Table 1. Characteristics of the study population at the time of nasal sampling.
| RA case (n = 46) |
Healthy control (n = 17) |
P | |
|---|---|---|---|
| Age at nasal sampling, years | 57.0 ± 8.1 | 56.8 ± 10.9 | 0.958 |
| Sex, female | 36 (78.3) | 16 (94.1) | 0.262 |
| Smoking | |||
| Never | 30 (65.2) | 17 (100) | 0.003 |
| Ever or current | 16 (34.8) | 0 | |
| Comorbidities | |||
| Diabetes mellitus | 11 (24.4) | 4 (23.5) | 1.000 |
| Hypertension | 13 (28.9) | 7 (41.2) | 0.356 |
| Viral hepatitis | 3 (6.8) | 0 | 0.553 |
| Dyslipidemia | 6 (13.3) | 1 (5.9) | 0.662 |
| RA-related characteristics | RA case (n = 45a) |
||
| Age at RA diagnosis | 48.3 ± 9.1 | ||
| Age at nasal sampling, years | 56.8 ± 8.1 | ||
| Disease duration | 9.2 ± 7.6 | ||
| RF positivity | 38 (82.6) | ||
| RF level | 96.1 ± 97.9 | ||
| Anti-CCP antibody positivity | 42 (91.3) | ||
| Anti-CCP antibody level | 131.9 ± 77.5 | ||
| ESR, mm/h | 22.4 ± 17.1 | ||
| CRP, mg/dl | 0.4 ± 0.7 | ||
| DAS28 (ESR) | 2.5 ± 0.9 | ||
| DAS28 (CRP) | 2.0 ± 0.7 | ||
| Radiographic damage | |||
| Erosion on hands or feet | 19 (41.3) | ||
| Joint space narrowing on hands or feet | 22 (47.8) | ||
| Medication | |||
| NSAIDs | 30 (65.2) | ||
| Steroid | 34 (73.9) | ||
| csDMARDs | 42 (91.3) | ||
| bDMARDs | 15 (32.6) |
aOne among the 46 cases was excluded in the analysis due to limited clinical information.
Data were presented as means with standard deviations or as number with percentages.
RA, Rheumatoid arthritis; RF, Rheumatoid factor; CCP, Cyclic citrullinated peptide; ESR, Erythrocyte sedimentation rate; CRP, C-reactive protein; DAS, Disease activity score; NSAIDs, Non-steroid anti-inflammatory drugs; csDMARDs, Conventional synthetic disease modifying antirheumatic drugs; bDMARDs, Biologic disease modifying antirheumatic drugs.