Table 2.
Baseline characteristics of CCP2+ RA patients with acetylated-histone reactivity.
| IgG KAc-His2B neg (n=213) | IgG KAc-His2B pos (n=65) | |||
|---|---|---|---|---|
| Frequency % Mean±SD (Median) | Frequency % Mean±SD (Median) | OR[CI] | p-values* | |
| Age | 49±23 (51) | 51±11 (53) | NS (p=0.37) | |
| Female | 73% (156/213) | 67% (44/65) | 1.3 [0.72-2.4] | NS (p=0.43) |
| HLA shared epitope | 88% (186/212) | 81% (52/65) | 0.6 [0.28-1.3] | NS (0.21) |
| HLA DRB1*01 | 25% (52/211) | 27% (17/64) | 1.1 [0.58-2.1) | NS (0.74) |
| HLA DRB1*04 | 69% (146/211) | 69% (44/64) | 0.98 [0.53-1.8] | NS (>0.99) |
| HLA DRB1*03 | 18% (39/211) | 6% (4/64) | 0.29 [0.10-0.85] | p=0.02 |
| Ever smoking | 70% (149/212) | 86% (58/65) | 2.6 [1.2-5.6] | p=0.007 |
| DAS28 | 5.1±1.46 (5.3) | 4.9±1.1 (5.1) | NS (p=0.31) | |
| CRP | 30.6±42.8(16.0) | 23.9±21.7 (17) | NS (p=0.86) | |
| IgG CCP2 levels (AU/ml) | 803±861 (470) | 1703±1096 (1417) | p<0.0001 | |
| IgG CCP2 high (>1000 AU/ml) | 28% (59/213) | 68% (44/65) | 5.5 [3.0-10.0] | p<0.0001 |
| IgA CCP2 pos | 58% (123/211) | 86% (52/60) | 4.7 [2.1-10.3] | p<0.0001 |
| IgA CCP2 levels (AU/ml) | 6.7±10.5 (2.6) | 13.6±12 (11) | p<0.0001 | |
| ACPA IgG fine-specificities | ||||
| Peptides with cit-gly motifs: | ||||
| Cit-Fil307-324 pos | 53% (111/208) | 87% (56/64) | 6.1 [2.8-13.5] | p<0.0001 |
| CEP-1 pos | 59% (122/208) | 84% (54/64) | 3.8 [1.8-7.9] | p=0.0002 |
| Cit-Fibβ36-52 pos | 65%% (134/208) | 90% (58/64) | 5.3 [2.1-13] | p<0.0001 |
| Cit-Fibα563-583 pos | 58% (121/208) | 84% (55/67) | 3.9 [1.9-8.0] | p<0.0001 |
| Cit-Fibα580-600 pos | 28% (58/208) | 64% (41/64) | 4.6 [2.5-8.3] | p<0.0001 |
| Cit-Fibα621-635 pos | 38% (79/208) | 71% (46/64) | 4.1 [2-3-7.7] | p<0.0001 |
| Peptides with other motifs: | ||||
| Cit-Vim60-75 pos | 62% (130/208) | 79% (51/64) | 2.4 [1.2-4.6] | p=0.01 |
| Cit-Vim2-17 pos | 45% (93/208) | 65% (42/64) | 2.4 [1.3-4.2] | p=0.004 |
| Cit-Fibα36-50 pos | 22% (46/208) | 14% (9/64) | 0.6 [0.36-1.25] | NS (p=0.21) |
| Cit-Fibβ60-74 pos | 80% (166/208) | 92% (59/64) | 3.0 [1.1-7.9] | p=0.002 |
| Number of ACPA IgG fine-specificities (of 10) | 5.1±2.7 (5) | 7.3±2.2 (8) | p<0.0001 | |
| AMPA IgG anti- | ||||
| Carb-CEP1 pos | 31% (64/208) | 59% (38/64) | 3.2 [1.8-5.9] | p<0.0001 |
| mod-Vim Orn(Ac) pos | 70% (150/212) | 87% (57/65) | 2.9 [1.3-6.5] | 0.005 |
| mod-Vim pos | 57% (121/212) | 58% (58/65) | 6.2 [2.7-14] | p<0.0001 |
| mod-Vim Lys(Ac) pos | 33% (70/212) | 73% (48/65) | 5.7 [3.1-11] | p<0.0001 |
| Carb-Fib pos | 54% (114/212) | 69% (45/65) | 1.9 [1.1-3.5] | p=0.03 |
| Carb-FCS pos | 47% (100/212) | 69% (45/65) | 2.5 [1.4-4.6] | p=0.002 |
| MAA high | 49% (105/213) | 49% (32/65) | 1.0 [0.57-1.7] | NS (p>0.99) |
| RF | ||||
| IgG pos | 70% (149/213) | 75% (49/65) | 1.3 [0.70-2.5] | NS (p=0.44) |
| IgA pos | 48% (103/213) | 49% (32/65) | 1.0 [0.59-1.8] | NS (p>0.99) |
| IgM pos | 84% (179/213) | 80% (52/65) | 0.8 [0.37-1.5] | NS (0.45) |
*p-value from Fisher’s exact test or Mann-Whitney analysis.
OR, Odds ratio; CI, 95% confidence interval; NS, Not statistically significant. Bold font highlights significant p-values.