Decreased specificity of an assay for recent infection in HIV-1-infected patients on highly active antiretroviral treatment: implications for incidence estimates.
The aim of this study was to estimate the rate of misclassification in treated HIV patients who initiated treatment at the chronic stage of HIV infection using an enzyme immunoassay (EIA) that discriminates between recent infection (RI; within 6 months) and established infection. The performance of EIA-RI was evaluated in 96 HIV-1 chronically infected patients on highly active antiretroviral therapy (HAART) with an undetectable viral load (VL) for at least 3 years. Demographic data, HIV-1 viral load, CD4(+) T-cell count, viral subtype, and treatment duration were collected. The subset of misclassified patients was further analyzed using samples collected annually. The impact on incidence estimates was evaluated by simulation. The specificity in treated patients was significantly lower (70.8 to 77.1%) than that observed in untreated patients (93.3 to 99.3%, P < 0.001). Patients falsely classified as recently infected had been treated for a longer period and had longer-term viral suppression than those correctly classified. The loss of specificity of the test due to treatment may have a dramatic impact on the accuracy of the incidence estimates, with a major impact when HIV prevalence is high. The cross-sectional studies intended to derive HIV incidence must collect information on treatment or, alternatively, should include detection of antiretroviral drugs in blood specimens to rule out treated patients from the calculations.
Inserm U966 and HIV National Reference Center, Université François Rabelais and CHU Bretonneau, Tours, France.
Antoine
A
Chaillon
Stéphane
S
Le Vu
Sylvie
S
Brunet
Guillaume
G
Gras
Frédéric
F
Bastides
Louis
L
Bernard
Laurence
L
Meyer
Francis
F
Barin
D019380:Anti-HIV Agents / Q000008:administration & dosage*; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003951:Diagnostic Errors / Q000706:statistics & numerical data; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013997:Time Factors; D019562:Viral Load
D019380:Anti-HIV Agents