IrsiCaixa begins to study the XMRV retrovirus, a new retrovirus that could be associated to chronic fatigue and prostate cancer

• IrsiCaixa´s experience in HIV research has enabled the study of another retrovirus, the XMRV, which also uses the machinery of cells to reproduce itself by introducing its genetic material.

• The presence of XMRV has been detected in 67% of patients with Chronic Fatigue Syndrome and in 40% of patients with prostate cancer, two diseases that globally affect nearly 15 people per each 1,000 inhabitants.
• IrsiCaixa, promoted by “la Caixa” Foundation and the Department of Health of the Generalitat of Catalonia, will participate in the First International Workshop on XMRV on the 7th and 8th of September in Maryland, USA.
  

The IrsiCaixa Institute for AIDS Research has announced a new research line on the new XMRV retrovirus (Xenotropic MLV-Related Virus) that could be associated to Chronic Fatigue Syndrome (CFS) and prostate cancer, two diseases that globally affect nearly 15 people per each 1,000 inhabitants. The initiation of this new research line coincides with the 1st International Workshop on XMRV on the 7th and 8th of September in Maryland, USA.

IrsiCaixa, supported by “la Caixa” Foundation and the Department of Health of the Generalitat of Catalonia, will transfer its experience in HIV research to this new field of research, given the similarity of both viruses. It is known that the XMRV, as with HIV, is a retrovirus as it uses cell machinery to reproduce itself by introducing its genetic material. It is also known that is a much simpler virus than HIV as while the latter contains its genetic information structured around 3 principal genes and other secondary genes, the XMRV only has 3 principal ones but with the same functions as those of the main HIV genes.

Nevertheless, the knowledge on this new retrovirus is still in very early stages. Studies carried out to date have detected the presence of genetic material and viral proteins in different cells only in some of the patients with prostate cancer and CFS. Because of this, the infection cycle, the replication site, and the response of the immune system as well as the transmission process in humans still remain unknown. The aim of IrsiCaixa is to make headway in this research field after detecting and isolating the CMRV in samples from patients suffering from prostate cancer or CFS.

The association of this virus with prostate cancer was identified in 2006 by using a ViroChip that sequenced all known viruses that affect human beings, animals, plants and bacteria and identified the presence of viruses from the XMRV family in 40% of patients with familial prostate cancer. Nonetheless, more recent studies have been able to identify the presence of XMRV in patients with this pathology but also in patients suffering from another type of prostate cancer known as sporadic prostate cancer, which would raise the number of patients with this condition in whom the virus is present.

With regard to the association with CFS, even though the presence of retrovirus in these patients was suspected, it has not been until very recently that new evidence has been obtained thanks to a US study that has detected the virus in 67% of patients with CFS and only in 3.7% of healthy patients. This fact has prompted the interest of a large number of pharmaceutical companies worldwide who have tried to reproduce these results amidst a strong controversy. In fact most of the studies (especially European ones) have been unable to confirm the presence of the virus in these patients; in fact only an American pharmaceutical company has been able to identify variants of this virus in a very high percentage of patients with chronic fatigue.

Despite the high prevalence of these pathologies, the triggering factors that cause them and their progression are still pretty much unknown. However, the data yielded by the mentioned studies have led the scientific community to start several research projects around the world which has in turn and for the first time prompted the organisation of an international gathering to share knowledge, the Maryland Workshop. One of the challenges of this congress is to close controversy on the prevalence of this virus in the different diseases with which it has been associated by establishing standard homogenised techniques among the different pharma companies which will make it possible to expand the study of this virus with reliable and validated results.

On prostate cancer

It is currently estimated that 20-25% of human cancers in the world have a known viral aetiology. Prostate cancer is the most frequently diagnosed non skin cancer in men in developed countries, being the second cause of death due to cancer in men. In 2009 approximately 192,000 men were diagnosed with prostate cancer and 27,000 are expected to die from this disease in the United States. In Spain, prostate cancer is the malignant tumour with the third highest death rate in men.

On chronic fatigue syndrome (CFS)

Chronic fatigue syndrome (CFS) is a disease that may progressively affect the immunologic, neurologic, cardiovascular and endocrine systems. This syndrome is characterised by severe fatigue, substantial loss of concentration and memory, spatial disorientation, unrefreshing sleep, intolerance to light, to the sun and to temperature changes, intolerance to emotional stress and physical activity, pain in the muscles and joints, multiple chemical sensitivities and a permanent feeling of having the flu, among other manifestations. At present there is no diagnosis or an effective medical treatment for this disease that affects 0.4-1% of the population.