Table 1.
ACPA fine specificities by anti-LtxA antibody status in RA.
| No anti-LtxA (n=112) |
Anti-LtxA +ve (n=84) |
p | |
|---|---|---|---|
| Any ACPA, n (%)† | 75 (67) | 69 (83) | 0.011 |
| ACPA fine specificities (citrullinated antigens) | |||
| Apolipoprotein A1 | 106 (52-367) | 246 (84-890) | <0.001 |
| Apolipoprotein E | 289 (210-520) | 352 (243-1129) | 0.004 |
| Fibrinogen alpha | 70 (47-224) | 102 (62-242) | 0.066 |
| Histone H2B | 1198 (264-4621) | 2365 (715-5898) | 0.020 |
| Vimentin | 544 (128-2012) | 1403 (239-3150) | 0.018 |
| Apolipoprotein E 277-296, cyclic peptide | 707 (136-2615) | 1374 (338-3751) | 0.032 |
| Enolase alpha, cyclic peptide | 1114 (120-3932) | 1698 (405-5445) | 0.13 |
| Filaggrin 48-65, cyclic peptide | 1452 (147-5410) | 1479 (323-6716) | 0.36 |
| Biglycan 247-266, cyclic peptide | 1214 (132-5090) | 1380 (422-4713) | 0.23 |
| Clusterin 231-250, cyclic peptide | 1604 (154-5950) | 3444 (870-10370) | 0.020 |
| HnRNP B1b (citRA33), n (% positive) | 42 (38) | 44 (52) | 0.038 |
Anti-LtxA, anti-leukotoxin A antibodies; ACPA, anti-citrullinated protein antibodies,
†
any positivity by multiplex assay as previously defined (23); ACPA fine specificity was expressed as median fluorescence intensity (IQR) (63); antibodies against citrullinated RA33 (citRA33) were quantified by full-protein ELISA using citrullinated heterogeneous nuclear ribonucleoprotein B1b (hnRNP B1b) as previously described (9).