Interferon Requirements and Precautions Before Starting JAK Inhibitors

Pre-JAK Inhibitor Screening and Vaccination Requirements

The National Comprehensive Cancer Network recommends tuberculosis testing before starting JAK inhibitors due to potential vulnerability to Mycobacterium tuberculosis infection, with IFN-gamma release assays preferred for TB screening 1
The British Journal of Dermatology suggests vaccination is an important tool for infection prevention in patients starting JAK inhibitors, with specific recommendations for completion before treatment initiation 2, 3
The British Journal of Dermatology recommends inactivated pneumococcal, influenza, and a two-dose Shingrix series should be administered prior to JAK inhibitor therapy for patients aged >18 years 2
The British Journal of Dermatology advises if the inactivated recombinant zoster vaccine is not available, the live zoster vaccine must be administered at least 3-4 weeks before initiating JAK inhibitors 2

The British Journal of Dermatology states JAK1/2 inhibition affects cellular cytotoxicity by blocking interferon-γ signaling, inhibiting cellular killing mechanisms and impairing the ability to fight infectious agents 2
The British Journal of Dermatology reports herpes zoster is an established complication of JAK inhibitors, with prevalence <3% in atopic dermatitis patients on oral JAK inhibitors 2
The European Task Force on Atopic Dermatitis recommends a 1-week pause of JAK inhibitor treatment after COVID-19 vaccination to prevent insufficient vaccination response 3

The European Medicines Agency recommends cautious use of JAK inhibitors as first-line agents in patients at risk for adverse cardiovascular outcomes 5
The FDA recommends JAK inhibitors only after failure or intolerance to TNF antagonists in patients with moderate-to-severe ulcerative colitis 5

The British Journal of Dermatology suggests prior to initiating JAK inhibitors, consider venous thromboembolism risk factors including history of VTE, age >65 years, inherited thrombophilias, exogenous estrogen use, recent surgery, immobility, and other cardiovascular risk factors 7, 8
The British Journal of Dermatology advises JAK inhibitors should not be used for patients with severe hepatic disease, although no dosage adjustment is needed for mild or moderate hepatic impairment 6
The British Journal of Dermatology states renal function significantly affects JAK inhibitor exposure; baricitinib and abrocitinib are not recommended in patients with severe renal impairment 6
The British Journal of Dermatology recommends laboratory monitoring is required for all JAK inhibitors due to potential safety issues 8

The British Journal of Dermatology warns JAK inhibitors can impair immune responses to vaccines; ideally complete vaccination series prior to JAK inhibitor initiation 2, 3
The British Journal of Dermatology advises be aware that JAK inhibitors may increase risk of malignancy, with all having boxed warnings for this potential safety issue 9