The determination of pyridinium crosslinks in urine and serum as a possible marker of cartilage degradation in rheumatoid arthritis.
The determination of the collagen crosslinks pyridinoline (Pyd) and deoxypyridinoline (Dpyd) seems to be a successful way of characterizing topic destructive processes in rheumatoid arthritis (RA). Dpyd is a specific marker of collagen I resorption in bone, whereas Pyd is released from types I and II collagen in bone and cartilage. Both crosslinks were examined in 38 RA patients concurrently by RP-gradient-HPLC in urine and serum. A positive correlation was found between the inflammatory activity (measured by CrP) and the level of collagen crosslinks in urine. A correlation between serum and urine concentrations was demonstrable for Pyd, but not for Dpyd. Different elimination kinetics for fragments containing either Pyd or Dpyd are a possible explanation for this observation. The ratio of Pyd/Dpyd is known to be a useful marker to distinguish between destruction of cartilage and bone collagen. Because the Pyd/Dpyd ratio in urine does not necessarily correspond to that in serum, probably as a result of metabolic or elimination processes, the usefulness of the relationship between the crosslinks in urine as a method of differentiating between cartilage and bone degradation must be questioned.
Hein
G
G
Department of Internal Medicine IV, Friedrich Schiller University Jena, Germany.
Franke
S
S
Müller
A
A
Bräunig
E
E
Eidner
T
T
Stein
G
G
D000328:Adult; D000596:Amino Acids / Q000737:chemistry* / Q000187:drug effects; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000652:urine*; D001175:Arthrography; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
D000596:Amino Acids; C015484:pyridinoline; C036020:deoxypyridinoline; D002097:C-Reactive Protein