A patient is taking methotrexate and adalimumab (Humira) for rheumatoid arthritis. Which laboratory test is most important to monitor before dental treatment?

Both methotrexate and adalimumab (a TNF-alpha inhibitor) can cause bone marrow suppression leading to neutropenia, thrombocytopenia, and anemia. A CBC is the most important laboratory test before dental treatment to assess: (1) neutrophil count — neutropenia increases infection risk; (2) platelet count — thrombocytopenia increases bleeding risk. Methotrexate also causes hepatotoxicity (requiring LFTs) and can impair renal function, but the most immediate concern for dental procedures is hematologic status. Immunosuppressed patients with low neutrophil counts may need antibiotic prophylaxis and should not receive elective surgery during active neutropenia.