RA patients on methotrexate and/or other DMARDS RA patients on anti-TNF drugs as monotherapy RA patients on anti-TNF +MTX and/or other DMARDSs Spondylarthropathy patients on anti-TNF drugs as monotherapy Spondylarthropathy patients on anti-TNF drugs +MTX Spondylarthropathy patients on NSAIDs (There is a possibility to stratify for steroid use).