AUG 10, 2017 1:25 PM PDT

When Chickenpox Turns Deadly

WRITTEN BY: Kara Marker

In very rare cases - two in 10,000 people experts say - a chickenpox infection can trigger extremely dangerous brain inflammation. Until now, scientists didn’t know why this happened, and there was nothing they could do to predict or prevent it. Now, they’ve discovered a clue: a small mutation in the immune system’s DNA.

 

Chicken pox caused by the varicella zoster virus. Credit: BruceBlaus

The problem isn’t necessarily a failed attack on the chickenpox virus; rather, it’s that the immune system never realizes that the virus is there at all. Varicella zoster virus (VZV), which causes chickenpox, can sneak in undetected on rare occasions when there is a mutation in the “POL III” sensor. The immune system relies on this sensor to ring the alarm when VZV makes its way into the body. Researchers discovered the role of POL III after mapping genomes of people who experienced these rare infections.

VZV is unique in that it only infects humans. It comes from the same family of viruses that cause herpes, and it often remains in the body after an initial infection, resurfacing years later causing shingles. In addition to causing brain inflammation in rare instances, VZV can also lead to severe pneumonia (twenty out of 10,000 people), which is especially dangerous for pregnant women.

A vaccine to prevent chickenpox entered the world in 1995, and the Centers for Disease Control and Prevention (CDC) reports that “each year, more than 3.5 million cases of varicella, 9,000 hospitalizations, and 100 deaths are prevented by varicella vaccination in the United States.”

"We cannot yet put an exact figure on how much the risk of complications is increased when you have this new immunodeficiency, since we have looked at relatively few patients in our study. Neither do we know how large a proportion of all those who have inflammation of the brain and pneumonia have the defect,” clarified Trine Hyrup Mogensen. “But we do know that this applies to both children and adults.”

Further analysis of the individual cells invaded by VZV confirmed that no immune response was initiated because the virus was never detected. But when researchers manually repaired the mutation, the immune system was suddenly aware of VZV, like taking off a blindfold.

Chickenpox isn’t the only infection that can enter the body undetected if there’s a specific mutation in the immune system’s DNA. Now that scientists know they can identify the genes responsible and even fix mutations to activate the immune system, this knowledge could spread to treat other diseases.

“We are now slowly becoming able to understand the individual differences in susceptibility to infections at both the genetic and molecular level,” said Soren Riis Paludan. He and the other researchers on the project see their study as a unique contribution to the advancement of personalized medicine, where treatments and diagnostics are based on individual cases and needs.

The present study was published in The Journal of Clinical Investigation.

Sources: Aarhus University, American Journal of Transplantation, CDC

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
NOV 27, 2019
Immunology
NOV 27, 2019
Playing "Tag" with the Immune System
Human cells employ an intricate tagging system to manage protein activity in the body. By “tagging” a protein with a certain modification, cell
DEC 16, 2019
Drug Discovery & Development
DEC 16, 2019
Vaccine To Protect Against The Zika Virus
Scientists at The University of Texas Medical Branch at Galveston present for the first time how a single high dose vaccine can protect a pregnant mouse al
FEB 10, 2020
Immunology
FEB 10, 2020
Measles infections can give the immune system amnesia
The immune system detects the presence of invading microbes that it recognizes from previous infections, and initiates a full-blown immune response. New re
FEB 23, 2020
Immunology
FEB 23, 2020
New discovery could help preterm babies breathe easy
Babies born more than three weeks before full term are met with complicated and often life-threatening health challenges. Most notably, these tiny preterm
MAR 20, 2020
Drug Discovery & Development
MAR 20, 2020
4 Potential Treatments for SARS-CoV-2 Currently Under Testing
Currently, no medicine nor vaccine has been approved as effective for the prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despi
MAR 30, 2020
Neuroscience
MAR 30, 2020
In Quarantine? Studies Show Meditation Boosts Immune System
As the coronavirus pandemic has shut billions around the world under lockdown- two things have become key. The first of course, is to stay hygienic and avo
Loading Comments...