In The News

Two large studies of prostate cancer screening, one from the US and one from Europe, have given uncertain results. The problem is that screening and treatment may do more harm than good for men who have a slow-growing cancer. The studies provide no evidence to suggest that the current UK approach to screening should be changed at present.

The British Medical Journal has highlighted a ‘consensus statement’ from UK specialist associations and patient groups about the diagnosis and treatment of an underactive thyroid gland (hypothyroidism). The statement makes it clear that blood tests for thyroid stimulating hormone (TSH) and free thyroxine (T4) are essential to diagnose hypothyroidism since symptoms alone can be misleading.

In 2007, a new worldwide standard for HbA1c measurement was introduced and shortly the NHS will adopt this standard and change the way it reports this important lab test. The NHS now expects diabetics to have HbA1c measurements at least twice a year.

The risk of having a heart attack or stroke increases with factors such as raised cholesterol, raised blood pressure, increased weight, smoking and taking little exercise, but the risk becomes less related to these factors with increasing age. Newer lab tests that are are linked to heart attacks, including homocysteine which is an amino acid present in blood, have recently been shown to add very little to the calculation of risk in people aged up to about 80.Research workers from Leiden University in the Netherlands have carried out a small study of risk factors in very old people. Their subjects were 302 residents of Leiden who were 85 at the start of the five year study and who had no history of heart disease. They found that at this age conventional risk assessment no longer accurately predicted death. In contrast, plasma homocysteine on its own identified those at high risk of dying from heart attack or stroke. The authors suggest that their findings warrant checking in further groups of the very old because, if confirmed, homocysteine alone could be used to select old people for preventive treatment.

A new test can rapidly detect the presence of viruses that cause cervical cancer (cancer of the neck of the womb). It will be cheaper than existing methods and does not require highly trained personnel, mains electricity or running water, so researchers hope it will help developing countries improve screening for cervical cancer. A study comparing this experimental test with established cervical cancer screening tests found it to be promising and potentially appropriate for use in resource-constrained screening programs.

Pre-eclampsia, a combination of increased blood pressure with protein in the urine, develops in about 4% of first pregnancies. Those affected need to be monitored closely because about one in 50 develop full eclampsia in the last three months of pregnancy or during labour. With full eclampsia come fits, fluid in the lungs, kidney failure and clotting problems. Professor David Bates from the Microvascular Research Laboratories in the University of Bristol and co-workers have investigated a protein called VEGF165b that inhibits the growth of new blood vessels. They found that women with normal pregnancies showed a 10-fold increase in VEGF165b in their blood plasma by the 12th week, while women who went on to develop pre-eclampsia had no increase. The researchers concluded that low plasma VEGF165b may prove to be a clinically useful marker in the first three months of pregnancy for an increased risk of developing pre-eclampsia.

In the early weeks of pregnancy screening with blood tests and an ultrasound scan of the baby can help to assess the risk of the baby having a chromosome abnormality such as Down's syndrome, which is caused by an extra copy of chromosome 21. To make a firm diagnosis it is necessary to test tissue from the placenta or fluid from around the baby in the uterus, invasive procedures that carry the risk of causing a miscarriage. Fragments of baby's DNA can be detected in mother's plasma early in pregnancy. Workers from Stanford University have used a new technique to measure tens of millions of short chemical sequences of DNA fragments in mother's plasma and then 'mapped' the sequences to the chromosome map developed by the Human Genome Project. They found that chromosome 21 was clearly over-represented in the plasma of nine mothers carrying babies with Down's syndrome (one as early as the 14th week) but not in nine other mothers. They plan to repeat the study in a larger number of women.

Recently two independent groups of researchers have shown that heart attacks are less frequent in those with a low ‘bad’cholesterol (LDL cholesterol) if their ‘good’ cholesterol (HDL cholesterol) is normal or high. HDL cholesterol is still an important risk factor even though drugs (statins) may have reduced LDL cholesterol to very low levels. Life style factors that help to maintain the level of ‘good’ cholesterol are not smoking, having a normal body weight and taking regular exercise.

A new lab test is reported to be able to predict with high probability which patients with mild memory loss will develop Alzheimer's disease years before a clinical diagnosis can be made. The test is based on the measurement of 18 proteins in blood plasma and the use of a computer program that looks for clusters of patients that show similar changes in concentration. The research, led from Stanford University School of Medicine, was published online in the international journal Nature Medicine on 14 October 2007. It involved 25 doctors and scientists from 14 clinical departments and laboratories, largely in the USA but also from Italy, Poland and Sweden. The researchers hope that, if their work is confirmed, it will lead to improvements in diagnosis and treatment.

Alzheimer's Disease is an irreversible form of dementia that affects nearly half a million people in the UK, a number likely to double by 2050. Many have looked for a disease marker in the cerebrospinal fluid that bathes the brain, but with limited success. Researchers from King's College London have now reported increased blood levels of specific proteins in more than 500 patients with Alzheimer's compared with those with other forms of dementia. The lab tests used for the 5 year project were complex and are not available for routine use. However, the discovery of specific protein differences means that researchers can now concentrate on refining and simplifying lab tests to help identify and monitor progression of the disease.