Sustained Macrophage Infiltration upon Multiple Intra-Articular Injections: An Improved Rat Model of Rheumatoid Arthritis for PET Guided Therapy Evaluation

Table 1

Arthritis induction in rat: variations of the original model to the modified groups.

Code group	Original	Group A	Group B	Group C	Group D	Group E; (control)	Group F; (control)
Number of boost	No	No	No	3	5	No	No
Sacrificed (days post)	6	6	28	19	28	6	28
1st immunization (mBSA/CFA/CBP antigen)^*
No. of rats	11	3	4	3	6	4	4
Volume (µL)	200	200	200	200	200	200	200
Administration route	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.
Administration location	Tail base	Tail base	Tail base	Tail base	Tail base	Tail base	Tail base
2nd immunization (mBSA/CFA/CBP antigen)^*
Volume (µL)	200	100	100	100	100	100	100
Administration route	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.
Administration location	Tail base	Neck and upper flank	Neck and upper flank	Neck and upper flank	Neck and upper flank	Neck and upper flank	Neck and upper flank
Delayed time hypersensitivity (DTH) CBP antigen
Volume (µL)^**		25	25	25	25	25	25
Route	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.	s.c.
Administration site	Right ear	Right ear	Right ear	Right ear	Right ear	Right ear	Right ear
Local (i.a.) arthritis induction (mBSA)						Saline
i.a. injection (mBSA^*** or saline)	1	1	1	1	1	1	1
mBSA^#, boost i.a. injections	0	0	0	3	5	0	0
Injected volume (µL)	20	60	60	60	60	60	60
Route	i.a.	i.a.	i.a.	i.a.	i.a.	i.a.	i.a.
Administration site	knee joint	knee joint	knee joint	knee joint	knee joint	knee joint	knee joint

50 mg mBSA in 1 mL 0.9% NaCl emulsified with an equal volume of complete Freund’s adjuvant antigen (CFA) and custom Bordetella pertussis (CBP) antigen (1 × 10¹¹ cells/mL), ^**CBP antigen (2.7 × 10¹⁰ cells/mL 0.9% NaCl), ^***10 mg mBSA in 1 mL 0.9% NaCl, and ^#1 mg mBSA in 1 mL 0.9% NaCl.