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.
Records from Elicit search
n = 200
Papers screened using: RA Population, Abatacept Intervention, Cytokine Measurements, Human Study, Adult Population, Study Design, RA-Specific Data, Publication Status
n = 200 Papers screened out
n = 190 Papers included for extraction
Paper search
We performed a semantic search across over 138 million academic papers from the Elicit search engine.
Screening
We screened in sources based on their abstracts that met these criteria:
- RA Population: Does the study include participants with rheumatoid arthritis diagnosed according to established criteria?
- Abatacept Intervention: Is abatacept administered as the main therapeutic intervention in this study?
- Cytokine Measurements: Does the study measure at least one cytokine level with quantitative data?
- 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, systematic review, or meta-analysis?
- RA-Specific Data: Does the study provide RA-specific cytokine data rather than focusing solely on clinical outcomes?
- Publication Status: Is this a published full-text study?
Data extraction
We asked a large language model to extract each data column below from each paper:
- Study Design: Extract study design and sample characteristics for abatacept treatment in RA patients, including:
- Study type
- Sample size of RA patients
- Study duration and follow-up periods
- Control groups
- Patient Characteristics: Extract baseline characteristics of RA patients receiving abatacept treatment, including:
- Age and gender distribution
- RA disease duration
- Baseline disease activity
- Prior treatments
- ACPA/RF status
- Abatacept Treatment: Extract details about abatacept treatment regimen and clinical response, including:
- Dose and administration schedule
- Treatment duration at time of cytokine measurement
- Cytokines Measured: Extract comprehensive list of all cytokines measured in RA patients receiving abatacept.
- Cytokine Changes: Extract quantitative data on cytokine changes from baseline to post-abatacept treatment, including:
- Baseline values
- Post-treatment values
- Direction of change
- Measurement Methods: Extract methodology for cytokine assessment in abatacept-treated RA patients.
- Clinical Correlations: Extract relationships between cytokine changes and clinical outcomes in abatacept-treated RA patients.
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. Scarsi et al., 2013 | No | Before-after | 24 | ≥6 months | 16 healthy donors | Not specified |
| M. Alenazy et al., 2021 | Yes | Before-after | 31 | ≥6 months (average 13 months) | 31 RA patients on other treatments | 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 |
Patient populations were relatively homogeneous across studies. Where reported, patients were predominantly female with mean ages ranging from 46.9 to 55 years. Disease duration varied from a median of 2 years to 10 years. Baseline disease activity was generally high, with DAS28 scores ranging from 5.2 to 7.1. Most patients had failed prior DMARD or biologic therapy. Seropositivity rates were high, with 75-84.4% being RF-positive and/or ACPA-positive.
Clinical response rates were favorable across studies. Good or moderate EULAR responses were achieved in 60-86% of patients.
Cytokines measured across studies
Studies employed varied methodological approaches to cytokine assessment. Plasma or serum levels were measured using ELISA, multiplex assays, or MicroVue immunoassay. Cellular cytokine production was assessed via flow cytometry with intracellular staining following in vitro stimulation.
| Cytokine | Studies Measuring | Classification | Measurement Type |
|---|---|---|---|
| IL-6 | M. Murakami et al., 2013; M. Weisman et al., 2006; M. Buch et al., 2008; L. Gómez-García et al., 2013; M. Borisova et al., 2017 | Pro-inflammatory | Plasma/serum; gene expression |
| IL-17 | M. Murakami et al., 2013; M. Scarsi et al., 2014; M. Scarsi et al., 2013; M. Alenazy et al., 2021; L. Gómez-García et al., 2013; M. Borisova et al., 2017; M. Scarsi et al., 2014a; M. Scarsi et al., 2013a | Th17 | Plasma/serum; cellular production |
| IFN-γ | M. Murakami et al., 2013; M. Scarsi et al., 2014; M. Buch et al., 2008; M. Scarsi et al., 2013; L. Gómez-García et al., 2013; M. Scarsi et al., 2013a | Th1 | Plasma/serum; cellular production; gene expression |
| TNF-α | M. Murakami et al., 2013; M. Weisman et al., 2006; M. Buch et al., 2008; L. Gómez-García et al., 2013; M. Borisova et al., 2017 | Pro-inflammatory | Serum; gene expression |
| IL-2 | M. Murakami et al., 2013 | Th1 | Plasma |
| IL-4 | M. Murakami et al., 2013 | Th2 | Plasma |
| IL-10 | M. Murakami et al., 2013; M. Alenazy et al., 2021 | 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. M. Murakami et al. reported that baseline IL-6 levels were significantly elevated in RA patients compared to healthy individuals (24.9±20.5 vs 7.1±4.0 pg/mL, p<0.001). Following 24 weeks of abatacept treatment, IL-6 levels decreased significantly (24.9±20.5 to 11.5±7.7 pg/mL, p<0.001), representing an approximate 54% reduction.
IL-17-producing T cells showed marked reductions, particularly in clinical responders
IL-17 demonstrated substantial reductions, though primarily measured as cellular production. M. Scarsi et al. (2013a) reported the most dramatic changes in clinical responders, with IL-17-producing CD4+ T cells decreasing from 19 (12-23) cells/μl to 9 (4-16) cells/μl after 6 months (p=0.017), representing an approximately 52.6% decrease.
IFN-γ showed moderate but significant reductions
IFN-γ demonstrated moderate reductions across multiple studies. M. Buch et al. reported a 52% reduction in IFN-γ gene expression in synovial tissue.
Other pro-inflammatory cytokines showed variable responses
TNF-α showed only modest reductions with abatacept.
Anti-inflammatory cytokines increased with treatment
M. Alenazy et al. reported significant increases in anti-inflammatory cytokines, including IL-35 and IFN-β.
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 (gene) | M. Buch et al., 2008 | Not specified | Not specified | -52% | <0.05 |
| IL-17 (cellular, CD4+) | 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 IL-17-producing cells (52.6-73% reductions in responders) and IFN-γ (21.4-52% reductions depending on measurement method). Anti-inflammatory cytokines IL-35 and IFN-β uniquely increased with treatment, suggesting abatacept may enhance regulatory mechanisms.