Leish-KIT, a stable direct agglutination test based on freeze-dried antigen for serodiagnosis of visceral leishmaniasis.
In order to increase the application potential of the direct agglutination test (DAT) for the detection of anti-Leishmania antibodies in human serum samples, we developed an antigen based on stained and freeze-dried Leishmania donovani promastigotes. We describe here the evaluation of the performance of the DAT based on this freeze-dried antigen. It was shown that the freeze-dried antigen remains fully active, even after storage at 56 degrees C for 18 months. With a cutoff value of 1:1,600, the sensitivity of the DAT was shown to be 92% and the specificity of the test was 99.7%, which were comparable with the results found for the DAT based on liquid antigen. The major advantages of the freeze-dried antigen are that the production of a large batch of this antigen allows reproducible results in the DAT over a long period of time and that the freeze-dried antigen can be stored at ambient temperature, which, as was shown, makes the test a valuable diagnostic tool for use in the field.
Meredith
S E
SE
Department of Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
Kroon
N C
NC
Sondorp
E
E
Seaman
J
J
Goris
M G
MG
van Ingen
C W
CW
Oosting
H
H
Schoone
G J
GJ
Terpstra
W J
WJ
Oskam
L
L
D000372:Agglutination Tests / Q000379:methods* / Q000706:statistics & numerical data; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000302:isolation & purification; D005612:Freeze Drying; D006801:Humans; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000276:immunology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods / Q000706:statistics & numerical data; D013696:Temperature
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan