Collagen induced arthritis in rats. Contrasting effect of subcutaneous versus intradermal inoculation of type II collagen.

OBJECTIVE

To determine the effect of subcutaneous (s.c.) as compared to intradermal (i.d.) inoculation of collagen type II (CII) in induction of collagen induced arthritis (CIA).

METHODS

Dark Agouti (DA) and Lewis rats were injected with CII either i.d. or s.c.. A group of s.c. inoculated DA rats was re-injected with CII intradermally 45 days after first injection (s.c./i.d.). Arthritis was assessed by macroscopic scoring, histology, and immunohistochemistry. Levels of anti-CII antibody subtypes were measured by ELISA.

RESULTS

Intradermal but not s.c. inoculation of CII resulted in histologically confirmed erosive arthritis in both Lewis and DA strains. Subcutaneous/intradermal inoculated DA rats developed mild CIA with lower arthritic scores and delayed onset. Lewis rats injected s.c. had lower levels of total Ig, IgG, IgG2a, and IgG2b and similar titers of IgG1 compared to i.d. inoculated rats. In contrast, only IgG2b levels were lower in s.c./i.d. compared to i.d. rats.

CONCLUSION

Our data suggest that s.c. administration of CII tolerises animals against autoimmune CIA.