KEP: Chronic Inflammatory Diseases -

The overarching aim of our work is to better understand the etiology, clinical course, treatment effects, outcome and costs of Rheumatoid Arthritis (RA) and other chronic inflammatory diseases.

Research Focus

We use combinations of data from clinical quality registers, from linkages to national health- and demographics registers, clinical research databases including biobanks, and have developed methods to work with large-scale linkage data.

Research Teams

Johan Askling

We aim to address clinically and etiologically relevant questions regarding chronic inflammatory diseases and their treatments, spanning from disease susceptibility, predictors of prognosis, and treatment response. We assess the comparative effectiveness and safety of available and emergent treatment options, society costs of disease and treatment outcomes.

Elizabeth Arkema

Our aim is to identify and quantify the risks for and consequences of sarcoidosis and systemic lupus erythematosus.

Thomas Frisell

We study treatments for rheumatic diseases and multiple sclerosis and family history of diseases with a keen interest in methodology and biostatistics to aid patients and caregivers in making informed clinical choices.

Martin Neovius

Our aim is to assess effectiveness, safety and economic outcomes of bariatric surgery using large register-enriched cohorts

Ola Olén

We explore the causes of inflammatory bowel disease, the prognosis for different patient groups and whether treatments are safe and cost effective.

Björn Pasternak

We use Scandinavian health care register data to investigate the safety and effectiveness of medical drugs, as used in routine clinical practice.


Much of our work is performed in close co-operation with other research groups within the Clinical Epidemiology Unit (KEP), other researchers in the inflammatory disease research network at Karolinska Institutet, and at the department of Rheumatology at Karolinska University Hospital, colleagues in rheumatology research from Lund, Göteborg, Umeå, and Uppsala, including the Swedish Society for Rheumatology quality register, and as part of international research collaborations.


Our work has received funding from several public funding bodies, including The Swedish Research Council (VR), The Swedish Foundation for Strategic Research (SSF), The Swedish Cancer Society (CF), Stockholm County Council (ALF), from EU IMI (BTCure). Our post-marketing safety surveillance of anti-rheumatic therapies based on data from the Swedish Quality of Care Register, and run in collaboration with the Swedish Rheumatology Association (the ARTIS group) includes agreements with several pharmaceutical companies.

Selected Publications

Anti-citrullinated protein antibody specificities, rheumatoid factor isotypes and incident cardiovascular events in patients with rheumatoid arthritis.
Westerlind H, Rönnelid J, Hansson M, Alfredsson L, Mathsson-Alm L, Serre G, et al
2020 May;():

Risk of breast cancer before and after rheumatoid arthritis, and the impact of hormonal factors.
Wadström H, Pettersson A, Smedby KE, Askling J
Ann. Rheum. Dis. 2020 05;79(5):581-586

Siblings of patients with rheumatoid arthritis are at increased risk of acute coronary syndrome.
Westerlind H, Holmqvist M, Ljung L, Frisell T, Askling J
Ann. Rheum. Dis. 2019 05;78(5):683-687

Tumor Necrosis Factor Inhibitors and Cancer Recurrence in Swedish Patients With Rheumatoid Arthritis: A Nationwide Population-Based Cohort Study.
Raaschou P, Söderling J, Turesson C, Askling J,
Ann. Intern. Med. 2018 09;169(5):291-299

Patient characteristics influence the choice of biological drug in RA, and will make non-TNFi biologics appear more harmful than TNFi biologics.
Frisell T, Baecklund E, Bengtsson K, Di Giuseppe D, Forsblad-d'Elia H, Askling J, et al
Ann. Rheum. Dis. 2018 05;77(5):650-657

Malignant Neoplasms in Patients With Rheumatoid Arthritis Treated With Tumor Necrosis Factor Inhibitors, Tocilizumab, Abatacept, or Rituximab in Clinical Practice: A Nationwide Cohort Study From Sweden.
Wadström H, Frisell T, Askling J,
JAMA Intern Med 2017 11;177(11):1605-1612

Long-term outcomes and secondary prevention after acute coronary events in patients with rheumatoid arthritis.
Mantel Ä, Holmqvist M, Jernberg T, Wållberg-Jonsson S, Askling J
Ann. Rheum. Dis. 2017 Dec;76(12):2017-2024

Acute coronary syndrome in new-onset rheumatoid arthritis: a population-based nationwide cohort study of time trends in risks and excess risks.
Holmqvist M, Ljung L, Askling J
Ann. Rheum. Dis. 2017 Oct;76(10):1642-1647

How well do ACPA discriminate and predict RA in the general population: a study based on 12 590 population-representative Swedish twins.
Hensvold AH, Frisell T, Magnusson PK, Holmdahl R, Askling J, Catrina AI
Ann. Rheum. Dis. 2017 Jan;76(1):119-125

Can rheumatoid arthritis (RA) registries provide contextual safety data for modern RA clinical trials? The case for mortality and cardiovascular disease.
Michaud K, Berglind N, Franzén S, Frisell T, Garwood C, Greenberg JD, et al
Ann. Rheum. Dis. 2016 10;75(10):1797-805

Rheumatoid arthritis, anti-tumour necrosis factor treatment, and risk of squamous cell and basal cell skin cancer: cohort study based on nationwide prospectively recorded data from Sweden.
Raaschou P, Simard JF, Asker Hagelberg C, Askling J,
BMJ 2016 Jan;352():i262

Rheumatoid arthritis, anti-tumour necrosis factor treatment, and risk of squamous cell and basal cell skin cancer: cohort study based on nationwide prospectively recorded data from Sweden.
Raaschou P, Simard JF, Asker Hagelberg C, Askling J,
BMJ 2016 Jan;352():i262

Rheumatoid arthritis is associated with a more severe presentation of acute coronary syndrome and worse short-term outcome.
Mantel Ä, Holmqvist M, Jernberg T, Wållberg-Jonsson S, Askling J
Eur. Heart J. 2015 Dec;36(48):3413-22

To what extent is the familial risk of rheumatoid arthritis explained by established rheumatoid arthritis risk factors?
Jiang X, Frisell T, Askling J, Karlson EW, Klareskog L, Alfredsson L, et al
2015 Feb;67(2):352-62

Familial risks and heritability of rheumatoid arthritis: role of rheumatoid factor/anti-citrullinated protein antibody status, number and type of affected relatives, sex, and age.
Frisell T, Holmqvist M, Källberg H, Klareskog L, Alfredsson L, Askling J
Arthritis Rheum. 2013 Nov;65(11):2773-82

Risk of venous thromboembolism in patients with rheumatoid arthritis and association with disease duration and hospitalization.
Holmqvist ME, Neovius M, Eriksson J, Mantel Ä, Wållberg-Jonsson S, Jacobsson LT, et al
JAMA 2012 Oct;308(13):1350-6

Sick leave and disability pension before and after initiation of antirheumatic therapies in clinical practice.
Neovius M, Simard JF, Klareskog L, Askling J,
Ann. Rheum. Dis. 2011 Aug;70(8):1407-14

Do rheumatoid arthritis and lymphoma share risk factors?: a comparison of lymphoma and cancer risks before and after diagnosis of rheumatoid arthritis.
Hellgren K, Smedby KE, Feltelius N, Baecklund E, Askling J
Arthritis Rheum. 2010 May;62(5):1252-8

Characteristics of Hodgkin's lymphoma after infectious mononucleosis.
Hjalgrim H, Askling J, Rostgaard K, Hamilton-Dutoit S, Frisch M, Zhang JS, et al
N. Engl. J. Med. 2003 Oct;349(14):1324-32