Division of Emerging and Transfusion Transmitted Diseases Bioterrorism Preparedness Initiatives Hira L. Nakhasi, Ph.D.

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Division of Emerging and Transfusion Transmitted
Diseases Bioterrorism Preparedness
InitiativesHira L. Nakhasi, Ph.D.
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Division of Emerging and Transfusion Transmitted
Diseases (DETTD) Mission

• Plans and conducts basic and applied research
• development, manufacture , pathogenesis and
  testing
• of Viral (HIV , HTLV, hepatitis), Parasitic ,
  Bacterial , potential BT agents and Transmissible
  Spongiform Encephalopathy agents or prions.
• Ensures the safety of Nations blood supply
• by reviewing, evaluating and recommending
  actions
• PLAs, PMAs, INDs, IDEs, 510(k)s for blood
  screening and diagnostic testing for above
  mentioned agents.
• Develops and revises FDA Guidance for users of
  blood screening and diagnostic products.

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Division of Emerging and Transfusion Transmitted
Diseases (DETTD) Mission

• Performs lot-release testing for approval of
  investigational tests and of licensed products.
• Develops reference materials for lot-release
  testing.
• Performs inspections of manufacturers of licensed
  products, manufacturing facilities.
• Provides expert scientific and technical advice
  to other Agency and Government components.
• Presents issues related to the safety and
  efficacy of blood donor screening testing at the
  Blood Product Advisory Committee and TSE Advisory
  Committee meetings

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DETTD Strategic Plan to Counter Terrorism- policy
and regulation

• Donor screening/suitability
• Agent exposure (diagnostic or detection)
• Emergency release of blood components
• Product Release
• Exemptions
• Testing
• Sensitivity and Specificity

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Actions to protect the blood supplyDETTD-Policy

• Use of ongoing and proposed vaccine trials to
  define the period of viremia/ bacteremia after
  vaccination
• Development of a plan to vaccinate repeat donors
• Consider whether immunosupressed blood recipients
  should get IG or antitoxins with transfusion

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RegulationTest kit performance Specificity

• Clinical
• -Donor populations, e.g. intended use for blood
  and plasma donor testing
• Analytical
• -Other diseases
• -Interference

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RegulationTest kit performance Sensitivity

• Clinical
• Known positives and high risk populations
• Seroconversion panels
• Variants
• Analytical
• Endpoint dilutions
• Well characterized reference materials (WHO and
  CBER standards)
• Reproducibility
• multiple sites, operators, kit lots

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DETTD Strategic Plan to Counter Terrorism

• Actions to Protect the Blood Supply
• - Research
• Detection and donor screening
• Microarray technology
• Nucleic Acid Testing
• Pathogen Removal/Inactivation
• Tests for Blood and Blood products
• Tests for Plasma Derivatives
• Pathogenesis of BT agents in blood

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Actions to protect the blood supplyDETTD
Research Plan-short range plan

• I. Devise donor screening methods and tests to
  assure that affected individuals do not spread
  bioterrorism agents.
• Adapt previously established nucleic acid based
  tests to detect BT agents in blood.
• Develop primers and possibly probes for
  fluorogenic-based PCR for BT agents.
• Collaborate with other agencies to test our
  reagents in their systems.
• Encourage industry to submit INDs for serologic
  and nucleic acid based tests for blood screening
  and diagnosis.

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Actions to protect the blood supply-long range
plan

• II. Investigate experimental testing
  methodologies to facilitate evaluation of
  industry methods.
• For detection of several agents simultaneously
• Development of a DNA oligonucleotide microarray
  for detection of bioweapon agents such as Variola
  major (Smallpox), Filoviruses, Yersinia pestis
  (Plague), Francisella tularensis (Tularemia),
  Bacillus anthracis (Anthrax) in blood and blood
  product based on their potential for transmission
  by blood during the asymptomatic incubation
  period.

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Microarray as a Blood/BT Agent Diagnostic Tool
HIV TAGGAATACCACATCCCGCA HCV ACCCCCCCTCCCGGGAGAGC
Leishmania. CTTTCCCATCGCAACTTCGGT T.cruzi
TTTTGGGAGGGGCGTTCAAA Plague CTTTCCGTGAGAAGACATCC
B. anthracis GAACTCAAGAAAAAAGCGA Smallpox ACGACTCT
CCATACGATGAT
Synthesize probes, Print on microchip
Extract genetic material from blood or blood
products
Pathogen sequences from databases
Hybridize to microarray (hypothetical result)
Amplify and label the target with
multiple, pathogen-specific primers
HIV genotyping array (Lipshutz et al., Nat.
Gen., 1999)
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Actions to protect the blood supplyDETTD
Research Plan-long range plan

• III. Develop antiviral compounds against viral BT
  agents capable of neutralizing and preventing
  viral growth.
• For in-vitro inactivation of BT agents in blood
  and blood products

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Screening of small-molecules that bind to the
Ebola virus RNA-dependent RNA-polymerase
Addition of purified RNA-polymerase
Binding of RNA-polymerase
Small-molecule microarray
Detection of binding by plasmon resonance
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DETTD Strategic Plan to Counter Terrorism

• Outcome
• Develop laboratory expertise in new technologies
• Utilize this expertise for evaluation of related
  submissions from industry
• Transfer technology for industry development
• Lot-release testing
• Understand the molecular mechanisms of
  pathogenesis of BT agents in blood