Abstract: The present invention relates to method for assaying anti-cyclic citrullinated peptide antibodies in a clinical sample, said method comprising contacting said sample with at least one homogeneous reagent comprising at least one specific binder for anti-CCP antibodies, whereby to form a solution or suspension of an anti-CCP-binding partner complex in a homogeneous sample mixture and detecting the presence or level of said anti-CCP-binding partner complex in a homogeneous liquid-phase. The invention also relates to a method for the assessment of the existence of; risk of; potential for; or propensity to RA in a subject.