Baseline Laboratory Testing for Skyrizi (Guselkumab)
Before initiating Skyrizi, you must obtain tuberculosis screening and, for Crohn's disease or ulcerative colitis patients, baseline liver enzymes (AST/ALT) and bilirubin levels.
Required Testing Based on Indication
For All Indications (Psoriasis, Psoriatic Arthritis, Crohn's Disease, Ulcerative Colitis):
- Tuberculosis screening is mandatory before starting Skyrizi 1. This should include:
- Tuberculin skin test (TST) or interferon-gamma release assay (IGRA)
- Chest radiograph if TB screening is positive or patient has risk factors for latent TB
For Inflammatory Bowel Disease (Crohn's Disease and Ulcerative Colitis) ONLY:
Obtain baseline hepatic function tests 1:
- Serum AST (SGOT) or ALT (SGPT)
- Bilirubin
This requirement is specific to IBD indications because drug-induced liver injury has been reported during induction therapy for these conditions 1. The FDA label explicitly states these labs must be obtained prior to initiating treatment and monitored during induction up to at least 12 weeks 1.
For Psoriasis and Psoriatic Arthritis:
No routine baseline laboratory testing is required beyond TB screening. The FDA label does not mandate baseline labs for these dermatologic/rheumatologic indications 1.
Important Caveats
Vaccination status should be verified and age-appropriate immunizations completed before starting Skyrizi, as live vaccines should be avoided during treatment 1.
Do not confuse Skyrizi monitoring with other biologics. Unlike some TNF inhibitors or other immunosuppressants, Skyrizi does not require routine baseline CBC, comprehensive metabolic panel, or hepatitis screening for psoriasis/psoriatic arthritis patients. The evidence provided about tuberculosis medications [2-3] is not relevant to Skyrizi monitoring.
The distinction between IBD and dermatologic indications is critical—hepatotoxicity monitoring is only mandated for the former due to observed liver injury during induction phases in these patient populations 1.