Higher titres of RF and anti-CCP antibodies at RA pre-treatment baseline correlate with higher serum TNF levels, higher CRP (disease activity), and greater depletion of the infused anti-TNF Infliximab used in treatment. This suggests that higher RF/ACPA predicts for worse RA disease which is TNF driven, but may require higher doses of TNF inhibitors to achieve disease control.
SNPs can complement GWAS in predicting RA patients likely to progress rapidly to joint damage, thus singly them out for costly but effective early aggressive treatment.
But such testing is way too expensive and unwieldy. This means that we are still left to our well-honed clinical acumen to guide therapeutic decisions for a very long time yet.
Joint erosions are pathonomonic of aggressive RA disease, widely agreed to be predictive of further progression to joint destruction and disability.
However, just as MRI-evident bone edema at the sacroiliac joints can be present in asymptomatic athletes and does not equate Ankylosing Spondylitis, MRI-detected erosions at MCPJs and MTPJs are also seen in normal subjects without RA.
The presence of high grade erosions especially involving the 5th MTPJ in younger symptomatic people could be more specific for RA.