Performance of the HIV Blot 2.2, INNO-LIA HIV I/II Score, and Geenius HIV 1/2 Confirmatory Assay for use in HIV confirmation

Abstract

In view of recent revised recommendations for human immunodeficiency virus (HIV) confirmatory testing, the performance of 3 HIV confirmatory assays was compared. Using the HIV Blot 2.2 (MP-WB), the INNO-LIA HIV I/II Score (INNO), and the Geenius HIV 1/2 Confirmatory Assay (Geenius), we tested 199 HIV-1 positive, 161 HIV negative, 65 HIV western blot indeterminate, 26 HIV seroconversion, 34 early HIV infection and 4 HIV-2 positive archived specimens. We show that all 3 assays had comparable test sensitivity in the detection of HIV-1 positive cases. However, less non-specific reactivity was observed with the INNO and Geenius assays, where both of them were able to resolve MP-WB indeterminate cases. When early HIV cases were considered, INNO and Geenius were more likely to confirm an early-stage infection as positive. Nevertheless, overall poor sensitivity (25.5% - 44.7%) of these assays for the detection of early cases was observed, likely because these cases had very low or non-detectable levels of HIV antibodies. Hence, further testing by a nucleic acid test or a p24 antigen test of specimens reactive on screening with a fourth generation Ag/Ab assay that are negative on confirmatory testing for HIV-specific antibody, may be useful. In conclusion, INNO and Geenius had comparable test performance, although the ease of use and shorter assay time for Geenius may make it the preferred choice for laboratories. In that regard, of note is our observation of non-specific reactivity of lipaemic specimens to the HIV-2 gp140 band in the Geenius assay, which should prompt caution when interpreting results of such specimens.

Are Confirmatory Assays Reliable for HIV-1/HIV-2 Infection Differentiation? A Multicenter Study

“…On the opposite, assays designed only to identify HIV-2 infection, HIV-2 Blot 1.2 and New Lav Blot II, exhibited high rates of undetermined results and misclassified as HIV-2 some HIV-1 only infections (7% and 5%, respectively), a consequence of cross-reactivity between HIV-1 antibodies and HIV-2 proteins. These results are consistent with previous studies regarding HIV-1 infection sensitivities and undetermined results for INNO-LIA (27,36,37), HIV Blot 2.2 (36,38), New Lav Blot I and II (39,40) and Geenius (27, 36-39, 41, 42), summarized in Fig. 1.…”

“…New Lav Blot II and HIV-2 Blot 1.2 had reported sensitivities of at least 95% (32,43). INNO-LIA had a reported sensitivity of 100% (36,37), while sensitivity ranged from 85% to 100% for Geenius (27,(39)(40)(41)(42)44). However, most of these studies included a very limited number of patients.…”

Performance of HIV rapid testing algorithm in Nigeria: Findings from a household-based Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS)

“…Positive confirmation continues to be even more important as we expand initiation on antiretroviral therapy (ART) immediately after receiving HIV-positive test results [4]. The false positive rate observed by a testing algorithm can be significantly reduced by including a third HIV RT or by including a confirmatory test such as Geenius HIV-1/2 RT (Geenius) or HIV-1 Western blot (WB) [5][6][7][8]. However, the Geenius and WB tests are more complex, expensive, and require appropriate laboratory infrastructure and instrument maintenance.…”

Evaluation of Geenius HIV-1/2 Confirmatory Assay for the confirmatory and differential diagnosis of HIV-1/HIV-2 in Japan and reliability of the Geenius Reader in the diagnosis of HIV-2

“…Montesinos et al reported that five of 11 specimens from the acute phase of HIV-1 infection were identified as HIV-1-positive using Geenius [ 10 ]. Abbate et al [ 11 ] and Wong et al [ 12 ] reported that the sensitivity of the test for acute HIV-1 infection was low. Kondo et al reported that seven of 20 specimens from the acute phase of HIV-1 infection were identified as HIV-1-positive [ 13 ].…”