Antibody reactivity to MAG1 in RA and clinical variables. Control peptide CON2 (RRSPRGRASHS) related to a Gag non-open reading segment of endogenous virus HERV-K10 present in the human population15: 27 patients with RA and 27 healthy controls were tested using an alkaline phosphatase conjugate/substrate system23. Mean OD values are given with standard errors in parentheses. No significant difference was found between male and female patients within RF-positive or -negative groups (p = 0.128).
| Variable | n | OD (SEM) | Analysis | p |
|---|---|---|---|---|
| Control peptide CON2 | 27 | RA: 1.163 (0.081) | t test | 0.804 |
| 27 | N: 1.130 (0.104) | |||
| RF | 16 | RF+: 0.762 (0.127) | ANOVA | 0.576 |
| 10 | RF−: 0.643 (0.076) | |||
| Sex | 13 | Male: 0.645 (0.078) | ANOVA | 0.768 |
| 17 | Female: 0.818 (0.127) | |||
| RF and bone radiograph positive | 18/23 (78%) | chi-square | 0.001* |
↵* Significant (p < 0.05). RA: rheumatoid arthritis; OD: optical density; RF: rheumatoid factor.