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
AUG 05, 2020
Immunology
Intercepting Cancer Cells Before They Can Dodge the Immune System
AUG 05, 2020
Intercepting Cancer Cells Before They Can Dodge the Immune System
The battle that naturally occurs between the body’s immune system and cancerous cells is one that scientists have ...
AUG 17, 2020
Immunology
Nervous Protein Neuromedin B May Prevent Immune Reactivity
AUG 17, 2020
Nervous Protein Neuromedin B May Prevent Immune Reactivity
A protein produced by the nervous system seems to play a role in regulating the immune system. For people with inflammat ...
SEP 03, 2020
Immunology
A Low-Cost COVID-19 Treatment, Made in Horses
SEP 03, 2020
A Low-Cost COVID-19 Treatment, Made in Horses
Researchers in Costa Rica are turning to horses as an unlikely source of potential therapeutic antibodies against COVID- ...
SEP 17, 2020
Coronavirus
A Biomarker May Predict the Most Severe COVID-19 Cases
SEP 17, 2020
A Biomarker May Predict the Most Severe COVID-19 Cases
Researchers may have found a way to identify the COVID-19 patients that will need targeted therapies the most.
OCT 24, 2020
Immunology
New CRISPR-Based Imaging Tool Is Going to Be HiUGE
OCT 24, 2020
New CRISPR-Based Imaging Tool Is Going to Be HiUGE
A team of researchers at Duke University have developed an imaging technology for tagging structures at a cellular level ...
NOV 04, 2020
Coronavirus
Damaging Antibodies Can Lead to Blood Clots in COVID-19 Patients
NOV 04, 2020
Damaging Antibodies Can Lead to Blood Clots in COVID-19 Patients
COVID-19, the illness caused by the pandemic virus SARS-CoV-2, is known to cause blood clots all over the body in some p ...
Loading Comments...