HIV Diagnostic Tests

Bernard M. Branson, M.D. Associate Director for Laboratory Diagnostics

Division of H IV/AIDS Prevention Centers for Disease Control & Prevention

The views expressed in this presentation are those of the author and do not necessarily represent those of the Centers for Disease Control and Prevention

Generations

1st and 2nd Generation EIA Plasma/serum (1 h/37o C)

Plasma/serum

Color reagent

Antigen 1st - Viral lysate 2nd – Recombinant proteins or synthetic peptides

IgG HIV antibody

enzyme

anti-human IgG

Detects HIV IgG

Enzyme- detection

EIA

Western blot

IFA

3rd Generation “Sandwich” EIA

Antigen: Recombinant proteins or synthetic peptides Enzyme-

detection

Color reagent

Plasma/serum HIV antibody

enzyme

HIV antigen

Detects HIV IgM or IgG

IgG IgM

4th Generation Combo EIA

Color reagent

Enzyme- detection

HIV antigen p24 antibody

Plasma/serum HIV antibodies p24 antigen

HIV antigen

p24 antibody

Detects IgM or IgG

antibody or p24 antigen

i

HIV Infection and Laboratory Markers

HIV RNA (plasma) HIV Antibody

0 10 20 30 40 50 60 70 80 90 100

HIV p24 Ag

22

1st gen

2nd gen

3rd gen

Days

Modified after Busch et al. Am J Med. 1997

Infection

9

4th gen

1985 Abbott

HIV-1 EIA

1987 Vironostika

EIA

1992 Abbott

HIV-1/HIV-2 EIA

2000 Genetic Systems

HIV-1/HIV-2 Peptide EIA

2002 OraQuick

HIV-1/HIV-2 Rapid Test

2003 GS HIV-1

HIV-2 Plus O EIA

2004 Multispot

HIV-1/HIV-2 Rapid Test

2006 Aptima

Qualitative RNA

2006 Advia Centaur

1/O/2 CIA

2008 Ortho Vitros

HIV 1+2 CIA

1991 Cambridge

Western blot

1992 Fluorognost

IFA

1998 Genetic Systems

rLAV (HIV-1)

2003 Unigold Reveal

HIV-1 Rapid Tests

2010 Abbott

Architect Ag/Ab

Combo CIA

2011 Bio-Rad Ag/Ab Combo

EIA

2010 INSTI HIV-1

Rapid Test

2009 Avioq HIV-1

EIA

3rd & 4th gen lab screening tests

2nd gen rapid tests 1st gen confirmatory

Uni-Gold Recombigen 2003

Multispot HIV-1/HIV-2 2004

Reveal G3 2003

OraQuick Advance 2002

Clearview Complete HIV 1/2 2006

Clearview HIV 1/2 Stat Pack 2006

Rapid HIV Test Results without

Rapid Test Kits

On-board Refrigeration of Multiple Different Assays

Random Access Multiplatform analyzers for HIV testing

STAT sample requests without pausing Results in < 60 minutes

Random Access Multiplatform analyzers for HIV testing

ADVIA® Centaur™ H IV 1/O /2 Enhanced (EH IV) Chemiluminescent

immunoassay

3rd generation format - H IV-1: gp41, p24 - H IV-2: gp36 - group O

Time to result < 1 hour

FDA-approved July 2006

Ortho VITROS ECi/ECiQ Chemiluminescent

immunoassay

3rd generation format - H IV-1: gp41, gp120, p24 - H IV-2: gp36 - group O

Time to result < 1 hour

Repeat only borderline results

FDA-approved March 2008

Chemiluminescent immunoassay

Detects p24 antigen and H IV antibody

Time to result: 29 minutes

FDA-approved

June 22, 2010

Abbott Architect 4th Generation Ag/Ab Combo Assay

APTIMA Qualitative HIV-1 RNA Assay Aid to H IV-1 diagnosis

Diagnosis of acute H IV-1

infection in antibody-negative persons

Confirmation of H IV-1 infection in antibody-positive persons when it is reactive

FDA-approved July 2006

Bio-Rad GS HIV Combo Ag/Ab EIA

Microwell plate EIA

3rd generation format: - HIV-1: gp160 - HIV-2: gp36 - Group O

p24 antigen

FDA-approved July 25, 2011

Relative Seroconversion Sensitivity

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0.90

1.00

-50 -40 -30 -20 -10 0 10 20 30

Genprobe

Architect 4th

BioRad 4th

Advia 3rd

Vitros 3rd

Abbott 3rd

BioRad 3rd

Insti

Multispot

Reveal

Statpak

Complete

Unigold

Oraq Adv

Cum

ulat

ive

frequ

ency

of p

ositi

ve te

sts

days to WB positive

26 seroconverters were analyzed with 14 tests 17 seroconverters with WB positive used for cumulative frequency analysis

Sequence of Test Positivity Relative to WB 166 specimens, 17 Seroconverters - 50 % Positive Cumulative Frequency

Modified from Masciotra et al, J Clin Virol 2011

Days before WB positive

WB

posi

tive

APT

IMA

(-26)

GS

1/2+

O (

-12)

Mul

ti-Sp

ot (

-7)

Reve

al G

3,

(-6)

Viro

nost

ka (+

2)

Ora

Qui

ck (-

1)

Uni

gold

(-2)

25

20

10

5 0 15

Arch

itect

Ag/

Ab C

ombo

(-2

0)

COM

PLET

E H

IV-1

/2 (

-5)

HIV

-1/2

STA

T-PA

K (-

5)

Advi

a (-

14)

Vitr

os (

-13)

INST

I (-9

)

Bio-

Rad

Ag/

Ab C

ombo

(-1

9)

and Owen et al, J Clin Micro 2008

Avio

q

Det

erm

ine

Ag/A

b Co

mbo

(-1

5)

Acute Infections in MSM detected by RNA only

0.3% of 14,005 frequently tested MSM in Seattle STD clinic; 20% of all HIV infections detected

26 (74%) of 35 AHI cases detected in LA at MSM clinic; 25% of all HIV infections detected

0.08% of 21,425 STD clinic patients in New York City; 9% of all HIV infections detected; 94% were MSM

- Stekler et al, Clin Infect Dis 2009

- Shepard et al, MMWR 2009

- Patel et al, Archives Int Med 2010

RNA vs. 4th Generation Ag/Ab Assay

RNA+ / 3rd gen-negative specimens detected by 4th generation EIA: 38 of 46 (83%) – Australia* 10 of 14 (71%) – CDC AHI study** 51 of 61 (84%) – CDC panel***

4 days after RNA – 9 seroconversion panels***

* Cunningham P, HIV Diagnostics Conf 2007 ** Patel P, CROI 2009 *** Owen M, CROI 2009

On the Horizon…

Ag/Ab Rapid Test

Point-of-careHIV-1/2 antibody differentiation assay with

automated reader

Point-of-care finger-stick viral load and CD4

analyzer