What's the Connection Between Multiple Sclerosis and the JC Virus?

Date: Jun-17-2016 The John Cunningham Virus, also known as the JC virus, is a typically harmless virus.

It is found in the blood samples of 70 to 90 percent of people worldwide.

Children with JC virus often show no symptoms. The JC virus can also be found in the body much later in life without complications. It is commonly found in the kidneys, bone marrow, and some body tissues.

According to an article published in the World Journal of Neuroscience, the virus "remains on renal tissue and can be eliminated in urine in 40-75 percent of individuals around the age of 30."

JC virus is typically a harmless infection. However, some people with the virus are at a high risk of developing a potentially life-threatening condition called progressive multifocal leukoencephalopathy (PML).

Contents of this article:

Multiple sclerosis and the JC virus

Why are people with multiple sclerosis at risk for developing PML?

Symptoms of PML

Diagnosis and treatment of PML

Multiple sclerosis and the JC virus

In PML, the protective coating of the nerve cells breaks down, causing damage to the central nervous system.

The risk of PML is higher in people who take certain medications to treat multiple sclerosis.

The risk for PML increases in those whose immune system is depressed, such as with an HIV infection or receiving certain medications to treat autoimmune conditions such as multiple sclerosis (MS). The JC virus that is dormant in the body can reactivate and cause infection.

This reactivation of the JC virus and development of incurable PML can lead to severe physical effects. Complications include dementia, blindness, paralysis, and seizures.

Up to 50 percent of those diagnosed with PML die within the first few months receiving a diagnosis.

Ramírez and Palacio explain in an article published in the World Journal of Neuroscience, that PML has three stages:

Stage 1: Initial infection with the JC virus without symptoms

Stage 2: Inactive JC virus remains present in the urinary tract, bone marrow, tonsils, lungs, spleen, and gut tissue

Stage 3: Active virus spreading toward the brain and central nervous system

Why are people with multiple sclerosis at risk for developing PML?

People at risk for developing PML include:

Patients whose immune systems are impaired due to HIV or treatment with certain medications

Patients with autoimmune diseases such as multiple sclerosis (MS) that are treated with drugs that depress the immune system

Medications linked with PML include:

Cyclophosphamide

Corticosteroids

Mycophenolate mofetil

Monoclonal antibodies including natalizumab (Tysabri), rituximab (Mabthera) and alemtuzumab (MabCampath)

For those with MS taking the medication natalizumab, the risks for reactivation of the JC virus and progression to PML are elevated.

A study published in the New England Journal of Medicine evaluated 19 patients with MS receiving treatment with natalizumab. The researchers found a rise in JC virus urine levels after starting treatment with the drug. Virus levels rose from 19 percent to 63 percent after 12 months of using natalizumab.

After a further 6 months, blood samples further revealed that the virus had entered the blood cells of 60 percent of the patients.

The researchers also found that the body's immune response to the JC virus had fallen after 12 months of treatment with natalizumab.

They reported that among many of the MS patients using the drug, the virus that was found in their urine or blood samples had already undergone changes linked with the virus' ability to reach the brain and cause PML.

None of the study participants, however, developed PML brain lesions.

Symptoms of PML

Infection with the JC virus can cause cells to die. The virus can also break down the protective coating of the nerve cells, affecting the white matter of the brain.

The JC virus can break down the protective coating of nerve cells in the brain.

PML is an aggressive, potentially fatal disease caused by a brain infection by the JC virus. Symptoms of PML may be quick and evolve over a few weeks. They may also progress slowly, developing over a period of months, and can result in death. Currently, there is no cure for PML.

Symptoms typically include:

Clumsiness

Increasing weakness

Paralysis or lack of coordination

Changes in vision such as blindness

Speech impairments

Personality and behavioral changes

Seizures

Diagnosis and treatment of PML

PML can be diagnosed using various methods. These include:

Physical examination

Magnetic resonance imaging (MRI) of the brain

Examining the spinal fluid with a lumbar puncture to test for the presence of the JC virus

A diagnosis of PML cannot be entirely ruled out with a negative spinal fluid test, which can happen in the early stages of the disease.

Another way to diagnose PML is by finding JC virus DNA or proteins after a brain biopsy. While this test is considered the "gold standard" in PML diagnosis, it is rarely used due to the risks involved.

The symptoms of a relapse of MS can sometimes appear to be the symptoms of PML. Patients with MS should talk about their symptoms with a healthcare team to fully evaluate the situation.

Once a doctor has diagnosed PML, treatment may include the use of plasma exchange to remove the medications causing the condition. Supportive care can also help.

Currently, there is no effective treatment for PML and no virus-specific antiviral medications exist. The U.S. Food and Drug Administration may give permission for certain experimental medications to be used in special circumstances.

At times, a condition called immune reconstitution inflammatory syndrome (IRIS) can occur. If this happens, drugs known as corticosteroids may be used in patients who do not have HIV.

People with MS should speak with their healthcare team to discuss their personal risks for developing PML.

Written by Lori Smith BSN MSN CRNP

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.