Caution should be exercised when using Natalizumab to treat PML

Progressive multifocal leukoencephalopathy (PML) is an opportunistic viral infection caused byJC virus (JCV). It usually occurs only in immunocompromised patients and usually leads to death or severe disability. It has occurred in patients receiving natalizumab (Natalizumab). Three factors are known to increase the risk of PML in patients treated with Taxol-based drugs: antiThe presence of JCV antibodies (antiPatients who are positive for JCV antibodies develop PML disease The risk is higher), the duration of treatment is longer (especially more than2 years), and previous immunosuppressive treatment (such as mitoxantrone, azathioprine, methotrexate, cyclophosphamide, mycophenolate mofetil).

These factors should be considered based on expected benefit when initiating and continuing treatment with natalizumab. The seroconversion rate (going from negative to positive for anti-anti-JCV antibodies and remaining positive on subsequent tests) in patients with multiple sclerosis has been reported to be 3% to 8% per year. In patients with multiple sclerosis, an MRI scan should be obtained before starting treatment with natalizumab. This MRI may help distinguish subsequent MS symptoms from PML. In patients with Crohn's disease, baseline brain MRI may also be helpful in distinguishing pre-existing lesions from emerging lesions, but baseline brain lesions that may cause diagnostic difficulties during natalizumab treatment are uncommon.

Healthcare professionals should monitor patients taking natalizumab for any new signs or symptoms suggestive of PML. Symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness in the limbs, visual disturbances, and changes in thinking, memory, and orientation, leading to confusion and personality changes. The development of the defect often leads to death or severe disability within weeks or months. At the first sign or symptom suggestive of PML, discontinue natalizumab immediately and conduct appropriate diagnostic evaluation.

There are currently no known interventions that reliably preventPML virus or adequately treat PML virus when it occurs. Reportedly, no symptoms of PML were observed after the patient discontinued natalizumab. Patients should continue to be monitored for the development of any new signs or symptoms that may be suggestive of PML for at least six months after discontinuation of natalizumab. Due to the risk of PML virus, natalizumab is only available through a restricted distribution program, the TOUCH Prescription Program.

Natalizumab's original patent drug is not marketed in the country and cannot be included in medical insurance. Currently, the generic drug natalizumab on the market overseas may cost more than 8,000 US dollars per box (the price may fluctuate due to exchange rates), which is very expensive. For more drug information and specific prices, please consult Yaode Medical Consultant.