Comparison of variables at diagnosis between patients with GrB positivity and negativity
| Variables | All patients (N=78) | Serum GrB negativity (N=56) | Serum GrB positivity (N=22) | P value |
| Variants of AAV, n (%) | 0.147 | |||
| MPA | 41 (52.6) | 33 (58.9) | 8 (36.4) | |
| GPA | 21 (26.9) | 12 (21.4) | 9 (40.9) | |
| EGPA | 16 (20.5) | 11 (19.6) | 5 (22.7) | |
| Demographic data | ||||
| Age (years) | 62.0 (21.3) | 62.0 (22.0) | 64.5 (16.3) | 0.762 |
| Male gender, n (%) | 26 (33.3) | 19 (33.9) | 7 (31.8) | 0.859 |
| ANCA, n (%) | ||||
| MPO-ANCA (or P-ANCA) | 45 (57.7) | 32 (57.1) | 13 (59.1) | 0.875 |
| PR3-ANCA (or C-ANCA) | 7 (9.0) | 3 (5.4) | 4 (18.2) | 0.075 |
| ANCA negativity | 26 (33.3) | 21 (37.5) | 5 (22.7) | 0.213 |
| AAV-specific indices | ||||
| BVAS | 6.0 (10.3) | 6.0 (11.5) | 6.5 (8.5) | 0.857 |
| FFS | 1.0 (1.0) | 1.0 (1.0) | 1.0 (1.3) | 0.380 |
| Clinical manifestations, n (%) | ||||
| General | 26 (33.3) | 19 (33.9) | 7 (31.8) | 0.859 |
| Cutaneous | 9 (11.5) | 7 (12.5) | 2 (9.1) | 0.672 |
| Mucous membranes/eyes | 5 (6.4) | 4 (7.1) | 1 (4.5) | 0.673 |
| Otorhinolaryngological | 35 (44.9) | 21 (37.5) | 14 (63.6) | 0.037 |
| Pulmonary | 50 (64.1) | 34 (60.7) | 16 (72.7) | 0.320 |
| Cardiovascular | 4 (5.1) | 2 (3.6) | 2 (9.1) | 0.320 |
| Gastrointestinal | 0 (0) | 0 (0) | 0 (0) | N/A |
| Renal | 39 (50.0) | 30 (53.6) | 9 (40.9) | 0.314 |
| Nervous | 17 (21.8) | 11 (19.6) | 6 (27.3) | 0.463 |
| Laboratory results | ||||
| White blood cell count (/mm3)11.8 (3.7) | 7685.0 (4,240.0) | 7155.0 (3,980.0) | 8580.0 (7,100.0) | 0.035 |
| Hemoglobin (g/L) | 118 (37) | 117 (37) | 120 (45) | 0.863 |
| Platelet count (×1000/mm3) | 252.5 (136.0) | 252.0 (112.8) | 263.5 (234.3) | 0.105 |
| Fasting glucose (mg/dL) | 101.0 (35.3) | 102.0 (38.8) | 94.0 (28.3) | 0.222 |
| Blood urea nitrogen (mg/dL) | 18.9 (17.1) | 18.7 (22.2) | 19.7 (11.4) | 0.240 |
| Creatinine (mg/dL) | 0.9 (1.6) | 0.9 (1.9) | 0.9 (1.1) | 0.235 |
| Total protein (g/dL) | 6.4 (0.9) | 6.6 (1.0) | 6.4 (0.7) | 0.623 |
| Serum albumin (g/dL) | 3.7 (0.9) | 3.7 (0.9) | 3.7 (1.0) | 0.356 |
| Aspartate aminotransferase (IU/L) | 18.0 (9.0) | 18.0 (8.8) | 17.0 (9.0) | 0.399 |
| Alanine aminotransferase (IU/L) | 18.0 (12.3) | 18.5 (14.0) | 17.0 (11.3) | 0.281 |
| Total bilirubin (mg/dL) | 0.5 (0.3) | 0.5 (0.4) | 0.5 (0.3) | 0.564 |
| ESR (mm/hr) | 37.5 (43.3) | 35.5 (36.0) | 39.4 (61.5) | 0.216 |
| CRP (mg/L) | 2.4 (14.6) | 1.9 (9.6) | 8.0 (30.6) | 0.237 |
Values are expressed as a median (IQR) or n (%).
AAV, antineutrophil cytoplasmic antibody-associated vasculitis; ANCA, antineutrophil cytoplasmic antibody; BVAS, Birmingham Vasculitis Activity Score; C, cytoplasmic; CRP, C reactive protein; EGPA, eosinophilic granulomatosis with polyangiitis; ESR, erythrocyte sedimentation rate; FFS, Five-Factor Score; GPA, granulomatosis with polyangiitis; GrB, granzyme B; MPA, microscopic polyangiitis; MPO, myeloperoxidase; N/A, not applicable; P, perinuclear; PR3, proteinase 3.