CD8A and interstitial lung disease: Univariate regression analysis identified female sex, age > 57 years, ferritin > 1002.6 ng/mL, LDH > 388 U/L, ESR > 63 mm/h, CD3+ T lymphocyte count, CD8+ T lymphocyte count, anti-Ro52ab level, and RP-ILD as significant factors (p < 0.05), and these variables were therefore included as covariates in the multivariate regression analysis.