Characteristics of the Results of Testing for HIV-1 Infection by the Geenius HIV-1/2 Confirmatory Assay in Cases with Acute HIV-1 Infection

<p>The Geenius HIV-1/2 Confirmatory Assay (Geenius), which allows simultaneous detection of anti-HIV-1 and -2 antibodies has recently been introduced as a confirmatory test for HIV infection. Because of the limited number of patients with acute HIV-1 infection in whom this test has been conducted, further accumulation of information in patients with acute HIV-1 infection is required. In particular, the reliability and trend of the Geenius test results in each stage (six stages, I-VI) of the acute and early phase classification of HIV-1 infection (Fiebig stage, hereafter FS) and the characteristics of the associated viral pathological conditions are not yet fully understood. Herein, we report the results of a retrospective analysis conducted to clarify these issues.</p><p>First, since all cases after FS V showed an HIV-1-positive result, the confidence limit by Geenius was set at FS V. Next, we found unique relationships with pathological conditions in each FS: 1) a positive correlation was observed between the blood viral load (VL) and the signal-to-cutoff ratio (S/CO) of the fourth-generation screening test in the group of cases that was HIV-1-negative by Geenius; 2) a negative correlation between VL and CD4-positive T cell counts was found in the HIV-1-positive early case group, in whom the VL was significantly low. These observations suggest that the positivity rate by the Geenius assay in patients with acute-phase infection cases is correlated with the viral pathological features in each FS. These results may provide important information to clarify the relationship between the test results by the Geenius assay and the viral pathological conditions in patients with acute-stage HIV-1 infection.</p>