IL1B and systemic lupus erythematosus: LPS challenge did not affect splenic IL-1β in SLE (8.6 × 105 ± 3.8 × 105 vs. 3.3 × 105 ± 2.5 × 105 intensity units, p = 0.136) nor control (3.2 × 105 ± 8.0 × 104 vs. 1.7 × 105 ± 7.0 × 104 intensity units, p = 0.646) mice.