Poster Presentation

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Model system for reliable results of laboratory
tests for HCV liver diseaseDr Navin DangNew
Delhi
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Diagnostic markers

• anti HCV antibodies
• riba
• SIA strip immune blot assay
• HCV RNA viral assay

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Anti-HCV markers
anti HCV antibodies
1st generation c-100-3 epitope from NS-4
region sero conversion 16 weeks 2nd
generation 5-1-1 antigen sero conversion
10 weeks 3rd generation NS-5 protein sero
conversion 7-8 weeks
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Advantages and disadvantages of a model system

• Advantages
• Ease of Automation
• Ease of use
• Relative cost effectiveness
• High Sensitivity

MODEL SYSTEM EIA or Modified EIA

• Disadvantages
• Suboptimal sensitivity specificity
• Abundance of false positive in low
• prevalence population
• Poor sensitivity in post liver
• transplant patients

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Commercial availability
Abbot HCV 3.0
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Axsym Architect prism
Provide Random Continuous Access Testing

• Incorporates 3 separate
• analytical technologies
• Micro particle immunoassay
• FPIA
• Ion capture immunoassay

AXSYM ARCHITECT PRISM
Centrifugation Mixing Using stored samples
Primary tube sampling
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Final reaction - Axsym
Enzyme
Substrate
FLOURESCENT
Antibody
END PRODUCT
Substrate
Enzyme
FLOURESCENT
Antibody
END PRODUCT
Fluorescence is proportional to the
quantity of bound antibody.
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Abbots Architect prism
ADVANTAGES

• sensitivity
• specificity
• ease of automation

ASSAY METHODOLOGY
CHEMILUMINISCENCE
Combination of microparticle capture
direct detection of CL signal
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Kits
CHIRON HCV 3.0
KITS
MONOCLONAL HCV ( Sanofi Diagnostics )
ORTHO HCV 3.0
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Overlap syndrome
HCV
HIV
HBsAg Autoimmune Hepatitis
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Interferon therapy
Screen for
thyroiditis
SLE others
psoriasis
rheumatoid arthritis
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FALSE
POSITIVES
NEGATIVES

• Immune Suppression
• Viral heterogeneity
• Lab error

• Presence of RAF
• High levels of immunoglobulin
• Paraproteinemias
• Lab error

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Investigations
Liver Function Tests -
Bilirubin OT, PT, Alk phos, GGTP Total Proteins (
Alb, Glob ) LDH Cholesterol, Triglyceride Glucose
Ammonia
Complete Blood Count
Prothrombin Time
Alpha Feto Protein ( for hepatocellular
carcinoma )
Assessment of Iron Store -
Ferritin Serum Fe, TIBC (Promote viral growth)
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Model system for biochemistry Total quality
management for HCV liver disease

• Sample collection
• Equipment
• Reagents
• Getting set
• EQA

• Proper infrastructure
• Records
• Management

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Sample collection

• Vacutainers which are bar coded
• Labelling
• Transportation
• Supervision of a doctor no hemolysis
• no prolonged tourniquet
• no delay in separation

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Equipment

• Random Access Analyzers with Primary Tube
  Sampling
• Should use both common and technology specific
  subsystems controlled by real time soft ware
  scheduling processors.
• On board incubation refrigeration system.
• Ability to use multiple filters take care of
  hemolysed,
• turbid high coloured samples.
• On board auto dilution of the Samples which go
  beyond the
• linearity range.

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Advantages of multiple filters

• To take care of High Coloured Samples
• There should be no significant interference
  up to an icteric index of 44 for conjugated and
  62 for unconjugated bilirubin.
• To take care of Hemolysed Samples
• No significant interference up to a hemolytic
  index of 200
• ( approx. Hb concentration 200mg/dl. )
• To take care of Turbidity in Samples
• There should be no significant interference
  up to a Lipaemic index of 900.

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Reagents
Quality should be world class.
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Getting set
Equipment Daily photometric temperature
checks are required. Reagents Daily
calibration of reagents as absorption of
atmospheric CO2 by the opened reagent bottles
leads to impaired calibration
stability. Controls Daily TQA with normal
abnormal samples plotting of LJ
curve. Storage Calibrator values deteriorate
at 2-8 degree Celsius therefore, it should
be stored at -20 degree Celsius. (e.g.
bilirubin)
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Concluding
EQA To increase the confidence catch
mistakes Infrastructure Electricity, water,
flooring, room temperature etc. Information
Technology Records updated weekly Man
Power Dedicated Management