Table 2. Phenotypic features of 133 primary SS patients in relation to anti-IFI16 antibody status*.
| Phenotypic feature | IFI16 positive (n=38) | IFI16 negative (n=95) | P value |
|---|---|---|---|
| Age (years), mean±SD | 55.1±13.8 | 52.2±12.9 | 0.27 |
| Female | 37 (97) | 90 (95) | 0.67 |
| Caucasian | 21 (55) | 44 (47) | 0.44 |
| Schirmer <5 mm/5 min | 24 (63) | 32 (34) | 0.003 |
| UWS<0.5 ml/5 min | 32 (84) | 67 (71) | 0.13 |
| WBC<4000 | 9 (24) | 21 (23) | 1.0 |
| C4<16 mg/dl | 11 (29) | 17 (18) | 0.17 |
| IgG>1445 mg/dl | 28 (74) | 47 (49) | 0.02 |
| ANA ≥1:320 | 31 (82) | 55 (58) | 0.01 |
| SSA (Ro52 and/or Ro60) | 28 (74) | 70 (74) | 1.0 |
| SSB | 18 (47) | 50 (53) | 0.70 |
| Extraglandular disorder† | 8 (21) | 18 (19) | 0.81 |
| Germinal center-like structure in biopsy | 15 (39) | 17 (18) | 0.01 |
| Rheumatoid factor | 27 (71) | 56 (59) | 0.24 |
| Focus score, median (25th-75th percentile) | 3.4 (2.6-6.4) | 2.4 (1.6-3.7) | 0.005 |
*
Except where indicated otherwise, values are the number (%) of patients.
†
Physician-confirmed diagnoses of Grave's disease, Hashimoto's thyroiditis, interstitial nephritis, primary biliary cirrhosis, autoimmune hepatitis, renal tubular acidosis, glomerulonephritis, and lymphoma
Abbreviations: SS, Sjögren's syndrome; UWS, unstimulated whole saliva flow rate; WBC, white blood count; C4, complement 4; IgG, immunoglobulin G