New autoantibodies in early rheumatoid arthritis

Table 4 Autoantibodies to WIBG, GABARAPL2, ZNF706 peptides in patients with early RA

							WIBG P22, ZNF706 P1 and GABARAPL2 P15 combination
		Anti-CCP	RF	WIBG P22	ZNF706 P1	GABARAPL2 P15
RA <1 year (n = 60) vs 106 controls (AS, PsA, SLE, and healthy)	Sensitivity (%)	72	70	30	35	37	45
	Specificity (%)	100	nd	95	100	95	92
	PPV (%)	100	nd	78	100	81	75
	NPV (%)	86	nd	71	73	73	75
RA <1 year negative for anti-CCP (n = 17) vs 106 controls (AS, PsA, SLE, and healthy)	Sensitivity (%)	0	29	12	6	23	41
	Specificity (%)	nd	nd	95	100	95	92
	PPV (%)	nd	nd	18	10	31	44
	NPV (%)	nd	nd	87	86	88	91
RA <1 year negative for RF (n = 17) vs 106 controls (AS, PsA, SLE, and healthy)	Sensitivity (%)	29	0	12	12	18	35
	Specificity (%)	100	nd	95	100	95	92
	PPV (%)	100	nd	29	100	37	40
	NPV (%)	90	nd	87	88	88	90
RA <1 year negative for anti-CCP and RF (n = 12) vs 106 controls (AS, PsA, SLE, and healthy)	Sensitivity (%)	0	0	8	8	25	42
	Specificity (%)	nd	nd	95	100	95	92
	PPV (%)	nd	nd	17	100	37	36
	NPV (%)	nd	nd	90	91	92	93

WIBG, within BGCN homolog (Drosophila); GABARAPL2, GABA(A) receptor-associated protein-like 2; ZNF706, zinc finger protein 706; RA, rheumatoid arthritis; CCP, cyclic citrullinated peptide; RF, rheumatoid factor; AS, ankylosing spondylitis; PsA, psoriatic arthritis; SLE, systemic lupus eryth ematosus; SSc, systemic sclerosis; PPV, positive predictive value; NPV, negative predictive value; nd, not determined.

ISSN: 1478-6362