HIV detection during early infection can reduce transmission rates
Detecting HIV earlier, through screening programs that can identify the virus shortly after infection, may lead to lower rates of HIV transmission in local epidemics, suggest findings from a new study published in Clinical Infectious Diseases and available online. After an acute infection screening program was implemented in San Diego, there were fewer new HIV diagnoses than would have been expected without such testing. To screen for HIV, the program used nucleic acid and serology testing, which can detect the virus during the acute or primary stage of infection, as soon as 7 to 10 days after exposure, compared to several weeks or months for other tests. An estimated 30 to 50 percent of new infections originate from recently infected individuals, who carry higher viral loads. High-risk sexual behavior is also common during this stage, as individuals are often unaware of their status. The researchers believed that screening for primary infections would reduce HIV transmission during early infection and lead to lower overall incidence of the virus. Their cohort study analyzed HIV testing data collected by the San Diego County Department of Public Health and the San Diego Primary Infection Cohort between 1996 and 2012, and used genetic analysis to identify local chains of transmission. Researchers focused on the city's central region, including the Hillcrest neighborhood, the center of the city's gay community and an area of high HIV incidence. It was in this neighborhood that the researchers established an acute infection screening program, the Early Test, in 2007. Approximately 100 fewer new HIV diagnoses were observed in the central region in 2012 than would have been expected without the Early Test program. Genetic analysis also suggested that HIV transmission chains were more likely to end in areas where the early testing was marketed.
It's all about the proteins: PSA test can help detect prostate cancer
A promising new test is detecting prostate cancer more precisely than current tests, by identifying molecular changes in the prostate specific antigen (PSA) protein, according to Cleveland Clinic research presented today at the American Urological Association annual meeting. The study – part of an ongoing multicenter prospective clinical trial – found that the Isopsa test can also differentiate between high-risk and low-risk disease, as well as benign conditions. Although widely used, the current PSA test relies on detection strategies that have poor specificity for cancer – just 25 percent of men who have a prostate biopsy due to an elevated PSA level actually have prostate cancer, according to the National Cancer Institute – and an inability to determine the aggressiveness of the disease. The Isopsa test, however, identifies prostate cancer in a new way. Developed by Cleveland Clinic, in collaboration with Cleveland Diagnostics Inc., Isopsa identifies the molecular structural changes in protein biomarkers. It is able to detect cancer by identifying these structural changes, as opposed to current tests that simply measure the protein's concentration in a patient's blood. The clinical trial involves six health care institutions and 132 patients, to date. It examined the ability of Isopsa to distinguish patients with and without biopsy-confirmed evidence of cancer. It also evaluated the test's precision in differentiating patients with high-grade (Gleason = 7) cancer from those with low-grade (Gleason = 6) disease and benign findings after standard ultrasound-guided biopsy of the prostate. Substituting the Isopsa structure-based composite index for the standard PSA resulted in improvement in diagnostic accuracy. Compared with serum PSA testing, Isopsa performed better in both sensitivity and specificity.
Biomarker for obesity discovered
A new study led by University of Kentucky researchers and published in Nature shows a potential new biological marker for the development of obesity and a possible target for obesity prevention and treatment. Neurotensin (NT), a peptide produced mainly in the gastrointestinal tract and central nervous system, is released with fat ingestion and facilitates fatty acid absorption in the intestine. Previous research has shown that NT can also stimulate the growth of various cancers and increased fasting levels of pro-NT (an NT precursor hormone) are associated with development of cardiovascular disease and breast cancer. The new Nature study examined data from the Malmö Diet and Cancer Study, a population-based, prospective epidemiologic cohort of 28,449 men and women who were followed for an average of 16.5±1.5 years. The analysis showed that obese and insulin-resistant subjects have significantly elevated levels of fasting pro-NT, and the risk of developing obesity was doubled in non-obese subjects who had fasting pro-NT at the highest concentrations compared to subjects with the lowest concentrations. The study further used animal models to show that a deficiency in NT protects against obesity, insulin resistance and fatty liver disease associated with high fat consumption, thus identifying NT as a potential early marker of future obesity and a novel therapeutic target for this disease.