Below are summaries of 34 key research findings published in fiscal year 2012 that advanced our knowledge of blood, cardiovascular, and lung diseases. All studies had funding support from the NHLBI.
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An early-phase study at the NIH Clinical Center has shown that eltrombopag, a drug that was designed to stimulate production of platelets from the bone marrow and thereby improve blood clotting, can raise blood cell levels in some people with severe aplastic anemia who have failed to benefit from standard therapies. This encouraging study, published in July 2012, suggests that the drug can stimulate bone marrow stem cells and perhaps have wider utility than initially thought.
A liberal strategy for providing red blood cell transfusions to patients who developed anemia following hip fracture surgery neither lowered their post-surgical risk of death nor improved their recovery rates relative to a restrictive transfusion strategy. The finding, based on a clinical trial of 2,016 participants with an average age of 82, was published in December 2011.
An experimental gene therapy technique boosted the production of a vital blood clotting factor in six people with severe hemophilia B, according to research published in December 2011. If future studies support the findings, the approach could offer significant improvement in the quality of life for patients with the disease.
A study reported in November 2011 corrected sickle cell disease in mice using a new approach to activate production of fetal hemoglobin, a blood component normally produced before, but not after, birth. The experimental method, which entailed silencing a gene that ordinarily suppresses fetal hemoglobin production after birth, eliminated disease symptoms in laboratory mice bred to have the inherited blood disorder. Although more work is needed before the new approach can be tested in humans, this "proof of principle" demonstration constitutes a significant advance.
Researchers have shown for the first time that a substance called rutin is a promising candidate for development of a new drug to prevent blood clots. Scientists hoping to develop safer, more effective blood thinners recently identified rutin after screening nearly 5,000 molecules for their ability to block clot formation. Since it occurs naturally in many foods and is well tolerated by humans, researchers hope that it will prove useful for many patients without causing the harmful side effects that sometimes occur with currently available blood thinners.
People with Down syndrome—who have three copies of chromosome 21 instead of two—are born with abnormal blood counts and experience defects in blood formation throughout their lives. In reports published in October 2012, researchers described the successful use of induced pluripotent stem cells and embryonic stem cells to model the effects of the additional chromosome copy. They showed that when the additional chromosome is present, the formation of blood stem cells is disrupted. Not only do these results enable a better understanding of disease progression in people with Down syndrome, but the same approach can also be used to model other diseases.
Researchers have identified previously unknown genetic contributors to Diamond-Blackfan anemia, according to a study reported in July 2012. By sequencing the coding regions of DNA in two siblings and one other person with the disease, the researchers found mutations in a gene called GATA1 that encodes a protein needed for red blood cell development. The mutations were in a part of the GATA1 gene that affects the way the protein is pieced together.
Researchers have shown that two proteins, thrombomodulin and activated protein C, prolong survival and reduce injury in mice exposed to toxic doses of radiation. Giving the proteins to mice receiving radiation promoted the recovery of bone marrow stem cells and prolonged survival. The findings, published in July 2012, represent a step forward in the search for drugs to treat people accidentally exposed to radiation or to reduce side effects in patients undergoing radiation therapy.
TRALI is the leading lethal complication of blood transfusions, but its causes have remained elusive. A new study reported in July 2012 that structures called neutrophil extracellular traps (NETs) may explain the lung damage of TRALI. Dismantling the NETs or inhibiting their formation lessened lung injury in a mouse model of TRALI, raising hope that treatments targeting NET formation could ultimately help patients with TRALI.
A clinical trial of adults with mild or moderate asthma has demonstrated that fine-tuning a patient's medication dose based on his or her perception of symptoms may be just as effective as adjusting the dose based on periodic physician evaluation. The study investigators, who published their findings in September 2012, also examined a third dosing approach based on the results of a breath test to measure inflammation and found equivalent effectiveness. The lack of detectable differences in treatment failure or in other clinical measures considered important for patients with asthma suggests that a patient-directed approach to adjusting corticosteroid doses is a reasonable option for treating mild or moderate asthma.
Participants in a clinical study of childhood asthma who were treated with the inhaled corticosteroid drug budesonide ended up, in adulthood, about half an inch shorter than their study counterparts who did not take the drug. The finding, published in September 2012, comes from a follow-up of 1,041 participants in the NHLBI Childhood Asthma Management Program (CAMP) clinical trial. An association between inhaled corticosteroid use and decreased growth rate in children was initially reported in the early 1990s, but CAMP is the first large prospective randomized study to correlate childhood asthma treatment with final adult height.
Adding the stomach acid-suppressing drug lansoprazole to standard inhaled steroid treatment does not improve asthma control in young people who have no symptoms of acid reflux and may, in fact, increase risk of adverse events, according to a clinical trial reported in January 2012. The study results, which were consistent with findings of a similar trial in adults, will guide future efforts to manage asthma and avoid use of expensive, ineffective medications.
Current clinical guidelines recommend daily low-dose inhaled corticosteroids for young children with recurrent wheezing and a high risk of developing asthma, but adherence to the treatment is often problematic. A study reported in November 2011 found that high-dose treatment given only when a child had specific respiratory illness symptoms was just as effective and safe. Moreover, the intermittent regimen resulted in a much lower cumulative exposure to the corticosteroid during the year of the study.
Acute lung injury patients on ventilators who require a feeding tube have a similar number of ventilator-free hospital days and similar mortality rates whether they receive a low-calorie feeding program initially followed by a full-calorie program or a full-calorie program right away. Results of the study, conducted through the NHLBI Acute Respiratory Distress Syndrome Clinical Research Network, were published in February 2012.
Inhaling concentrated saline (salt water) mist does not appear to benefit infants and young children with cystic fibrosis, according to findings from the Infant Study of Inhaled Saline published in June 2012. Although twice-daily use of concentrated saline mist was well tolerated, it did not lower the rate of acute lung problems that required treatment with antibiotics.
A rigorous clinical trial of therapy for idiopathic pulmonary fibrosis has revealed that a commonly used three-drug regimen—prednisone, azathioprine, and N-acetylcysteine—may actually be harmful. The evaluation of the combination therapy was halted ahead of schedule in October 2011 when interim results showed that patients who received it had worse outcomes than those given a placebo. The trial, conducted through the NHLBI Idiopathic Pulmonary Fibrosis Clinical Research Network, will continue its planned assessment of N-acetylcysteine alone versus placebo.
Investigators have uncovered a new clue to the cause of pulmonary arterial hypertension, a progressive and frequently lethal disease that in many cases arises mysteriously. A report published in June 2012 describes findings suggesting that bone marrow-derived endothelial progenitor cells play a role in causing the vascular injury in the lung that underlies the disease.
Stem cells have the potential to repair various kinds of tissue injury, but the mechanisms by which they do so have been unclear. In May 2012, investigators reported that following sepsis-induced lung injury in a mouse model, stem cells attached themselves to injured lung cells and transferred their mitochondria (essential cell components that produce energy for living cells). Stem cell treatment improved lung function, reduced cellular damage, and decreased the lethality of infection.
New research reported in October 2011 shows that adult stem cells residing in the lung may enable lung structures to regenerate after catastrophic injury. A study in mice with induced lung damage found that a type of stem cell from the small airways proliferated rapidly, radiated to the injured regions, and assembled into alveoli-like structures. These findings provide a critical new understanding that may aid in the development of cell-based therapies for chronic lung diseases that presently have no cure.
For the first time, scientists have established a procedure to direct embryonic stem cells to differentiate into lung cells—overcoming a major barrier to realizing the potential of regenerative medicine in the lung. Researchers were able to use the same differentiation strategy to produce disease-specific lung progenitor cells from induced pluripotent stem cells derived from patients with cystic fibrosis. This advance, reported in April 2012, will improve scientists' ability to model lung diseases, test individual responses to treatments, and develop cell-based therapies for lung diseases.
A detailed exploration of the coding regions and flanking non-coding regions of selected DNA sequences has found rare variants of genes that influence asthma susceptibility in people of different backgrounds. Researchers determined that variants of four genes contributed to asthma susceptibility in African Americans, while a variant of one of the same genes was associated with asthma susceptibility in European Americans. The results, published in February 2012, may ultimately be useful in identifying people at risk for developing asthma.
NHLBI-funded investigators have reported several discoveries that may lead to new therapies for cystic fibrosis. Results of three separate studies suggest that clinicians treating cystic fibrosis may soon have a variety of new approaches to address defects in mucociliary transport—a process by which the lungs physically clear out accumulated mucus and inhaled pathogens—that can lead to chronic, life-threatening infections in people with cystic fibrosis.
LAM is a rare, slowly progressive lung disease that almost exclusively affects women of child-bearing age. Investigators used a mouse model of LAM to show that lung damage is caused by loss of tuberous sclerosis complex 2 gene function. They further showed that the combination of two drugs, sirolimus and simvastatin (a drug commonly used to lower cholesterol), prevents growth of lung lesions, prevents lung destruction, and causes a dramatic regression of established lung lesions. Published in October 2012, the results may lead to much-needed new therapy strategies for LAM.
Researchers found that inhibiting a key cell-development pathway known to be altered by cigarette smoke might slow or reverse progression of chronic obstructive pulmonary disease (COPD). Interrupting the TGF-β pathway in mice exposed to cigarette smoke reduced lung injury and improved lung function. The drug used in the mice, losartan, is already approved for the treatment of high blood pressure in humans and is currently being evaluated in a clinical trial as a treatment for Marfan syndrome.
Infants and children whose blood sugar levels were maintained within a narrow range during heart surgery fared no better than those whose levels were not, according to clinical trial results published in September 2012. The study compared tight blood sugar control to standard blood sugar management in 980 young patients who were undergoing open heart surgery with heart–lung bypass. Although participants in the tightly controlled group quickly achieved normal blood sugar levels, they did not experience fewer complications or shorter stays in the intensive care unit.
Heart catheter procedures guided by magnetic resonance imaging (MRI) are as safe as those guided by X-ray and take no more time, according to a pilot study reported in August 2012. The results of the study indicate that real-time MRI-guided catheterization could be a radiation-free alternative to certain X-ray-guided procedures.
Analysis of data from the Framingham Heart Study has shown that stiffening of the blood vessels occurs before the development of hypertension (high blood pressure), a discovery that runs counter to the widely held belief that increased arterial stiffness is instead a consequence of hypertension. The finding, reported in September 2012, sheds light on the mechanisms that cause hypertension and suggests new therapeutic approaches to prevent or delay its development.
Tissue engineering holds promise for regenerating damaged tissues and organs by stimulating them to heal themselves, but the approach has been associated with worrisome complications such as arrhythmias. In a study reported in September 2012, investigators transplanted heart cells grown from human embryonic cells into guinea pigs and showed that the cells electrically coupled and beat in sync with the animals’ hearts. With further development, this approach may prove useful for heart attack survivors who are left with damaged heart muscle that can lead to progressive heart failure.
Researchers probing the mysteries of blood vessel development have shown that the walls of arteries are constructed radially, from the inside out, by activation of two separate but coordinated processes. Results of this study, published in September 2012, improve understanding of arterial wall formation and could lead to treatments for cardiovascular diseases such as aortic aneurysm, coronary artery atherosclerosis, and pulmonary hypertension.
Investigators reported in April 2012 that pregnant women with preeclampsia have lower uterine levels of an enzyme called corin than women with normal pregnancies. Moreover, studies in mice showed that corin was involved in new blood vessel formation at the maternal–fetal interface of the placenta, with loss of corin from the uterus leading to impaired blood vessel formation and preeclampsia-like symptoms. The findings from this work could lead to new approaches, specifically those targeting corin, for treating preeclampsia.
Research findings published in December 2011 showed that pregnancy triples the prevalence of loud, frequent snoring (a hallmark of sleep-disordered breathing) in women and that new-onset snoring in pregnancy is associated with increased risks of gestational hypertension (high blood pressure) and preeclampsia relative to not snoring in pregnancy or having snored prior to pregnancy. The study suggests that identifying and treating sleep-disordered breathing in pregnant women may reduce the rates of gestational hypertension and of preeclampsia, with its associated risks of maternal death, miscarriage, and premature delivery.
A new study has suggested that a combination of mobile technology and remote coaching holds promise for encouraging healthier eating and physical activity behaviors in adults. The work, published in May 2012, focused on innovative approaches to changing multiple health behaviors.
A study published in June 2012 has shown that a "stepped" approach to weight loss that periodically adjusts goals and the frequency of counseling sessions based on a person’s progress can result in excellent weight loss and cost savings, compared with an approach that maintains a constant level of intensity and support regardless of progress. The stepped approach could be a cost-effective alternative to traditional lifestyle modification and even pharmacological weight loss strategies.
Much research has shown that being overweight in childhood raises a person’s cardiovascular disease risk in adulthood. However, a new analysis, published in November 2011, has indicated that the higher risk for developing type 2 diabetes, high blood pressure, and other cardiovascular risk factors associated with being overweight or obese as a child is not inevitable if healthy weight is achieved and maintained as an adult.
Last Updated: December 2012