What baseline laboratory tests, including tuberculosis screening, are required before initiating ixekizumab (Taltz) therapy?

Baseline Laboratory Testing for Taltz (Ixekizumab)

Before starting Taltz, you must obtain tuberculosis screening (PPD, QuantiFERON Gold, or T-Spot), complete blood count (CBC), comprehensive metabolic panel (CMP), and hepatitis B and C serologies (hepatitis B surface antigen, anti-hepatitis B surface antibody, anti-hepatitis B core antibody, and hepatitis C antibody). 1

Required Pre-Treatment Testing

The FDA label for Taltz explicitly mandates tuberculosis evaluation prior to initiation 1. The AAD-NPF guidelines for biologics in psoriasis provide the comprehensive baseline screening framework that applies to IL-17 inhibitors like Taltz 2:

Mandatory Tests:

• Tuberculosis screening: Use PPD, QuantiFERON Gold, or T-Spot test 2, 1

  • Do NOT start Taltz if active TB is present 1
  • Initiate latent TB treatment before starting Taltz if screening is positive 1
  • Consider anti-TB therapy even in patients with past TB history where adequate treatment cannot be confirmed 1

• Complete Blood Count (CBC) 2

• Comprehensive Metabolic Panel (CMP) 2

• Hepatitis panel 2:

  • Hepatitis B surface antigen
  • Anti-hepatitis B surface antibody
  • Anti-hepatitis B core antibody
  • Hepatitis C antibody

Discretionary Testing:

• HIV testing: Recommended based on individual patient risk factors at the treating practitioner's discretion 2

• Chest radiography: Only if TB screening is positive 2

Important Clinical Context

The tuberculosis screening requirement is non-negotiable despite emerging evidence suggesting lower TB reactivation risk with IL-17 inhibitors. While recent research shows IL-17A inhibitors like ixekizumab have lower TB reactivation rates (0.78%) compared to TNF inhibitors 3, and one study of 306 patients showed only one TB case after 52 weeks 4, the FDA label and guidelines still mandate pre-treatment TB evaluation 1.

Real-world data reveals concerning gaps in adherence: only 11-59% of patients receive recommended TB screening before biologics, and testing rates are particularly low for IL-17 inhibitors 5. This represents a significant practice gap that should not be replicated.

Key Pitfalls to Avoid:

• Don't skip TB screening even though IL-17 inhibitors appear safer than TNF inhibitors—the requirement remains mandatory 1
• Don't assume prior negative TB tests are sufficient—obtain fresh screening within the pre-treatment window
• Don't start Taltz while waiting for latent TB treatment to complete—initiate and complete latent TB therapy first if indicated 1
• Don't forget hepatitis screening—this is often overlooked but explicitly recommended 2

Vaccination Considerations:

Complete all age-appropriate immunizations according to current guidelines before starting Taltz 1. Avoid live vaccines once treatment begins 1.

The hepatitis and CBC/CMP testing provides baseline values for monitoring potential infection risk and helps identify contraindications, though Taltz itself does not require ongoing routine laboratory monitoring like some other immunosuppressants 2.