The fine specificity of immunoglobulin G (IgG) and IgM anticitrullinated protein antibodies (ACPAs). The absorbance (Abs) at 415 nm of ACPA IgG (A) and IgM (B) ACPA fine specificity. ***P < 0.001. Data for gout controls from three ELISA plates are depicted. α-eno = α-enolase; Arg = arginine; CCP2 = cyclic citrullinated peptide 2; Cit = citrulline; Fib = fibrinogen; MBP = myelin basic protein; Vim = vimentin.