Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene for immune deficiency syndromes found

12.07.2005


Finding may yield a new test to explain recurring infections



A newly discovered gene mutation may account for many cases of immune deficiency, in particular two syndromes known as immunoglobulin A (IgA) deficiency and Common Variable Immunodeficiency (CVID), report researchers in the July issue of Nature Genetics. The discovery may lead to a new diagnostic test for these conditions, which make people highly susceptible to infections and often go unrecognized because of a lack of good tests.

IgA deficiency affects 1 in 600 people; CVID is less common but more severe. Children and adults with either condition suffer relentlessly recurring ear infections, sinus infections, bronchitis, pneumonias and gastrointestinal infections. IgA deficiency and CVID can occur in the same family, and also predispose people to autoimmunity, particularly affecting the thyroid gland and resulting in thyroid hormone insufficiency. Finally, people with CVID are susceptible to B-cell lymphomas.


The researchers, led by Raif Geha, MD, and Emanuela Castigli, PhD, in the Division of Immunology at Children’s Hospital Boston, found mutations in a gene known as TACI in 4 of 19 unrelated patients with CVID and in 1 of 16 unrelated patients with IgA deficiency. None of 50 healthy people tested had a TACI mutation. Four of the 5 patients with TACI mutations were studied further, and all 4 had relatives with the same mutations. Eleven of the 12 identified relatives with TACI or IgA deficiency reported a history of recurrent infections and were found to have low levels of immunoglobulin A (IgA), immunoglobulin G (IgG) or both.

TACI mutations interfere with two aspects of the immune response that involve maturation of B cells, the white blood cells that make immunoglobulins, which function as antibodies, to fight infections. Normally, TACI triggers B cells to switch from making immunoglobulin M (IgM), an antibody produced early in the body’s immune response, to making other immunoglobulins like IgA and IgG. More important, TACI signals B cells to produce antibodies with a high affinity for specific attackers. Because TACI mutations are dominant, people with even one copy of the mutation will be unable to mount a strong antibody response.

"A test for TACI would allow for diagnosis of more children and their relatives," says Geha, senior author of the study and a professor of pediatrics at Harvard Medical School. "Many children who are sick are now missed, because they can have normal IgA and IgG levels, yet they still have poor antibody responses and get the same bacteria and viruses again and again."

The gene discovery will immediately not change therapy, Geha adds. "For the time being, it’s prophylactic antibiotics or IV immunoglobulin infusions every three weeks," he says.

Geha’s team previously demonstrated that TACI binds to two other proteins made by cells in the respiratory and gastrointestinal lining, known as APRIL and BAFF, to trigger the signal for B cells to mature. Geha believes that additional cases of immune deficiency result from mutations in the APRIL and BAFF genes, and plans to verify this in further studies.

Aaron Patnode | EurekAlert!
Further information:
http://www.childrens.harvard.edu
http://www.childrenshospital.org/research

More articles from Life Sciences:

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>