Administration of Neutralizing Antibodies to Interleukin-6 (IL-6) Reduces Experimental Autoimmune Encephalomyelitis and Is Associated with Elevated Levels of IL-6 Bioactivity in Central Nervous System and Circulation

Table 2 Effect of antibodies to IL-6 on the disease course of adoptive transfer EAE

Experimental Group	Time of Treatment (days relative to transfer)	Disease Incidence	Mortality	Mean Maximal Disease Score (±SEM)	Mean Cumulative Disease Score^a
Experimental Group	Time of Treatment (days relative to transfer)	Disease Incidence	Mortality	Mean Maximal Disease Score (±SEM)	Absolute (±SEM)	%
Experiment 1
PBS	−1, 4, 8	5/5	2/5	3.0 ± 0.84	28.6 ± 13.1	100
Anti-β-gal.	−1, 4, 8	5/5	0/5	2.4 ± 0.25	20.8 ± 2.7	73
Anti-IL-6	−1, 4, 8	4/5	0/5	1.2 ± 0.37^b	5.4 ± 2.6^b	19
Experiment 2
PBS	−1, 4, 8	5/5	5/5	5.0 ± 0.00	68.6 ± 0.6	100
Anti-IL-6	−1, 4, 8	5/5	1/5^c	3.4 ± 0.40^b	44.2 ± 9.4	64
Experiment 3
PBS	−1, 6	10/10	6/10	4.2 ± 0.33	44.8 ± 4.2	100
Anti-β-gal.	−1	5/5	3/5	4.2 ± 0.49	48.4 ± 8.1	108
	6	5/5	2/5	3.8 ± 0.49	46.0 ± 6.4	103
Anti-IL-6	−1	5/5	1/5	3.2 ± 0.49	32.4 ± 10.3	72
	6	5/5	1/5	2.8 ± 0.58^b	32.2 ± 5.7	72

EAE was adoptively transferred in PLSJLF1 mice by i.v. injection of 3.5–5 × 10⁶ encephalitogenic T lymphocytes (reactive to MBP_Ac1-11). 0.5 mg of the mAb or the same volume of PBS were given i.p. on the indicated time points. Animals were scored daily as described in Materials and Methods.
^aThe mean cumulative disease score was calculated by adding the mean daily disease scores from all the animals in a group over the observation period (20 days) (expressed as the absolute value ± SEM and as the percentage of the score of the PBS group in each experiment). Scores for each group are compared with the scores for the PBS group in that experiment.
^bp < 0.05, Mann-Whitney U test.
^cp < 0.05, one-tailed Fisher exact test.

ISSN: 1528-3658