In The News

The World Health Organization has endorsed the new rapid automated molecular test system that can detect tuberculosis (TB) A rapid test for tuberculosis has been endorsed by the WHO (World Health Organisation). Trials of this new two hour test in countries with high rates of TB have been successful and we await donor organisation support to extend this service to all at risk populations.

Ectopic pregnancy, where the baby develops outside the womb, can be life-threatening. Early diagnosis is essential but can take days. New research shows that the normal levels of placental growth factor become undetectable in ectopic pregnancies, and therefore provide the potential for rapid diagnosis.

‘PSA blood tests are still not good enough to screen for prostate cancer’ remains the recommendation of the UK National Screening Committee. They conclude that the high levels of test false positives cause worry and anxiety and that these harms outweigh potential benefits.

The UK National Screening Committee (UKNSC) has published a guide to help the public make decisions about private screening tests. Before people pay for tests they should check that the company is properly regulated and provides clear written information about the benefits, the risks and what will happen if the test picks something up. The document emphasises that people with symptoms should see their doctor; if they have no symptoms they should ask themselves what they hope to get from the test. The guide is available through the UKNSC Screening Portal.

The definitive diagnosis of pulmonary tuberculosis (TB) needs the culture of sputum which takes up to six or eight weeks. Molecular diagnostic tests that give results within a day are available to only a very small proportion of the more than nine million people worldwide who become infected with TB each year. Delay in diagnosis and treatment leads to increased spread of the disease and increased deaths. A new rapid automated molecular test system is able to detect TB and find out whether it is resistant to the drug rifampicin in less than two hours. The apparatus needs minimal hands-on time and can be operated by relatively unskilled workers without laboratory facilities. The test system results on sputum specimens from 1462 people from Peru, Azerbaijan, South Africa and India with symptoms suggestive of active TB of the respiratory tract were reported in the New England Journal of Medicine on 9 September 2010. The results were compared with the microscope examination of sputum smears and with sputum cultures as the “gold standard”. The system was found to be highly sensitive for the detection of TB and drug resistance. The researchers say that its simplicity, safety and cost-effectiveness could allow its use outside reference centres to speed up diagnosis without the need to build large numbers of specialised laboratories.

Persistent or recurrent abdominal pain and diarrhoea can be caused by the inflammatory bowel diseases, Crohn’s disease or ulcerative colitis, but can also be a feature of the irritable bowel syndrome. Diagnosis often needs colonoscopy which is both time consuming and unpleasant. The large bowel needs to be emptied and a flexible tube is passed under sedation to allow inspection of the lining of the large bowel and collection of samples for microscopic examination. On 15 July 2010 BMJ.com published a statistical analysis of research papers that had measured a protein called calprotectin in the stool of patients who had colonoscopy for suspected inflammatory bowel disease. The authors, from Groningen University in the Netherlands, concluded that a raised calprotectin levels in the stool identifies those who are most likely to need colonoscopy for diagnosis. A low faecal calprotectin safely excluded the condition in adults but was less good in children. Screening with calprotectin would reduce the number of adults needing colonoscopy by 67%.

More than 36,500 people in the UK are diagnosed with bowel cancer each year. A five-minute screening procedure could cut their number by a third. On 28 April 2010 the Lancet published online the remarkable results of a 16 year controlled trial led by Imperial College, London and carried out in 14 UK centres. A one-off ‘Flexi-Scope’ examination of the inside of the lower bowel in people between the ages of 55 and 64 picked up pre-cancerous polyps on the bowel wall. These were removed before they could develop into cancer. Screening was carried out on 57,099 participants, with 112,939 unscreened people as a control group. After follow up for an average of eleven years, the incidence of bowel cancer was one-third lower in those screened than in the controls, and mortality was more than 40% lower. The results of this study are so significant that Cancer Research UK is calling on the government to introduce Flexi-Scope screening alongside the current nation-wide bowel cancer screening programme that tests for traces of occult blood in faeces.

Most cases of breast and ovarian cancer do not run in families. However, two genes known as BRCA1 and BRCA2 can be passed on from parent to child and increase their risk of cancers. In 1998 Myriad Genetics was granted US patents that gave them a monopoly over lab tests for the BRCA genes. Research from Duke University in the US published in Genomics on 3 March 2010 showed that the pieces of DNA included in the patents were so broad as to extend to parts of most human genes. The American Civil Liberties Union challenged the patents in a US District Court, and on 30 March the patents were ruled invalid because Myriad had simply removed DNA that exists naturally in the body. Dr Jim Evans of the University of North Carolina at Chapel Hill, who chaired a federal task force about the role of gene patents in lab tests, said the decision was monumental and would ultimately have a big impact once it has worked its way through appeals. Many medical and scientific groups have stated that patents should not interfere with medical investigations and treatment or limit the dissemination of medical knowledge. We await challenges to this important legal decision.

Doctors in Israel have found that levels of glucose at the high-end of the normal range in fasting women during the first 12 weeks of pregnancy, predicts diabetes later in pregnancy. The study, published in the September issue of Diabetes Care, looks at 6,129 women who had a normal fasting glucose early in pregnancy. The risk of developing diabetes increased from 1.0% in those with the lowest glucose levels to 11.7% in those the highest levels. The authors suggest that large trial would confirm their observations and see if diet and exercise could reduce the risk of diabetes in those at highest risk.

If the result of a genetic test result could have a big effect on the life of the person tested, it should be sold to the public only with informed consent and with the provision of information about access to support from a doctor or genetic counsellor. These recommendations form part of a draft framework that has been drawn up by a working group of the UK government’s advisory body on developments in human genetics that includes experts in regulation, clinical and molecular genetics and representatives of the genetic testing industry. It is being circulated widely for consultation.