What assessments and baseline tests are required before initiating tofacitinib (Xeljanz) for a patient with Howard‑Pelitz syndrome?

Pre-Treatment Assessment for Tofacitinib

Before initiating tofacitinib, you must complete a comprehensive baseline evaluation including tuberculosis screening, hepatitis B/C testing, complete blood count with differential, liver and renal function tests, lipid panel, and ensure vaccination status is current—particularly for herpes zoster if feasible. 1, 2

Mandatory Laboratory Testing

Complete Blood Count Requirements

• Full blood count with differential white cell count is essential 1
• Do not start tofacitinib if: 2
  • Absolute lymphocyte count <500 cells/mm³
  • Absolute neutrophil count <1000 cells/mm³
  • Hemoglobin <9 g/dL

Hepatic and Renal Function

• Liver enzymes (particularly transaminases) 1
• Renal function tests (creatinine clearance) 1
  • Critical for dosing: severe renal impairment (CrCl <30 mL/min) requires dose reduction to 5 mg once daily 1
  • Severe hepatic disease (Child-Pugh C) is a contraindication 1

Lipid Profile

• Baseline lipid levels should be checked unless recently obtained 1
• Note: CPK testing is not required 1

Infectious Disease Screening

Tuberculosis Evaluation

TB screening is mandatory with risk similar to TNF inhibitors 1. This includes:

• Tuberculin skin test or interferon-gamma release assay
• Chest X-ray (unless recently performed) 1
• Treat latent TB before starting tofacitinib 2
• Continue monitoring for active TB throughout treatment, even if initial screening is negative 2

Hepatitis B Virus Testing

All patients require HBV screening with the following panel 1:

• Anti-HBs (surface antibody)
• Anti-HBc (core antibody)
• HBsAg (surface antigen)

Management algorithm:

• Positive HBsAg (chronic infection): Avoid tofacitinib if possible; if unavoidable, start antiviral prophylaxis (entecavir, tenofovir, or tenofovir alafenamide) with hepatology consultation 1
• Positive anti-HBc only: Obtain baseline HBV DNA to exclude occult infection. If negative, proceed with tofacitinib but monitor regularly for HBV DNA and HBsAg reappearance 1

Hepatitis C and HIV

• Hepatitis C screening for at-risk patients 1
• HIV testing recommended for those with risk factors 1
• The FDA label specifically mentions hepatitis B/C reactivation risk and recommends pre-treatment blood tests 2

Clinical History Assessment

Critical Risk Factors to Evaluate

Venous Thromboembolism History:

• Carefully evaluate patients with prior VTE before initiating tofacitinib 1
• Increased VTE risk (especially pulmonary embolism) observed with higher doses (10 mg twice daily) in patients with cardiovascular risk factors 1
• Patients on anticoagulation may have counteracted risk 1

Cardiovascular Risk Factors:

• Document all cardiovascular comorbidities 1
• Higher rate of major adverse cardiovascular events (MI, stroke, CV death) observed versus TNF blockers 2

Infection History:

• Prior serious infections
• Recurrent infections
• Risk factors for opportunistic infections 1

Malignancy History:

• Prior malignancy within 5 years typically excluded from studies 1
• Higher rates of lymphomas and lung cancers observed versus TNF blockers 2

Age Considerations

• Patients >65 years: EMA has restricted use due to increased serious infection risk 1
• Patients >70 years: Consider dose reduction (though this applies more to baricitinib) 1
• Patients <18 years: Safety and efficacy not established (except for specific pediatric indications) 1

Medication Review

Document all concomitant medications, specifically: 1

• COX-2 inhibitors
• Prednisone doses >7.5 mg daily
• Oral contraceptives
• CYP2C19 and CYP3A4 inhibitors (require dose adjustments) 2

Contraindicated combinations: 1, 2

• Biologic DMARDs (tocilizumab, etanercept, adalimumab, infliximab, rituximab, abatacept, anakinra, certolizumab, golimumab, ustekinumab, secukinumab, vedolizumab, ixekizumab)
• Potent immunosuppressants (azathioprine, cyclosporine, tacrolimus)

Vaccination Status

Update immunizations before starting therapy 1, 2:

• Herpes zoster vaccine is particularly important given 3-4 fold increased reactivation risk (up to 9 per 100 patient-years in Asian populations) 1
• Complete all age-appropriate vaccinations per regional guidelines
• Avoid live vaccines once tofacitinib is started 2

Physical Examination

Skin Assessment

• Baseline skin check for non-melanoma skin cancer in at-risk patients 1
• Document any existing skin lesions

Special Populations

Pregnancy and Lactation

• Contraception required for both female and male patients 1
• Tofacitinib is teratogenic in animal studies 1
• Wait 4 weeks after last dose before attempting conception 1
• Contraindicated during breastfeeding 1, 2
• After stopping tofacitinib, wait 18 hours (immediate-release) or 36 hours (extended-release) before resuming breastfeeding 2

Common Pitfalls to Avoid

1. Starting with inadequate blood counts: Always verify lymphocyte, neutrophil, and hemoglobin thresholds are met 2
2. Missing occult HBV: Don't rely on HBsAg alone; check anti-HBc to identify prior exposure 1
3. Overlooking VTE risk factors: This is a critical safety concern, especially with cardiovascular comorbidities 1, 2
4. Inadequate TB screening: Reactivation risk is real; don't skip this step 1, 2, 3
5. Forgetting herpes zoster vaccination: The reactivation rate is significantly elevated 1, 3
6. Ignoring age restrictions: Patients >65 years have substantially higher infection risk 1