Table 3.
A comparison of the absolute and percent PR3-ANCA increase per year in GPA patients versus matching healthy controls
| PR3 Antibody Elevation | Patients (%) | Controls (%) | Odds Ratio | 95% Confidence Interval | P Value (Fisher’s Exact Test) |
|---|---|---|---|---|---|
| U/ml per year | |||||
| >0 | 81 (21/26) | 15 (8/26) | 23.1 | 5.5 to 98 | <0.001 |
| >1 | 62 (16/26) | 0 (0/26) | 44.2a | 5.2 to 377a | <0.001 |
| >2 | 50 (13/26) | 0 (0/26) | 28a | 3.3 to 237a | <0.001 |
| >10 | 27 (7/26) | 0 (0/26) | 11.0a | 1.3 to 95a | 0.01 |
| % per year | |||||
| >0 | 81 (21/26) | 15 (4/26) | 23.1 | 5.5 to 98 | <0.001 |
| >20 | 77 (20/26) | 4 (1/26) | 83 | 9.3 to 750 | <0.001 |
| >200 | 50 (13/26) | 0 (0/26) | 28a | 3.3 to 237a | <0.001 |
| >1000 | 23 (6/26) | 0 (0/26) | 9.1a | 1.0 to 80a | 0.02 |
Of the 27 study patients, 26 had multiple serum samples available for calculation. Calculations of change in percentage per year better adjust for patient variable serum sample time intervals before diagnosis. PR3, proteinase-3; GPA, granulomatosis with polyangiitis.
a
Estimated due to actual infinite value.