Further studies of a putative cross-linking amino acid (3-deoxypyridinoline) in skin from patients with abdominal aortic aneurysms.

A recent report claimed that an amine in human skin (believed to be pyridinoline) was deficient in specimens from patients with abdominal aortic aneurysms (AAA). Further studies suggest that this work was erroneous in two respects. First, the amine has been isolated and partially characterized; the major component of the peak of interest is a deoxyanalogue of pyridinoline. It may be a collagen cross-link of some biologic importance, because it is not detectable in skin from a patient with Marfan's syndrome. Second, further studies in an additional 19 patients with AAA and an additional 13 controls suggest that this amine is abnormally abundant in skin from patients with AAA. This difference cannot be accounted for by any potential source of artifact that has been traceable. The effects of age, diabetes, sex, race, site of biopsy, and source of specimen (autopsy versus surgery) have been studied; none of these variables can account for the high ratio of pyridinolines to hydroxylysine found in skin from patients with AAA.