In the study, patients with neutropenia exhibited significantly lower baseline blood neutrophil count levels (4.2 × 109/L; 95% CI: 3.8, 4.6 × 109/L), and a previous neutropenia history related to DMARD therapy increased the neutropenia risk upon receiving TNF-α inhibitors (hazard ratio 2.97; 95% CI: 1.69–5.25). This evidence concerns the gene TNF and neutropenia.