Evidence map›Paper›PMID 41779206›Full record

ArticleRheumatology international2026

Calprotectin and serum amyloid A for disease activity assessment in giant cell arteritis and polymyalgia rheumatica: results from a prospective single-centre cohort study.

Marc Schmalzing, Matthias Froehlich, Patrick P Strunz, Konstanze V Guggenberger, Ottar Gadeholt, Rudolf A Werner, Hannah Labinsky, Jan Portegys, Marcus Dittrich, Thorsten A Bley and 2 more

Abstract read
PubMed Publisher
In one paragraph

Article in Rheumatology international, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Marc SchmalzingDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany. schmalzing_m@ukw.de.
Matthias FroehlichDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany.ORCID http://orcid.org/0000-0001-7745-3903
Patrick P StrunzDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany.
Konstanze V GuggenbergerDepartment of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.
Ottar GadeholtRheumatologische Schwerpunktpraxis, Würzburg, Germany.
Rudolf A WernerThe Russell H Morgan Department of Radiology and Radiological Science, Division of Nuclear Medicine and Molecular Imaging, Johns Hopkins School of Medicine, Baltimore, MD, USA.
Hannah LabinskyDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany.
Jan PortegysDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany.
Marcus DittrichDepartment of bioinformatics, University of Würzburg, Am Hubland, Würzburg, Germany.
Thorsten A BleyDepartment of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany.
Tobias MuellerDepartment of bioinformatics, University of Würzburg, Am Hubland, Würzburg, Germany.
Michael GernertDepartment of Internal Medicine 2, Rheumatology/Clinical Immunology, University Hospital Würzburg, 97080, Würzburg, Germany.

Funding

Novartis Pharma Novartis Pharma
6 · The paper itself

Abstract

Monitoring disease activity in giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) is commonly based on C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Both markers are unreliable during interleukin-6 receptor inhibitor (IL-6Ri) therapy. We evaluated calprotectin (CALPR) and serum amyloid A (SAA) as alternative biomarkers. In a prospective single-centre cohort, we obtained 576 serial measurements from 98 patients with GCA (n = 81) or PMR (n = 17) between 2019 and 2022. Disease activity was classified as “active” or “remission” according to current EULAR recommendations. CRP, ESR, CALPR, and SAA were analysed and compared between patients treated with and without tocilizumab (TCZ). Univariate mixed-effects logistic regression models were fitted for the marker and used for receiver operating characteristic (ROC) analyses; multivariable mixed-effects models were used to adjust for clinical covariates. Active disease was present at 131 of 576 visits (22.7%), and 140 visits (24.3%) occurred under tocilizumab (TCZ) treatment. In patients without TCZ, ROC analysis showed the best discrimination for CRP (AUC 0.76, 95% CI 0.69–0.83), followed by SAA (0.74, 0.67–0.81), ESR (0.70, 0.63–0.78), and calprotectin (CALPR; 0.66, 0.59–0.73). Under TCZ treatment, SAA achieved the highest AUC (0.72, 95% CI 0.51–0.90), outperforming CRP (0.58, 0.42–0.77), CALPR (0.56, 0.32–0.74), and ESR (0.48, 0.30–0.67). In multivariable mixed-effects models, CRP, ESR, and SAA remained significantly associated with active disease in patients without TCZ, whereas none of the markers distinguished active disease from remission under TCZ treatment. SAA outperformed conventional markers in detecting active disease during IL-6Ri therapy in univariate analysis, but no biomarker retained significance after adjustment. These findings underscore the limitations of current laboratory monitoring in GCA and PMR under IL-6 inhibition and highlight the need for further evaluation of IL-6–independent biomarkers.

Indexed as

Giant Cell ArteritisLeukocyte L1 Antigen ComplexPolymyalgia RheumaticaSerum Amyloid A ProteinAgedAged, 80 and overAntibodies, Monoclonal, HumanizedBiomarkersBlood SedimentationC-Reactive ProteinFemaleHumansMaleMiddle AgedProspective StudiesSeverity of Illness IndexAntibodies, Monoclonal, HumanizedBiomarkersC-Reactive ProteinLeukocyte L1 Antigen ComplexSerum Amyloid A ProteintocilizumabAmyloid ABiomarkersCalprotectinGiant cell arteritisPolymyalgia rheumaticaSerumTocilizumabVasculitis

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.