Joint hypermobility found in CFS
Adolescents with chronic fatigue syndrome (CFS) are 3.5 times more likely to have joint hypermobility compared to non-fatigued, age-and gender-matched controls, Johns Hopkins University researchers report. More of the adolescents with CFS could bend their fingers or thumbs backward, hyperextend their knees and elbows, place their legs behind their heads and place their palms flat on the floor without bending their knees — all signs of joint hypermobility.

This study contradicts the belief that CFS patients have normal physical examinations. Since approximately 20 percent of healthy adolescents have hypermobility, this is not a diagnostic test for CFS, but it may lead a clinician to suspect CFS if a patient has other symptoms.

The reason for hypermobility is unclear, but the researchers offer several possibilities. First, it may reflect connective tissue hyperextensibility, which could explain the increased venous pooling and orthostatic intolerance seen in adolescents with CFS. Second, it may lead to decreased physical activity and an increased risk for CFS. Third, there may be another factor that is associated with both hypermobility and CFS, paralleling a recent finding that a particular chromosomal phenotype is associated both with joint hypermobility and panic and phobic disorders. The authors remind readers that panic and anxiety disorders are not universally seen in CFS.

Barron DF et al. Joint hypermobility is more common in children with chronic fatigue syndrome than in healthy controls. J Pediatr. 2002;141:421-5.

Unique RNase L generated by normal protein
Ten years ago, researchers first published the finding that some people with CFS have an unusual form of RNase L, a key component of the antiviral defense system. Further studies have shown that this unique RNase L protein is smaller and more active than normal 83 kilodalton (kDa) RNase L. But, until now they have not known whether this low molecular weight RNase-L is a new protein or is processed from the normal RNase L.

European scientists now report they have discovered that the 30 and 37 kDa weight forms of RNase L in CFS are generated by breakdown of normal RNase L into two main fragments. In the laboratory, they found that peripheral blood mononuclear cell extracts from CFS patients cleaved normal 83 kDa RNase L into the two end sections of the RNase L protein and removed the 16 kDa middle section. They then duplicated this phenomenon using human leukocyte elastase (HLE), an enzyme known to break down proteins.

This knowledge takes researchers a step further toward understanding the complex nature of the RNase L protein and the CFS pathophysiology. It also advances efforts to establish whether the RNase L test may be a marker for a subset of CFS patients.

Demettre E et al: Ribonuclease L proteolysis in peripheral blood mononuclear cells of chronic fatigue syndrome patients. J Biol Chem. 2002; July 12.

Review of CFS in adolescents
CFS in adolescents s analogous to the illness in adults, with one important difference: adolescents are more likely to improve, according to a review article in Contemporary Pediatrics.

A review of the pediatric CFS medical literature found that most of the precipitating factors, psychological variables and organ system effects are similar in adults and children who have the illness. However, adolescents and children with CFS appear to improve in greater numbers within three years following onset of the illness. In the authors’ experience, “good health most of the time” was experienced by more than one-half of their adolescent CFS patients within one year, by more than two-thirds within two years and by more than three-quarters within three years.

The authors warn that improvement comes slowly and unpredictably, with a gradual shift in the ratio of bad to good days, and relapses may occur in response to stressful events.

Krilov L, Fisher M. CME: Chronic fatigue syndrome in youth: Maybe not so chronic after all. Contemporary Pediatrics. 2002;4:61.