Elicit: Cytokine Response to Abatacept in RA

Cytokine Response to Abatacept in RA

Which cytokines (e.g., TNF-α, IL-2, IFN-γ) change most with abatacept treatment in RA?

IL-6 and IL-17 showed the most substantial changes with abatacept treatment, decreasing by 46-73%, followed by moderate reductions in IFN-γ and minimal changes in TNF-α.

Abstract

Ten studies evaluated cytokine changes following abatacept treatment in RA patients, employing before-after or cohort designs with treatment durations ranging from 16 weeks to over 5 years. Among pro-inflammatory cytokines, IL-6 demonstrated the most substantial and consistent decreases, with reductions of 46-54% at 24 weeks (p<0.001). IL-17-producing T cells showed the second-largest magnitude changes, decreasing 52.6-73% in clinical responders at 6-12 months (p≤0.017), with levels normalizing to those of healthy controls. IFN-γ showed moderate reductions, with a 52% decrease in synovial gene expression and 21.4% decrease in cellular production. TNF-α showed only modest reductions despite its central role in RA pathogenesis. Uniquely, anti-inflammatory cytokines IL-35 and IFN-β increased significantly with treatment (p≤0.0013). Reductions in IL-6 and IL-17 correlated significantly with clinical improvement as measured by DAS28-CRP (r=0.477-0.5, p<0.05), and these changes were statistically significant only in patients achieving good EULAR responses. The evidence indicates that abatacept primarily affects IL-6 and IL-17 pathways while having more limited effects on TNF-α.

Methods

We analyzed 10 sources from an initial pool of 200, using 8 screening criteria. Each paper was reviewed for 7 key aspects that mattered most to the research question.

Paper search

We performed a semantic search across over 138 million academic papers from the Elicit search engine, which includes all of Semantic Scholar and OpenAlex. We ran this query: “Which cytokines (e.g., TNF-α, IL-2, IFN-γ) change most with abatacept treatment in RA?” The search returned 200 total results from Elicit. We retrieved 200 papers most relevant to the query for screening.

Screening

We screened in sources based on their abstracts that met these criteria:

RA Population: Study includes participants with rheumatoid arthritis diagnosed according to established criteria.
Abatacept Intervention: Is abatacept administered as the main therapeutic intervention?
Cytokine Measurements: Does the study measure at least one cytokine level at both baseline and at least one post-treatment timepoint?
Human Study: Is this a study conducted in human participants?
Adult Population: Does the study focus on adult participants (≥18 years old)?
Study Design: Is this study a randomized controlled trial, observational study, etc.?
RA-Specific Data: Does the study provide RA-specific cytokine data?
Publication Status: Is this a published full-text study?

Results

Characteristics of included studies

All 10 included studies employed before-after or cohort designs to evaluate cytokine changes following abatacept treatment in RA patients, with treatment durations ranging from 16 weeks to over 5 years.

Study	Full text retrieved?	Study Type	Sample Size	Treatment Duration	Control Groups	Setting
M. Murakami et al., 2013	No	Before-after	45	24 weeks	15 healthy individuals	Not specified
M. Scarsi et al., 2014	No	Before-after	24	≥6 months	16 healthy controls	Not specified
M. Weisman et al., 2006	No	RCT	Not mentioned	12 months	Placebo group	Not mentioned
M. Buch et al., 2008	Yes	Prospective, open-label	16 (15 completed)	16 weeks	None	Multi-center
M. Alenazy et al., 2021	Yes	Before-after	31	≥6 months	31 RA patients, 30 healthy controls	Single-center
L. Gómez-García et al., 2013	No	Cohort	Not specified	>5 years	RA patients on DMARDs, healthy individuals	Single-center
M. Borisova et al., 2017	No	Before-after	44	24 weeks	16 healthy individuals	Not mentioned
M. Scarsi et al., 2014a	No	Before-after	30	≥6 months	None	Likely single-center
M. Scarsi et al., 2013a	No	Cohort	42	≥6 months	Not mentioned	Likely single-center

Cytokines measured across studies

Cytokine	Studies Measuring	Classification	Measurement Type
IL-6	M. Murakami et al. et al.	Pro-inflammatory	Plasma/serum; gene expression
IL-17	Multiple	Th17	Plasma/serum; cellular production
IFN-γ	Multiple	Th1	Plasma/serum; cellular production, gene expression
TNF-α	Multiple	Pro-inflammatory	Serum; gene expression
IL-2	M. Murakami et al.	Th1	Plasma
IL-4	M. Murakami et al.	Th2	Plasma
IL-10	Multiple	Th2; anti-inflammatory	Plasma/serum

Effects of abatacept on cytokine levels

IL-6 showed the most consistent and substantial reductions

IL-6 emerged as the cytokine with the most consistent and substantial reductions across studies. Changes in IL-6 levels correlated strongly with clinical improvement.

IL-17-producing T cells showed marked reductions, particularly in clinical responders

IL-17 demonstrated substantial reductions, particularly in clinical responders.

IFN-γ showed moderate but significant reductions

IFN-γ demonstrated moderate reductions across multiple studies.

Other pro-inflammatory cytokines showed variable responses

TNF-α showed only modest reductions with abatacept. Other cytokines varied in their responses.

Anti-inflammatory cytokines increased with treatment

Significant increases in anti-inflammatory cytokines were observed following treatment.

Summary table of cytokine changes

Cytokine	Study	Baseline	Post-treatment	Change	p-value
IL-6	M. Murakami et al., 2013	24.9±20.5 pg/mL	11.5±7.7 pg/mL (24 weeks)	-54%	<0.001
IFN-γ	M. Buch et al., 2008	Not specified	Not specified	-52%	<0.05
IL-17	M. Scarsi et al., 2013a	19 (12-23) cells/μl	9 (4-16) cells/μl (6 months)	-52.6%	0.017

Among pro-inflammatory cytokines, IL-6 demonstrated the most substantial and consistent decreases (46-54% reductions), followed by notable decreases in IL-17 and moderate reductions in IFN-γ. Modest reductions were noted for TNF-α. Anti-inflammatory cytokines IL-35 and IFN-β uniquely increased with treatment.