toxicity, immune system, toxicity

1. Syed Baseeruddin Alvi
M.pharm-pharmacology
Roll no. 09
IMMUNOTOXICITY

2. CONTENT
• INTRODUCTION
• FRAMEWORK FOR IMMUNOTOXICITY
• GENERAL TERMINOLOGY
• PRINCIPLES OF THE TEST METHODS
• TEST PROCEDURES
• IMMUNOTOXICITY TESTS
• DATA & REPORTING

3. INTRODUCTION
• immunity is the state of having
sufficient biological defense to
avoid infections, disease, or other
unwanted biological invasion.

4. Humoral Immunity

5. CELL MEDIATED
IMMUNITY

6. FRAMEWORK FOR IMMUNOTOXICITY
• Risk assessment

7. A risk assessment should be preceded by a
problem formulation phase

8. • Hazard identification:
This aims identify the nature of the
potential health effects of a chemical
substance.
• Hazard characterization:
Information on MOA can be used to
determine the human relevance for
immunotoxicity.
It gives dose effect relation ship
Threshold for toxicity can be established on
the basis of NOAEL –(BMD)

9. • Exposure assessment:
Exposure at or below the RfD/RfC or
ADI/TDI
is considered to be safe.
In this information regarding previous, current
and expected exposure is collected and
quantitatively described.
• Risk characterization:
exposure assessment results are integrated
with and assessed in relation to the hazard
characterization.

10. GENERAL TERMINOLOGY
• Purpose:
It provides information on
suppression of immune system which might
be due to repeated
exposure of test
substance..
• Antibodies or immunoglobulin's (Ig)
• CD or cluster of differentiation
• Immunotoxicity
• Natural Killer (NK) cells

11. Principles of the test methods
• To asses the functional responsiveness of the
immune system against T cell dependent
antigen (SRBC)
• Rat/mice are exposed to the test/control
• Animal must be immunized either by i.v/i.p with
SRBC.
• At the end of the test PFC assay of ELISA is done
to determine the conc. Of anti-SRBC levels

12. • If the test substance show no significant
effect on the anti-SRBC assay.
• A functional test for NK cells must be
performed to test for a chemical’s effect on
non-specific immunity.
• Limit test:
With the dose of 1000mg/kg, if no toxic
effect is observed then a full study is not
required using 3 doses.

13. TEST PROCEDURES
• Animal selection
• Age/weight
• Sex
• Numbers
• Husbandry
• Control and test substances
• Dose levels
• Administration of the test substance
• Observation

14. IMMUNOTOXICITY TESTS
PFC Assay
FUNCTIONAL
TESTS
Immunoglobulin
Quantification

15. PFC ASSAY

18. IMMUNOGLOBULIN QUANTIFICATION
ELISA

19. HOST RESISTANCE ASSAY
• It is done when there is evidence suggesting
that chemical causes reduction in host
resistance
• Suppression of host defense gives a clear
evidence of immunosuppression
• Suppression
combination
of
with
host
resistance
associate
in
immune
function increases the strength of data.

20. Haematology
• It is done when the evidence suggests
haematological changes.
• Severe haematological changes alone are
sufficient to demonstrate adverse
immunosuppression
• immunosuppression with histopathological
evidence may add strength to the report

21. Histopathology & Organ weight
• Histopathological evidence from multiple
immune
organs
may
indicate
immunotoxicity.
• Decreased weight of immune organ may also
support the evidence of Immunesuppression
• Immune organ weight and histopathological
considerations are not enough to derive
effect levels…

22. DATA & REPORTING
• Treatment of results
• Evaluation of study results
• Test report as per GLP standards
– The test substance characterization
– The test system
– The test procedure
– Test results