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Toxicological information

Immunotoxicity

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Administrative data

Endpoint:
immunotoxicity
Remarks:
other: immunological response to IPDI conjugates
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
not described
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1987
Report Date:
1983

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
Intradermal or inhalative exposure of animals with IPDI haptene followed by a subcutane challenge with the IPDI conjugate . Blood samples are evaluated for specific antibody classes which may relate to challenge results.
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
no details descibed about purity of the test substance

Test animals

Species:
guinea pig
Strain:
other: English smooth haired
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS: 
- Species: guinea pigs
- Strain: English smooth haired
- Sex: female
- Source: Hilltop Lab Animals, Scottdale (PA, USA)
- Weight at study initiation: 250-300 g
- Number of animals: 4

Administration / exposure

Route of administration:
other: intradermal
Vehicle:
not specified
Details on exposure:
ADMINISTRATION/EXPOSURE 
- Preparation of test substance for induction:   hapten alone and conjugation with guinea pig serum albumin (GPA)
- Induction schedule: multiple intradermal injections for 3-5 months,  total dose ca. 250 µl
- Concentration in Freunds Complete Adjuvant (FCA):   IPDI-GPA conjugate applied emulsified in FCA
- Challenge schedule: subcutaneous injection 5 days before being bled of  animals
Analytical verification of doses or concentrations:
not specified
Details on analytical verification of doses or concentrations:
no further details
Duration of treatment / exposure:
3-5 months
Frequency of treatment:
Induction schedule: multiple intradermal injections for 3-5 months,  total dose ca. 250 µl
No. of animals per sex per dose:
4
Details on study design:
The immunologic evaluation of allergenic hapten-protein conjugates with isophorone diisocyanate (IPDI) was reported. The specificity of the  
IPDI-ovalbumine was verified with antiserum by ELISA. The reactivity of  guinea-pig sera to an IPDI-ovalbumine conjugate after aerosol- or  
intradermal exposure of donor animals to IPDI was tested using ELISA  optical density at 490 nm.

Examinations

Observations and clinical examinations performed and frequency:
not described
Sacrifice and pathology:
bleeding of animals 5 days after challenge, examinations not described
Cell viabilities:
not applicable
Humoral immunity examinations:
Examination of guinea pig sera for IgG1 and IgG2 with reactivity for hapten-conjugates
Specific cell-mediated immunity:
not described
Non-specific cell-mediated immunity:
not descibed
Other functional activity assays:
no
Other examinations:
attempts to demonstrate activity in these sera by passive hemagglutination have not been successful. However, absorption of positive sera with hapten-conjugate-bearing sheep red blood cells specifically reduced ELISA reactivity.
Positive control:
not described
Statistics:
not described

Results and discussion

Results of examinations

Clinical signs:
not specified
Mortality:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Gross pathological findings:
not specified
Details on results:
7/8 intradermally injected guinea-pigs were positive for IgG1-antibody to  IPDI. 4 had titer greater than 1/1000. None of 16 
guinea-pigs exposed to  IPDI aerosol showed a positive reaction (optical density > 0.22, dilution  1/20).

Specific immunotoxic examinations

Cell viabilities:
not specified
Humoral immunity examinations:
effects observed, treatment-related
Specific cell-mediated immunity:
not specified
Non-specific cell-mediated immunity:
not specified
Other functional activity assays:
not specified
Other findings:
effects observed, treatment-related

Effect levels

Dose descriptor:
other: IgG concentration measured as optical density at 490 nm
Effect level:
other: optical density at 490nm
Sex:
female
Basis for effect level:
other: no effect level described

Any other information on results incl. tables

no further remarks

Applicant's summary and conclusion

Conclusions:
Significant quantities of anaphylactically active class of immunoglobulin have been found in sera from guinea pigs sensitised to IPDI only by dermal exposure. No significant increase of anaphylactically active class of immunoglobulin have been found in sera from guinea pigs sensitised to IPDI by inhalation of IPDI aerosol.
Executive summary:

The immunologic evaluation of allergenic Isophorone diisocyanate-protein conjugates was reported. Antibodies to the test item have been detected by an ELISA procedure. In detail, significant quantities of anaphylactically active class of immunoglobulin have been found in sera from guinea pigs sensitised to IPDI only by dermal exposure. No significant increase of anaphylactically active class of immunoglobulin have been found in sera from guinea pigs sensitised to IPDI by inhalation of IPDI aerosol. These antibodies were specifically inhibited by homologous hapten.