Detection of galactomannan antigenemia by enzyme immunoassay for the diagnosis of invasive aspergillosis: variables that affect performance.
Invasive aspergillosis (IA) is a frequent complication of blood or marrow transplantation. Previous studies have reported that the Aspergillus galactomannan enzyme immunoassay (GM EIA) may be a useful diagnostic tool for IA, but its sensitivity is variable. We examined the performance of the GM EIA in 986 serum samples from 67 patients. Results demonstrated that decreasing the index cutoff for positivity to 0.5 increased its sensitivity, with minimal loss of specificity. The low cutoff increased the duration of test positivity before diagnosis by clinical means. Sensitivity was highest in patients who did not receive preventative mold-active antifungals (87.5%). A rabbit model demonstrated that the level of circulating antigen correlated with the tissue fungus burden. A quantifiable response to antifungal therapy in clinical samples and the rabbit model supports the development of this assay for early diagnosis and therapeutic monitoring. The 0.5 cutoff may allow for better performance as an early diagnostic test.
Marr
Kieren A
KA
Fred Hutchinson Cancer Research Center and University of Washington, Seattle, Washington 98109, USA. kmarr@fhcrc.org
Balajee
S Arunmozhi
SA
McLaughlin
Lisa
L
Tabouret
Marc
M
Bentsen
Christopher
C
Walsh
Thomas J
TJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000946:Antigens, Fungal / Q000097:blood*; D001228:Aspergillosis / Q000175:diagnosis* / Q000382:microbiology; D001230:Aspergillus / Q000302:isolation & purification*; D016026:Bone Marrow Transplantation / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D004195:Disease Models, Animal; D005260:Female; D016469:Fungemia / Q000175:diagnosis* / Q000382:microbiology; D005690:Galactose / Q000031:analogs & derivatives; D006801:Humans; D007124:Immunoenzyme Techniques; D008172:Lung Diseases, Fungal / Q000175:diagnosis / Q000382:microbiology; D008297:Male; D008351:Mannans / Q000097:blood*; D008875:Middle Aged; D011817:Rabbits; D012680:Sensitivity and Specificity
D000946:Antigens, Fungal; D008351:Mannans; C012990:galactomannan; D005690:Galactose