Skip Navigation

Your Environment. Your Health.

International Myositis Assessment & Clinical Studies Group (IMACS)

Global Approaches To Improved Treatments And Understanding Of Myositis

News & Events

Latest News:

New Myositis Classification Criteria and Response Criteria Developed by IMACS and International Myositis Research Community

New criteria have been finalized to classify patients as having an idiopathic inflammatory myopathy (IIM) and distinguish them from other mimicking conditions. The 2017 European League Against Rheumatism (EULAR) /American College of Rheumatology (ACR)EULAR/ACR classification criteria for adult and juvenile IIM, now published and also provisionally endorsed by the EULAR and ACR, are based on a probability score in which 16 clinical and laboratory features are summed to develop a probability of having an IIM. For patients classified as having an IIM, a classification tree approach is used for sub-classification among different clinical forms, including polymyositis, inclusion body myositis, and adult and juvenile dermatomyositis.  These criteria are recommended for use in research studies for patients at least 6 months from diagnosis. (Classification Criteria webpage)

A second major milestone was the recent publication of the 2016   and Juvenile Dermatomyositis. The new response criteria are a conjoint analysis definition of response that provides a threshold for minimal, moderate and major clinical improvement, with different cut points used in juvenile and adult patients. The criteria use the IMACS core set measures of activity in adults, and either IMACS or PRINTO core set measures in pediatric patients, and are based on the absolute percentage change in these measures.  They have been fully validated, published and are endorsed by both the ACR and EULAR. (Myositis Response Criteria webpage)

Many IMACS members contributed substantially to the development and finalization of these new classification and response criteria as part of projects that each were of more than one decade in duration.

Archived News:

About IMACS

The International Myositis Assessment and Clinical Studies Group (IMACS) is a coalition of health care providers and researchers with experience and interest in the myositis syndromes.

The goals of IMACS are to improve the lives of children and adults who suffer from myositis by discovering better therapies through understanding the causes of these diseases.

IMACS members work to achieve these goals by developing consensus and standards on the conduct and reporting of adult and juvenile myositis studies, performing collaborative therapeutic trials and by planning, facilitating and conducting international collaborative myositis research.

Clinical Research Center

The administrative arm of IMACS is housed in offices of the National Institute of Environmental Health Sciences (NIEHS) in the Mark O. Hatfield Clinical Research Center at the National Institutes of Health, Bethesda, MD, USA. This facility is the world's largest clinical research complex, serving a dual role: providing humane and healing patient care as well as the environment clinical researchers need to advance clinical science.

The Clinical Center complex is part of the NIH's intramural science research program. NIH is part of the U.S. Department of Health and Human Services and the medical research agency of the U.S Government.

This is the public site for IMACS. If you are already a member, you may wish to visit the members site on the NIEHS Extranet  

If you are not a member yet and would like to be one, please go to the IMACS Membership page