A new diagnostic test for a worm infection that can lead to severe enlargement and deformities of the legs and genitals is far more sensitive than the currently used test, according to results of a field study in Liberia, in West Africa, where the infection is endemic.
The new test found evidence of the infection – lymphatic filariasis – in many more people that the standard test had missed.
The study, the first to independently evaluate the new test, was led by researchers at Washington University School of Medicine in St. Louis and funded by the Bill & Melinda Gates Foundation.
The infection affects 120 million people living in 73 countries, leaving some 40 million profoundly disfigured and incapacitated. Both tests detect the presence of worms that cause lymphatic filariasis, a devastating mosquito-borne illness also known as elephantiasis.
But the new test has significant advantages over the test that has been used for more than a decade not only to diagnose the disease, but to map, monitor and evaluate the success of a massive global public health program aimed at completely eliminating the disease by 2020.
‘The older test has had a major impact, but the new one is even better,’ says lead author Gary J. Weil, MD, an infectious diseases specialist at Washington University School of Medine. ‘Annually, medication to treat and prevent the infection is distributed to more than 500 million people worldwide. The improved sensitivity of the new test will help determine whether the mass treatment program has been effective and also identify regions that need additional attention.’
An accompanying editorial by Maria Rebollo, MD, and Moses Bockarie, PhD, at the Centre for Neglected Tropical Diseases in the United Kingdom says the new diagnostic test ‘represents a major breakthrough for rapid diagnosis of lymphatic filariasis in the blood.’
The new test also has a longer shelf life, estimated at two years without refrigeration, compared with three months for the older version, and is expected to cost less.
Weil’s research team worked with colleagues at the Liberian Institute for Medical Research to conduct a side-by-side comparison of the new test strip and the currently used test. They evaluated the tests in 503 people ranging in age from 6 to 89.
Both versions of the test are manufactured by Alere Scarborough Inc. of Maine and detect the presence in the blood of a protein produced by the worm parasite Wuchereria bancrofti that causes lymphatic filariasis. The new test is performed by pricking the finger and placing a person’s blood onto the test strip, which looks similar to an over-the-counter pregnancy test. Like many pregnancy tests, the lymphatic filariasis test is positive if two lines appear in the test window and negative if only one line shows.
The study’s results show that the new test is highly sensitive, detecting nearly 26 percent more infections of lymphatic filariasis than the standard test (124/503 infections vs. 98/503 infections). The new test also was easier to perform and results were easier to read.
‘This gives us some indication of the numbers of infections we were missing with the older test,’ Weil says. ‘On a global scale, it’s a huge number of cases. We need to have an accurate test to be sure we are reaching all the people who have the disease or are at risk of developing it.’
Worldwide, some 1.4 billion people are at risk of lymphatic filariasis, which is endemic in many countries in Africa, Southeast Asia and other tropical regions. Worm larvae deposited by the bite of an infected mosquito enter the body and migrate to the lymphatic system, where they mature into adult worms.
The thread-like parasitic worms can live and reproduce in the body for years. Ultimately, this damages the lymphatic vessels that drain fluid from the tissues and causes the enormous swelling and disabling deformity of the legs and in males, the scrotum.
Weil has been active for years in efforts to eliminate lymphatic filariasis via mass drug administration, an approach that involves giving antifilarial drugs to everyone in areas with high infection rates. Organizers of the Global Programme to Eliminate Lymphatic Filariasis, launched in 2000, co-ordinate periodic, repeated mass drug administration of antifilarial medications to more than 500 million people annually, making it the world’s largest public health intervention program based on mass drug administration. Washington University School of Medicine

Unusually high calcium levels in the blood can almost always be traced to primary hyperparathyroidism, an under-treated, underreported condition that affects mainly women and the elderly, according to a new study by UCLA researchers.

The condition, which results from overactive parathyroid glands and includes symptoms of bone loss, depression and fatigue that may go undetected for years, is most often seen in African American women over the age of 50, the researchers discovered.
The study is one of the first to examine a large, racially and ethnically diverse population — in this case, one that was 65 percent non-white. Previous studies had focused on smaller, primarily Caucasian populations.
The four parathyroid glands, which are located in the neck, next to the thyroid, regulate the body’s calcium levels. When one is dysfunctional, it can cause major imbalances — for example, by releasing calcium from the bones and into the bloodstream. Over time, calcium loss from bones often leads to osteoporosis and fractures, and excessive calcium levels in the blood can cause kidney stones and worsening kidney function.
The UCLA researchers determined that hyperparathyroidism is the leading cause of high blood-calcium levels and is responsible for nearly 90 percent of all cases.
‘The findings suggest that hyperparathyroidism is the predominant cause of high calcium levels, so if patients find they have high calcium, they should also have their parathyroid hormone level checked,’ said the study’s lead author, Dr. Michael W. Yeh, an associate professor of surgery and endocrinology at the David Geffen School of Medicine at UCLA.

Hyperparathyroidism, which affects approximately 1 percent of the population, can be detected by measuring parathyroid hormone levels to determine if they are elevated or abnormal. UCLA

The first multi-gene test that can help predict cancer patients’ responses to treatment using the latest DNA sequencing techniques has been launched in the NHS, thanks to a partnership between scientists at the University of Oxford and Oxford University Hospitals NHS Trust.
The test detects mutations across 46 genes in cancer cells, mutations which may be driving the growth of the cancer in patients with solid tumours. The presence of a mutation in a gene can potentially determine which treatment a patient should receive.
The researchers say the number of genes tested marks a step change in introducing next-generation DNA sequencing technology into the NHS, and heralds the arrival of genomic medicine with whole genome sequencing of patients just around the corner.
The new £300 test could save significantly more in drug costs by getting patients on to the right treatments straightaway, reducing harm from side effects as well as the time lost before arriving at an effective treatment.
The many-gene sequencing test has been launched through the National Institute for Health Research (NIHR) Oxford Biomedical Research Centre (BRC), a collaboration between Oxford University Hospitals NHS Trust and Oxford University.
The BRC Molecular Diagnostics Centre carries out the test. The lab, based at Oxford University Hospitals, covers all cancer patients in the Thames Valley area. But the scientists are looking to scale this up into a truly national NHS service through the course of this year.
‘We are the first to introduce a multi-gene diagnostic test for tumour profiling on the NHS using the latest DNA sequencing technology,’ says Dr Jenny Taylor of the Wellcome Trust Centre for Human Genetics at Oxford University, who is programme director for Genomic Medicine at the NIHR Oxford BRC and was involved in the work. ‘It’s a significant step change in the way we do things. This new 46 gene test moves us away from conventional methods for sequencing of single genes, and marks a huge step towards more comprehensive genome sequencing in both infrastructure and in handling the data produced.’
Dr Anna Schuh, who heads the BRC Molecular Diagnostics Centre and is a consultant haematologist at Oxford University Hospitals, adds: ‘Patients like the idea of a test that can predict and say up front whether they will respond to an otherwise toxic treatment. What the patient sees is no different from present. A biopsy is taken from the patient’s tumour for genetic testing with a consultant talking through the results a few days later. It is part of the normal diagnostic process.’
Cancer is often described as a genetic disease, since the transition a cell goes through in becoming cancerous tends to be driven by changes to the cell’s DNA. And increasingly, new cancer drugs depend on knowing whether a mutation in a single gene is present in a patient’s cancer cells.
For example, a lung cancer patient may have a biopsy taken to check for changes in the EGFR gene. If there is a mutation, the patient may then be treated with a drug that works as an EGFR inhibitor. If there is no mutation, such drugs won’t work and the patient would get a different drug that would be more effective for them. Knowing the presence or absence of mutations in a certain gene can choose the treatment path for that patient.
The NHS can currently test for mutations in 2 or 3 genes – genes called BRAF, EGFR or KRAS – using older sequencing technology that has been around for decades. Efforts are being made to look at increasing the number of cancer genes sequenced to nine as standard.
The Oxford scientists are the first to make such multi-gene tests possible in the NHS using the latest DNA sequencing techniques. The NHS service they have launched looks for mutations in 46 genes, and they are now working towards verifying the use of a test involving 150 genes. University of Oxford

Researchers from Huntsman Cancer Institute (HCI) at the University of Utah have developed a novel and powerful technique to identify the targets for a group of enzymes called RNA cytosine methyltransferases (RMTs) in human RNA. They applied their technique to a particular RMT, NSUN2, which has been implicated in mental retardation and cancers in humans, finding and validating many previously unknown RMT targets—an indication of the technique’s power.

‘Although RMTs have been known for many years, virtually nothing is known about the majority of these enzymes in humans,’ said Bradley R. Cairns, co-author of the study and Senior Director of Basic Science at HCI. ‘This new technique will now allow the very rapid identification of the direct target RNAs for each human RMT, and we are excited about conducting that work.’

Within all living cells, RNA acts as a critical intermediate in transmitting genetic information from DNA—RNA is made from DNA and then used to encode proteins called enzymes that control cell functions. A process called cytosine methylation attaches methyl molecules to cytosine bases in DNA and RNA molecules. RMTs act as catalysts to allow methylation at particular locations in RNA molecules. Methylation can regulate the flow of genetic information (from RNA to protein production) in cells, and it can change the way RNA interacts with proteins.

RNA methylation is currently poorly understood, partly because of limitations in the technique currently used to identify which RNA molecules and cytosine bases are RMT targets. As each cell contains thousands of different types of RNA molecules, often with only a small percentage being targets for a specific RMT, the first step in a study of RNA methylation is to sort out and concentrate the precise target RNA molecules for a particular RMT, in a process called enrichment.

The work involved a novel enrichment method, which applied a special ‘chemical cross-linker’ to physically join the RMT to an RNA that it is trying to methylate, said Vahid Khoddami, the study’s co-author and a member of the Cairns Lab. ‘Our new technique takes advantage of the mechanism of the enzyme. The drug/crosslinker we used looks like cytosine, so it is incorporated in place of the cytosine in the RNA. The RMT tries to methylate this drug— thinking it is a normal target cytosine—but instead becomes crosslinked to the RNA, defining the precise location of the intended methylation. As our reaction-based method requires that the enzyme both bind the RNA and commit to the act of methylation, it greatly increases our identification of true positives,’ said Khoddami.

‘This technique gives us 200-fold enrichment, when two-fold enrichment has been considered a great result in the past,’ said Khoddami. ‘In fact, for some RNA types, the enrichment is more than 700-fold.’

After the enrichment process, high-throughput gene sequencing is used to analyse the RNA samples obtained.

‘Our enrichment results were fantastic by themselves, but in the sequencing process we made another important discovery,’ Khoddami said. ‘We found that after sequencing, the target cytosine in the modified RNA instead appeared as an alternative molecule, guanosine, more than 50% of the time. After sequencing, you can look for these cytosine to guanosine transversions and know you have the precise target—in a single experiment.’

According to Khoddami, ten cytosine RMTs are known in humans, and only two of them have been partially characterised. ‘None of the other eight have been studied in the laboratory,’ he explained, ‘although some of them have been shown to have connections to cancer, infertility, and particular genetic disorders in humans.
‘These diseases have been puzzling because previously we did not have the tools to analyse the RNA. Now we have beautiful tools,’ said Khoddami. Huntsman Cancer Institute

Researchers at the University of Michigan Comprehensive Cancer Center sequenced the tumour’s genome through a new program called MI-ONCOSEQ, which is designed to identify genetic mutations in tumours that might be targeted with new therapies being tested in clinical trials.

The sequencing also allows researchers to find new mutations. In this case, an unusual occurrence of two genes – NAB2 and STAT6 – fusing together. This is the first time this gene fusion has been identified.

"In most cases, mutations are identified because we see them happening again and again. Here, we had only one case of this. We knew NAB2-STAT6 was important because integrated sequencing ruled out all the known cancer genes. That allowed us to focus on what had been changed," says lead study author Dan R. Robinson, research fellow with the  Michigan Center for Translational Pathology.

Once they found the aberration, the researchers looked at 51 other tumour samples from benign and cancerous solitary fibrous tumours, looking for the NAB2-STAT6 gene fusion. It showed up in every one of the samples.

"Genetic sequencing is extremely important with rare tumours," says study co-author  Scott Schuetze, M.D., associate professor of internal medicine at the U-M Medical School. "Models of rare cancers to study in the laboratory are either not available or very limited. The sequencing helps us to learn more about the disease that we can use to develop better treatments or to help diagnose the cancer in others."

The NAB2-STAT6 fusion may prove to be a difficult target for therapies, but researchers believe they may be able to attack the growth signalling cycle that leads to this gene fusion.

"Understanding the changes induced in the cell by the NAB2-STAT6 gene fusion will help us to select novel drugs to study in patients with advanced solitary fibrous tumours. Currently this is a disease for which there are no good drug therapies available and patients are in great need of better treatments," Schuetze says.

No treatments or clinical trials are currently available based on these findings. Additional testing in the lab is needed to assess the best way to target NAB2-STAT6. The gene fusion could also potentially be used to help identify solitary fibrous tumours in cases where diagnosis is challenging.The University of Michigan Health System