[Reduction in the window period of an acute infection by chemiluminescence enzyme immunoassay of HIV-1 p24 antigen].
To evaluate the detectability of HIV-1 p24 antigen in the window period of an acute infection, 172 HIV-1-infected and 78 HIV-1-uninfected adult serum (plasma) samples were assayed by chemiluminescence enzyme immunoassay (CLEIA, 2 step sandwich method) and EIA. All 78 HIV-uninfected samples (100%) were p24 antigen negative by both methods. Thirty five of the 172 HIV-1-infected samples (32.1%) were p24 antigen negative by EIA, and p24 antigen positive by CLEIA. The HIV-1 RNA levels of the 35 discrepant samples were 8.1 x 10(3)-7.9 x 10(5) copies/ml, TH/I lymphocyte levels of them were less than 200 cells/microliter except 9 cases, and phases of them were AIDSs of CDC 1993 classification except 7 cases. The antigen detection limit of CLEIA was 3.1-6.3 pg/ml, and that of EIA was 12.5-25.0 pg/ml. The coefficient of variations of CLEIA were 3.0-6.3% determined after the assay on 5 samples on 5 different days, 6 times per day. On the basis of these results, it was inferred that the reason for the discrepancy between the two methods was due to the fact that the detection limit of CLEIA was lower than that of EIA. On an antibody-negative RNA-positive (5.0 x 10(4) copies/ml) serum sample in the window period of an acute infection, p24 antigen was detected by CLEIA 7 days earlier than by EIA. CLEIA was judged to be a useful assay for reducing the window period, and a cost-effective (effect/cost > 1.0) method.
Handa
N
N
Department of Laboratory Medicine, Tokyo Metropolitan Komagome Hospital.
Kato
M
M
Ishihama
Y
Y
Masuda
G
G
D000328:Adult; D016655:HIV Core Protein p24 / Q000097:blood*; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1; D006801:Humans; D007124:Immunoenzyme Techniques; D008163:Luminescent Measurements; D013997:Time Factors
D016655:HIV Core Protein p24