Included below are news items from the last six months.
The presence of foetal DNA from an extra chromosome 21 in the mother’s blood during early pregnancy predicts Down’s syndrome more accurately than standard non-invasive screening with maternal ultrasound examination and biochemical tests. A multicentre comparison of the two methods in women undergoing routine prenatal screening was published online in the New England Journal of Medicine on 1 April 2015. In 15,841 women who completed both screenings, DNA testing predicted all 38 babies with Down’s syndrome with only nine false positives (0.06%). Standard screening predicted 30 of the 38 but with 854 false positives (5.4%). A UK research team is evaluating the requirements for implementing the DNA test as part of the NHS Down’s syndrome screening programme.
Lab Tests Online-UK has published a series of articles on unvalidated and misleading laboratory tests. It is important that members of the public are made aware that these sorts of tests are increasingly available to purchase directly without consulting any qualified health professionals. Please click on the link above for the full article.
There is variation in the way that individuals respond to two of the most effective treatments to give up smoking: nicotine patches and the prescription drug varenicline. Researchers from the US and Canada reported online in The Lancet Respiratory Medicine on 11 January 2015 the results of a randomised controlled trial of these two treatments. Individuals were classed as either ‘normal’ or ‘slow’ metabolisers of nicotine on the basis of a laboratory test result: the ratio of the plasma concentrations of the nicotine breakdown products, conitine and 3’-hydroxyconitine. The authors concluded that treating normal metabolisers with varenicline and slow metabolisers with nicotine patches could maximise the number quitting while minimising the side effects of treatment.
Muscle damage releases proteins called troponins into the bloodstream. Recently, highly sensitive and reproducible assays for serum heart-specific troponin have become available. Last year the National Institute for Health and Care Excellence (NICE) recommended that they could be used to help rule out a heart attack. NICE recognised that the upper limit of normal of the new tests may be lower in women than men. Researchers have now compared a standard and a new high-sensitivity troponin test both with and without a lower diagnostic value for women than for men to find out whether diagnosis can be improved. They investigated 1126 consecutive patients who presented to the Royal Infirmary of Edinburgh with a suspected heart attack. Their conclusion, published online in the British Medical Journal on 21 January 2015, was that the high-sensitivity troponin test with a sex specific diagnostic value may double the diagnosis of heart attack in women and identify those at high risk of a further heart attack and death.
There have been stories in the media recently regarding the UK launch of a personal/home DNA testing kit by the US-based biotech company 23&Me. For a nominal fee, users can have their DNA analysed for some common gene sequences associated with increased risk of developing a certain disease condition or physical trait. Whilst we at Lab Tests Online-UK are in favour of enhancing patient knowledge and understanding of information regarding healthcare, we strongly recommend that users consider their options carefully before purchasing their genetic information. Please click on the link above for the full story.