New Panel of Arthritis Biomarkers Diagnoses Disease With 93.2% Accuracy

WRITTEN BY: Tara Fernandes

Rheumatoid arthritis, or RA, is a painful and debilitating autoimmune disorder of the joints, particularly those of the wrists and hands. The disease can also affect other parts of the body, causing inflammation of vital organs and anemia. As of 2015, 24.5 million people are estimated to be living with RA.

A study published in Arthritis Research & Therapy has detailed the development of a panel of four RA biomarkers, improving the accuracy and reliability of RA diagnoses, of which false negatives are an ongoing issue.

This panel of four includes measurements of angiotensinogen (AGT), serum amyloid A-4 protein (SAA4), vitamin D-binding protein (VDBP), and retinol-binding protein-4 (RBP4). These were determined through an in-depth analysis of samples from a cohort of over 250 RA patients alongside 230 healthy individuals.

Conventional diagnostic biomarkers, immunoglobin M and anti-CCP aren’t the most reliable for detecting RA, particularly at the early stages. “Existing biomarkers have limitations concerning RA diagnosis. For example, the sensitivity and specificity of RF are 60-90% and 85%, respectively,” wrote the authors.

“To improve the efficiency of RA diagnosis, anti-CCP is used with RF. Anti-CCP has higher ACCP positivity than RF positivity among RA patients; however, the sensitivity and specificity of the 2 markers do not significantly differ.”

The newly-identified panel of four biomarkers performs significantly better, say the authors. “Together, the 4-biomarker panel accurately classified 234 healthy controls and 210 RA patients with a classification accuracy of 93.2% and 91.7% for healthy controls and RA patients, respectively.”

Though there is no cure for the disease and no known prevention other than a reduction of risk factors where possible, an early diagnosis is critical in managing the disease. The hope is that evolving clinical practices to detect and monitor RA more effectively will improve the quality of life for these patients.