Chronic Fatigue Syndrome (CFS) is a complex disease that affects the immune, neurological, cardiovascular and endocrine systems. It causes constant fatigue that cannot be attributed to recent exertion and that does not improve with rest, meaning that sufferers are forced to significantly reduce their everyday activities.
The origin of the disease is currently unknown. It causes a substantial loss of concentration and intolerance to light, emotional stress and physical activity. It can also involve muscle and joint pain, multiple chemical sensitivities and a permanent flu-like feeling. In Spain it is estimated that it affects 1 out of every 1000 people.
A study led by scientists from the Institute for AIDS Research IrsiCaixa , jointly funded by “la Caixa” Foundation and the Catalan Government’s Department of Health, and the Health Sciences Research Institute of the Germans Trias i Pujol Foundation (IGTP), has for the first time identified a group of 8 immune system molecules that the investigators associate with the poor immune response of CFS patients. The Vall d’Hebron Institut de Recerca (VHIR) Chronic Fatigue Research Group and Clínica SFC from Tarragona participated in the study, which had the support of different CFS patient associations. Fight against AIDS Foundation and Clínica Delfos were also involved.
"Alterations in these molecules in people with CFS could help to improve the reliability and speed of the diagnosis of a complex disease that up until now has been poorly defined on a molecular level", says Julià Blanco, Miguel Servet Senior Investigator at the Health Sciences Research Institute of the Germans Trias i Pujol Foundation (IGTP) in IrsiCaixa, the study coordinator and person responsible for the Virology and Cell Immunology Group.
The diagnosis of CFS is currently based solely on an assessment of the aforementioned clinical symptoms, after ruling out other conditions. Its diagnosis is not quantitative and requires exertion or neurological tests that can be more inconvenient for patients than just taking a blood sample.
The study was recently published in the Journal of Translational Medicine and could also explain the greater impact of some viral infections in these patients. The scientists, however, have highlighted the need for further studies to confirm the results.
The relationship between CFS and the immune system
Since the early 90s, one of the lines of research related to CFS has focused on studying how the disease is related to the weakening of the immune system. The importance of this line of research lies in the fact that the onset of CFS symptoms coincides with viral infections in many patients, and in a greater sensitivity to certain infections, all of which suggests an immune system dysfunction.
The Institute for AIDS Research IrsiCaixa was interested in the relationship between CFS and different viral infections. The investigators focused on viral and immunological markers in CFS patients. As it was impossible to establish a reliable relationship with viral infections, and as there is no molecular diagnostic tool to characterise CFS patients, they decided to analyse and compare more than 100 features of the immune system of CFS sufferers and healthy people.
The study made it possible to identify the presence of 8 altered molecules in people with CFS, in both T-cells and NK-cells, the cells responsible for coordinating immune response and destroying malignant cells, respectively.
"The relationship between CFS and the immune system is fundamental for progressing in the complete description of the clinical symptoms of people with CFS", said Julià Blanco, "but we also have to study the role of the neurological, cardiovascular and endocrine systems, which are also affected by the disease. These different aspects may have a common origin, which remains unknown", he concluded.
Article published in Journal of Translational Medicine:
Screening NK-, B- and T-cell phenotype and function in patients suffering from Chronic Fatigue Syndrome