NGF and systemic lupus erythematosus: In contrast, serum levels of NGF (426.12 ± 70.8 vs 462.6 ± 47.1 pg/mL, NS) and NT-3 (2986.9 ± 954.5 vs 2911.7 ± 1248.8 pg/mL, NS) remained unchanged after treatment of the SLE flare.