[Role of collagen conformation in type II anticollagen immunity in rheumatoid polyarthritis]

Type II anticollagen (CII) autoimmunity is a frequently reported, but non-specific, phenomenon in rheumatoid arthritis (RA). The authors show that in 88 sera samples from patients suffering from RA, the incidence of antibodies targeted against endogenous human CII was the same as that found for 149 control blood donors (14.8% versus 11.4%). However, a significant difference was found for the incidence of antibodies targeted against the alpha-chains of CII (26.1% versus 6.0%, p less than 0.001). As a result of investigating the specificity of the anti-CII antibodies in greater detail by means of an immunoprinting of the CII peptide fragments obtained after splitting the molecule by cyanogen bromide, the authors have demonstrated that the largest CII peptides (CB10 and CB11) were better recognized than the smaller peptides (CB8, CB9.7), with no significant difference between PR and control plasmas. Using competitive methods, evidence was obtained in support of heterogeneous recognition by the anti-CII antibodies: some recognize conformational determinants only, whereas others are targeted against the primary sequences of the alpha-1 (II) chain.