Once performing correlations between clinical and biological markers of the disease with pulmonary function variables, no statistically significant values were found; however, we identified a relationship between anti-HLA antibodies with the CRP levels, and we found a positive correlation with the percentage of reactivity, (p = 0.02, r2 = 0.60) in the RA-ILD group. The gene discussed is CRP; the disease is interstitial lung disease.