aDivision of AIDS, Korea National Institute of Health, Cheongju, Korea
bDivision of Biobank for Health Sciences, Korea National Institute of Health, Cheongju, Korea
© 2015 Published by Elsevier B.V. on behalf of Korea Centers for Disease Control and Prevention.
This is an Open Access article distributed under the terms of the CC-BY-NC License (http://creativecommons.org/licenses/by-nc/3.0).
Cutoff value | Concentration of Guanidine | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1.0M | 1.5M | 2.0M | ||||||||||
No. of R (n = 70) | Sensitivity (%) | No. of E (n = 80) | Specificity (%) | No. of R (n = 70) | Sensitivity (%) | No. of E (n = 80) | Specificity (%) | No. of R (n = 70) | Sensitivity (%) | No. of E (n = 80) | Specificity (%) | |
0.70 | 20 | 28.6 | 75 | 93.8 | 37 | 52.9 | 75 | 93.8 | 42 | 60.0 | 73 | 91.3 |
0.75 | 23 | 32.9 | 75 | 93.8 | 40 | 57.1 | 75 | 93.8 | 49 | 70.0 | 64 | 80.0 |
0.80 | 31 | 44.3 | 75 | 93.8 | 44 | 62.9 | 75 | 93.8 | 56 | 80.0 | 56 | 70.0 |
0.85 | 40 | 57.1 | 75 | 93.8 | 48 | 68.6 | 71 | 88.8 | 59 | 84.3 | 45 | 56.3 |
0.90 | 42 | 60.0 | 71 | 88.8 | 55 | 78.6 | 63 | 78.8 | 64 | 91.4 | 45 | 36.3 |
0.95 | 50 | 71.4 | 59 | 73.8 | 60 | 85.7 | 42 | 52.5 | 69 | 98.6 | 19 | 23.8 |
1.00 | 61 | 87.1 | 45 | 56.3 | 67 | 95.7 | 24 | 30.0 | 70 | 100.0 | 12 | 15.0 |
Categories | Number (%) | Cumulative no. (%) |
---|---|---|
Fiebig stages | ||
Eclipse phase | — | — |
I | 2 (2.5) | 2 (2.5) |
II | 33 (40.7) | 35 (43.2) |
III | 6 (7.4) | 41 (50.6) |
IV | 38 (46.9) | 79 (97.5) |
V | 2 (2.5) | 81 (100.0) |
VI | — | 81 (100.0) |
Estimated days (d) following HIV transmission | ||
1–30 | 20 (10.4) | 20 (10.4) |
31–60 | 55 (28.5) | 75 (38.9) |
61–90 | 33 (17.1) | 108 (56.0) |
91–120 | 29 (15.0) | 137 (72.0) |
121–150 | 22 (11.4) | 159 (82.4) |
151–180 | 10 (5.2) | 169 (87.6) |
181–200 | 5 (2.6) | 174 (90.2) |
>200 | 19 (9.8) | 193 (100.0) |
Cutoff value | Avidity assay (1.5M Guanidine) | |||
---|---|---|---|---|
Recent infection (n = 174) | Established infection (n = 105) | |||
Sensitivity (%) | False-reactive (%) | Specificity (%) | Nonreactive (%) | |
0.55 | 123 (70.7) | 51 (29.3) | 95 (90.5) | 10 (9.5) |
0.60 | 132 (75.9) | 42 (24.1) | 94 (89.5) | 11 (10.5) |
0.65 | 141 (81.0) | 33 (19.0) | 92 (87.6) | 13 (12.4) |
0.70 | 143 (82.2) | 31 (17.8) | 91 (86.7) | 14 (13.3) |
0.75 | 150 (86.2) | 24 (13.8) | 89 (84.8) | 16 (15.2) |
0.80 | 157 (90.2) | 17 (9.8) | 88 (83.8) | 17 (16.2) |
0.85 | 158 (90.8) | 16 (9.2) | 76 (72.4) | 29 (27.6) |
0.90 | 163 (93.7) | 11 (6.3) | 65 (61.9) | 40 (38.1) |
Test results | Recent infection (n = 174) | Established infection (n = 105) |
---|---|---|
BED(Incidence), Avidity(Incidence) | 153 (87.9%) | 13 (12.3%) |
BED(Incidence), Avidity(Established) | 11 (6.3%) | 11 (10.5%) |
BED(Established), Avidity(Incidence) | 6 (3.4%) | 4 (3.8%) |
BED(Established), Avidity(Established) | 4 (2.3%) | 77 (73.3%) |
No. | Axsym HIV Ag/Ab (OD/CO) | Avidity index (mean ± SD) | CV (%) |
---|---|---|---|
1 | 16.59 | 0.69 ± 0.03 | 5.03 |
2 | 53.63 | 1.11 ± 0.10 | 9.28 |
3 | 48.19 | 0.98 ± 0.04 | 4.58 |
4 | 36.87 | 1.00 ± 0.07 | 7.10 |
5 | 26.33 | 0.92 ± 0.04 | 4.12 |
6 | 9.71 | 0.19 ± 0.01 | 4.55 |
7 | 48.40 | 0.97 ± 0.08 | 8.23 |
8 | 35.11 | 0.89 ± 0.05 | 5.67 |
9 | 24.32 | 0.82 ± 0.03 | 4.13 |
10 | 18.22 | 0.68 ± 0.05 | 7.66 |
11 | 24.45 | 0.85 ± 0.05 | 5.84 |
12 | 46.05 | 0.93 ± 0.04 | 4.62 |
13 | 20.45 | 0.50 ± 0.03 | 5.25 |
14 | 48.76 | 1.06 ± 0.03 | 3.16 |
15 | 31.31 | 0.93 ± 0.03 | 3.34 |
16 | 15.83 | 0.28 ± 0.02 | 7.72 |
17 | 19.75 | 0.98 ± 0.03 | 2.92 |
18 | 18.08 | 0.65 ± 0.04 | 5.93 |
19 | 18.05 | 0.48 ± 0.04 | 8.80 |
20 | 28.35 | 1.13 ± 0.04 | 3.86 |
21 | 32.66 | 0.91 ± 0.05 | 5.55 |
22 | 40.01 | 0.97 ± 0.04 | 4.28 |
23 | 17.91 | 0.59 ± 0.04 | 6.21 |
24 | 17.71 | 0.96 ± 0.05 | 5.00 |
25 | 33.34 | 0.90 ± 0.04 | 4.34 |
26 | 24.92 | 0.41 ± 0.03 | 8.24 |
27 | 25.91 | 0.89 ± 0.04 | 4.81 |
28 | 48.64 | 1.00 ± 0.03 | 2.63 |
29 | 31.35 | 0.95 ± 0.02 | 2.35 |
30 | 38.51 | 0.90 ± 0.07 | 7.61 |
Based on the BED assay results, 30 Korean HIV-positive samples were classified: 14 were recent infections and the other 16 were established infections. These HIV-infected Koreans tested positive in three HIV tests—nucleic acid amplification, HIV antigen/antibody ELISA, and Western blot—and had not received antiretroviral therapy. For the avidity assay, 1.0M, 1.5M, and 2.0M Guanidine concentrations were used, and the 30 HIV positive samples were tested repeatedly using the assay five times ( E = established infection; ELISA = enzyme-linked immunosorbent assay; HIV = human immunodeficiency virus; R = recent infection.
ELISA = enzyme-linked immunosorbent assay; HIV = human immunodeficiency virus. Fiebig stage of each person was classified into six laboratory stages of primary HIV infection based on the antigen–antibody response patterns (HIV RNA, ELISA antigen, ELISA antibody, Western blots) found in the sample Eighty-one individuals were classified according to the Fiebig system of using the first bleeding date sample, and the estimated HIV infection period for all 193 samples was derived from longitudinal samples of the individuals.
Recent infection ( Established infection: samples collected from long-term infected persons for more than 2 years after initial diagnosis of human immunodeficiency virus.
The correlation coefficient of between S/Co of AxSYM HIV Ag/Ab and mean of avidity index is 0.706 ( CV = coefficient of variation; HIV = human immunodeficiency virus; OD/CO = ratio of optical density to cutoff value; S/CO = signal/cutoff; SD = standard deviation.