NCLEX Practice Quiz on Understanding TNF Inhibitors in the Treatment of Rheumatoid Arthritis (RA) Understanding TNF Inhibitors in the Treatment of Rheumatoid Arthritis (RA) The nurse in a clinic is reviewing the medical record of a patient who has been prescribed etanercept, a tumor necrosis factor (TNF) inhibitor. What is the most important test result that the nurse should check before initiating this treatment?* 1. C-reactve protein (CRP) 2. Prothrombin time (PT) 3. Serum LDL cholesterol 4. Tuberculin skin test (TST) Δ