False positivity for Aspergillus antigenemia related to the administration of piperacillin/tazobactam.
BACKGROUND
Invasive aspergillosis is a challenge to the internist, and difficulties diagnosing the disease remain an everlasting problem.


METHODS
We reviewed the data of 65 patients with hematological malignancies and aplastic anemia who were tested for the galactomannan (GM) antigen of Aspergillus between March and November 2003.


RESULTS
GM antigen levels were false-positive in at least two consecutive samples in 5 out of 23 patients who did not have evidence of invasive aspergillosis (false positivity rate of 21.7%) but who received concomitant piperacillin/tazobactam (P/T) compared to 0 of 28 patients who did not.


CONCLUSIONS
The use of P/T in febrile, neutropenic patients decreases the specificity of GM antigen testing, which may lead to incorrect and unnecessary attempts at diagnosis and therapy.
Tanriover
Mine Durusu
MD
Department of Internal Medicine, Hacettepe University School of Medicine, 06100, Sihhiye, Ankara, Turkey. mdurusu@hacettepe.edu.tr
Metan
Gökhan
G
Altun
Belgin
B
Hascelik
Gulsen
G
Uzun
Omrum
O