Accepted Manuscript Title: Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay Author: Isabel Montesinos Joelle Eykmans Marie-Luce Delforge PII: DOI: Reference:
S1386-6532(14)00177-2 http://dx.doi.org/doi:10.1016/j.jcv.2014.04.025 JCV 3025
To appear in:
Journal of Clinical Virology
Received date: Revised date: Accepted date:
7-3-2014 29-4-2014 30-4-2014
Please cite this article as: Montesinos I, Eykmans J, Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay, Journal of Clinical Virology (2014), http://dx.doi.org/10.1016/j.jcv.2014.04.025 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
1
Title Page
2 3
Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay
ip t
4 Authors:
6
1. Montesinos, Isabel. MD PhD. Microbiology Department. Erasmus Hospital. Route de
7
Lennik 808. 1070 Brussels, Belgium.
8
e-mail: [email protected]
9
2. Eykmans, Joelle. Microbiology Department. Erasmus Hospital. Route de Lennik 808.
an
us
cr
5
1070 Brussels, Belgium.
11
e-mail: Joelle.Eykmans@ erasme.ulb.ac.be
12
3. Delforge, Marie-Luce, MD. AIDS Reference Laboratory. Microbiology Department.
13
Erasmus Hospital. Route de Lennik 808. 1070 Brussels, Belgium.
14
e-mail: Marie-Luce.Delforge@ erasme.ulb.ac.be
15
te
d
M
10
Corresponding author:
17
Montesinos, Isabel. MD PhD. Microbiology Department. Erasmus Hospital. Route de
18
Lennik 808. 1070 Brussels, Belgium.
19
e-mail: [email protected]
20
Telephone number: 003225558102
Ac ce p
16
21 22
Short communication: 1263 words
23 24 25 26 1
Page 1 of 11
26
Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay
27
Authors: Montesinos I, Eykmans J, Delforge ML
28
Highlights :
cr
Geenius HIV1/2 is evaluated in comparison with MP HIV BLOT 2.2 Geenius HIV1/2 confirmatory system represents a reliable alternative to other confirmatory assays in HIV testing algorithm. Geenius HIV1/2 assay was markedly less time consuming, allowed full traceability, automatic reading and interpretation
us
30 31 32 33 34 35 36 37
ip t
29
an
38 Abstract:
40
Objectives: We have evaluated the recently CE-marked Bio-Rad Geenius HIV1/2 as a
41
rapid and simple alternative to Western Blot for confirmation of HIV screening results.
42
Methods: A total of 160 serum samples were tested: 44 HIV-1 reactive samples by a 4th
43
generation Murex HIV Ag/Ab and/or Vidas HIV Duo Ultra, 5 HIV-2 reactive samples, 15
44
HIV-1 non-B subtype samples and 11 confirmed HIV-1 early seroconversion samples, 72
45
nonreactive samples, 8 indeterminate samples by MP HIV BLOT 2.2 confirmed negative
46
after follow up, 5 low reactive samples by EIA negative by MP HIV BLOT 2.2. The
47
samples were tested according to the manufacturer’s guidelines.
48
Results: Overall sensitivity for Bio-Rad Geenius HIV1/2 assay was 92%. Five out of 11
49
early seroconversion samples were tested positive, 4 negative and 2 indeterminate. All
50
HIV-1 non-B subtype samples were tested positive. Two out of the 5 HIV-2 reactive
51
samples were tested positive HIV-2, 2 positive HIV-2 with HIV-1 cross reaction, and 1
52
HIV positive untypable. After excluding early seroconversion samples, the sensitivity of
53
Bio-Rad Geenius HIV1/2 assay reached 100%. Overall specificity was 96%. All HIV
Ac ce p
te
d
M
39
2
Page 2 of 11
negative serums by 4th generation EIA were tested negative. All 5 low reactive samples
55
by EIA, negative by HIV BLOT 2.2 were tested negative by Bio-Rad Geenius HIV1/2. Two
56
out of the 8 indeterminate samples by MP HIV BLOT 2.2 that were confirmed negative
57
after follow up were tested indeterminate and one invalid, the other 5 were negative.
58
After excluding these last 13 samples, the specificity of Bio-Rad Geenius HIV1/2 assay
59
reached 100%. In comparison with MP HIV BLOT 2.2, the Bio-Rad Geenius HIV1/2
60
assay was markedly time saving, allowed full traceability, automatic reading and
61
interpretation.
62
Conclusions: The Bio-Rad Geenius HIV1/2 confirmatory system represents a reliable
63
alternative to other confirmatory assays in HIV testing algorithms and provides clear
64
improvement in quality management.
M
an
us
cr
ip t
54
65 Keywords:
67
HIV confirmatory tests; Geenius HIV1/2; HIV Western blot
68
Abbreviations:
69
WB: Western blot
70
Bio-Rad Geenius HIV1/2: Geenius
71
MP HIV BLOT 2.2: HIV BLOT 2.2
72
New LAV BLOT II: LAV BLOT II
73
Enzyme-immunoassay screening test: EIA
74
Bio-Rad Multispot HIV1/2: Multispot test
75
Clinical and Laboratory Standard Institute: CLSI
76
Centers for Diseases Control and Prevention: CDC
77
Nucleic acid amplification test: NAAT
Ac ce p
te
d
66
78
3
Page 3 of 11
79 80 81
ip t
82 83
cr
84
us
85 86 Background and Objectives
88
The current laboratory diagnostic algorithm for HIV includes a supplemental assay, such
89
as the Western Blot (WB), to confirm the presence of antibodies and differentiate HIV-1
90
and HIV-2 on repeated reactive samples examined by a 4th generation enzyme-
91
immunoassay (EIA) screening test. WB testing takes several hours of technical time,
92
requires training and expertise in data interpretation. Moreover it may produce
93
indeterminate results and delay reporting, and may be misinterpreted in patients with
94
HIV-2 infection due to antigenic cross-reactivity (1, 2). A new diagnostic testing
95
algorithm has recently been proposed by the Centers for Diseases Control and
96
Prevention (CDC) taking into account testing efficiency, test complexity, turnaround
97
time and cost. In the new algorithm, specimens that are reactive on screening test are
98
subjected to an antibody test that differentiates HIV-1 from HIV-2 (3). We have evaluate
99
the recently CE-marked Bio-Rad Geenius HIV1/2 (Geenius) (Bio-Rad, Marnes-la-
100
Coquette, France), a single use immunochromatographic test, as a rapid and simple
101
alternative to MP HIV BLOT 2.2 (HIV BLOT 2.2) (MP Diagnostics, Ingbert, Germany) to
102
confirm the presence of antibodies and differentiate HIV-1 from HIV-2.
Ac ce p
te
d
M
an
87
4
Page 4 of 11
Methods: A total of 160 serum samples initially determined to be positive or negative
104
by a 4th generation Murex HIV Ag/Ab (Diasorin, Saluggia, Italy) (n=156) and/or Vidas
105
HIV Duo Ultra (bioMérieux, Marcy-l’Etoile, France) (n=78) were tested by Geenius test.
106
The diagnostic performance and the quality management (automated reader,
107
traceability and reporting features) of the test were assessed. Two sets of samples were
108
used to analyse assay diagnostic performances. A total of 75 serums were tested for
109
sensitivity: 44 HIV-1 reactive samples by EIA and HIV BLOT 2.2, 5 HIV-2 reactive
110
samples suspected by HIV BLOT 2.2 and confirmed by New LAV BLOT II, (LAV BLOT II)
111
(Bio-Rad, Marnes-la-Coquette, France), 15 HIV-1 non-B subtype samples (8 CRF02, 1
112
CRF01, 1 CRF11, 1 CRF15, 2 subtype G, 1 subtype F1, 1 subtype C) genotyped with
113
TRUGENE HIV-1 Genotyping Kit and OpenGene DNA Sequencing System (Visible
114
Genetics, Inc), and 11 confirmed HIV-1 early seroconversion samples by HIV testing
115
algorithm including detection of Agp24 (Innotest HIV Antigen mAb, Innogenetics, Gent,
116
Belgium). A total of 85 serums were tested for specificity: 72 nonreactive samples by 4th
117
generation EIA, 8 indeterminate samples by HIV BLOT 2.2 confirmed negative after
118
follow up (no evolution or non reactive result in a second sample), 5 low reactive
119
samples by EIA negative by HIV BLOT 2.2. The samples were tested according to the
120
manufacturer’s guidelines. Geenius cassettes were read and interpreted by an
121
automated reader by means of a proprietary algorithm.
122
Results: The sensitivity and specificity of Geenius are shown in Table 1.
123
Table 1: Sensitivity and specificity of Bio-Rad Geenius HIV1/2 Sensitivity Specificity 92%1 96%1 2 100% 100%3 1Overall sensitivity and specificity. 2Sensitivity excluding seroconversion samples. 3Specificity excluding samples low reactive by 4th generation EIA and confirmed negatives.
124 125 126
Ac ce p
te
d
M
an
us
cr
ip t
103
5
Page 5 of 11
Overall sensitivity for Geenius assay was 92% compared with 89% for the HIV BLOT 2.2.
128
All HIV-1 confirmed positive by HIV BLOT 2.2 were tested HIV-1 positive by Geenius
129
including HIV-1 non-B subtype samples. Five out of the 11 early seroconversion samples
130
were tested positive, 2 indeterminate and 4 negative by Geenius. By HIV BLOT 2.2 these
131
11 early seroconversion samples were tested as follow: 3 positive, 6 indeterminate and
132
2 negative (Table 2).
142 143
cr us an
1
Murex Ab/Ag1 12/35
Vidas Ab/Ag2 0/5
HIV Blot 2.2
Neg4
Ind
HIV p24 Ag (pg/mL) 1174
2
22/272
NP3
Ind5
Neg
>3000
3
0/211
0/5
Ind
Ind
>3000
4
0/59
NP
Neg
Ind
1531
5
3/107
0/5
Neg
Ind
2537
6
79/10
23/0
HIV-1
HIV-1
746
7
17/265
13/0
Neg
Neg
>3000
8
96/22
5/0
HIV-1
Ind
548
9
26/58
NP
HIV-1
Ind
>3000
10
101/14
18/0
HIV-1
HIV-1
359
11
90/11
NP
HIV-1
HIV-1
985
Ac ce p
Patients
1Index, 2Test
M
Geenius
d
Table 2: Seroconversion samples tests results
te
133 134 135 136 137 138 139 140 141
ip t
127
value, 3Not performed, 4Negative, 5Indeterminate
6
Page 6 of 11
After having excluded early seroconversion samples, the sensitivity of Geenius and HIV
145
BLOT 2.2 reached 100%. The ability to differentiate HIV-1 and HIV-2 by Geenius was as
146
follow: 2 out of the 5 HIV-2 reactive samples were tested positive HIV-2 (by HIV BLOT
147
2.2: HIV-1 indeterminate with HIV-2 specific band indicated; by LAV BLOT II HIV-2
148
positive), 2 positive HIV-2 with HIV-1 cross reaction (by HIV BLOT 2.2: HIV-1 positive
149
with HIV-2 specific band indicated; by LAV BLOT II HIV-2 positive), and 1 HIV positive
150
untypable (by HIV BLOT 2.2: HIV-1 positive with HIV-2 specific band indicated; by LAV
151
BLOT II HIV-2 positive). Overall specificity for the Geenius assay was 96%. All HIV
152
negative serums by 4th generation EIA were tested negative. All 5 low reactive samples
153
by EIA negative by HIV BLOT 2.2 were tested negative by Geenius. Two out of the 8
154
indeterminate samples by HIV BLOT 2.2 confirmed negative by follow-up were tested
155
indeterminate and one invalid while the other 5 were negative. After excluding these
156
last 13 samples, the specificity of Geenius assay reached 100%. In comparison with HIV
157
BLOT 2.2, the Geenius assay is markedly time saving (3000
Ind
Ind
>3000
4
0/59
NP
Neg
Ind
1531
5
3/107
0/5
Neg
Ind
2537
6
79/10
23/0
HIV-1
HIV-1
746
7
17/265
13/0
Neg
Neg
>3000
Ac ce p
Neg4
M
Patients
us
Table 2: Seroconversion samples tests results
d
235 236 237 238 239
Table 1: Sensitivity and specificity of Bio-Rad Geenius HIV1/2 Sensitivity Specificity 92%1 96%1 2 100% 100%3 1Overall sensitivity and specificity. 2Sensitivity excluding seroconversion samples. 3Specificity excluding samples low reactive by 4th generation EIA and confirmed negatives.
te
229 230 231 232 233 234
HIV Blot 2.2 Ind
HIV p24 Ag (pg/mL) 1174
8
96/22
5/0
HIV-1
Ind
548
9
26/58
NP
HIV-1
Ind
>3000
10
101/14
18/0
HIV-1
HIV-1
359
11
90/11
NP
HIV-1
HIV-1
985
1Index, 2Test
value, 3Not performed, 4Negative, 5Indeterminate
242 243 244 245
9.
11
Page 11 of 11
S1386-6532(14)00177-2 http://dx.doi.org/doi:10.1016/j.jcv.2014.04.025 JCV 3025
To appear in:
Journal of Clinical Virology
Received date: Revised date: Accepted date:
7-3-2014 29-4-2014 30-4-2014
Please cite this article as: Montesinos I, Eykmans J, Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay, Journal of Clinical Virology (2014), http://dx.doi.org/10.1016/j.jcv.2014.04.025 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
1
Title Page
2 3
Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay
ip t
4 Authors:
6
1. Montesinos, Isabel. MD PhD. Microbiology Department. Erasmus Hospital. Route de
7
Lennik 808. 1070 Brussels, Belgium.
8
e-mail: [email protected]
9
2. Eykmans, Joelle. Microbiology Department. Erasmus Hospital. Route de Lennik 808.
an
us
cr
5
1070 Brussels, Belgium.
11
e-mail: Joelle.Eykmans@ erasme.ulb.ac.be
12
3. Delforge, Marie-Luce, MD. AIDS Reference Laboratory. Microbiology Department.
13
Erasmus Hospital. Route de Lennik 808. 1070 Brussels, Belgium.
14
e-mail: Marie-Luce.Delforge@ erasme.ulb.ac.be
15
te
d
M
10
Corresponding author:
17
Montesinos, Isabel. MD PhD. Microbiology Department. Erasmus Hospital. Route de
18
Lennik 808. 1070 Brussels, Belgium.
19
e-mail: [email protected]
20
Telephone number: 003225558102
Ac ce p
16
21 22
Short communication: 1263 words
23 24 25 26 1
Page 1 of 11
26
Evaluation of the Bio-Rad Geenius HIV-1/2 test as a confirmatory assay
27
Authors: Montesinos I, Eykmans J, Delforge ML
28
Highlights :
cr
Geenius HIV1/2 is evaluated in comparison with MP HIV BLOT 2.2 Geenius HIV1/2 confirmatory system represents a reliable alternative to other confirmatory assays in HIV testing algorithm. Geenius HIV1/2 assay was markedly less time consuming, allowed full traceability, automatic reading and interpretation
us
30 31 32 33 34 35 36 37
ip t
29
an
38 Abstract:
40
Objectives: We have evaluated the recently CE-marked Bio-Rad Geenius HIV1/2 as a
41
rapid and simple alternative to Western Blot for confirmation of HIV screening results.
42
Methods: A total of 160 serum samples were tested: 44 HIV-1 reactive samples by a 4th
43
generation Murex HIV Ag/Ab and/or Vidas HIV Duo Ultra, 5 HIV-2 reactive samples, 15
44
HIV-1 non-B subtype samples and 11 confirmed HIV-1 early seroconversion samples, 72
45
nonreactive samples, 8 indeterminate samples by MP HIV BLOT 2.2 confirmed negative
46
after follow up, 5 low reactive samples by EIA negative by MP HIV BLOT 2.2. The
47
samples were tested according to the manufacturer’s guidelines.
48
Results: Overall sensitivity for Bio-Rad Geenius HIV1/2 assay was 92%. Five out of 11
49
early seroconversion samples were tested positive, 4 negative and 2 indeterminate. All
50
HIV-1 non-B subtype samples were tested positive. Two out of the 5 HIV-2 reactive
51
samples were tested positive HIV-2, 2 positive HIV-2 with HIV-1 cross reaction, and 1
52
HIV positive untypable. After excluding early seroconversion samples, the sensitivity of
53
Bio-Rad Geenius HIV1/2 assay reached 100%. Overall specificity was 96%. All HIV
Ac ce p
te
d
M
39
2
Page 2 of 11
negative serums by 4th generation EIA were tested negative. All 5 low reactive samples
55
by EIA, negative by HIV BLOT 2.2 were tested negative by Bio-Rad Geenius HIV1/2. Two
56
out of the 8 indeterminate samples by MP HIV BLOT 2.2 that were confirmed negative
57
after follow up were tested indeterminate and one invalid, the other 5 were negative.
58
After excluding these last 13 samples, the specificity of Bio-Rad Geenius HIV1/2 assay
59
reached 100%. In comparison with MP HIV BLOT 2.2, the Bio-Rad Geenius HIV1/2
60
assay was markedly time saving, allowed full traceability, automatic reading and
61
interpretation.
62
Conclusions: The Bio-Rad Geenius HIV1/2 confirmatory system represents a reliable
63
alternative to other confirmatory assays in HIV testing algorithms and provides clear
64
improvement in quality management.
M
an
us
cr
ip t
54
65 Keywords:
67
HIV confirmatory tests; Geenius HIV1/2; HIV Western blot
68
Abbreviations:
69
WB: Western blot
70
Bio-Rad Geenius HIV1/2: Geenius
71
MP HIV BLOT 2.2: HIV BLOT 2.2
72
New LAV BLOT II: LAV BLOT II
73
Enzyme-immunoassay screening test: EIA
74
Bio-Rad Multispot HIV1/2: Multispot test
75
Clinical and Laboratory Standard Institute: CLSI
76
Centers for Diseases Control and Prevention: CDC
77
Nucleic acid amplification test: NAAT
Ac ce p
te
d
66
78
3
Page 3 of 11
79 80 81
ip t
82 83
cr
84
us
85 86 Background and Objectives
88
The current laboratory diagnostic algorithm for HIV includes a supplemental assay, such
89
as the Western Blot (WB), to confirm the presence of antibodies and differentiate HIV-1
90
and HIV-2 on repeated reactive samples examined by a 4th generation enzyme-
91
immunoassay (EIA) screening test. WB testing takes several hours of technical time,
92
requires training and expertise in data interpretation. Moreover it may produce
93
indeterminate results and delay reporting, and may be misinterpreted in patients with
94
HIV-2 infection due to antigenic cross-reactivity (1, 2). A new diagnostic testing
95
algorithm has recently been proposed by the Centers for Diseases Control and
96
Prevention (CDC) taking into account testing efficiency, test complexity, turnaround
97
time and cost. In the new algorithm, specimens that are reactive on screening test are
98
subjected to an antibody test that differentiates HIV-1 from HIV-2 (3). We have evaluate
99
the recently CE-marked Bio-Rad Geenius HIV1/2 (Geenius) (Bio-Rad, Marnes-la-
100
Coquette, France), a single use immunochromatographic test, as a rapid and simple
101
alternative to MP HIV BLOT 2.2 (HIV BLOT 2.2) (MP Diagnostics, Ingbert, Germany) to
102
confirm the presence of antibodies and differentiate HIV-1 from HIV-2.
Ac ce p
te
d
M
an
87
4
Page 4 of 11
Methods: A total of 160 serum samples initially determined to be positive or negative
104
by a 4th generation Murex HIV Ag/Ab (Diasorin, Saluggia, Italy) (n=156) and/or Vidas
105
HIV Duo Ultra (bioMérieux, Marcy-l’Etoile, France) (n=78) were tested by Geenius test.
106
The diagnostic performance and the quality management (automated reader,
107
traceability and reporting features) of the test were assessed. Two sets of samples were
108
used to analyse assay diagnostic performances. A total of 75 serums were tested for
109
sensitivity: 44 HIV-1 reactive samples by EIA and HIV BLOT 2.2, 5 HIV-2 reactive
110
samples suspected by HIV BLOT 2.2 and confirmed by New LAV BLOT II, (LAV BLOT II)
111
(Bio-Rad, Marnes-la-Coquette, France), 15 HIV-1 non-B subtype samples (8 CRF02, 1
112
CRF01, 1 CRF11, 1 CRF15, 2 subtype G, 1 subtype F1, 1 subtype C) genotyped with
113
TRUGENE HIV-1 Genotyping Kit and OpenGene DNA Sequencing System (Visible
114
Genetics, Inc), and 11 confirmed HIV-1 early seroconversion samples by HIV testing
115
algorithm including detection of Agp24 (Innotest HIV Antigen mAb, Innogenetics, Gent,
116
Belgium). A total of 85 serums were tested for specificity: 72 nonreactive samples by 4th
117
generation EIA, 8 indeterminate samples by HIV BLOT 2.2 confirmed negative after
118
follow up (no evolution or non reactive result in a second sample), 5 low reactive
119
samples by EIA negative by HIV BLOT 2.2. The samples were tested according to the
120
manufacturer’s guidelines. Geenius cassettes were read and interpreted by an
121
automated reader by means of a proprietary algorithm.
122
Results: The sensitivity and specificity of Geenius are shown in Table 1.
123
Table 1: Sensitivity and specificity of Bio-Rad Geenius HIV1/2 Sensitivity Specificity 92%1 96%1 2 100% 100%3 1Overall sensitivity and specificity. 2Sensitivity excluding seroconversion samples. 3Specificity excluding samples low reactive by 4th generation EIA and confirmed negatives.
124 125 126
Ac ce p
te
d
M
an
us
cr
ip t
103
5
Page 5 of 11
Overall sensitivity for Geenius assay was 92% compared with 89% for the HIV BLOT 2.2.
128
All HIV-1 confirmed positive by HIV BLOT 2.2 were tested HIV-1 positive by Geenius
129
including HIV-1 non-B subtype samples. Five out of the 11 early seroconversion samples
130
were tested positive, 2 indeterminate and 4 negative by Geenius. By HIV BLOT 2.2 these
131
11 early seroconversion samples were tested as follow: 3 positive, 6 indeterminate and
132
2 negative (Table 2).
142 143
cr us an
1
Murex Ab/Ag1 12/35
Vidas Ab/Ag2 0/5
HIV Blot 2.2
Neg4
Ind
HIV p24 Ag (pg/mL) 1174
2
22/272
NP3
Ind5
Neg
>3000
3
0/211
0/5
Ind
Ind
>3000
4
0/59
NP
Neg
Ind
1531
5
3/107
0/5
Neg
Ind
2537
6
79/10
23/0
HIV-1
HIV-1
746
7
17/265
13/0
Neg
Neg
>3000
8
96/22
5/0
HIV-1
Ind
548
9
26/58
NP
HIV-1
Ind
>3000
10
101/14
18/0
HIV-1
HIV-1
359
11
90/11
NP
HIV-1
HIV-1
985
Ac ce p
Patients
1Index, 2Test
M
Geenius
d
Table 2: Seroconversion samples tests results
te
133 134 135 136 137 138 139 140 141
ip t
127
value, 3Not performed, 4Negative, 5Indeterminate
6
Page 6 of 11
After having excluded early seroconversion samples, the sensitivity of Geenius and HIV
145
BLOT 2.2 reached 100%. The ability to differentiate HIV-1 and HIV-2 by Geenius was as
146
follow: 2 out of the 5 HIV-2 reactive samples were tested positive HIV-2 (by HIV BLOT
147
2.2: HIV-1 indeterminate with HIV-2 specific band indicated; by LAV BLOT II HIV-2
148
positive), 2 positive HIV-2 with HIV-1 cross reaction (by HIV BLOT 2.2: HIV-1 positive
149
with HIV-2 specific band indicated; by LAV BLOT II HIV-2 positive), and 1 HIV positive
150
untypable (by HIV BLOT 2.2: HIV-1 positive with HIV-2 specific band indicated; by LAV
151
BLOT II HIV-2 positive). Overall specificity for the Geenius assay was 96%. All HIV
152
negative serums by 4th generation EIA were tested negative. All 5 low reactive samples
153
by EIA negative by HIV BLOT 2.2 were tested negative by Geenius. Two out of the 8
154
indeterminate samples by HIV BLOT 2.2 confirmed negative by follow-up were tested
155
indeterminate and one invalid while the other 5 were negative. After excluding these
156
last 13 samples, the specificity of Geenius assay reached 100%. In comparison with HIV
157
BLOT 2.2, the Geenius assay is markedly time saving (3000
Ind
Ind
>3000
4
0/59
NP
Neg
Ind
1531
5
3/107
0/5
Neg
Ind
2537
6
79/10
23/0
HIV-1
HIV-1
746
7
17/265
13/0
Neg
Neg
>3000
Ac ce p
Neg4
M
Patients
us
Table 2: Seroconversion samples tests results
d
235 236 237 238 239
Table 1: Sensitivity and specificity of Bio-Rad Geenius HIV1/2 Sensitivity Specificity 92%1 96%1 2 100% 100%3 1Overall sensitivity and specificity. 2Sensitivity excluding seroconversion samples. 3Specificity excluding samples low reactive by 4th generation EIA and confirmed negatives.
te
229 230 231 232 233 234
HIV Blot 2.2 Ind
HIV p24 Ag (pg/mL) 1174
8
96/22
5/0
HIV-1
Ind
548
9
26/58
NP
HIV-1
Ind
>3000
10
101/14
18/0
HIV-1
HIV-1
359
11
90/11
NP
HIV-1
HIV-1
985
1Index, 2Test
value, 3Not performed, 4Negative, 5Indeterminate
242 243 244 245
9.
11
Page 11 of 11
