Small study finds signs of herpes in lesions
By JOE MANNING
of the Journal Sentinel staff
Last Updated: Nov. 10, 2000
A small, 4-year-old private viral diagnostic company in Milwaukee County Research Park may have unlocked a key to the cause of multiple sclerosis, a disease marked by the destruction of a protective covering of nerve fibers.
For the first time, a human herpes virus has been isolated from lesions on tissues of the central nervous system that are characteristic of MS.
Konstance K. Knox, one of the founders of ViraCor Diagnostic Laboratories in Wauwatosa, said the finding makes a strong case for the virus, called HHV-6, or human herpes virus six, being the cause of the infections.
Knox feels that with this information, MS potentially could be stemmed in the early stages of infection through the use of anti-viral medication.
ViraCor is the only commercial lab in the country that can detect and grow HHV-6, Knox said.
Multiple sclerosis is a chronic, often disabling disease of the central nervous system in which the immune system turns on nerve tissue and destroys it.
Symptoms may be mild, such as numbness in the limbs, or severe, including paralysis or loss of vision. Most people with MS are diagnosed between ages 20 and 40. About 7,500 people have the disease in Wisconsin and 350,000 nationwide.
The destruction of myelin, the fatty sheath that surrounds and insulates the nerve fibers, causes the nerve impulses to be slowed or halted and produces the symptoms of MS.
Knox believes it is an infection with the virus that triggers the initial destruction of the myelin. Then, after the body's natural defenses have fought the infection for years, the immune system mistakenly begins to attack the myelin tissue in the later stages of MS, she said.
While Knox and other researchers have speculated on HHV-6 being a viral trigger for some time, Knox and others contributing to her research have now found the active virus in lesions of the central nervous system destroying the myelin layer.
Knox is the main author of a research paper on HHV-6 and multiple sclerosis in the current publication of Clinical Infectious Diseases.
"It's not a new concept that a virus may be involved as a trigger. What is unique (in the study) is that this is the first time a virus has been shown to be directly infecting and actively replicating in patients with MS," she said in an interview.
"We have an agent at the site of the disease."
Knox said cells actively infected with HHV-6 were found in 89% (17 out of 19) of tissue samples that showed active destruction of myelin. That compares with 13% (three of 23) tissue samples that were free of active disease.
Knox said outbreaks of HHV-6 are like other herpes infections - such as cold sores or fever blisters - that do a lot of tissue damage before the immune system gets them under control.
The typical blisters of cold sores come and go, as people afflicted with that virus are well aware, she said. She feels it's the same with HHV-6 in its attack on myelin in the spinal cord and brain.
The good news, Knox said, is that early in an HHV-6 infection, the virus can be treated with a medication called Ganciclovir. But, she said, she is having difficulty convincing the world of science of that possibility. Anti-viral treatment is not now part of standard treatment for MS, Knox said. In fact, there is little treatment for the disease, she said.
In a way, Knox said she feels like a voice crying in the wilderness because, at this point, few researchers want to listen. She points to the discovery about six years ago in which definitive evidence showed that stomach ulcers are caused not by excess stomach acid, as had long been presumed, but by the bacterium Helicobacter pylori.
Today, ulcers are treated primarily with antibiotics instead of acid-blocking drugs, she said.
"We will find there are viral agents underlying a lot of chronic inflammatory diseases," Knox predicted.
According to the National Multiple Sclerosis Society, "more than a dozen viruses including measles, canine distemper and HHV-6 have been investigated to determine if they are involved in the development of MS, but it has not yet been definitively proven that any one virus triggers MS," said the society, which funded a portion of Knox's work with a $27,500 grant.
"Although the number of people in this (Knox's) study was small, the findings offer intriguing new evidence for possible association of HHV-6 with multiple sclerosis," the Wisconsin Chapter of the National Multiple Sclerosis Society in Waukesha said in a statement.
While "there is no evidence from these studies that HHV-6 either causes MS or is responsible for attacks or worsening of disease," the statement said the society was funding research into the role of HHV-6 in multiple sclerosis - something the society has spent $2 million for since 1990.
"This was a small study, but we have an important piece of the puzzle," Knox said, adding that larger studies and clinical trials are needed.
"We are trying to convince other investigators to look at and support this. There is huge resistance. We can put a lid on these infections," she said.
Most of the funding for the study came from ViraCor, which provided
funds to the Institute for Viral Pathogenesis, a not-for-profit research
arm of ViraCor that conducted the study, Knox said.
Appeared in the Milwaukee Journal Sentinel on Nov. 11, 2000.