Session Information
Date: Monday, November 6, 2017
Session Type: ACR Poster Session B
Session Time: 9:00AM-11:00AM
Background/Purpose: Tocilizumab, a humanized anti-human IL-6 receptor antibody that blocks the signaling of IL-6/IL-6R complex, is an effective treatment in chronic inflammatory rheumatoid arthritis (RA). Although IL-6 contributes significantly to RA pathology, it is unknown how tocilizumab regulates the immune response of these patients.
Methods: Heparinized blood and clinical data from 47 RA patients were collected before treatment (t0) and after 12 months (t12m). Plasmatic cytokines were measured by ELISAs and phenotyping of circulating T CD4+ lymphocytes (memory, naïve, Tregs and Th subsets) was analyzed by flow cytometry.
Results:
Clinical and disease characteristics of the patients are shown in table 1. At t0 and at t12m, the concentrations of IL-6 and IL-10 and the concentrations of IL-17, VEGF and IL-22 correlated. After 12m with tocilizumab, the concentrations of sIL-6R and IL-10 significantly increased. Despite the decrease of CD4+ T lymphocytes, the percentages of Tregs and the Treg subset CD45RA+ significantly increased. No differences were observed in the percentages of Th1, Th2 and Th17 between t0 and t12m. However, the percentages of Th9 and Th9 CD45RO+ significantly decreased (Table 2). When patients were segregated according to EULAR response to tocilizumab (NR= no responders, R= responders), sIL6R (at t12m, NR=652±83 vs. R=1731±160 ng/ml, p=0.02) and monocytes/ul (at t12m, NR=840±40 vs. R=610±30, p=0.02) decreased and the ratio t12m/t0 of TregCD45RO+ increased (NR=0.49±0.15 vs. R=0.91±0.005, p=0.01) only in those patients with good or moderate response.
Conclusion: Despite the blocking of IL-6/IL-6R in all RA patients, changes in soluble mediators and T cell subsets were different between EULAR responders and non-responders to tocilizumab. Further information would be necessary to understand the immunological mechanisms operating in the different groups of patients.
Table 1. Baseline demographic and disease characteristics of the RA patients |
|
Age; years (mean±SD) |
53.8±11.1 |
Women; n (%) |
40 (85.1) |
Years of disease (mean±SD) |
12.7±8.4 |
Positive Rheumatoid Factor; n (%) |
31 (66%) |
Positive ACPAs; n (%) |
35 (74.5%) |
Tocilizumab on monotherapy |
17 (36.2%) |
Used as first line biologic therapy; n (%) |
14 (29.8%) |
DAS28 (mean±SD) |
5.65±1.15 |
CDAI (mean±SD) |
28.2±13.3 |
ESR; mm/h (mean±SD) |
46.5±30.8 |
CRP; mg/l (mean±SD) |
24.9±30.8 |
Table 2. Immunological parameters at baseline and after 1 year of treatment |
|||||||
t0 |
t12m |
|
|||||
mean |
|
sem |
mean |
|
sem |
(paired t-test) |
|
IgG |
1193.55 |
± |
66.83 |
915.52 |
± |
65.94 |
0.001 |
IgA |
309.03 |
± |
21.60 |
232.14 |
± |
18.39 |
<0.001 |
IgM |
156.09 |
± |
14.00 |
128.30 |
± |
15.86 |
0.195 |
Monocytes |
0.67 |
± |
0.07 |
0.66 |
± |
0.08 |
0.445 |
Neutrophils |
4.82 |
± |
0.33 |
3.93 |
± |
0.33 |
0.017 |
Lymphocytes |
2.22 |
± |
0.16 |
2.11 |
± |
0.15 |
0.287 |
IL6pg/ml |
670.52 |
± |
129.89 |
849.74 |
± |
183.31 |
0.066 |
sIL6R ng/ml |
332.59 |
± |
45.10 |
1592.92 |
± |
158.32 |
<0.001 |
IL17 pg/ml |
2044.40 |
± |
945.86 |
1481.00 |
± |
638.81 |
0.187 |
IL22 pg/ml |
4960.60 |
± |
1261.10 |
5461.28 |
± |
1288.02 |
0.414 |
VEGF pg/ml |
590.07 |
± |
227.16 |
566.15 |
± |
246.19 |
0.261 |
IL10 pg/ml |
100.00 |
± |
39.00 |
119.00 |
± |
18.00 |
0.035 |
CD4 (% lymphocytes) |
46.99 |
± |
1.58 |
44.92 |
± |
1.22 |
0.041 |
Treg (% CD4+ T cells) |
6.66 |
± |
0.28 |
7.38 |
± |
0.27 |
0.026 |
Th1 (% CD4+ T cells) |
7.79 |
± |
1.05 |
6.72 |
± |
0.51 |
0.420 |
Th17 (% CD4+ T cells) |
10.78 |
± |
1.85 |
6.81 |
± |
0.48 |
0.130 |
Th2 (% CD4+ T cells) |
8.53 |
± |
1.35 |
6.41 |
± |
0.32 |
0.220 |
Th9 (% CD4+ T cells) |
13.75 |
± |
1.85 |
6.78 |
± |
0.64 |
0.002 |
To cite this abstract in AMA style:
Diaz-Torné C, Estrada P, Moya P, Ortiz MA, de la Fuente D, Moreno M, Busquets N, Ramírez J, Moragues C, Ros S, Casado Burgos E, Torrente V, Garcia E, Pujol M, Ponce A, Vidal S, de Agustín JJ. Changes in the Immune Response of RA Patients Induced By 1 Year of Tocilizumab [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/changes-in-the-immune-response-of-ra-patients-induced-by-1-year-of-tocilizumab/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/changes-in-the-immune-response-of-ra-patients-induced-by-1-year-of-tocilizumab/