The specificity of anti-carbamylated protein antibodies for rheumatoid arthritis in a setting of early arthritis

Table 1 The test characteristics of different autoantibodies in RA

	Sensitivity	Specificity	PPV	NPV	LR+	LR–
Anti-CarP	44 %	89 %	78 %	65 %	4.2	0.62
Anti-CCP2	54 %	96 %	94 %	64 %	12.9	0.48
IgM-RF	59 %	91 %	86 %	72 %	6.9	0.44
Anti-CarP in anti-CCP-negative patient	12 %	91 %	37 %	71 %	1.3	0.97

A comparison is provided on the test characteristics of anti-CarP, anti-CCP and IgM RF for diagnosing RA. In addition the performance of anti-CarP in the CCP2-negative stratum is analyzed
Anti-CarP Anti-carbamylated protein, Anti-CCP2 Anti-cyclic citrullinated peptide 2, IgM-RF Immunoglobulin M-rheumatoid factor, LR+ Positive likelihood ratio, LR– Negative likelihood ratio, NPV Negative predictive value, PPV Positive predictive value, RA Rheumatoid arthritis

ISSN: 1478-6362