FS patients with severe neutropenia (absolute neutrophil count < 0.5 × 109/l) had higher ACPA titers than those with modest neutropenia (ANC ≥ 0.5, but below normal range), and particularly those in the normal range (2.5–4 × 109/l) (Fig. 5c). This evidence concerns the gene PRTN3 and Decreased total neutrophil count.