State taking part in West Nile tests
Israeli blood key to experiment
Kerry Fehr-Snyder
The Arizona Republic
Jul. 26, 2004 12:00 AM
An experimental treatment using human plasma from Israeli blood donors will be tested at two Valley hospitals for patients with the most severe cases of West Nile virus.
A hospital in Tucson also is expected to participate in the expanded clinical trial sponsored by the National Institutes of Health.
The Phase I/II study is a safety trial to determine whether immunoglobulins, or antibodies, in blood from Israel, where the mosquito-borne virus is endemic, can lessen the disease's severity in patients with West Nile encephalitis or those at risk of developing the brain-swelling complication.
Patients with flacid paralysis, Parkinson's-like tremors and those who slip into comas also are eligible to receive the Israeli product, which contains antibodies to fight the disease.
Mario Gamez, a 39-year-old electrician in Phoenix, said he would have been interested in participating in the study after he was admitted to Barrow Neurological Institute, part of St. Joseph's Hospital and Medical Center, with West Nile encephalitis for six days.
The father of three boys received another experimental treatment, a form of interferon. It was not as part of a scientifically controlled trial such as the NIH study but is recommended by a West Nile virus doctor in New York, where the U.S. outbreak began in 1999.
"I was open to anything for the fact that I got to get back on my feet and back to running my business," he said.
Several weeks into his illness, Gamez is still too exhausted to work and is coping with weight loss and partial paralysis of his face. The paralysis, which resembles a stroke, may be permanent.
'Supportive care'
There is no approved treatment for people who contract West Nile virus, which is spread by mosquitoes that feed on infected birds and then bite humans. The majority of those infected will have no symptoms, but about 20 percent will develop West Nile fever, meningitis or encephalitis.
Those who are sick enough to be hospitalized typically receive "supportive care," including pain medication, fever reducers and intravenous fluids. In the most serious cases, patients will be moved to an intensive-care unit, given a feeding tube and placed on a ventilator to assist in breathing.
In the NIH trial, patients will be infused with one dose of immunoglobulin within seven days of exhibiting symptoms of the disease. But because this is a double-blinded controlled scientific trial, some patients will receive a placebo, immunoglobulin taken from U.S. blood donors or saline. They will not be told which substance they are given, nor will their doctors know, and will be monitored.
Each patient will have a greater than 50 percent chance of getting the Israeli blood product, said Walla Dempsey, who is overseeing the study as an NIH clinical trials program officer.
"When you have a new disease emerge, it's difficult to know what's going to work because many people get better on their own," she added.
The treatment study is planned at Mayo Clinic Scottsdale and Barrow Neurological Institute pending approval by their institutional review boards. The Arizona Health Sciences Center, part of the University of Arizona and associated with University Medical Center in Tucson, also expects to participate once it has approval and receives any human cases in Pima County.
Arizona continues to be the epicenter of this year's West Nile outbreak, reporting more human cases than all other states combined. Of the 137 confirmed cases as of Thursday, 131 have been in Maricopa County, the state's most-populated county. None have been from Pima County, the state's second-most-populous county.
Of those infected, 39 developed encephalitis and 55 developed meningitis, or swelling of the tissue around the brain and spinal cord. Two of those infected have died. The remainder developed West Nile fever or their symptoms were unknown by the Arizona Department of Health Services, which tracks the cases.
Dempsey said the immunoglobulin product appears to show promise because unlike natural antibodies made by the human body known as IgM, evidence suggests that smaller IgG antibodies contained in the product can cross the blood-brain barrier and reduce the neurological effects from the virus.
"We hope that it will help ameliorate the disease, in other words, go after the virus," Dempsey said.
The NIH began testing the product at 36 sites in September, the end of mosquito season for most states. It is expected to add 24 sites this summer.
Study participants have enrolled nine patients in the study and hope to get 100 by the end of this year's mosquito season.
Arizona braces
Arizona has been bracing for the virus to hit hard this year, its second since the virus was detected. The Arizona hospitals were not invited to participate in the trial until only recently so any results likely will come after the season is over.
"But we're very excited for the sites in Phoenix and Arizona to come on board," Dempsey said.
Dr. Janis Blair, chairwoman of infectious diseases at Mayo Clinic Scottsdale, said she expects to enroll about a dozen patients if the hospital gets permission from its human subjects committee.
"I think it's nice to have something to offer because when you see these people, they are terribly ill, and it is really awful for people," she said.
Dr. Philip Fracica, director of medical critical care and respiratory services at Barrow Neurological Institute, agreed, saying the hospital expects to get more West Nile virus patients in coming weeks and months. The hospital has treated 13 patients with the virus.
"I think it's important to learn as quickly as possible what is effective," he said. "The sooner we have this information, the sooner we'll know how to best treat patients."
Dr. Eskild Petersen, chief of infectious disease control and professor of medicine at the University of Arizona, said he is eager to begin using the experimental treatment if approved by the institution and a patient becomes infected in the area.
"The reason that I'm interested in this (is) at least it gives us an opportunity to see if something is going to work."
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