Considering the data included in the present study, 24.49% of RA patients were negative for RF and ACPA, which is consistent with previously published data, where it is indicated that the prevalence of RA patients showing negative RF/ACPA results may vary depending on the subjects’ selection, but around 20–30% of patients studied in cohorts and clinical trials present seronegative results [18]. This evidence concerns the gene PRTN3 and rheumatoid arthritis.