Posts Tagged "Immune system"

Using less than a drop of blood, a new test can reveal nearly every virus a person has ever been exposed to, scientists reported on Thursday.

The test, which is still experimental, can be performed for as little as $25 and could become an important research tool for tracking patterns of disease in various populations, helping scientists compare the old and the young, or people in different parts of the world.

It could also be used to try to find out whether viruses, or the body’s immune response to them, contribute to chronic diseases and cancer, the researchers said.

“I’m sure there’ll be lots of applications we haven’t even dreamed of,” said Stephen J. Elledge, the senior author of the report, published in the journal Science, and a professor of genetics at Harvard Medical School and Brigham and Women’s Hospital.

“That’s what happens when you invent technology — you can’t imagine what people will do with it,” Dr. Elledge said. “They’re so clever.”

The test can detect past exposure to more than 1,000 strains of viruses from 206 species — pretty much the entire human “virome,” meaning all the viruses known to infect people. The test works by detecting antibodies, highly specific proteins that the immune system has made in response to viruses.

Tried out in 569 people in the United States, South Africa, Thailand and Peru, the blood test found that most had been exposed to about 10 species of virus — mostly the usual suspects, like those causing colds, flu, gastrointestinal illness and other common ailments.

Source: New York Times

This test is not yet commercially available but our comprehensive physicals include testing for individual viral infections and inflammation.

Lung cancer can lie dormant for more than 20 years before turning deadly, helping explain why a disease that kills more than 1.5 million a year worldwide is so persistent and difficult to treat, scientists said on Thursday.

Two papers detailing the evolution of lung cancer reveal how after an initial disease-causing genetic fault — often due to smoking — tumor cells quietly develop numerous new mutations, making different parts of the same tumor genetically unique.

By the time patients are sick enough to be diagnosed with cancer, their tumors will have developed down multiple evolutionary pathways, making it extremely hard for any one targeted medicine to have an effect.

The findings show the pressing need to detect lung cancer before it has shape-shifted into multiple malignant clones.

“What we’ve not been able to understand before is why this is really the emperor of all cancers and one of the hardest diseases to treat,” said Charles Swanton, an author on one of the papers from Cancer Research UK’s London Research Institute.

“Previously, we didn’t know how heterogeneous these early-stage lung cancers were.”

Lung cancer is the world’s deadliest cancer, killing an estimated 4,300 people a day, according to the World Health Organization. Around 85 percent of patients have non-small cell lung cancer (NSCLC), the type analyzed in the two studies.

To get a clearer understanding of the disease, the two groups of British and American scientists looked at genetic variability in different regions of lung tumors removed during surgery and worked out how genetic faults had developed over time.

What they found was an extremely long latency period between early mutations and clinical symptoms, which finally appeared after new, additional faults triggered rapid disease growth.

In the case of some ex-smokers, the initial genetic faults that started their cancer dated back to the time they were smoking cigarettes two decades earlier. But these faults became less important over time and more recent mutations were caused by a new process controlled by a protein called APOBEC.

The research was published in the journal Science.

Ramaswamy Govindan of Washington University School of Medicine, who was not involved in the studies, said better understanding of such genetic alterations was key to developing more effective treatments.

There are also hopes for a new generation of immunotherapy drugs that boost the immune system’s ability to detect and fight tumors, which could be particularly applicable to lung cancer.

“The large number of mutations may be the tumor’s Achilles heel because every time a new mutation forms there is a chance for the immune system to recognize it,” Swanton told Reuters.

Immunotherapy drugs from companies such as Bristol-Myers Squibb, Merck & Co, Roche and AstraZeneca are already undergoing tests in lung cancer, with data on Bristol’s medicine Opdivo due later this year.

Apart from better drugs, a critical challenge is to find improved ways to detect lung cancer before it develops the multiple genetic faults that eventually trigger rapid tumor growth and spread.

Currently, doctors use computerized tomography (CT) to detect lung cancer — but by the time a nodule is big enough to be spotted it on a scan it may contain a billion genetically diverse cancer cells.

For the future, oncologists are pinning hopes on a new approach, known as liquid biopsy, that may be able to detect signs of cancer much earlier from DNA circulating in the blood.

The current prognosis for NSCLC is grim, with most patients diagnosed when the disease has already spread and only around 15 percent surviving for at least five years after that.

Source: Reuters

A single alcohol binge can cause bacteria to leak from the gut and increase levels of bacterial toxins in the blood, according to a study funded by the National Institutes of Health. Increased levels of these bacterial toxins, called endotoxins, were shown to affect the immune system, with the body producing more immune cells involved in fever, inflammation, and tissue destruction.

Binge drinking is defined by NIAAA as a pattern of drinking alcohol that brings blood alcohol concentration (BAC) to 0.08g/dL or above. For a typical adult, this pattern corresponds to consuming five or more drinks for men, or four or more drinks for women, in about two hours. Some individuals will reach a 0.08g/dL BAC sooner depending on body weight. Binge drinking is known to pose health and safety risks, including car crashes and injuries. Over the long term, binge drinking can damage the liver and other organs.

“While the negative health effects of chronic drinking are well-documented, this is a key study to show that a single alcohol binge can cause damaging effects such as bacterial leakage from the gut into the blood stream,” said Dr. George Koob, director of the National Institute on Alcohol Abuse and Alcoholism, part of NIH.

The study was led by Gyongyi Szabo, M.D., Ph.D., Professor and Vice Chair of Medicine and Associate Dean for Clinical and Translational Sciences at the University of Massachusetts Medical School. .

In the study, 11 men and 14 women were given enough alcohol to raise their blood alcohol levels to at least .08 g/dL within an hour. Blood samples were taken every 30 minutes for four hours after the binge and again 24 hours later.

The researchers found that the alcohol binge resulted in a rapid increase in endotoxin levels in the blood and evidence of bacterial DNA, showing that bacteria had permeated the gut. Endotoxins are toxins contained in the cell wall of certain bacteria that are released when the cell is destroyed. Compared to men, women had higher blood alcohol levels and circulating endotoxin levels.

“We found that a single alcohol binge can elicit an immune response, potentially impacting the health of an otherwise healthy individual,” said Dr. Szabo. “Our observations suggest that an alcohol binge is more dangerous than previously thought.”

Earlier studies have tied chronic alcohol use to increased gut permeability, wherein potentially harmful products can travel through the intestinal wall and be carried to other parts of the body. Greater gut permeability and increased endotoxin levels have been linked to many of the health issues related to chronic drinking, including alcoholic liver disease.

About the National Institute on Alcohol Abuse and Alcoholism (NIAAA): The National Institute on Alcohol Abuse and Alcoholism, part of the National Institutes of Health, is the primary U.S. agency for conducting and supporting research on the causes, consequences, prevention, and treatment of alcohol abuse, alcoholism, and alcohol problems. NIAAA also disseminates research findings to general, professional, and academic audiences.

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases.

Source: NIH