Navigation Links
Pregnant women with hepatitis C may pass heartier viral strain to newborns, study suggests
Date:10/28/2013

Infants who get hepatitis C from their mothers during childbirth may inherit a viral strain that replicates more quickly than strains found in non-pregnant hosts, according to a new study published Oct. 27 in Nature Medicine. The findings, from a team in The Research Institute at Nationwide Children's Hospital, are the first to describe how a virus that has infected 180 million people worldwide takes advantage of immune changes during pregnancy.

About 1 percent of all pregnant women worldwide have hepatitis C, caused by a highly adaptable virus known as HCV that infects liver cells. In 3 to 5 percent of these pregnancies, the virus is passed to the newborns, accounting for the majority of new childhood HCV infections. Between 15 and 45 percent of people infected with HCV are able to mount an immune response sufficient to eradicate the virus. But in most cases, the virus eludes immunity, leading to a chronic infection that increases the risk of liver failure or liver cancer.

As part of a larger study of HCV in pregnant women and infants, researchers at Nationwide Children's followed two women with hepatitis C over a five-year period. Both women had two children during this time, and researchers were able to track the virus before, during and after pregnancy. Their analysis revealed surprising changes in HCV genomes that not only allowed the virus to thrive, but also ensured that the strain passed on by one of the women during childbirth was particularly good at replication, says Jonathan R. Honegger, MD, an infectious disease specialist and principal investigator in the Center for Vaccines and Immunity at Nationwide Children's.

"We found that better replicating versions of the virus emerged during pregnancy, and these 'fit' viruses were passed to the babies." Dr. Honegger says. "The findings actually provide unique insight into the impact of pregnancy on the mothers' control of viral infections, and also a striking illustration of this virus' ability to adapt to changing environmental pressures."

HCV persists in the general population, in part, because the virus outwits the immune system with mutations that can render it undetectable to CD8+ T-cells, important weapons in the body's antiviral immune arsenal. Although these viral variationscalled immune escape mutationsprotect the virus from attack by T-cells, they sometimes slow the virus replication machinery.

During pregnancy, T-cells are restrained to prevent the body from attacking the fetus as foreign tissue. Viral levels of HCV have also been known to increase during pregnancy, but whether this was related to changes in T-cell function was unknown. Working closely with Chris Walker, director of the Center for Vaccines and Immunity, and colleagues at Emory University and the University of North Carolina, Dr. Honegger found that during pregnancy, certain T-cell escape mutations were lost, resulting in a virus that could replicate far more quickly.

"This surprised us because the virus' immune escape mutations are usually stable in a patient," Dr. Honegger says. "The loss of these immune escape mutations from HCV during pregnancy provided strong evidence that the immune changes of pregnancy, intended to protect the fetus, significantly impaired the ability of CD8+ T-cells to exert pressure on the virus."

Loss of the escape mutations also meant that the babies got a version of the virus that was optimized for viral replication, Dr. Honegger adds. In the children they studied, the virus persisted and did not mutate in a way to suggest that it was under significant attack by their CD8+ T-cells.

"We don't yet know whether getting the fast-replicating, immune-susceptible version of the virus would be an advantage for the baby or the virus," says Dr. Honegger, who also is an assistant professor of pediatrics at The Ohio State University. "We suspect that if the baby doesn't mount a swift and strong immune response, then fast viral replication may increase the risk of persistent infection in the baby."

On the other hand, viral loads in the mothers dropped more than 1,000 fold by 12 weeks after delivery and viral genetic analysis showed that immune escape mutations had returned. "We interpreted this to mean that T-cell activity against hepatitis C in the liver increased sharply after delivery," Dr. Honegger says.

Researchers now are following a larger group of pregnant women with HCV, hoping to learn more about how viral mutations affect the way the body controls hepatitis C in pregnant women and infants.

"We believe that better understanding of the natural history of the infection in these patients will be critical for designing rational strategies to treat or prevent HCV in these populations."


'/>"/>

Contact: Mary Ellen Peacock
maryellen.peacock@nationwidechildrens.org
614-355-0495
Nationwide Children's Hospital
Source:Eurekalert

Related medicine news :

1. “IVF Success Program” Reveals To People A Lot Of Tips To Get Pregnant With In Vitro Fertilization – Vinamy
2. Comfort & Harmony™ Congratulates Pregnant in Heels Star Rosie Pope on Pregnancy, Expecting Fourth Child
3. Pregnancy Miracle - There is Still Hope For Women Over 40 Years old to Become Pregnant
4. Austin Chiropractor, Dr. Julia Pinkerton Addresses Benefits of Chiropractic Care for Pregnant Woman in New Blog
5. “Pregnant? New Baby? Need Sleep!” is the Title of Dr. Richard Hansler’s Latest Book
6. Reassuring findings for mothers who have influenza vaccine while pregnant
7. Laser Gum Surgery in Cumming, GA Can Now Safely Treat Pregnant Gum Disease Patients to Help Reduce the Risk of Low Birth Weight With Dr. Page Barden
8. Laser Gum Surgery is Now Used to Treat Gum Disease in Pregnant Mothers to Reduce Risk of Premature Delivery and Low Birth Weight with Dr. Steven Rice in Rockville, MD
9. Pregnant women with high/low BMI are at higher risk of complications and hospital admissions
10. 18% Pregnant Women Endangering Infants By Drinking During Pregnancy
11. Safe Exercises for Pregnant Women
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... Lafayette, California (PRWEB) , ... ... ... a pioneer in the patient payment industry today announced its strategic partnership ... and health system workflows. , The two companies’ proven, proprietary technology combine ...
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating in cancer ... they remain in the eye of the beholder, according to experts who offered insights ... American Journal of Managed Care. For the full issue, click here . , ...
(Date:6/26/2016)... North Carolina (PRWEB) , ... June 26, 2016 , ... ... release of a new product that was developed to enhance the health of felines. ... for centuries. , The two main herbs in the PawPaws Cat Kidney Support ...
(Date:6/25/2016)... ... June 25, 2016 , ... ... and applications at AcademyHealth’s Annual Research Meeting June 26-28, 2016, at the Hynes ... important health care topics including advance care planning, healthcare costs and patient and ...
(Date:6/25/2016)... ... June 25, 2016 , ... "With 30 hand-drawn hand gesture animations, ... Christina Austin - CEO of Pixel Film Studios. , ProHand Cartoon’s package transforms ... Final Cut Pro X . Simply select a ProHand generator and drag it above ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016  MedSource announced today ... its e-clinical software solution of choice.  This latest ... possible value to their clients by offering a ... preferred relationship establishes nowEDC as the EDC platform ... MedSource,s full-service clients.  "nowEDC has long been a ...
(Date:6/23/2016)... Any dentist who has made an implant supported ... Many of them do not even offer this as a ... laboratory costs involved. And those who ARE able to offer ... high cost that the majority of today,s patients would not ... Zadeh , founder of Dental Evolutions Inc. and inventor of ...
(Date:6/23/2016)... startling report released today, National Safety Council research shows ... plan to eliminate prescription opioid overdoses. Prescription Nation ... the worst drug crisis in recorded U.S. history, assigned a "Making ... , New Mexico , Tennessee ... states, three – Michigan , Missouri ...
Breaking Medicine Technology: