2382. Evaluation of Abbott ARCHITECT HIV Combo signal to cutoff ratio and ambiguous nucleotide frequency as markers of HIV infection duration
Session: Oral Abstract Session: HIV Prevention and Diagnosis
Saturday, October 29, 2016: 2:45 PM
Room: 288-290

Background:

Acute and early HIV infection infections contribute disproportionately to onward HIV transmission. Host antibody response and viral diversity increase with HIV infection duration and may serve as markers for acute and early infection. In a secondary analysis from a prospective study of acute HIV infection, we evaluated whether these outcomes were correlated with HIV infection duration.

Methods:

We used study HIV testing data, date of last negative HIV test prior to diagnosis (LN), and date of first positive HIV test (FP) to classify a subset of 675 participants into five groups (Table): (1) Acute (rapid HIV test (-), HIV RNA (+)); (2) LN <6 months prior; (3) LN 6-12 months prior; (4) LN 12-24 months prior; (5) Chronic (FP >24 months prior). We measured host antibody response using the signal to cutoff ratio (SCR) from the Abbott ARCHITECT HIV Combo assay in all individuals and viral diversity using proportion of HIV polymerase (pol) region ambiguous nucleotide bases (ANB) in 309 (56%) individuals for whom a genetic sequence was available. We used linear regression to evaluate group differences in mean SCR and Mantel-Haenszel c2 tests to evaluate group differences in ANB proportion.

Results:

Mean age of individuals in our analysis was 31 years, and 88% were men who have sex with men. Group mean SCR increased significantly as estimated time since infection increased: Acute (49); LN <6 (215); LN 6-12 (388); LN 12-24 (488); Chronic (805) (p<0.001; Figure 1). Similar proportions of individuals had <0.5% ANB in Acute (91%), LN <6 (90%), LN 6-12 (98%), and LN 12-24 (95%) groups (p=0.338; Figure 2), but a significantly smaller proportion of individuals in the Chronic group had <0.5% ANB compared to that of individuals in the other four non-Chronic groups (48% vs 92%, p<0.001).

Conclusion:

Our findings suggest that routine clinical testing data may provide accurate information on HIV infection duration, and reporting SCR and ANB can be of value. SCR increased over a two year interval following acute infection and showed greatest discriminatory power between individuals with and without acute infection. In contrast, ANB proportion only increased significantly in persons with chronic infection of duration greater than two years, indicating SCR and ANB proportion may be complementary measures.

 




Sarah E. Porter, MPH1, Shirley Lee Lecher, MD1, Anupama Shankar, MS1, Emily Westheimer, MS2, Cynthia L. Gay, MD, MPH3, Stephanie E. Cohen, MD, MPH4, Ellsworth Campbell, MS1, Nekabari Sigalo, BA5, Charles E. Rose, PhD1, Jing Zhou, MPH1, Jin-Fen Li, PhD1, Jeffrey a. Johnson, PhD1, William M. Switzer, MPH1 and Philip J. Peters, MD1, (1)Centers for Disease Control and Prevention, Atlanta, GA, (2)Bureau of STD Prevention and Control, New York City Department of Health and Mental Hygiene, Queens, NY, (3)University of North Carolina, Chapel Hill, NC, (4)San Francisco Department of Public Health, San Francisco, CA, (5)ICF International, Atlanta, GA

Disclosures:

S. E. Porter, None

S. L. Lecher, None

A. Shankar, None

E. Westheimer, None

C. L. Gay, None

S. E. Cohen, None

E. Campbell, None

N. Sigalo, None

C. E. Rose, None

J. Zhou, None

J. F. Li, None

J. A. Johnson, None

W. M. Switzer, None

P. J. Peters, None

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