Immunology
New role for Natural Killers!
Scientists at the University of York have discovered a new role for a population of white blood cells, which may lead to improved treatments for chronic infections and cancer.
Natural Killer (or NK) cells are abundant white blood cells that were recognised over 30 years ago as being able to kill cancer cells in the test tube. Since that time, a role for NK cells in activating other white blood cells (including ‘T’ lymphocytes and phagocytes) and in directing how the immune system responds to a wide range of infections has also been established.
Because of these properties, NK have been widely regarded as being of benefit in the fight against cancer and infection, and methods to increase NK cell activity underpin a range of new experimental anti-cancer drugs and anti-infectives.
Joint replacement may improve osteoarthritis symptoms in older adults
Older adults who have hip or knee replacement surgery for severe osteoarthritis may take several weeks to recover but appear to have excellent long-term outcomes, according to a report in the July 14 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
As the U.S. population ages, the number of older adults with osteoarthritis is increasing, according to background information in the article. The disease causes debilitating pain and often restricts older adults’ mobility. Non-invasive treatments such as medications and physical therapy appear to be of limited value for the advanced stages of osteoarthritis. However, surgery may be associated with risks and discomfort.
Mary Beth Hamel, M.D., M.P.H., and colleagues at Beth Israel Deaconess Medical Center, Boston, studied medical decision-making and treatment outcomes in 174 patients age 65 and older (average age 75.2) who had severe osteoarthritis of the hip or knee. Participants’ arthritis symptoms and functional status were assessed at the beginning of the study, between 2001 and 2004, and again 12 months later. Patients who chose to have joint replacement surgery were assessed six weeks, six months and 12 months after the procedure.
Special infant formulas cut long-term allergy risk
Hypoallergenic infant formulas may help lower the long-term risk of allergies in children who are genetically vulnerable to them, a new study suggests.
The products, known as hydrolyzed infant formulas, are designed to lower the likelihood of the allergic responses some infants have to standard formula.
Like standard formula, hydrolyzed products contain cow’s milk proteins; the difference is that the proteins are broken down so that they are less allergenic than the whole proteins in regular formula.
Major shift in HIV prevention priorities needed
According to a new policy analysis led by researchers at the Harvard School of Public Health (HSPH) and the University of California, Berkeley, the most common HIV prevention strategies—condom promotion, HIV testing, treatment of other sexually transmitted infections (STIs), vaccine and microbicide research, and abstinence—are having a limited impact on the predominantly heterosexual epidemics found in Africa. Furthermore, some of the assumptions underlying such strategies—such as poverty or war being major causes of AIDS in Africa—are unsupported by rigorous scientific evidence. The researchers argue that two interventions currently getting less attention and resources—male circumcision and reducing multiple sexual partnerships—would have a greater impact on the AIDS pandemic and should become the cornerstone of HIV prevention efforts in the high-HIV-prevalence parts of Africa.
The paper appears in the May 9, 2008 issue of the journal Science.
“Despite relatively large investments in AIDS prevention efforts for some years now, including sizeable spending in some of the most heavily affected countries (such as South Africa and Botswana), it’s clear that we need to do a better job of reducing the rate of new HIV infections. We need a fairly dramatic shift in priorities, not just a minor tweaking,” said Daniel Halperin, lecturer on international health in the HSPH Department of Population and International Health and one of the paper’s lead authors.
Study shows promising new approach to thwart HIV
Researchers have pinpointed a protein contain within key human immune system cells that is needed for the AIDS virus to infect the cells, and found that turning it off can greatly slow down the deadly virus.
Inactivating a protein called ITK in immune system cells called T cells reduces HIV’s ability to enter these cells and replicate itself, the researchers said on Monday.
A drug based on this approach could be useful as a complement to existing drugs used to treat HIV infection, said Andrew Henderson of Boston University, one of the researchers.
Daily asthma meds keep lungs in play during exercise
Taking asthma medication daily can help prevent the tightening of the airways or “bronchoconstriction” with physical exertion that affects many children with asthma, a new study from Poland confirms.
Dr. Iwona Stelmach of N. Copernicus Hospital in Lodz and colleagues found that of the four treatments they evaluated, the two including the anti-asthma drug montelukast (Singulair) were the most effective, but all were better than placebo.
“Control of childhood asthma with exercise-induced bronchoconstriction can be obtained by using regular controller treatment,” Stelmach and colleagues write in the Journal of Allergy and Clinical Immunology.
The HLA-DRB1 gene and premature death in rheumatoid arthritis
People with rheumatoid arthritis (RA), an inflammatory autoimmune disease, tend to die younger and, largely from cardiovascular disease (CVD). One explanation for this increasingly recognized fact is that inflammation promotes atherosclerosis. A marker of inflammation, elevation of the C-reactive protein (CRP) level has been shown to predict CVD in the general population. However, other highly inflammatory diseases—Crohn’s, for example—do not carry the same high risk of premature death from heart disease.
To identify other possible suspects, researchers in the United Kingdom investigated whether genetic variants linked to the likelihood of developing RA might also make patients more likely to die from CVD. Led by Dr. Tracey M. Farragher at the University of Manchester and funded by the Arthritis Research Campaign (arc), the study focused on two genes—HLA-DRB1and PTPN22—and their interactions with known RA risk factors. The evidence, presented in the February 2008 issue of Arthritis & Rheumatism, implicates HLA-DRB1 genotypes, already associated with RA susceptibility and severity, as a predictor of premature death from CVD for inflammatory arthritis patients. For RA patients in particular, having the shared epitope (SE)—a group of HLA-DRB1 alleles with kindred amino acid traits—plus anti-cyclic citrullinated peptide (anti-CCP) antibodies and current smoking is an especially deadly combination.
Deficient regulators in the immune system responsible for type 1 diabetes
The main regulators of the immune system, called CD4+Treg cells, are thought to be highly involved in a large range of immune diseases. The gradual reduction in their regulating capacity seems to play a critical role in the onset of type 1 diabetes, as demonstrated in the latest study by Dr. Ciriaco Piccirillo, a researcher in the Department of Microbiology and Immunology at the Research Institute of the McGill University Health Centre and the principal investigator for this project. This study was published this month in the journal Diabetes.
The immune system needs to be regulated so that it attacks only the site of an inflammation and focuses its attack on pathogens rather than on the body tissues, causing an autoimmune disease.
In a healthy patient, CD4+Treg cells deactivate any T lymphocytes, a type of immune cell, that are misprogrammed and could attack the body. Dr Piccirillo’s research indicates that in type 1 diabetic patients this control mechanism may be deficient, thereby allowing the misprogrammed T lymphocytes to proliferate and gain the ability to destroy the insulin-producing cells of the pancreas. This leads to type 1 diabetes.
Two Genes Are Important Key to Regulating Immune Response
A research team at Weill Cornell Medical College in New York City has identified two genes that may be crucial to the production of an immune system cytokine called interleukin-10 (IL-10).
The discovery fills in an important “missing link” in a biochemical pathway that’s long been tied to disorders ranging from lupus and Type 1 diabetes, to cancer and AIDS.
Many kids may not outgrow cow’s milk allergy
Cow’s milk allergy persists longer than previously reported, and the majority of children may retain the sensitivity into school age, study findings suggest.
“The old data saying that most milk allergy will be easily outgrown, usually by the age of 3 years, is most likely wrong,” Dr. Robert A. Wood, at Johns Hopkins University School of Medicine, told Reuters Health.
Experts call for vaccine to fight severe diarrhoea
Paediatricians are urging governments in Asia to bolster national immunization programs with vaccines against the rotavirus, the most common cause of severe diarrhoea in young children.
Rotavirus kills about 611,000 children worldwide each year, or a child every minute. Africa and Asia account for 90 percent of these deaths, with more than 180,000 occurring in Asia.
Therapy Effective for Reducing Lupus Flares
Mayo Clinic researchers have shown that an immunosuppressive drug used in organ transplant cases is effective in reducing flare-ups in patients with systemic lupus erythematosus (SLE). SLE results in inflammation of connective tissues and can involve the skin, joints and kidneys. Its cause is unknown. The findings were announced today at the annual meeting of the American College of Rheumatology in Boston.
“Our findings show this therapy reduces lupus flares overall and is especially effective in reducing severe flares by roughly half,” says Mayo rheumatologist Kevin Moder, M.D., who led the research.
