Short summary

The aim of this study is to evaluate the utility of IgM rheumatoid factor in blood test screening for rheumatoid arthritis in the primary care sector.

Rationale

Rheumatoid arthritis is a chronic immune mediated disease primarily affecting the joints, leading to serious morbidity and increased mortality. Early diagnosis and treatment is essential to reduce long term harmful effects. Presence of anti-CCP antibodies and/or IgM rheumatoid factor can be used to classify the disease. However, these blood tests are often misused for screening purposes. This is problematic due to the fact that especially IgM rheumatoid factor is neither highly specific nor sensitive for rheumatoid arthritis. The aim of this study is therefore to evaluate the utility of IgM rheumatoid factor in blood test screening for rheumatoid arthritis in the primary care sector.

Description of the cohort

The cohort was extracted from an internal laboratory information system at the Department of Clinical Immunology, Odense University Hospital. The cohort consists of patients for whom coherent anti-CCP antibody test and an IgM rheumatoid factor test have been ordered during the period of 01.01.2009 and 31.12.2015 (appr. 25000).

Data and biological material

Data regarding anti-CCP antibody and IgM rheumatoid factor analyses and requestor have been extracted from an internal laboratory information system at the Department of Clinical Immunology, Odense University Hospital. Data regarding diagnosis will be extracted from the National Patient Registry.

Collaborating researchers and departments

Department of Clinical Immunology, Odense University Hospital

• Søren Thue Lillevang, MD,PhD