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High Throughput Donor Plasma NAT Screening Assay Applied to Acute HIV Detection in a Public Health Setting December 5, 2007 Josh Goldsmith, Ph.D. National.

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Presentation on theme: "High Throughput Donor Plasma NAT Screening Assay Applied to Acute HIV Detection in a Public Health Setting December 5, 2007 Josh Goldsmith, Ph.D. National."— Presentation transcript:

1 High Throughput Donor Plasma NAT Screening Assay Applied to Acute HIV Detection in a Public Health Setting December 5, 2007 Josh Goldsmith, Ph.D. National Genetics Institute, a LabCorp Company

2 S L I D E 2 Presentation Outline Current challenges with acute HIV screening NGI PCR and pooling methods A prospective clinical study to validate the method for plasma donor screening Acute HIV demonstration project with SFDPH

3 S L I D E 3 Challenges in the Implementation of PCR- Based Acute HIV Screening Programs Availability of validated methods Availability of off-the-shelf methods Availability of cost-effective methods Availability of scalable methods where broad- based screening programs are envisioned

4 S L I D E 4 National Genetics Institute (NGI) Profile A provider of automated, sensitive PCR methods for infectious disease testing Offers assays for HIV, HAV, HBV, HCV, and other infectious agents Screens the majority of US supply of source plasma for infectious agents (~8M donations/year) with pools of 512 samples A licensed clinical laboratory and approved by FDA CBER to perform pooled nucleic acid testing for donor plasma screening A subsidiary of LabCorp with access to blood draw centers and courier networks throughout the US

5 S L I D E 5 Dilution Profile Analytical Sensitivity of UltraQual HIV- 1 PCR Probit Analysis 99% detection cut-off = 5 copies/ml 512 x 5 copies/ml = 2560 copies/ml (minimum titer in individual sample to have 99% probability of detection in 512 sample pool

6 S L I D E 6 NGI Pooling and Pool Resolution Process Launch Executable File

7 S L I D E 7 NGI Prospective Clinical Study Study Objectives To demonstrate HIV-1 PCR testing of pooled plasma samples can accurately detect HIV-1 infection To validate plasma pooling and pool resolution process for pools 512 individual samples To determine the clinical sensitivity and specificity of the pooling and pool resolution process

8 S L I D E 8 NGI Prospective Clinical Study Study Design 342,729 plasma donations collected from ~48,000 donors donating at 33 donor centers over a 3.5 months Informed consent obtained for HIV Ab and RT-PCR testing Individual plasma samples tested for HIV Ab (Bio-Rad) and HIV-1 p24 antigen (Coulter) and HIV RNA (NGI)

9 S L I D E 9 NGI Prospective Clinical Study Pool Numbers and Sizes

10 S L I D E 10 NGI Prospective Clinical Study Results

11 S L I D E 11 NGI Prospective Clinical Study Results Clinical Specificity-false positives samples HIV-1 PCR (-) Clinical Specificity = samples HIV-1 (- )* * HIV-1 (-) defined as samples for which test results for HIV-1 PCR, HIV EIA, and/or p24 antigen are negative 342,668 HIV-1 PCR (-) Clinical Specificity = 342,668 HIV-1 (-)* (HIV-1 PCR) = 100%** **95% CI %

12 S L I D E 12 NGI Prospective Clinical Study Results Clinical Sensitivity-false negatives samples HIV-1 PCR (+) Clinical Sensitivity = samples HIV-1 (+)* * HIV-1 (+) defined as subjects for which test results for HIV-1 PCR, HIV EIA, and/or p24 antigen are positive 18 HIV-1 PCR (+) Clinical Sensitivity = (HIV-1 PCR) 18 HIV-1 (+)* = 100%** **95% CI %

13 S L I D E 13 NGI Prospective Clinical Study Study Conclusions HIV-1 PCR testing of pooled plasma samples can accurately detect HIV-1 infection Plasma pooling and pool resolution process for pools 512 individual samples is validated Clinical sensitivity and specificity of the pooling and pool resolution process is high NGI received FDA biologics license from FDA (CBER) for screening of donated plasma based on the study results

14 S L I D E 14 San Francisco Department of Public Health (SFDPH) Demonstration Project - Study Overview Patient samples were collected from the SFDPH city clinics and community based services over a 5-month period Samples were screened by SFDPH for HIV antibodies with standard EIA (Vironostika) or rapid HIV antibody tests (Orasure Technologies) HIV Ab (-) samples were picked up by LabCorp couriers and transported to NGI for testing NAT positive samples were identified in pools of 64 samples and confirmed by individual NAT All patients identified as positive were counseled and referred for HIV care and follow-up by SFDPH.

15 S L I D E 15 San Francisco Department of Public Health (SFDPH) Demonstration Project Study Results NAT testing identified 5 additional HIV-positive samples increasing the overall HIV detection rate by 12% to 3.1%.

16 S L I D E 16 Conclusions A pooled specimen HIV PCR assay has been validated for large-scale plasma donor screening involving pools of up to 512 samples The method was applied to the detection of acute HIV in a public health setting with SFDPH As this method is routinely used for screening millions of blood plasma donations per year, opportunities exist to implement broad-based acute HIV screening programs in a highly cost-effective fashion

17 S L I D E 17 Acknowledgements San Francisco Department of Public Health Jeff Klausner MD, MPH Nicola Zetola, Ph.D. Katherine Ahrens, MPH National Genetics Institute/LabCorp Mark Richardson, CLSpMB Richard Smith, Ph.D. Hawazin Faruki, Ph.D.


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