Wertigkeit von Anti-Citrullin-Antikörpern in der rheumatologischen Diagnostik

A comparison of methods of three different immunoassays for the
proof of anti – citrullin antibodies in the rheumatoid diagnosis
Greiner A, Kellner H, Plischke H, Schattenkirchner M, Gruber R
Rheumazentrum München, Klinikum der Universität, Medizinische
Poliklinik – Innenstadt Background: Up to now the rheumatoid factor
was the most sensitive and most specific laboratory method in the
diagnosis of rheumatoid arthritis (RA). By the detection of the
antibodies against citrullinated peptide with the help of the newly
developed ELISA – Systems a more sensitive and specific test in the
field of differential diagnosis of RA has been made available. In
this study three different anti – CCP – tests have been examined
concerning their value in the comparison of the rheumatoid factor
and concerning the clinical diagnosis of the RA. Methods: Sera of
275 rheumatoid patients who get outdoor treatment were examined for
anti – CCP – antibodies with three different conventional
(commercially accessible) ELISAs (EUROIMMUN, INNOVA, GENERIC
ASSAYS). For 93 patients the clinical diagnosis was made through
the ACR – criteria. This group included all who will surely and
probably get the RA – disease. The evaluation among the single
tests and in comparison to the rheumatoid factor was determined.
Results: A comparison of the single tests among themselves showed
the following sensitivity and specificity: GA: 81,2% / 97,9% ,
EUROIMMUN: 79,6% / 98,3% , INNOVA: 77,5% / 99,4%. All three CCP –
tests are more sensitive and specific compared to the rheumatoid
factor (73,1%/91,6%). In the calculation of the sensitivity for
surly and probably affected persons with RA the following results
appeared: GA: sure: 89,2% / probably 55,0%, EUROIMMUN 87,3% /
54,5%, INOVA 86,6% / 52,4%, rheumatoid factor: 81,4% / 47,6%.
Conclusion: There were no significant differences of the
sensitivity and the specificity of the 3 CCP – tests concerning the
rheumatoid factor but also among the single CCP – tests. The
sensitivities of the surly predicted diseases was significantly
higher compared to the probable diagnosis RA.