Chronic Fatigue Syndrome May Start in Your Immune System

Immune system markers show this physical disease is not “all in your head.”

Imagine being so tired you can rarely go grocery shopping or do laundry. You sleep for 12 hours but wake up feeling like you just took a brief nap. When you stand, your heart races. You’re dizzy and sometimes can’t think clearly. Almost any physical activity at all leaves you drained and aching.

Adding to your misery is the fact you’ve felt this way for over six months but haven’t found a diagnosis, much less help. Doctors say you are physically healthy. Your multiple complaints are dismissed as figments of your imagination or signs of a psychological problem.

This nightmarish scenario is all too real for countless people suffering from myalgic encephalomyelitis/chronic fatigue syndrome (CFS). The Institute of Medicine (IOM) estimates between 836,000 and 2.5 million Americans suffer from CFS, which is characterized by profound fatigue, sleep abnormalities, autonomic nervous system complaints, pain, and other symptoms and can sometimes resemble other disorders or even mimic side effects from some medication.  

“When I do any activity that goes beyond what I can do — I literally collapse — my body is in major pain,” a patient told the IOM. “It hurts to think. I can’t find the words. I feel my insides are at war.”  

But with no definitive test to make a diagnosis of this disease, fewer than one-third of medical schools even teaching that CFS exists, and less than half of medical textbooks mentioning it, this debilitating condition has often been dismissed as not serious or not real.

To sort medical facts from possible fiction, the Department of Health and Human Services (HHS), the National Institutes of Health, the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration, and other U.S. government agencies directed the IOM to examine the evidence for CFS. The results of the IOM’s extensive report were definitive: CFS is a physical disease that can destroy your ability to work and enjoy life. The cause is unknown, although it may be triggered by infections, such as the Epstein-Barr virus (EBV).  

“There is an urgent need for more research to discover what causes CFS, understand the mechanisms associated with the development and progression of the disease, and develop effective diagnostic markers and treatments,” the IOM researchers concluded.

The good news for chronic fatigue sufferers is that breakthroughs are happening. For example, scientists at Columbia University's Mailman School of Public Health found distinct immune changes in CFS patients who have had the disease for three years or less. Compared to a control group, the chronic fatigue sufferers had increased amounts of many types of cytokines (molecules produced by the immune system) — especially interferon gamma, which has long been linked to fatigue following viral infections, including EBV.  

"We now have evidence confirming what millions of people with this disease already know, that CFS isn't psychological," said Mady Hornig, MD, director of translational research at the Center for Infection and Immunity and associate professor of Epidemiology at Columbia's Mailman School. "Our results should accelerate the process of establishing the diagnosis after individuals first fall ill as well as discovery of new treatment strategies focusing on these early blood markers."

A follow-up study showed there are other immune system markers in later stages of the disease, too. Hornig and colleagues identified a unique pattern of cytokines in the cerebrospinal fluid of long-term CFS patients who had been sick an average of seven years.  

The CFS sufferers had depressed levels of most cytokines, including the inflammatory immune molecule interleukin 1, compared to a control group of healthy people and a group of multiple sclerosis (MS) patients. One cytokine (eotaxin) was elevated in both the CFS and MS groups.

"We now know that the same changes to the immune system that we recently reported in the blood of people with CFS with long-standing disease are also present in the central nervous system," said Hornig. "These immune findings may contribute to symptoms in both the peripheral parts of the body and the brain, from muscle weakness to brain fog."  

Although more research is needed, the study raises the possibility that therapies that regulate the immune response could correct the imbalance in cytokine levels seen in people with CFS at different stages, according to epidemiologist W. Ian Lipkin, MD, director of the Center for Infection and Immunity at the Mailman School of Public Health.

A study from Stanford University has found distinct differences between the brains of patients with CFS and those of healthy people. Altered immune responses could be the explanation, according to the researchers.  

MRIs revealed multiple abnormal areas in the CFS patients, including reduced overall white matter (nerve tracts that carry nerve signals from one part of the brain to another), possibly the result of chronic inflammation in response to a virus or other trigger.

“In addition to potentially providing the CFS-specific diagnostic biomarker we've been desperately seeking for decades, these findings hold the promise of identifying the area or areas of the brain where the disease has hijacked the central nervous system," said Jose Montoya, MD, professor of infectious diseases and geographic medicine at Stanford.

A study by scientists at the University of Florida has found a possible explanation for the profound fatigue often felt by people with CFS after daily activities — extreme sensitivity to substances released by their muscles. When you use muscles, metabolites are produced that activate neural pathways (bundles of nerve cells connecting one part of the nervous system to another). This normal process typically lets you know when you’ve stressed your muscles enough and need to rest. But in CFS patients, the Florida study suggests, these fatigue pathways have become hypersensitive to muscle metabolites, resulting in excessive fatigue after little activity.

"For most of us, at the end of strenuous exertion we feel exhausted and need to stop — but we will recover rapidly," researcher Roland Staud, MD, professor of rheumatology and clinical immunology in the Florida College of Medicine said. "However, these individuals (with CFS) tire much more rapidly and sometimes just after moving across a room, they are fully exhausted. This takes a toll on their lives."