Factors Associated with Incorrect Identification of Recent HIV Infection Using the BED Capture Immunoassay

摘要

The BED capture enzyme immunoassay (BED-CEIA) was developed for estimating HIV incidence from cross-sectional data. This assay misclassifies some individuals with nonrecent HIV infection as recently infected, leading to overestimation of HIV incidence. We analyzed factors associated with misclassification by the BED-CEIA. We analyzed samples from 383 men who were diagnosed with HIV infection less than 1 year after a negative HIV test (Multicenter AIDS Cohort Study). Samples were collected 2–8 years after HIV seroconversion, which was defined as the midpoint between the last negative and first positive HIV test. Samples were analyzed using the BED-CEIA with a cutoff of OD-n ≤0.8 for recent infection. Logistic regression was used to identify factors associated with misclassification. Ninety-one (15.1%) of 603 samples were misclassified. In multivariate models, misclassification was independently associated with highly active antiretroviral treatment (HAART) for >2 years, HIV RNA <400 copies/ml, and CD4 cell count <50 or <200 cells/mm³; adjusted odds ratios (OR) and 95% confidence intervals (CI) were 4.72 (1.35–16.5), 3.96 (1.53–10.3), 6.85 (2.71–17.4), and 11.5 (3.64–36.0), respectively. Among 220 men with paired samples, misclassification 2–4 years after seroconversion was significantly associated with misclassification 6–8 years after seroconversion [adjusted OR: 25.8 (95% CI: 8.17–81.5), p<0.001] after adjusting for race, CD4 cell count, HIV viral load, and HAART use. Low HIV viral load, low CD4 cell count, and >2 years of HAART were significantly associated with misclassification using the BED-CEIA. Some men were persistently misclassified as recently infected up to 8 years after HIV seroconversion.