Varying combinations of rheumatoid factor and anti-cyclic citrullinated peptide antibodies in 295 patients with rheumatoid arthritis
| RF combinations | All | CCP positive | CCP negative |
|---|---|---|---|
| Values are n (%). | |||
| CCP, anti-cyclic citrullinated peptide antibodies; Ig, immunoglobulin; RA, rheumatoid arthritis; RF, rheumatoid factor. | |||
| All RA patients | 295 (100) | 190 (64.4) | 105 (35.6) |
| All three RF isotypes positive | 107 (36.3) | 91 (85.0) | 16 (15.0) |
| All three RF isotypes negative | 87 (29.5) | 30 (34.5) | 57 (65.5) |
| At least one RF isotype positive | 208 (70.5) | 160 (76.9) | 48 (23.1) |
| At least one RF isotype negative | 188 (63.7) | 99(52.7) | 89 (47.3) |
| Only IgG-RF negative | 166 (56.3) | 86 (51.8) | 80 (48.2) |
| Only IgA-RF negative | 145 (49.2) | 67 (46.2) | 78 (53.8) |
| Only IgM-RF negative | 99 (33.6) | 38 (38.4) | 61 (61.6) |
| Only IgG-RF positive | 2 (1) | 2 (100) | 0 (0.0) |
| Only IgA-RF positive | 8 (2.7) | 4 (50) | 4 (50) |
| Only IgM-RF positive | 38 (12.9) | 26 (68.4) | 12 (31.6) |
| At least IgG positive | 129 (43.7) | 104 (80.6) | 25 (19.4) |
| At least IgA positive | 150 (50.9) | 123 (82.0) | 27 (18.0) |
| At least IgM positive | 196 (66.4) | 152 (77.6) | 44 (22.4) |