NEW YORK — Psoriasis patients taking biologic therapies require careful monitoring, including a number of lab tests and vaccinations, Dr. Mark Lebwohl said at a meeting on medical and surgical dermatology sponsored by the Mount Sinai School of Medicine.
Seasonal flu vaccines, for example, are not mandated but are widely received by patients taking all five of the top biologics to treat psoriasis—alefacept (Amevive), efalizumab (Raptiva), adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade).
Dr. Lebwohl outlined the current consensus on proper monitoring and vaccination based on package inserts, medical literature, a survey of the medical advisory board members of the National Psoriasis Foundation, and the best practices from colleagues in other specialties.
Ideally, psoriasis patients on biologics should be given the influenza vaccine and the pneumococcal vaccine, if indicated by age, before treatment begins. However, studies have shown that there is still a healthy immune response after therapy begins, so they can be given after treatment is initiated as well, said Dr. Lebwohl, professor and chairman of the department of dermatology at Mount Sinai, in New York.
Tuberculosis tests are not mandated but are widely performed at baseline for alefacept and efalizumab and are recommended by most physicians at baseline for etanercept. TB tests are mandatory at baseline when treating patients with adalimumab and infliximab, Dr. Lebwohl said. The current recommendations from the Centers for Disease Control and Prevention call for TB testing before starting patients on all tumor necrosis factor-α blockers.
At follow-up, TB tests are widely performed annually for those on adalimumab, etanercept, and infliximab.
For patients who have had a bacille Calmette-Guérin (BCG) vaccine that could mask the presence of TB, Dr. Lebwohl recommends foregoing the standard purified protein derivative (PPD) TB skin test and instead using the QuantiFERON-TB Gold test. It specifically excludes the antigens that are in BCG.
“BCG does not interfere with this test,” he said.
The QuantiFERON test eliminates the reading bias, does not require a 48-hour follow-up visit, and has no booster effect. The downside is that it does require a blood draw and costs about $90. The test is not more specific or sensitive than the PPD test, he said, but with BCG-treated patients it is certainly more specific.
Obtaining CD4 counts is mandatory for alefacept at baseline and every 2 weeks thereafter.
A complete blood count plus platelet counts are mandatory at baseline for alefacept and efalizumab and are recommended by most physicians for adalimumab, etanercept, and infliximab. At follow-up, the test is generally recommended for all five.
The package insert for efalizumab shows that 8 out of 2,700 patients taking the drug experienced significant thrombocytopenia, which resolved in most patients in 35–112 days. Overall, the onset of platelet decline occurred 2–3 months after the first dose of efalizumab.
In his practice, Dr. Lebwohl checks platelet counts monthly for the first 3 months and every 3 months thereafter. Some evidence suggests the need to check platelets more often—every month for the first 6 months—“but the bottom line is that if you check your bloods for the first 3 months you're not likely to run into trouble with this,” he said.
Chemistry panels plus liver function tests are mandatory at baseline for infliximab and are widely performed but not mandated for alefacept, efalizumab, adalimumab, and etanercept. Annual follow-up is widely performed for most of the biologics and is recommended before infusions of infliximab, but there was not agreement about how often the follow-up should be performed.
Antinuclear antibody (ANA) tests are recommended at baseline by many physicians for adalimumab, etanercept, and infliximab.
The consensus among psoriasis experts, however, is that there is no reason to check ANA at follow-up because patients are supposed to develop ANAs over the course of treatment and it should not be a reason to stop the drug, he said.
“We know that autoimmunity occurs,” Dr. Lebwohl said. “There is no question that we get more ANAs in patients treated with TNF-α blockers.”
Of the few patients who have developed drug-induced lupus, the ANA is the most common change. But a fair number of papers also are emerging on the treatment of lupus with TNF-α blockers (Arthritis Rheum. 2002;46:1408–9).
If there are no other signs of lupus, a positive ANA should not prevent physicians from treating the patient with a TNF-α blocker, Dr. Lebwohl said.
Over the past year, Dr. Lebwohl has been a consultant and speaker for, or had pending consulting agreements with, a number of drug companies, including Abbott, Amgen, Astellas, Centocor, Connetics, Genentech, Novartis, and Warner Chilcott. He also has served as a speaker for Allergan.