Table 1

 Percentages of citrulline-specific reactivity and citrulline-preferred reactivity in sera of different patients groups

DiseaseCases(n)*CCP2 positive(COI citrulline >1)Citrulline-preferred (COI citrulline >2xCOI arginine)Citrulline-specific (COI citrulline >2xCOI arginine; COI arginine <1)Citrulline-independent (COI arginine >1 and COI citrulline <2xCOI arginine)
AIH-1, Type 1 autoimmune hepatitis; CCP, cyclic citrullinated peptide; COI, cut-off index; RA, rheumatoid arthritis.
*All these cases were previously reported as anti-CCP positive with first or second generation ELISA test, except 10 negative AIH-1 and 12 AIH-1 patients that were not CCP tested before.
†Patients with AIH-1 without overlapping diseases in which anti-CCP production has been reported.
‡Systemic sclerosis (n = 3), erosive osteoarthritis (n = 2), seronegative arthritis (n = 1).
§Primary biliary cirrhosis (n = 2), HCV-related hepatitis (n = 1).
AIH-157127 (58%)6 (50%)5 (42%)
“Pure” AIH-1†55105 (50%)4 (40%)5 (50%)
Psoriatic arthritis282727 (100%)27 (100%)0
Sjögren’s syndrome766 (100%)6 (100%)0
Palindromic rheumatism988 (100%)7 (88%)0
Systemic lupus erythematosus1396 (67%)6 (67%)3 (33%)
Other rheumatic diseases‡643 (75%)1 (25%)1 (25%)
Total non-RA rheumatic635450 (93%)47 (87%)4 (7%)
Other liver diseases§32002 (100%)
RA414141 (100%)36 (88%)0