Collagen cross-links in fibromyalgia (FM) syndrome

OBJECTIVE: The acceptance of fibromyalgia as a disease entity and

its definitive diagnosis have been hampered by a dearth of

knowledge concerning the underlying pathophysiology of this

disease and the lack of specific biochemical markers

applicable to its diagnosis. To determine whether abnormal

collagen metabolism is a characteristic of fibromyalgia, we

have analyzed collagen metabolites in the urine and serum of

patients with fibromyalgia.

METHODS: The diagnosis of

fibromyalgia was made according to the American College of

Rheumatology criteria. Urine and serum were collected under

standardized conditions from 39 patients and 55 age- and

sex-matched controls. Pyridinoline (Pyd) and deoxypyridinoline

(Dpyd), which represent products of lysyl oxidase-mediated

cross-linking in collagen and are indicators of connective

tissue and bone degradation, respectively, were analyzed by

ion-paired and gradient HPLC method with fluorescence

detection (HPLC). Levels of hydroxypyroline (Hyp), a collagen

turnover marker, were also measured. The findings were related

to creatinine levels and the Pyd/Dpyd ratio determined.

RESULTS: The Pyd/Dpyd ratios in the urine and serum and the

Hyp in the urine were significantly lower in patients with

fibromyalgia than in healthy controls.


levels of collagen cross-linking may contribute to remodeling

of the extracellular matrix and collagen deposition around the

nerve fibers in fibromyalgia and contribute to the lower pain

threshold at the tender points. Analysis of altered collagen

metabolism either by histologic examination on biopsy or,

preferably, by HPLC analysis of collagen metabolites in urine

or serum may aid to understand more about the pathogenesis of


1 Star2 Stars3 Stars4 Stars5 Stars (26 votes, average: 2.96 out of 5)

1 Star2 Stars3 Stars4 Stars5 Stars (26 votes, average: 2.96 out of 5)

Leave a Reply