Implication of baseline levels and early changes of C-reactive protein for subsequent clinical outcomes of patients with rheumatoid arthritis treated with tocilizumab.

Abstract

BACKGROUND:

Rheumatoid arthritis (RA) is characterised by clinical joint swelling and elevation of acute phase reactant levels, typically measured by the C-reactive protein (CRP). Clinical and inflammatory responses are usually concordant, except for inhibition of IL-6, which often disproportionally reduces the CRP due to direct inhibition of its hepatic production. We investigated whether pre-treatment CRP is a useful marker that can guide a preferential treatment choice towards IL-6 inhibition.

METHODS:

Data of 1126 treatment courses with tocilizumab (TCZ; early RA), 250 courses of rituximab (RTX; established RA) and 249 courses of methotrexate (MTX; established RA) were analysed. We compared clinical disease activity index (CDAI) values and change along 24 weeks' follow-up to CRP values at baseline or its early change. We validated the results using data from a separate TCZ trial in early RA.

RESULTS:

CRP levels in the TCZ group on average dropped by 74% within 4 weeks. Patients who attained CDAI remission at 24 weeks on TCZ had the highest baseline CRP levels while patients in high disease activity had the lowest; this association was reverse in the RTX and MTX groups. TCZ patients who achieved remission at 24 weeks showed the largest reductions of CRP levels by week 4 compared with those reaching higher disease activity states. Early CRP non-response was indicative of a risk of not achieving clinical treatment goals (p=0.038).

CONCLUSION:

Baseline CRP appears to have a positive association with reaching the therapeutic target on TCZ treatment, but is a negative predictor for RTX and MTX. Patients on TCZ without an early CRP response have a lower chance of achieving remission. CRP and its early course may inform, to some extent, the estimation of potential therapeutic success in patients with RA.

• Authors: Inbal Haya Shafran, Farideh Alasti, Josef S Smolen, Daniel Aletaha
• Journal: Annals of the rheumatic diseases (Ann Rheum Dis) Vol. 79 Issue 7 Pg. 874-882 (07 2020) ISSN: 1468-2060 [Electronic] England
• PMID: 32371387 (Publication Type: Evaluation Study, Journal Article)
• Copyright: © Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.

Chemical References

• Antibodies, Monoclonal, Humanized
• Antirheumatic Agents
• Biomarkers
• C-Reactive Protein
• tocilizumab

Topics

• Adult
• Aged
• Antibodies, Monoclonal, Humanized (therapeutic use)
• Antirheumatic Agents (therapeutic use)
• Arthritis, Rheumatoid (blood, drug therapy)
• Biomarkers (blood)
• C-Reactive Protein (analysis)
• Female
• Humans
• Male
• Middle Aged
• Randomized Controlled Trials as Topic
• Treatment Outcome