Research News
The latest information on research, treatment and diagnosis of CFIDS and related disorders

Shorter duration, better outcome
A shorter duration of illness seems to predict a better outcome for people with CFIDS, according to a recent study from the Netherlands led by Sieberen P. van der Werf.

One year after the study began, eight percent of subjects who had CFIDS or idiopathic chronic fatigue for less than 24 months reported that they were recovered, and 38 percent reported that their symptoms had improved. By contrast, a prior study of people who were ill for an average of 8.8 years found that only three percent reported they had recovered and 17 percent reported they had improved.

In the present study, published in the Journal of Psychosomatic Research, all of the recovered patients had been ill for less than 15 months. Other predictors of improvement were: fewer reported concentration problems at onset, acceptance that biological, psychological and social factors all may be involved in the illness, and better satisfaction with social support systems.

A limitation of this study is that improvement was assessed at a single point in time. Because CFIDS is known to be a relapsing-remitting illness, the authors suggest that future studies assess the patients’ abilities to maintain improvement over time.

Subclasses proposed for CFIDS cases
When a researcher uses the 1994 case definition of chronic fatigue syndrome (CFS) to select patients for a study, there is no guarantee that his test subjects will have the same symptoms — or even the same illness — as those of another researcher who is using the same case definition. Researchers have different ways of interpreting ambiguous symptom criteria (e.g., fatigue which “substantially” reduces activity), defining comorbid and exclusionary conditions (e.g, fibromyalgia) and selecting subjects based on particular features of interest (e.g., presence of HHV-6 antibodies). These problems with the case definition lead to an overly broad, diverse population who meet the CFS criteria, but may have different illness features.

For this reason, classifying research subjects into subsets of people with similar symptoms or illness history has been recommended as a way to more carefully describe and compare research subjects from one study to another. It has also been proposed that studying narrower subgroups may help researchers detect differences among the groups in terms of treatment and outcome. This could result in improved treatment for some portion of the larger CFIDS group.

One subclassification scheme, proposed by Eng M. Tan and colleagues, aims to address some of these problems. The researchers proposefour categories: A) nervous system involvement (impaired memory or concentration, headache); B) endocrine system involvement (unrefreshing sleep, postexertional malaise); C) musculoskeletal system involvement (muscle pain, joint pain); and D) immune system/infection involvement (sore throat, tender cervical or axillary lymph nodes).

Patients would be identified by letters, based upon the organ systems involved in their particular case. For example, someone with a history of headache, unrefreshing sleep and memory problems would be classified as CFS-AB, while another person with predominant muscle pain and sore throat would be classified as CFS-CD.

Although this particular subclassification scheme has not been tested or validated, the researchers hope that it will spur new ways of thinking about CFIDS and additional ways to develop more homogenous study groups. The scheme was published in the Journal of Clinical Immunology.

Infection increases risk of CFIDS
Ten years after an outbreak of Q fever in England, most of those infected continue to experience symptoms of CFIDS and profound fatigue. Compared to a matched group of control subjects, patients exposed to Q fever were nearly twice as likely to have profound fatigue (66.7% vs. 34.7%), 2.5 times more likely to have idiopathic chronic fatigue (34.7% vs. 13.9%) and nearly five times more likely to have CFIDS (19.4% vs. 4.2%).

Q fever is caused by an organism called Coxiella burnettii, which can be spread from infected farm animals to humans. In its acute phase, the illness causes headache, fatigue, sweating and other symptoms. The U.K. researchers who conducted this study continue to explore reasons for the increased incidence of CFIDS and profound fatigue among survivors of the 1989 Q fever outbreak, which occurred in the West Midlands portion of the country. This study, published in Quarterly Journal of Medicine, furthers the literature on the role of infections in precipitating CFS. The lead author in the study is M.J. Wildman.

CDC site offers CFIDS information
The Web site of the U.S. Centers for Disease Control and Prevention (CDC) offers an overview of its program for CFIDS research program. The site also features general information on CFIDS and treatments, plus a list of research papers relating to the illness. All the information on the site is in the public domain, meaning it can be reproduced and distributed. The site’s address is: http://www.cdc.gov/ncidod/diseases/cfs/index.htm.

CFIDS Glossary: Terms you need to know

Reading research studies can be daunting task for a lay audience. Beginning with this issue, the Chronicle will try to simplify things by defining key research terms in a CFIDS Glossary. If you have suggestions for terms to include in future editions of the glossary, please send them to chronicle@cfids.org, or to The CFIDS Association of America, PO Box 220398, Charlotte, NC 28222-0398, Attention: Chronicle glossary.

Arthralgia: Pain in a joint. In the 1994 case definition of CFIDS, arthralgia is included in the list of symptoms, provided that the joint pain is not accompanied by swelling or redness.

Double-blind study: A type of study in which neither the test subject nor the researcher knows what treatment, if any, the subject is receiving.

For example: In a test to determine whether a drug has an effect against CFIDS symptoms, some subjects will receive doses of the drug while others will receive fake, or placebo, doses. The researcher and subjects are unaware of who is receiving the drug until after the study is completed. This is designed to eliminate any bias, intentional or unintentional, that a researcher or test subject may have about the treatment.

Endocrine system: A body system consisting of a series of glands that produce hormones to control internal organ functions. The endocrine system includes the hypothalamus, pituitary gland, thyroid, parathyroids, adrenal glands, pineal gland and pancreas. Researchers speculate that malfunctions in the endocrine system may be related to some cases of CFIDS.

Idiopathic: Of, or relating to, a condition that has no known cause. Idiopathic fatigue, for instance, is fatigue that has no known cause.

RNase L: Ribonuclease L. This protein is part of the body’s defense system against viral infections. Researchers have discovered that some people with CFIDS have an unusual variation of this protein, one which is smaller and more active than normal. What role this version of RNAse L (called 37 kDa RNase L) plays in CFIDS remains uncertain.