University cancer center.


METHODS
One hundred sixteen patients with cancer and invasive aspergillosis.


RESULTS
The correlation between in vitro amphotericin B susceptibility, defined by both the National Committee for Clinical Laboratory Standards and Etest methods, and other prognostic factors with failure of initial amphotericin B therapy was retrospectively evaluated. Data for correlation could be clearly assessed in only 18 (16%) of the 116 patients. Admission to the intensive care unit was the only prognostic factor associated with failure of initial amphotericin B treatment in these 18 patients (p = 0.01).


CONCLUSIONS
Several important obstacles underlie the correlation of in vitro susceptibility testing with in vivo efficacy of individual antifungal agents in the treatment of invasive aspergillosis. Such correlations could be determined in only a small subset of patients.
Lionakis
Michail S
MS
Department of Infectious Diseases, Infection Control and Employee Health, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Lewis
Russell E
RE
Chamilos
Georgios
G
Kontoyiannis
Dimitrios P
DP
D000666:Amphotericin B / Q000627:therapeutic use*; D000935:Antifungal Agents / Q000627:therapeutic use*; D001228:Aspergillosis / Q000188:drug therapy* / Q000209:etiology; D001230:Aspergillus / Q000187:drug effects* / Q000302:isolation & purification; D025141:Drug Resistance, Fungal; D005260:Female; D019337:Hematologic Neoplasms / Q000150:complications*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D012189:Retrospective Studies; D016896:Treatment Outcome
D000935:Antifungal Agents; D000666:Amphotericin B