Table 4.
Factor analysis on sTNFR1 and neuropeptides in serum
| Variable | Factor | ||
| 1 | 2 | 3 | |
| sTNFR1 | 0.323 | 0.827 | |
| BN/GRP | 0.324 | 0.778 | |
| SP | 0.907 | ||
| VIP | 0.934 | ||
| CGRP | 0.63 | 0.575 | |
| NPY | 0.925 | ||
| ESR | 0.897 | ||
Principal-component analysis for sTNFR1 and five neuropeptides in serum from 21 patients with long-standing RA, and for the ESR. BN/GRP, bombesin/gastrin-releasing peptide; CGRP, calcitonin-gene-related peptide; ESR, erythrocyte sedimentation rate; NPY, neuropeptide Y; RA, rheumatoid arthritis; SP, substance P; sTNFR1, soluble tumour necrosis factor receptor 1; VIP, vasoactive intestinal peptide.