Which blood test is NOT required before starting DMARD therapy for rheumatoid arthritis?

Before starting disease-modifying antirheumatic drug (DMARD) therapy for rheumatoid arthritis, specific baseline laboratory tests are important to assess the patient's liver function, kidney function, and to screen for infections that could complicate treatment.

Among the tests listed, several provide critical information. For instance, measuring AST (aspartate aminotransferase) is essential to evaluate liver function because many DMARDs can affect the liver. Monitoring platelets is also vital, given that some DMARDs can cause bone marrow suppression, which may lead to thrombocytopenia. Hepatitis B serology is particularly important for screening patients, especially those who may have been exposed to the virus, as DMARD therapy can reactivate latent infections.

In contrast, a urinary analysis is not required as a standard pre-treatment test for DMARDs in rheumatoid arthritis management. While a urinary analysis may provide useful information about kidney function or detection of urinary infections, it does not specifically relate to the safety or risk factors associated with starting DMARD therapy. Therefore, it is the least relevant amongst the options when considering the necessary baseline tests before initiating treatment.