Specific, sensitive, and quantitative enzyme-linked immunosorbent assay for human immunoglobulin G antibodies to anthrax toxin protective antigen.
The bioterrorism-associated human anthrax epidemic in the fall of 2001 highlighted the need for a sensitive, reproducible, and specific laboratory test for the confirmatory diagnosis of human anthrax. The Centers for Disease Control and Prevention developed, optimized, and rapidly qualified an enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) antibodies to Bacillus anthracis protective antigen (PA) in human serum. The qualified ELISA had a minimum detection limit of 0.06 micro g/mL, a reliable lower limit of detection of 0.09 micro g/mL, and a lower limit of quantification in undiluted serum specimens of 3.0 micro g/mL anti-PA IgG. The diagnostic sensitivity of the assay was 97.8%, and the diagnostic specificity was 97.6%. A competitive inhibition anti-PA IgG ELISA was also developed to enhance diagnostic specificity to 100%. The anti-PA ELISAs proved valuable for the confirmation of cases of cutaneous and inhalational anthrax and evaluation of patients in whom the diagnosis of anthrax was being considered.
Quinn
Conrad P
CP
Centers for Desease Control and Prevention , Atlanta, Georgia 30333, USA. caq7@cdc.gov
Semenova
Vera A
VA
Elie
Cheryl M
CM
Romero-Steiner
Sandra
S
Greene
Carolyn
C
Li
Han
H
Stamey
Karen
K
Steward-Clark
Evelene
E
Schmidt
Daniel S
DS
Mothershed
Elizabeth
E
Pruckler
Janet
J
Schwartz
Stephanie
S
Benson
Robert F
RF
Helsel
Leta O
LO
Holder
Patricia F
PF
Johnson
Scott E
SE
Kellum
Molly
M
Messmer
Trudy
T
Thacker
W Lanier
WL
Besser
Lilah
L
Plikaytis
Brian D
BD
Taylor
Thomas H
TH
Freeman
Alison E
AE
Wallace
Kelly J
KJ
Dull
Peter
P
Sejvar
Jim
J
Bruce
Erica
E
Moreno
Rosa
R
Schuchat
Anne
A
Lingappa
Jairam R
JR
Martin
Sandra K
SK
Walls
John
J
Bronsdon
Melinda
M
Carlone
George M
GM
Bajani-Ari
Mary
M
Ashford
David A
DA
Stephens
David S
DS
Perkins
Bradley A
BA
D000881:Anthrax / Q000175:diagnosis / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology*; D001408:Bacillus anthracis / Q000276:immunology*; D001427:Bacterial Toxins / Q000276:immunology*; D023482:Bioterrorism; D004196:Disease Outbreaks; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D012680:Sensitivity and Specificity
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D007074:Immunoglobulin G; C030325:anthrax toxin