## **Core Concept**
Infliximab is a **tumor necrosis factor-alpha (TNF-alpha) inhibitor** used in the treatment of rheumatoid arthritis and other autoimmune diseases. It works by binding to TNF-alpha, preventing its interaction with TNF receptors on cell surfaces, thereby reducing inflammation. Given its immunosuppressive action, certain precautions and tests are necessary before initiating therapy.

## **Why the Correct Answer is Right**
The correct answer, ** tuberculin skin test (Mantoux test) or interferon-gamma release assay (IGRA)**, is required before starting infliximab therapy. This is because TNF-alpha inhibitors increase the risk of reactivating latent **tuberculosis (TB)** infection. The risk is significant enough that screening for latent TB is recommended for all patients before starting TNF-alpha inhibitors. This involves either a tuberculin skin test (TST) or an interferon-gamma release assay (IGRA) to detect the presence of latent TB infection.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is also blank and does not provide any relevant information.
- **Option C:** Similarly, this option is blank and cannot be considered.
- **Option D:** This option is blank as well.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that patients about to start **TNF-alpha inhibitors** like infliximab must be screened for **latent tuberculosis**. This is a critical step in preventing the reactivation of TB, which can be serious and life-threatening in immunocompromised individuals. The screening test of choice can be either the **tuberculin skin test (TST)** or **interferon-gamma release assays (IGRAs)**, depending on the patient's immune status and previous BCG vaccination.

## **Correct Answer:** . Tuberculin skin test (Mantoux test) or interferon-gamma release assay (IGRA)