'CDC Warns of Severe Arboviral Disease With B-Cell Drugs'

 The CDC on Tuesday warned doctors about the risk for severe arboviral neuroinvasive disease in patients on B cell-depleting or modulating agents, calling out anti-CD20 monoclonal antibodies in particular.

Published case reports indicate an overall mortality of about 40% for patients on anti-CD20 antibodies with arboviral neuroinvasive disease, and neurologic sequelae were common in survivors. The most common virus involved in the reports was West Nile, but severe cases also involved eastern equine encephalitis, Powassan, La Crosse, and others.

"In recent years, a novel clinical presentation of chronic, neurodegenerative encephalitis developing over months to years has been described in at least five patients receiving rituximab who were infected with an orthobunyavirus, including Jamestown Canyon virus, Cache Valley virus, or Potosi virus," the CDC said in a Health Alert Network advisory.

Arboviral viruses are transmitted by arthropods, most commonly mosquitoes and ticks, and are subclinical in most individuals. When symptoms do present they can include acute febrile or neurologic illness such as encephalitis or acute flaccid myelitis.

Beyond rituximab, the class of anti-CD20 monoclonal antibodies includes ocrelizumab (Ocrevus), obinutuzumab (Gazyva), ofatumumab (Kesimpta), ublituximab (Briumvi), and ibritumomab tiuxetan (Zevalin). They carry indications for leukemia, lymphoma, multiple sclerosis, and rheumatoid arthritis, among others. During the early days of the pandemic, anti-CD20 agents were also linked to worse outcomes with COVID-19.

"Be aware that patients with an arboviral disease who are immunocompromised can have a prolonged incubation period or an atypical course and might not present with illness during the usual months when mosquitoes and ticks are active," the CDC said.

No approved vaccines or treatments are approved for the types of arboviral virus endemic in the U.S., such as West Nile virus. Other common arboviral viruses transmitted by mosquitoes include chikungunya, dengue, and Zika, while Oropouche virus is spread mostly by biting midges and Powassan virus by ticks.

The CDC recommended that physicians educate on severe arboviral disease if a patient is starting on immunosuppressive agents such as B cell-depleting drugs and on preventive measures for mosquito and tick bites.

If arboviral disease is suspected in a patient presenting with a febrile or neurologic illness, the CDC recommended molecular testing with RT-PCR or metagenomic next-generation sequencing to detect the viral RNA, with the type of preferred specimen depending "on the clinical presentation and laboratory conducting the testing."

https://www.medpagetoday.com/infectiousdisease/generalinfectiousdisease/122572