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HIV Diagnosis: New Proposed Algorithms and Evolution of HIV Diagnostics

HIV Diagnosis: New Proposed Algorithms and Evolution of HIV Diagnostics. Margaret A Lampe, RN, MPH Bernard M. Branson, M.D. CDC Division of HIV/AIDS Prevention.

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HIV Diagnosis: New Proposed Algorithms and Evolution of HIV Diagnostics

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  1. HIV Diagnosis:New Proposed Algorithms and Evolution of HIV Diagnostics Margaret A Lampe, RN, MPH Bernard M. Branson, M.D. CDC Division of HIV/AIDS Prevention The findings and conclusions are those of the author and do not necessarily represent the official position of the Centers for Disease Control and Prevention

  2. Agenda Describe changes in HIV testing technology Outline relative sensitivity of immunoassays during early HIV infection Experience detecting Acute HIV Infection Diagnosis and misclassification of HIV-2 Proposed new diagnostic algorithm HIV screening in health-care settings

  3. Diagnostic Algorithm since 1989 • The Public Health Service recommends that no positive test results be given to clients/patients until a screening test has been repeatedly reactive on the same specimen and a supplemental, more specific test such as the Western blothas been used to validate those results.

  4. 1989: State of the Art

  5. Generations

  6. 1stand 2nd Generation EIA Plasma/serum (1 h/37o C) IgG HIV antibody Plasma/serum enzyme Antigen 1st - Viral lysate 2nd – Recombinant proteins or synthetic peptides Enzyme- detection anti-human IgG Detects HIV IgG Color reagent

  7. EIA Western blot IFA

  8. CLIA-Waived Point-of-Care Rapid HIV Tests OraQuick Advance Clearview Complete Uni-Gold Recombigen INSTI Clearview Stat Pak

  9. 3rdGeneration “Sandwich” EIA HIV antibody Plasma/serum IgM IgG enzyme Antigen: Recombinant proteins or synthetic peptides Enzyme- detection HIV antigen Detects HIV IgM or IgG Color reagent

  10. 4thGeneration Combo Assay HIV antibodies Plasma/serum p24 antigen HIV antigen Enzyme- detection HIV antigen p24 antibody p24 antibody Detects IgM or IgG antibody or p24 antigen Color reagent

  11. 2008 Ortho Vitros HIV 1+2 CIA 2011 Bio-Rad Ag/Ab Combo EIA 1992 Abbott HIV-1/HIV-2 EIA 2000 Genetic Systems HIV-1/HIV-2 Peptide EIA 2006 AdviaCentaur 1/O/2 CIA 2010 Abbott Architect Ag/Ab Combo CIA 3rd & 4thgen lab screening tests 2003 GS HIV-1 HIV-2 Plus O EIA 1987 Vironostika EIA 2002 OraQuick HIV-1/HIV-2 Rapid Test 2004 Multispot HIV-1/HIV-2 Rapid Test 2009 Avioq HIV-1 EIA 1992 Fluorognost IFA 1985 Abbott HIV-1 EIA 2003 Unigold Reveal HIV-1 Rapid Tests 1991 Cambridge Western blot 2006 AptimaQualitative RNA 1998 Genetic Systems rLAV(HIV-1) 2010 INSTI HIV-1 Rapid Test 1st gen confirmatory tests 2nd gen rapid tests

  12. APTIMA Qualitative HIV-1 RNA Assay • Aid to HIV-1 diagnosis • Diagnosis of acute HIV-1 infection in antibody-negative persons • Confirmation of HIV-1 infection in antibody-positive persons when it is reactive • FDA-approved July 2006

  13. Abbott Architect 4th Generation Ag/Ab Combo Assay • Chemiluminescent immunoassay • Detects p24 antigen and HIV antibody • Time to result: 29 minutes • FDA-approved June 22, 2010

  14. Bio-Rad GS HIV Combo Ag/Ab EIA • Microwell plate EIA • 3rd generation Ab format: - HIV-1: gp160 • HIV-2: gp36 • Group O • p24 antigen • FDA-approved July 25, 2011

  15. Determine Combo Rapid HIV 1/2 Ag/AbTest • CLIA moderate complexity • Distinguishes Ag from Ab • Whole blood, serum plasma • FDA-approved August 2013

  16. Antigen Control Antibody

  17. 0 10 20 30 40 50 60 70 80 90 100 HIV Infection and Laboratory Markers HIV RNA (plasma) HIV Antibody HIV p24 Ag 22 Days 4th gen 3rd gen 2nd gen Infection 1st gen Acute HIV Infection Modified after Busch et al.  Am J Med. 1997

  18. Relative Seroconversion Sensitivity Cumulative frequency of positive tests days before positive Western blot • 26 seroconverters were analyzed with 14 tests • 17 seroconverters with WB positive used for cumulative frequency analysis

  19. Sequence of Test Positivity Relative to WB (serum)166 specimens, 17 Seroconverters -50 % Positive Cumulative Frequency Vitros (-13) Determine Ag/Ab Combo (-15) Architect Ag/Ab Combo (-20) Bio-Rad Ag/Ab Combo (-19) Reveal G3, (-6) Avioq COMPLETE HIV-1/2 (-5) HIV-1/2 STAT-PAK (-5) GS 1/2+O (-12) APTIMA (-26) OraQuick (-1) Vironostka(+2) Multi-Spot (-7) INSTI (-9) DPP (-8) Unigold (-2) Advia(-14) WB positive 25 15 10 20 5 0 Days before WB positive Modified from Masciotra et al, J ClinVirol 2011 and Owen et al, J Clin Micro 2008

  20. Why Does It Matter? - Stekler et al, ClinInfDis 2009 • Sensitivity among frequently-tested MSM in Seattle • 192 infected with HIV • 23 (12%) detected only by RNA • (15/16 tested detected by Ag/Ab immunoassay) • 169 (88%) detected by serum Ab immunoassay • 153 (80%) detected by oral fluid rapid test

  21. 5 4 3 2 Acute Infection 6 wks AIDS Asymptomatic Infection HIVProgression Increased Risk of Sexual Transmission of HIV 1/30- 1/200 Virus 75-750 times more infectious HIV RNA in Semen (Log10 copies/ml) 1/100- 1/1000 1/500 - 1/2000 1/1000 - 1/10,000 Cohen & Pilcher, J Infect Dis. 2005

  22. Transmission Rate by Stage of Infection Hollingsworth et al, JID 2008

  23. HIV-1 Transmission, by Stage of Infection and Behavior Pattern Hollingsworth et al, JID 2008

  24. Clinical Syndrome of Acute HIV • Kahn et al, NEJM 199 • Weintrobet al, Arch Int Med 2003 • 40-90% develop symptoms of Acute HIV • 50%-90% with symptoms seek medical care • Of those diagnosed with Acute HIV, 50% of patients seen at least 3 times before diagnosis

  25. Clinical Manifestations 101 seroconverters, HIVNET cohort 1995-98 - Celum et al, JID 2001

  26. Pooled RNA Screening for Acute HIV Infection

  27. CDC Acute HIV Infection Study 1-Stage RNA Pooling, antibody-negative specimens 16 Specimens A B C D E F G H I J K L M N O P 1 Master Pool • 80 HIV testing clinics in Florida • 14 STD clinics and 1 MSM clinic in Los Angeles • 3 STD clinics in New York - Patel et al, Archives Int Med 2010

  28. Acute HIV Screening: 99,111 tested - Patel et al, CDC , Archives Int Med 2010

  29. Acute HIV Screening: 99,111 tested - Patel et al, CDC , Archives Int Med 2010

  30. Phoenix ED Screening July 2011 through February 2013 -MMWR June 21, 2013 • 4th gen screening of patients who had blood drawn • 15% of patients declined testing • 13,014 patients tested • 37 (0.3%) new HIV infections • 12 (32.4%) had Acute HIV Infection (antibody negative) • Median viral load: • Patients with acute infections: 6 million • Patients with established infections: 25,000

  31. RNA vs. 4thGeneration Ag/Ab Assay * Cunningham P, HIV Diagnostics Conf 2007 ** Patel P, CROI 2009 • 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*** *** Owen M, CROI 2009

  32. Limitations of the 1989 Algorithm Antibody tests do not detect infection in ~ 10% of infected persons at highest risk of transmission Western blot confirmation is less sensitive during early infection than many widely used screening tests Antigen/antibody combo tests now FDA-approved that can detect most antibody-negative persons during highly infections acute infection stage

  33. HIV-2 Infection • Remains uncommon in U.S., but • Does not respond to NNRTIs, some PIs (first line therapy) • Undetectable by HIV-1 viral load tests • Misclassification by HIV-1 Western blot: • 54/58 (93%) HIV-2 patients tested had positive HIV-1 WB (NYC)* • 97/163 (60%) HIV-2 cases reported had positive HIV -1 WB (CDC)** • HIV-2 often diagnosed after immunologic deterioration in patient with negative viral load *Torian et al, Clinical Infectious Disease 2010 **MMWR July 2011

  34. CDC/APHL Proposed New HIV Testing Algorithm

  35. 4th generation HIV-1/2 immunoassay (-) (+) Negative for HIV-1 and HIV-2 antibodies and p24 Ag HIV-1/HIV-2 antibody differentiation immunoassay HIV-1 (-) HIV-2 (+) HIV-2 antibodies detected HIV-1 (+) HIV-2 (+) HIV antibodies detected HIV-1 (-) or indeterminate HIV-2 (-) HIV-1 (+) HIV-2 (-) HIV-1 antibodies detected NAT NAT (+) Acute HIV-1 infection NAT (-)Negative for HIV-1

  36. Multispot HIV-1/HIV-2 Rapid Test • CLIA moderate complexity with serum, plasma • Perform test in 15 minutes • Shelf life: 1 year refrigerated, 3 months room temperature • FDA-approved for use in algorithm March 28, 2013

  37. Several timed reagent & wash steps

  38. FDA-approved HIV-1/HIV-2 Antibody Differentiation Assay Reactive Control Recombinant HIV-1 Peptide HIV-2 Peptide HIV-1

  39. 4th generation HIV-1/2 immunoassay (-) (+) Negative for HIV-1 and HIV-2 antibodies and p24 Ag HIV-1/HIV-2 antibody differentiation immunoassay HIV-1 (-) HIV-2 (+) HIV-2 antibodies detected HIV-1 (+) HIV-2 (+) HIV antibodies detected* HIV-1 (-) or indeterminate HIV-2 (-) HIV-1 (+) HIV-2 (-) HIV-1 antibodies detected NAT NAT (+) Acute HIV-1 infection NAT (-)Negative for HIV-1 *Additional testing required to rule out dual infection

  40. Validation Results – NY State 38,257 specimens – 1,659 GS HIV-1/2 Plus O (3rd gen) EIA repeatedly reactive New Algorithm Current Algorithm 1,546 HIV-1 positive 32 discrepant specimens: 28 indeterminate 4 negative • 1,579 HIV-1 positive (MS) • 32 discrepant specimens: • 29 RNA+ • 3 follow-up specimens + -Styer et al, J ClinVirol, 2011

  41. Validation Results – NY State 38,257 specimens – 1,659 GS HIV-1/2 Plus O (3rd gen) EIA repeatedly reactive New Algorithm Current Algorithm 1,546 HIV-1 positive 32 discrepant specimens: 28 indeterminate 4 negative • 1,579 HIV-1 positive (MS) • 32 discrepant specimens: • 29 RNA+ • 3 follow-up specimens + • 75 required RNA • 3 RNA detected • 63 RNA-negative -Styer et al, J ClinVirol, 2011

  42. Validation Results – NY State 38,257 specimens – 1,659 GS HIV-1/2 Plus O (3rd gen) EIA repeatedly reactive New Algorithm Current Algorithm 1,546 HIV-1 positive 32 discrepant specimens: 28 indeterminate 4 negative 48 indeterminate • 1,579 HIV-1 positive (MS) • 32 discrepant specimens: • 29 RNA+ • 3 follow-up specimens + • 75 required RNA • 3 RNA detected • 63 RNA-negative • 9 indeterminate (RNA unsuitable) -Styer et al, J ClinVirol, 2011

  43. Validation Results – NY State 38,257 specimens – 1,659 GS HIV-1/2 Plus O (3rd gen) EIA repeatedly reactive New Algorithm Current Algorithm 5 HIV-2 112 HIV-2 EIA on WB-neg or indeterminate specimens 5 Multispot supplemental 36,649 (99.95%) correctly reported negative • 5 HIV-2 (Multispot) • 36,661 (99.98%) correctly reported negative -Styer et al, J ClinVirol, 2011

  44. Abbott Architect Ag/Ab Evaluation:Specimens from 4 CDC studies -Chavez et al, J ClinVirol 2011

  45. Implementation: MassachusettsFirst 12 months • 7,984 specimens tested • 258 (3.2%) positive for HIV-1 • 1 (0.01%) positive for HIV-2 • 8 (0.10%) acute HIV infections • 6 = 3rd gen EIA negative, WB negative • 2 = 3rd gen EIA reactive, WB indeterminate • 15% reduction in overall testing costs

  46. Implications • Ability to detect acute HIV infection • Focus for partner services and intervention efforts • New surveillance case definition: Stage 0 • Ability to detect HIV-2 infections • False-Negative results with viral load tests • Do not respond to many ARVs, e.g. NNRTI’s and several protease inhibitors

  47. Summary New assays detect HIV infection sooner Acute HIV infection plays a major role in sustaining onward HIV transmission New testing algorithm will routinely detect acute HIV infection and HIV-2 Tests to determine whether HIV infection is recent are on the horizon and will allow staging and potential treatment interventions

  48. References Evaluation of an alternative HIV diagnostic algorithm using specimens from seroconversion panels and persons with established HIV infections. Mascitora S, et al. J ClinVirol. 2011 Dec;52 Suppl 1:S17-22. Update on HIV Diagnostic Testing Algorithms. Journal of Clinical Virology – open access http://www.journalofclinicalvirology.com/supplements# Criteria for Laboratory Testing and Diagnosis of Human Immunodeficiency Virus Infection; Approved Guideline. Clinical and Laboratory Standards Institute CLSI document M53-A

  49. Acknowledgements CDC: Bernie Branson, Michele Owen Bio-Rad: Chris Bentsen

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