MedNews

You are here: Home / Archives for Health & Medical News

Barriers to Screening May Increase Colorectal Cancer Deaths

By Leave a Comment

Colorectal cancer is the second leading cause of cancer-related deaths in the United States. Despite evidence and guidelines supporting the value of screening for this disease, rates of screening for colorectal cancer are consistently lower than those for other types of cancer, particularly breast and cervical. Although the screening rates in the target population of adults over age 50, have increased from 20-30 percent in 1997 to nearly 55 percent in 2008 — the rates are still too low. An NIH state-of-the-science panel was convened this week to identify ways to further increase the use and quality of colorectal cancer screening in the United States.

“We recognize that some may find colorectal cancer screening tests to be unpleasant and time-consuming. However, we also know that recommended screening strategies reduce colorectal cancer deaths,” said Dr. Donald Steinwachs, panel chair, and professor and director of the Health Services Research and Development Center at the Johns Hopkins University. “We need to find ways to encourage more people to get these important tests.”

The panel found that the most important factors associated with being screened are having insurance coverage and access to a regular health care provider. Their recommendations highlighted the need to remove out-of-pocket costs for screening tests.

Given the variety of tests available, the panel emphasized that informed decisions incorporating personal preferences may help reluctant individuals determine which test’s combined attributes — invasiveness, frequency, and required preparation — are preferable to them, helping them identify and obtain the most palatable test. For example, an individual may choose a more invasive test requiring less frequent follow-up or a less invasive test requiring more frequent follow-up.

Noting differences in screening rates across racial and ethnic groups, socioeconomic status, and geographic location, the panel emphasized the need for targeted strategies for specific subgroups. Compared with non-Hispanic whites, Hispanics are less likely to be screened.

The panel also noted that if efforts to increase utilization are successful, there will be a greater demand for colorectal cancer screening services. Available capacity involves not only facilities and appropriately trained providers, but also support for informed decision making, resources to coordinate screening services and communicate results effectively, and enhanced monitoring practices to ensure that positive results are followed up with colonoscopy. Depending on the scale of increases in screening rates, there may be a need to increase local and national capacity.

In addition to increasing first-time screening rates, the panel also identified the need to ensure that individuals return for subsequent testing at the recommended intervals. A variety of colorectal cancer screening tests are available and different guidelines recommend them at different intervals.

The conference was sponsored by the NIH Office of Medical Applications of Research and the National Cancer Institute along with other NIH and Department of Health and Human Services components. This conference was conducted under the NIH Consensus Development Program, which convenes conferences to assess the available scientific evidence and develop objective statements on controversial medical issues.

The 13–member conference panel included experts in the fields of cancer surveillance, health services research, community-based research, informed decision-making, access to care, health care policy, health communication, health economics, health disparities, epidemiology, statistics, thoracic radiology, internal medicine, gastroenterology, public health, end-of-life care, and a public representative. A complete listing of the panel members and their institutional affiliations is included in the draft conference statement.

In addition to the material presented at the conference by speakers and the comments of conference participants presented during discussion periods, the panel considered pertinent research from the published literature and the results of a systematic review of the literature. The systematic review was prepared through the Agency for Healthcare Research and Quality Evidence-based Practice Centers (EPC) program, by the RTI International-University of the North Carolina Evidence-based Practice Center. The EPCs develop evidence reports and technology assessments based on rigorous, comprehensive syntheses and analyses of the scientific literature, emphasizing explicit and detailed documentation of methods, rationale, and assumptions.

Source: National Institutes of Health (Feb. 4, 2010)

Twenty Percent of American Teens Have Abnormal Lipid Levels

By Leave a Comment

Twenty percent of young people aged 12-19 years in the United States have at least one abnormal lipid level, according to a study from the Centers for Disease Control and Prevention.  Abnormal lipid levels are major risk factors for heart disease, the leading cause of death among adults in the United States.

The report, “Prevalence of Abnormal Lipid Levels among Youths —United States, 1999–2006,” was published today in CDC’s Morbidity and Mortality Weekly Report (MMWR).

The report examined data for 1999–2006 from the National Health and Nutrition Examination Survey (NHANES), an ongoing study that explores the health and nutritional status of about 6,000 participants every year.  Researchers analyzed measurements of low-density lipoprotein, or “bad,” cholesterol (LDL-C); high-density lipoprotein, or “good,” cholesterol (HDL-C); and triglycerides.

The researchers found that young people who were overweight or obese were more likely to have one or more abnormal lipid levels compared to normal weight youth.  Fourteen percent of normal weight, 22 percent of overweight, and 43 percent of obese youth had one or more abnormal lipid levels.

The study also found that 32 percent of these young people would be candidates for lipid screening based on American Academy of Pediatrics (AAP) guidelines.  The AAP recommends lipid screening for young people with a family history of high blood cholesterol or premature cardiovascular disease, or the presence of at least one major risk factor for heart disease, such as smoking, high blood pressure, diabetes, or overweight/obesity.

Reviewing health indicators for 3,125 youths, researchers found that differences in lipid levels were associated with sex, age, and race/ethnicity. Specifically:

  • More boys (24 percent) than girls (16 percent) had at least one abnormal lipid level.
  • Fourteen- and 15-year-olds (9 percent) and 18- and 19-year-olds (10 percent) were more likely to have low HDL cholesterol levels than 12- and 13-year-olds (5 percent).
  • Non-Hispanic white youths were more likely to have low levels of HDL cholesterol (8 percent) and high triglycerides (12 percent), compared to non-Hispanic black youths (5 percent and 4 percent, respectively).

Typically, heart disease develops in adulthood. But its risk factors, such as abnormal lipid levels and overweight/obesity often emerge during childhood and adolescence.

“Overweight and obese young people are at far greater risk of having abnormal lipid levels than are youths with normal weights,” said Ashleigh May, Ph.D.,  Epidemic Intelligence Service Officer in CDC’s Division for Heart Disease and Stroke Prevention, and lead author of the report.  “The current epidemic of childhood obesity makes this a matter of significant and urgent concern.”

In the past three decades, obesity among American youths has increased from 5 percent to more than 17 percent.  In light of this, the study’s authors suggested that clinicians should be aware of guidelines for lipid screening and treatment among youths.

Source: Centers for Disease Control (Jan. 21, 2010)

NIH Clinical Center Devices Will Automatically Record Radiation Exposure

By Leave a Comment

Radiology and Imaging Sciences at the National Institutes of Health Clinical Center has taken a significant step to further safeguard clinical research patients at the NIH Clinical Center who are exposed to radiation during certain imaging tests. Computed tomography (CT) and positron emission tomography (PET)/CT equipment purchased by the Clinical Center will now be required to routinely record radiation dose exposure in a patient’s hospital-based electronic medical record.

“When a hospital or clinic patient receives a medication or a treatment, it is routinely recorded in the patient’s medical record,” said John I. Gallin, M.D., director of the Clinical Center, NIH’s clinical research hospital in Bethesda, Md. “The Clinical Center’s approach is an important first step in making it possible to more easily document and track information about a patient’s exposure to radiation.”

Today, electronic radiology information systems in hospitals generally do not collect or report radiation exposures. “CT and PET/ CT scanners do not currently forward data on radiation dose to our radiology information systems,” said Dr. David A. Bluemke, M.D., Ph.D. Bluemke is director of Radiology and Imaging Sciences at the Clinical Center.

The risk of exposure to low doses of medical radiation from diagnostic medical-imaging tests isn’t known, but very high radiation doses have the potential to cause cancer. The ability to keep track of an individual’s exposure to radiation through routine imaging tests is needed so that researchers can begin to determine if these exposures pose a health risk.

“The National Council on Radiation Protection and Measurements reported recently that Americans received seven times more radiation exposure from medical tests in 2006 than was the case in the 1980s,” said Ronald Neumann, M.D., chief of nuclear medicine and deputy associate director for imaging sciences at the Clinical Center. “CT and cardiac nuclear medicine studies accounted for much of this increased medical radiation exposure.”

Ultimately, radiation dosage could become a standard element of a universal electronic medical record used to assess radiation risk from life-long medical testing, the Clinical Center radiologists said. “Recording radiation dose is technically possible and an ethical imperative, ” Neumann said.

“The NIH Clinical Center also will require that newly purchased equipment allows patients to record their radiation dose exposure in their own personal health record,” Bluemke added. Online resources to help individuals organize their health information as a personal medical record are becoming more prevalent. Currently, patients can easily receive their diagnostic imaging studies records on CD-ROM, Bluemke said. The NIH Clinical Center’s imaging program will work with vendors who supply Clinical Center imaging equipment to develop software tools to extract the examination type, date, and radiation dose exposure from the CD-ROM, for uploading to a personal health record. As both the American College of Radiology and the Radiological Society of North America have recommended, patients should keep a record of their X-ray history.

About 25,000 CT and 1,250 PET/CT scans are performed at the Clinical Center each year as part of NIH research protocols. The clinical research hospital currently houses five CT scanners, and two PET/CT scanners.

Source: NIH, August 17, 2009

Pregnant Women Should Take Greater Care of Novel H1N1 (“Swine Flu”) Virus

By Leave a Comment

A recent study indicates that pregnant women are more severely impacted by a new H1N1 flu virus and should seek immediate treatment with antivirals.

Pregnant women infected with 2009 novel H1N1 had a higher rate of hospitalization and greater risk of death than the general population due to the H1N1 flu.

The data collected and analyzed by the Centers for Disease Control and Prevention (CDC) are the most comprehensive available to date on the impact of this novel H1N1 flu virus among pregnant women.

“The death of a pregnant woman is always heartbreaking, and unfortunately we have been hearing reports of otherwise healthy women dying from H1N1. If a pregnant woman feels like she may have influenza, she needs to call her healthcare provider right away,” said CDC′s Dr. Denise Jamieson, lead author of the study. “Clinicians who treat pregnant women should have a system in place for triaging pregnant women with influenza-like symptoms and they should not delay in initiating appropriate antiviral therapy. Some clinicians hesitate treating pregnant women with antiviral medications because of concerns for the developing fetus, but this is the wrong approach. It is critical that pregnant women, in particular, be treated promptly. ”

Six deaths of pregnant women with H1N1 were reported to CDC between April 15 and June 16, 2009, representing 13 percent of the total 45 deaths reported to CDC during that time period. All were healthy prior to infection of H1N1 and subsequently developed primary viral pneumonia leading to acute respiratory distress requiring mechanical ventilation. All pregnant women who died did not receive antivirals soon enough to benefit their treatment. CDC recommends that pregnant women with suspected or confirmed influenza infection receive prompt treatment with antiviral medication.

Based on past influenza pandemics and on seasonal influenza epidemics, pregnant women have increased rates of illness and death from influenza infection.

Despite recommendations from the Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists for inactivated flu vaccine for all pregnant women, seasonal flu vaccine coverage among pregnant women is very low (less than 14 percent).

Source: Centers for Disease Control (CDC), July 29, 2009; Lancet, August 8, 2009.

Onglyza, a New Type 2 Diabetes Drug Approved by FDA

By Leave a Comment

The U.S. Food and Drug Administration (FDA) today approved Onglyza (saxagliptin), a once-daily tablet to treat Type 2 diabetes in adults. The medication is intended to be used with diet and exercise to control high blood sugar levels.

The hormone insulin keeps blood sugar (glucose) levels within a narrow range in people who don’t have diabetes. People with Type 2 diabetes are either resistant to insulin or do not produce enough insulin to maintain normal blood sugar levels.

Onglyza is in a class of drugs known as dipeptidyl peptidase-4 (DPP-4) inhibitors which stimulate the pancreas to make more insulin after eating a meal.

“Keeping blood sugar levels in adequate control is essential to the good health of the 24 million people in the United States with Type 2 diabetes,” said Mary Parks, M.D., director of the Division of Metabolism and Endocrinology Products in the FDA’s Center for Drug Evaluation and Research. “High blood sugar levels can cause blurry vision and excessive urination and eventually result in such serious conditions as kidney and eye disease.”

The most common side effects observed with Onglyza are upper respiratory tract infection, urinary tract infection, and headache. Other side effects include allergic-like reactions such as rash and hives.

Approval of Onglyza was primarily based on the results of eight clinical trials. The application seeking FDA approval was submitted before December 2008 when the agency recommended that manufacturers of new diabetes drugs carefully design and evaluate their clinical trials for cardiovascular safety. Although Onglyza was not associated with an increased risk for cardiovascular events in patients who were mainly at low risk for these events, the FDA is requiring a postmarket study that will specifically evaluate cardiovascular safety in a higher risk population.

Onglyza is manufactured by Bristol-Myers Squibb Co. of Princeton, N.J., and marketed by Bristol-Myers and AstraZeneca Pharmaceuticals LP, of Wilmington, Del.

Source: FDA, July 31, 2009

HIV May Be Transmitted via Pre-Chewed Food

By Leave a Comment

Researchers have uncovered the first cases in which HIV almost certainly was transmitted from mothers or other caregivers to children through pre-chewed food. The source of HIV in the pre-chewed food was most likely the infected blood in the saliva of the people who pre-chewed the food before giving it to the children. The researchers said their findings suggest that HIV-infected mothers or other caregivers should be warned against giving infants pre-chewed food and directed toward safer feeding options.

The cases indicate that physicians and clinics should routinely include questions about pre-chewing food in their health screening of infant caregivers who have HIV or are suspected of the infection. Also, possible cases of HIV transmission through pre-chewed food should be reported to public health agencies to help increase understanding of the prevalence of such transmission.

Led by Aditya Gaur, M.D., of St. Jude Children’s Research Hospital, with colleagues from St. Jude (Marion Donohoe, CPNP), the University of Miami (Charles Mitchell, M.D., and Delia Rivera, M.D.) and the Centers for Disease Control and Prevention (Kenneth Dominguez, M.D., Marcia Kalish, Ph.D., and John Brooks, M.D.), the researchers published their findings in the August 2009 issue of the journal Pediatrics. Gaur is an assistant member of the St. Jude Infectious Diseases department.

Giving infants pre-chewed food has been reported to transmit infections such as streptococcus and the hepatitis B virus, Gaur said. However, until these cases there was no evidence that the blood-borne HIV could be similarly transmitted. The source of blood in the saliva of the person pre-chewing the food for the child may likely have been visible or microscopic bleeding from the gums or some other part of the mouth, he added.

In their paper, the researchers described three cases in which pre-chewed food was likely the source of HIV transmission to infants.

The case that led to this published report was a 9-month-old infant who was referred to St. Jude because she was HIV positive after earlier tests had been negative.

“Her HIV-positive mother had not breastfed her, and further investigation had ruled out transmission by blood transfusion, injury or sexual abuse,” Gaur said. Also, genetic testing, led by Kalish at the CDC, showed that the daughter had been infected with the same HIV strain as the mother.

“Fortunately, the St. Jude nurse practitioner, Marion Donohoe, was very thorough in her questioning about feeding practices, and she asked about pre-mastication. It turned out this mother had fed her daughter pre-chewed food,” Gaur said.

When Gaur contacted Dominguez at the CDC about the possible case of transmission via pre-chewed food, the center alerted him to two similar cases previously reported by senior author Mitchell and colleague Rivera from the University of Miami. Those cases were not reported to the public at the time because of the lack of sufficient evidence of transmission via pre-chewed food. One case involved pre-chewing by an HIV-infected mother, and the other an HIV-infected aunt who was the caregiver.

Gaur said that information in the three cases suggests that one factor aiding such transmission was mouth bleeding in the caregiver, as well as in the infant due to teething or infection. He also said caregivers’ lack of adherence to their own drug-treatment regimens probably increased their blood HIV levels, increasing the likelihood of transmission.

“These three cases are persuasive enough that they justify cautioning HIV-positive caregivers against giving infants pre-chewed foods,” Gaur said. “Also, we hope increased awareness of this possible mode of transmission will bring more cases to light and more thorough studies, which can either substantiate or refute this transmission route.” Also important, Gaur said, will be the results of surveys now being conducted in collaboration with other research groups in the United States and abroad to determine the extent of infant feeding using pre-chewed food.

The findings do not warrant a blanket recommendation against pre-chewed food for infants, the researchers emphasized. The practice, which has been reported from many parts of the world including the United States may be integral to providing adequate infant nutrition and grounded in culture and tradition. On a global level, educating HIV-positive caregivers will require cognizance of culturally sensitive issues and potential nutritional consequences linked to pre-chewing, the investigators said. The findings also do not imply that HIV can be transmitted through saliva during oral contact such as kissing. In the cases the researchers studied, HIV transmission was likely enabled by bleeding gums or open mouth sores.

“Importantly, this report does not challenge the accepted belief that saliva does not carry HIV and that transmission does not occur in kissing,” Gaur said. “The exception is that transmission can occur when the people involved have damaged mucosa in their mouths, and blood is mixed with the saliva.”

Source: St. Jude Children’s Research Hospital; Pediatrics, August, 2009

New Technique Shows Which Patients Will Benefit from Avastin for Brain Tumor Treatment

By Leave a Comment

The U.S. Food and Drug Administration approved the use of Avastin last month for the treatment of brain cancer. The powerful drug shrinks tumors by choking off their blood supply. However, about fifty percent of patients don’t respond to the therapy, exposing them to unnecessary side effects and medication costing up to $10,000 per month.

Now UCLA scientists have uncovered a new way to image tumors and forecast which patients are most likely to benefit from Avastin before starting a single dose of treatment. The findings are published in this month’s issue of the journal Radiology.

“Avastin is an expensive drug, yet only 50 percent of patients with recurring brain cancers respond to it,” said lead author Dr. Whitney Pope, assistant professor of radiological sciences at the David Geffen School of Medicine at UCLA. “Until now, there has been no good way to identify these patients in advance. Our work is the first to suggest that we can predict which tumors will respond before the patient ever starts therapy.”

Pope and his colleagues focused on glioblastoma, the most common and deadly form of adult brain tumor, striking 12,000 Americans a year.

The UCLA team studied 82 patients who had undergone surgery and radiation therapy to remove glioblastoma. Half of the patients received infusions of Avastin every two weeks. All underwent monthly brain scans by magnetic resonance imaging (MRI) to monitor change.

The researchers analyzed the MRI scans of the patients whose tumors returned. Explaining what the team saw requires an understanding of how the tumor creates an independent blood supply.

Cancer cells secrete a growth factor called VEGF that spurs the growth of new blood vessels to supply the tumor with oxygen and nutrients. Avastin blocks VEGF, essentially starving the tumor to death.

This process launches a chain of events that is detectable by MRI. Oxygen-starved cells produce more VEGF, which causes blood vessels to leak fluids into the tumor and surrounding tissue. This results in swelling, which boosts water’s ability to move freely in the tumor and brain tissue. As cells disintegrate, they no longer pose a physical barrier to water movement.

“We theorized that tumors with more water motion would also have higher VEGF levels,” explained Pope. “Because Avastin targets VEGF, it made sense that the drug would work better in tumors with high levels of the growth factor.”

By measuring the amount of water motion within the tumor, the researchers were able to predict with 70 percent accuracy which patients’ tumors would progress within six months and which would not. They detected greater water movement in the tumors of those persons who later responded best to Avastin.

“When we realized that high levels of VEGF are linked to greater cell death and increased water movement, we were able to predict the patients’ response to Avastin before they began treatment,” explained Pope. “We were correct 70 percent of the time. Previously, identifying which patients would respond was like flipping a coin. This is a huge improvement.”

The research finding presents clear clinical benefits to the patient, says Pope. “Knowing this information ahead of time will help doctors personalize therapy for each patient and decrease exposure to side effects,” he noted.

Pope and his colleagues plan to confirm their findings in a larger study. The team will also test the new method’s ability to identify responsive patients prior to surgical removal of their tumor.

Despite therapy with surgery, radiation and chemotherapy, the average glioblastoma patient lives only 12 to 15 months after diagnosis. Survival rates drop even lower if the tumor returns. Conventional therapies produce little benefit; only 8 to 15 percent of patients survive without tumor progression six months after treatment.

Source: University of California, Los Angeles (UCLA), Health Sciences, July 30, 2009

Targeted Therapy Delivers Chemo Directly to Ovarian Cancer Cells

By Leave a Comment

With a novel therapeutic delivery system, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center has successfully targeted a protein that is over-expressed in ovarian cancer cells. Using the EphA2 protein as a molecular homing mechanism, chemotherapy was delivered in a highly selective manner in preclinical models of ovarian cancer, the researchers report in the July 29 issue of the Journal of the National Cancer Institute.

EphA2 is attractive for such molecularly targeted therapy because it has increased expression in ovarian and other cancers, including breast, colon, prostate and non-small cell lung cancers and in aggressive melanomas, and its expression has been associated with a poor prognosis.

“One of our goals has been to develop more specific ways to deliver chemotherapeutic drugs,” said senior author Anil K. Sood, M.D., professor and in the Departments of Gynecologic Oncology and Cancer Biology at M. D. Anderson. “Over the last several years we have shown that EphA2 is a target that is present quite frequently in ovarian and other cancers, but is either present in low levels or is virtually absent from most normal adult tissues. EphA2’s preferential presence on tumor cells makes it an attractive therapeutic target.”

The researchers used a carrier system to deliver chemotherapy directly to ovarian cancer cells. The immunoconjugate contains an anti-EphA2 monoclonal antibody linked to the chemotherapy drug monomethyl auristatin phenylalanine (MMAF) through the non-cleavable linker maleimidocaproyl. Research has shown that auristatins induce cell cycle arrest at the G – M border, disrupt microtubules and induce apoptosis (programmed cell death) in cancer cells.

The investigators evaluated the delivery system’s specificity in EphA2-positive HeyA8 and EphA2-negative SKMel28 ovarian cancer cells through antibody-binding and internalization assays. They also assessed viability and apoptosis in ovarian cancer cell lines and tumor models and examined anti-tumor activity in orthotopic mouse models with mice bearing HeyA8-luc and SKOV3ip1 ovarian tumors.

According to Sood, who is also co-director of both the Center for RNA Interference and Non-Coding RNA and the Blanton-Davis Ovarian Cancer Research Program at M. D. Anderson, the immunoconjugate was highly specific in delivering MMAF to the tumor cells that expressed EphA2 while showing minimal uptake in cells that did not express the protein. In the models, the therapy inhibited tumor growth in treated mice by 85 percent – 98 percent compared to control mice.

“Once we optimized the dosing regimen, the drug was highly effective in reducing tumor growth and in prolonging survival in preclinical animal models,” Sood said. “We actually studied bulkier masses because that is what one would see in a clinical setting where there are pre-existent tumors, and even in this setting the drug was able to reduce or shrink the tumors.”

As for future research with the EphA2-silencing therapy, Sood said, “We are gearing up to bring it to phase I clinical trials. A lot of the safety studies are well under way or nearing completion and we anticipate that this drug will enter clinical trials within the next few months.”

He added that his group is simultaneously conducting preclinical testing on other chemotherapy drugs to determine which agents might combine well with the immunoconjugate used in the current study.

“There is growing interest in molecularly targeted therapy so that we are not indiscriminately killing normal cells,” Sood noted. “The goal is to make the delivery of chemotherapy more specific. The immunoconjugate we used is in a class of drugs that is certainly quite attractive from that perspective.”

Source: University of Texas M. D. Anderson Cancer Center

40% of Emergency Room Visits Billed to Public Insurance, Says Report

By Leave a Comment

More than 40 percent of the 120 million visits that Americans made to hospital emergency departments in 2006 were billed to public insurance, according to the latest News and Numbers from the Agency for Healthcare Research and Quality.

According to the analysis by the federal agency, about 50 million emergency department visits were billed to Medicaid and Medicare. The uninsured accounted for another 18 percent of visits for emergency care, while 34 percent of the visits were billed to private insurance companies and the rest were billed to workers compensation, military health plan administrator Tricare and other payers.

The agency’s study of hospital emergency department use in 2006 also found that:

  • About 38 percent of the 24.2 million visits billed to Medicare ended with the patients being admitted, compared with 11 percent of the 41.5 million visits billed to private insurers, 9.5 percent of the 26 million visits billed to Medicaid and 7 percent of the 21.2 million visits by the uninsured.
  • The uninsured were the most frequent users of hospital emergency departments. Their rate was 1.2 times greater than that of people with public or private insurance – 452 visits per 1,000 population vs. 367 visits per 1,000 population, respectively.
  • The uninsured were also the most likely to be treated and released – a possible indication of their use of hospital emergency departments as their usual source of care. Their "treat-and-release" rate was 421 visits per 1,000 population vs. 301 per 1,000 population for the insured.

Source: Agency for Healthcare Research and Quality (AHRQ)

Sun Exposure May Trigger Auto Immune Disease in Women

By Leave a Comment

Ultraviolet (UV) radiation from sunlight may be associated with the development of certain autoimmune diseases, particularly in women, according to a study by researchers at the National Institute of Environmental Health Sciences (NIEHS), part of the National Institutes of Health.

“This study found that women who lived in areas with higher levels of UV exposure when they developed an autoimmune muscle disease called myositis were more likely to develop the form known as dermatomyositis, which weakens the muscles and causes distinctive rashes, instead of the form called polymyositis that does not have a rash,” said Frederick W. Miller, M.D., Ph.D., chief of the Environmental Autoimmunity Group, Program of Clinical Research, at NIEHS. “Although we have not shown a direct cause and effect link between UV exposure and this particular autoimmune disease, this study confirms the association between UV levels and the frequency of dermatomyositis that we found in a previous investigation,” said Miller.

The study, published in the August issue of Arthritis & Rheumatism, is also the first to evaluate and find a possible UV radiation association in autoimmune diseases in women.

According to Miller, women are more likely than men to develop many autoimmune diseases, but the reasons for this have not been clear. “We only found the association between UV exposure and dermatomyositis in women and not in men, and it could be that inherent differences in how women and men respond to UV radiation may play a role in the development of certain autoimmune diseases,” said Dr. Miller. Miller also noted that other researchers have shown that female mice develop more skin inflammation after UV light exposure compared to male mice and these effects may be related to the new findings in dermatomyositis.

The study was designed to determine if there was a relationship between the level of UV exposure at the onset of the disease and the type of myositis and autoantibodies that people developed. Dermatomyositis and polymyositis are the two major forms of myositis and both are considered autoimmune diseases, in which the body’s immune system attacks muscle or skin and sometimes other tissues. Dermatomyositis is typically accompanied by a distinctive reddish-purple rash on the upper eyelids or over the knuckles and is often made worse with sun exposure.

To conduct the study, the NIEHS researchers collaborated with myositis centers across the country that had seen 380 patients who had been diagnosed with dermatomyositis or polymyositis and determined their autoantibodies. “Patients with autoimmune diseases make a variety of autoantibodies that are unique to different conditions. One autoantibody specifically associated with dermatomyositis is called the anti-Mi-2 autoantibody and we know from our previous research that UV radiation increases levels of the Mi-2 protein that this autoantibody binds to,” said Miller.

In addition to finding an association between the level of UV radiation and the proportion of women who developed dermatomyositis compared to polymyositis, the researchers found an association between UV levels and the proportion of women with the anti-Mi-2 autoantibody. “More research is clearly needed to understand the potential links between UV radiation and the development of autoimmune diseases and autoantibodies in women,” said Miller.

“While the causes of autoimmune diseases are not known, we suspect from emerging research that they develop after one or more environmental exposures in genetically susceptible people,” said NIEHS Director Linda Birnbaum, Ph.D. “This study adds UV radiation to the growing list of environmental exposures possibly important in the development of autoimmune diseases.”

Source: National Institute of Environmental Health Sciences (NIEHS), July 30, 2009