Table 3.
Baseline clinical parameters and immunological characteristics of 585 primary SS patients
| All (n = 585) | ACA alone (n = 33) | SSA alone (n = 464) | Double-positive (n = 26) | Seronegative (n = 73) | p value | |
|---|---|---|---|---|---|---|
| IgG (mg/dl) | 1934 ± 821 | 1246 ± 177 | 2045 ± 833 | 1805 ± 500 | 1497 ± 694 | < 0.001 |
| Hyper IgG, n (%) | 305, 53% | 0, 0% | 278, 61% | 13, 52% | 14, 20% | < 0.001 |
| IgA (mg/dl) | 300 ± 142 | 246 ± 78 | 312 ± 145 | 330 ± 162 | 236 ± 107 | < 0.001 |
| Hyper IgA, n (%) | 101, 18% | 1, 5% | 90, 20% | 7, 28% | 3, 4% | 0.0018 |
| IgM (mg/dl) | 144 ± 119 | 109 ± 43 | 150 ± 128 | 140 ± 72 | 117 ± 68 | 0.029 |
| Hyper IgM, n (%) | 46, 8% | 0, 0% | 41, 9% | 2, 8% | 3, 4% | 0.26 |
| C3 (mg/dl) | 89 ± 24 | 89 ± 23 | 88 ± 23 | 93 ± 22 | 91 ± 27 | 0.28 |
| Low C3, n (%) | 88, 16% | 2, 9% | 71, 17% | 2, 8% | 13, 18% | 0.49 |
| C4 (mg/dl) | 23 ± 7 | 25 ± 6 | 22 ± 7 | 23 ± 4 | 25 ± 8 | 0.0012 |
| Low C4, n (%) | 23, 4% | 0, 0% | 18, 4% | 0, 0% | 5, 7% | 0.33 |
| CH50 (U/ml) | 49.0 ± 8.8 | 49.1 ± 6.4 | 48.7 ± 8.6 | 51.1 ± 6.5 | 49.6 ± 10.9 | 0.26 |
| Low CH50, n (%) | 19, 4% | 0, 0% | 16, 4% | 0, 0% | 3, 4% | 0.58 |
| WBC count (/μl) | 4910 ± 1558 | 5332 ± 1311 | 4772 ± 1445 | 4577 ± 1583 | 5773 ± 1977 | < 0.001 |
| Leukocytopenia, n (%) | 91, 15% | 1, 5% | 78, 17% | 5, 19% | 4, 5% | 0.034 |
| Neutrophils (%) | 58.4 ± 10.6 | 61.8 ± 8.3 | 58.2 ± 10.9 | 58.4 ± 10.5 | 58.4 ± 9.4 | 0.37 |
| Lymphocytes (%) | 32.6 ± 9.9 | 29.7 ± 8.1 | 32.8 ± 10.1 | 30.8 ± 9.2 | 32.7 ± 9.4 | 0.44 |
| Hemoglobin (g/dl) | 12.7 ± 1.3 | 12.6 ± 0.8 | 12.6 ± 1.4 | 12.8 ± 1.0 | 13.2 ± 1.4 | < 0.001 |
| Anemia, n (%) | 94, 16% | 0, 0% | 84, 18% | 2, 8% | 8, 11% | 0.037 |
| Platelet count (× 103/μl) | 223 ± 65 | 210 ± 30 | 220 ± 65 | 216 ± 62 | 246 ± 68 | 0.062 |
| Thrombocytopenia, n (%) | 45, 8% | 0, 0% | 42, 9% | 3, 12% | 0, 0% | 0.021 |
| ANA positive, n (%) | 489, 84% | 22, 100% | 411, 89% | 26, 100% | 30, 41% | < 0.001 |
| RF positive, n (%) | 274, 47% | 2, 10% | 250, 55% | 11, 44% | 7, 10% | < 0.001 |
Presented as mean and standard deviation. The Kruskal–Wallis test was used to assess the statistical significance of differences between groups
ACA anti-centromere antibody, SSA anti-SS-A antibody, Hyper IgG IgG > 1700 mg/dl, Hyper IgA IgA > 410 mg/dl, Hyper IgM IgM > 260 mg/dl, Low C3 C3 < 65 mg/dl, Low C4 C4 < 13 mg/dl, Low CH50 CH50 < 31.6 U/ml, ANA anti-nuclear antibodies, RF rheumatoid factor