Risk of CTD occurrence in autoantibody-positive patients with primary ITP
| Groups | n | Cases, n (%) | Crude HR (95% CI) | P value |
| ANA−/ENA− | 373 | 2 (0.5) | Reference | – |
| ANA+/ENA− | 73 | 8 (11.0) | 21.9 (4.7 to 103.3) | <0.001 |
| ANA−/ENA+ | 76 | 7 (9.2) | 16.8 (3.5 to 81.3) | <0.001 |
| ANA+/ENA+ | 48 | 10 (20.8) | 47.7 (10.4 to 218.2) | <0.001 |
CTD, connective tissue disease; ENA, extractable nuclear antigen antibodies.